git-commit-vandalism/cache.h

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#ifndef CACHE_H
#define CACHE_H
#include "git-compat-util.h"
#include "strbuf.h"
Create pathname-based hash-table lookup into index This creates a hash index of every single file added to the index. Right now that hash index isn't actually used for much: I implemented a "cache_name_exists()" function that uses it to efficiently look up a filename in the index without having to do the O(logn) binary search, but quite frankly, that's not why this patch is interesting. No, the whole and only reason to create the hash of the filenames in the index is that by modifying the hash function, you can fairly easily do things like making it always hash equivalent names into the same bucket. That, in turn, means that suddenly questions like "does this name exist in the index under an _equivalent_ name?" becomes much much cheaper. Guiding principles behind this patch: - it shouldn't be too costly. In fact, my primary goal here was to actually speed up "git commit" with a fully populated kernel tree, by being faster at checking whether a file already existed in the index. I did succeed, but only barely: Best before: [torvalds@woody linux]$ time git commit > /dev/null real 0m0.255s user 0m0.168s sys 0m0.088s Best after: [torvalds@woody linux]$ time ~/git/git commit > /dev/null real 0m0.233s user 0m0.144s sys 0m0.088s so some things are actually faster (~8%). Caveat: that's really the best case. Other things are invariably going to be slightly slower, since we populate that index cache, and quite frankly, few things really use it to look things up. That said, the cost is really quite small. The worst case is probably doing a "git ls-files", which will do very little except puopulate the index, and never actually looks anything up in it, just lists it. Before: [torvalds@woody linux]$ time git ls-files > /dev/null real 0m0.016s user 0m0.016s sys 0m0.000s After: [torvalds@woody linux]$ time ~/git/git ls-files > /dev/null real 0m0.021s user 0m0.012s sys 0m0.008s and while the thing has really gotten relatively much slower, we're still talking about something almost unmeasurable (eg 5ms). And that really should be pretty much the worst case. So we lose 5ms on one "benchmark", but win 22ms on another. Pick your poison - this patch has the advantage that it will _likely_ speed up the cases that are complex and expensive more than it slows down the cases that are already so fast that nobody cares. But if you look at relative speedups/slowdowns, it doesn't look so good. - It should be simple and clean The code may be a bit subtle (the reasons I do hash removal the way I do etc), but it re-uses the existing hash.c files, so it really is fairly small and straightforward apart from a few odd details. Now, this patch on its own doesn't really do much, but I think it's worth looking at, if only because if done correctly, the name hashing really can make an improvement to the whole issue of "do we have a filename that looks like this in the index already". And at least it gets real testing by being used even by default (ie there is a real use-case for it even without any insane filesystems). NOTE NOTE NOTE! The current hash is a joke. I'm ashamed of it, I'm just not ashamed of it enough to really care. I took all the numbers out of my nether regions - I'm sure it's good enough that it works in practice, but the whole point was that you can make a really much fancier hash that hashes characters not directly, but by their upper-case value or something like that, and thus you get a case-insensitive hash, while still keeping the name and the index itself totally case sensitive. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-23 03:41:14 +01:00
#include "hash.h"
#include "advice.h"
#include SHA1_HEADER
fix openssl headers conflicting with custom SHA1 implementations On ARM I have the following compilation errors: CC fast-import.o In file included from cache.h:8, from builtin.h:6, from fast-import.c:142: arm/sha1.h:14: error: conflicting types for 'SHA_CTX' /usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here arm/sha1.h:16: error: conflicting types for 'SHA1_Init' /usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here arm/sha1.h:17: error: conflicting types for 'SHA1_Update' /usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here arm/sha1.h:18: error: conflicting types for 'SHA1_Final' /usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here make: *** [fast-import.o] Error 1 This is because openssl header files are always included in git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not set, which somehow brings in <openssl/sha1.h> clashing with the custom ARM version. Compilation of git is probably broken on PPC too for the same reason. Turns out that the only file requiring openssl/ssl.h and openssl/err.h is imap-send.c. But only moving those problematic includes there doesn't solve the issue as it also includes cache.h which brings in the conflicting local SHA1 header file. As suggested by Jeff King, the best solution is to rename our references to SHA1 functions and structure to something git specific, and define those according to the implementation used. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-01 20:05:20 +02:00
#ifndef git_SHA_CTX
#define git_SHA_CTX SHA_CTX
#define git_SHA1_Init SHA1_Init
#define git_SHA1_Update SHA1_Update
#define git_SHA1_Final SHA1_Final
#endif
fix openssl headers conflicting with custom SHA1 implementations On ARM I have the following compilation errors: CC fast-import.o In file included from cache.h:8, from builtin.h:6, from fast-import.c:142: arm/sha1.h:14: error: conflicting types for 'SHA_CTX' /usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here arm/sha1.h:16: error: conflicting types for 'SHA1_Init' /usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here arm/sha1.h:17: error: conflicting types for 'SHA1_Update' /usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here arm/sha1.h:18: error: conflicting types for 'SHA1_Final' /usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here make: *** [fast-import.o] Error 1 This is because openssl header files are always included in git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not set, which somehow brings in <openssl/sha1.h> clashing with the custom ARM version. Compilation of git is probably broken on PPC too for the same reason. Turns out that the only file requiring openssl/ssl.h and openssl/err.h is imap-send.c. But only moving those problematic includes there doesn't solve the issue as it also includes cache.h which brings in the conflicting local SHA1 header file. As suggested by Jeff King, the best solution is to rename our references to SHA1 functions and structure to something git specific, and define those according to the implementation used. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-01 20:05:20 +02:00
#include <zlib.h>
#if defined(NO_DEFLATE_BOUND) || ZLIB_VERNUM < 0x1200
#define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
#endif
void git_inflate_init(z_streamp strm);
void git_inflate_end(z_streamp strm);
int git_inflate(z_streamp strm, int flush);
#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
#define DTYPE(de) ((de)->d_type)
#else
#undef DT_UNKNOWN
#undef DT_DIR
#undef DT_REG
#undef DT_LNK
#define DT_UNKNOWN 0
#define DT_DIR 1
#define DT_REG 2
#define DT_LNK 3
#define DTYPE(de) DT_UNKNOWN
#endif
/* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
#define S_IFINVALID 0030000
/*
* A "directory link" is a link to another git directory.
*
* The value 0160000 is not normally a valid mode, and
* also just happens to be S_IFDIR + S_IFLNK
*
* NOTE! We *really* shouldn't depend on the S_IFxxx macros
* always having the same values everywhere. We should use
* our internal git values for these things, and then we can
* translate that to the OS-specific value. It just so
* happens that everybody shares the same bit representation
* in the UNIX world (and apparently wider too..)
*/
#define S_IFGITLINK 0160000
#define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
/*
* Intensive research over the course of many years has shown that
* port 9418 is totally unused by anything else. Or
*
* Your search - "port 9418" - did not match any documents.
*
* as www.google.com puts it.
*
* This port has been properly assigned for git use by IANA:
* git (Assigned-9418) [I06-050728-0001].
*
* git 9418/tcp git pack transfer service
* git 9418/udp git pack transfer service
*
* with Linus Torvalds <torvalds@osdl.org> as the point of
* contact. September 2005.
*
* See http://www.iana.org/assignments/port-numbers
*/
#define DEFAULT_GIT_PORT 9418
/*
* Basic data structures for the directory cache
*/
#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
struct cache_header {
unsigned int hdr_signature;
unsigned int hdr_version;
unsigned int hdr_entries;
};
/*
* The "cache_time" is just the low 32 bits of the
* time. It doesn't matter if it overflows - we only
* check it for equality in the 32 bits we save.
*/
struct cache_time {
unsigned int sec;
unsigned int nsec;
};
/*
* dev/ino/uid/gid/size are also just tracked to the low 32 bits
* Again - this is just a (very strong in practice) heuristic that
* the inode hasn't changed.
*
* We save the fields in big-endian order to allow using the
* index file over NFS transparently.
*/
struct ondisk_cache_entry {
struct cache_time ctime;
struct cache_time mtime;
unsigned int dev;
unsigned int ino;
unsigned int mode;
unsigned int uid;
unsigned int gid;
unsigned int size;
unsigned char sha1[20];
unsigned short flags;
char name[FLEX_ARRAY]; /* more */
};
/*
* This struct is used when CE_EXTENDED bit is 1
* The struct must match ondisk_cache_entry exactly from
* ctime till flags
*/
struct ondisk_cache_entry_extended {
struct cache_time ctime;
struct cache_time mtime;
unsigned int dev;
unsigned int ino;
unsigned int mode;
unsigned int uid;
unsigned int gid;
unsigned int size;
unsigned char sha1[20];
unsigned short flags;
unsigned short flags2;
char name[FLEX_ARRAY]; /* more */
};
struct cache_entry {
struct cache_time ce_ctime;
struct cache_time ce_mtime;
unsigned int ce_dev;
unsigned int ce_ino;
unsigned int ce_mode;
unsigned int ce_uid;
unsigned int ce_gid;
unsigned int ce_size;
unsigned int ce_flags;
unsigned char sha1[20];
struct cache_entry *next;
char name[FLEX_ARRAY]; /* more */
};
#define CE_NAMEMASK (0x0fff)
#define CE_STAGEMASK (0x3000)
#define CE_EXTENDED (0x4000)
"Assume unchanged" git This adds "assume unchanged" logic, started by this message in the list discussion recently: <Pine.LNX.4.64.0601311807470.7301@g5.osdl.org> This is a workaround for filesystems that do not have lstat() that is quick enough for the index mechanism to take advantage of. On the paths marked as "assumed to be unchanged", the user needs to explicitly use update-index to register the object name to be in the next commit. You can use two new options to update-index to set and reset the CE_VALID bit: git-update-index --assume-unchanged path... git-update-index --no-assume-unchanged path... These forms manipulate only the CE_VALID bit; it does not change the object name recorded in the index file. Nor they add a new entry to the index. When the configuration variable "core.ignorestat = true" is set, the index entries are marked with CE_VALID bit automatically after: - update-index to explicitly register the current object name to the index file. - when update-index --refresh finds the path to be up-to-date. - when tools like read-tree -u and apply --index update the working tree file and register the current object name to the index file. The flag is dropped upon read-tree that does not check out the index entry. This happens regardless of the core.ignorestat settings. Index entries marked with CE_VALID bit are assumed to be unchanged most of the time. However, there are cases that CE_VALID bit is ignored for the sake of safety and usability: - while "git-read-tree -m" or git-apply need to make sure that the paths involved in the merge do not have local modifications. This sacrifices performance for safety. - when git-checkout-index -f -q -u -a tries to see if it needs to checkout the paths. Otherwise you can never check anything out ;-). - when git-update-index --really-refresh (a new flag) tries to see if the index entry is up to date. You can start with everything marked as CE_VALID and run this once to drop CE_VALID bit for paths that are modified. Most notably, "update-index --refresh" honours CE_VALID and does not actively stat, so after you modified a file in the working tree, update-index --refresh would not notice until you tell the index about it with "git-update-index path" or "git-update-index --no-assume-unchanged path". This version is not expected to be perfect. I think diff between index and/or tree and working files may need some adjustment, and there probably needs other cases we should automatically unmark paths that are marked to be CE_VALID. But the basics seem to work, and ready to be tested by people who asked for this feature. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-09 06:15:24 +01:00
#define CE_VALID (0x8000)
#define CE_STAGESHIFT 12
/*
* Range 0xFFFF0000 in ce_flags is divided into
* two parts: in-memory flags and on-disk ones.
* Flags in CE_EXTENDED_FLAGS will get saved on-disk
* if you want to save a new flag, add it in
* CE_EXTENDED_FLAGS
*
* In-memory only flags
*/
#define CE_UPDATE (0x10000)
#define CE_REMOVE (0x20000)
#define CE_UPTODATE (0x40000)
#define CE_ADDED (0x80000)
Fix name re-hashing semantics We handled the case of removing and re-inserting cache entries badly, which is something that merging commonly needs to do (removing the different stages, and then re-inserting one of them as the merged state). We even had a rather ugly special case for this failure case, where replace_index_entry() basically turned itself into a no-op if the new and the old entries were the same, exactly because the hash routines didn't handle it on their own. So what this patch does is to not just have the UNHASHED bit, but a HASHED bit too, and when you insert an entry into the name hash, that involves: - clear the UNHASHED bit, because now it's valid again for lookup (which is really all that UNHASHED meant) - if we're being lazy, we're done here (but we still want to clear the UNHASHED bit regardless of lazy mode, since we can become unlazy later, and so we need the UNHASHED bit to always be set correctly, even if we never actually insert the entry into the hash list) - if it was already hashed, we just leave it on the list - otherwise mark it HASHED and insert it into the list this all means that unhashing and rehashing a name all just works automatically. Obviously, you cannot change the name of an entry (that would be a serious bug), but nothing can validly do that anyway (you'd have to allocate a new struct cache_entry anyway since the name length could change), so that's not a new limitation. The code actually gets simpler in many ways, although the lazy hashing does mean that there are a few odd cases (ie something can be marked unhashed even though it was never on the hash in the first place, and isn't actually marked hashed!). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23 05:37:40 +01:00
#define CE_HASHED (0x100000)
#define CE_UNHASHED (0x200000)
#define CE_CONFLICTED (0x800000)
#define CE_WT_REMOVE (0x400000) /* remove in work directory */
unpack-trees.c: prepare for looking ahead in the index This prepares but does not yet implement a look-ahead in the index entries when traverse-trees.c decides to give us tree entries in an order that does not match what is in the index. A case where a look-ahead in the index is necessary happens when merging branch B into branch A while the index matches the current branch A, using a tree O as their common ancestor, and these three trees looks like this: O A B t t t-i t-i t-i t-j t-j t/1 t/2 The traverse_trees() function gets "t", "t-i" and "t" from trees O, A and B first, and notices that A may have a matching "t" behind "t-i" and "t-j" (indeed it does), and tells A to give that entry instead. After unpacking blob "t" from tree B (as it hasn't changed since O in B and A removed it, it will result in its removal), it descends into directory "t/". The side that walked index in parallel to the tree traversal used to be implemented with one pointer, o->pos, that points at the next index entry to be processed. When this happens, the pointer o->pos still points at "t-i" that is the first entry. We should be able to skip "t-i" and "t-j" and locate "t/1" from the index while the recursive invocation of traverse_trees() walks and match entries found there, and later come back to process "t-i". While that look-ahead is not implemented yet, this adds a flag bit, CE_UNPACKED, to mark the entries in the index that has already been processed. o->pos pointer has been renamed to o->cache_bottom and it points at the first entry that may still need to be processed. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-07 23:59:54 +01:00
#define CE_UNPACKED (0x1000000)
/*
* Extended on-disk flags
*/
#define CE_INTENT_TO_ADD 0x20000000
#define CE_SKIP_WORKTREE 0x40000000
/* CE_EXTENDED2 is for future extension */
#define CE_EXTENDED2 0x80000000
#define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE)
/*
* Safeguard to avoid saving wrong flags:
* - CE_EXTENDED2 won't get saved until its semantic is known
* - Bits in 0x0000FFFF have been saved in ce_flags already
* - Bits in 0x003F0000 are currently in-memory flags
*/
#if CE_EXTENDED_FLAGS & 0x803FFFFF
#error "CE_EXTENDED_FLAGS out of range"
#endif
/*
* Copy the sha1 and stat state of a cache entry from one to
* another. But we never change the name, or the hash state!
*/
#define CE_STATE_MASK (CE_HASHED | CE_UNHASHED)
static inline void copy_cache_entry(struct cache_entry *dst, struct cache_entry *src)
{
unsigned int state = dst->ce_flags & CE_STATE_MASK;
/* Don't copy hash chain and name */
memcpy(dst, src, offsetof(struct cache_entry, next));
/* Restore the hash state */
dst->ce_flags = (dst->ce_flags & ~CE_STATE_MASK) | state;
}
static inline unsigned create_ce_flags(size_t len, unsigned stage)
{
if (len >= CE_NAMEMASK)
len = CE_NAMEMASK;
return (len | (stage << CE_STAGESHIFT));
}
static inline size_t ce_namelen(const struct cache_entry *ce)
{
size_t len = ce->ce_flags & CE_NAMEMASK;
if (len < CE_NAMEMASK)
return len;
return strlen(ce->name + CE_NAMEMASK) + CE_NAMEMASK;
}
#define ce_size(ce) cache_entry_size(ce_namelen(ce))
#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
ondisk_cache_entry_size(ce_namelen(ce)))
#define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
#define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
#define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
#define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
static inline unsigned int create_ce_mode(unsigned int mode)
{
if (S_ISLNK(mode))
return S_IFLNK;
if (S_ISDIR(mode) || S_ISGITLINK(mode))
return S_IFGITLINK;
return S_IFREG | ce_permissions(mode);
}
static inline unsigned int ce_mode_from_stat(struct cache_entry *ce, unsigned int mode)
{
extern int trust_executable_bit, has_symlinks;
if (!has_symlinks && S_ISREG(mode) &&
ce && S_ISLNK(ce->ce_mode))
return ce->ce_mode;
if (!trust_executable_bit && S_ISREG(mode)) {
if (ce && S_ISREG(ce->ce_mode))
return ce->ce_mode;
return create_ce_mode(0666);
}
return create_ce_mode(mode);
}
static inline int ce_to_dtype(const struct cache_entry *ce)
{
unsigned ce_mode = ntohl(ce->ce_mode);
if (S_ISREG(ce_mode))
return DT_REG;
else if (S_ISDIR(ce_mode) || S_ISGITLINK(ce_mode))
return DT_DIR;
else if (S_ISLNK(ce_mode))
return DT_LNK;
else
return DT_UNKNOWN;
}
static inline unsigned int canon_mode(unsigned int mode)
{
if (S_ISREG(mode))
return S_IFREG | ce_permissions(mode);
if (S_ISLNK(mode))
return S_IFLNK;
if (S_ISDIR(mode))
return S_IFDIR;
return S_IFGITLINK;
}
#define flexible_size(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
#define cache_entry_size(len) flexible_size(cache_entry,len)
#define ondisk_cache_entry_size(len) flexible_size(ondisk_cache_entry,len)
#define ondisk_cache_entry_extended_size(len) flexible_size(ondisk_cache_entry_extended,len)
struct index_state {
struct cache_entry **cache;
unsigned int cache_nr, cache_alloc, cache_changed;
struct string_list *resolve_undo;
struct cache_tree *cache_tree;
struct cache_time timestamp;
void *alloc;
unpack_trees(): protect the handcrafted in-core index from read_cache() unpack_trees() rebuilds the in-core index from scratch by allocating a new structure and finishing it off by copying the built one to the final index. The resulting in-core index is Ok for most use, but read_cache() does not recognize it as such. The function is meant to be no-op if you already have loaded the index, until you call discard_cache(). This change the way read_cache() detects an already initialized in-core index, by introducing an extra bit, and marks the handcrafted in-core index as initialized, to avoid this problem. A better fix in the longer term would be to change the read_cache() API so that it will always discard and re-read from the on-disk index to avoid confusion. But there are higher level API that have relied on the current semantics, and they and their users all need to get converted, which is outside the scope of 'maint' track. An example of such a higher level API is write_cache_as_tree(), which is used by git-write-tree as well as later Porcelains like git-merge, revert and cherry-pick. In the longer term, we should remove read_cache() from there and add one to cmd_write_tree(); other callers expect that the in-core index they prepared is what gets written as a tree so no other change is necessary for this particular codepath. The original version of this patch marked the index by pointing an otherwise wasted malloc'ed memory with o->result.alloc, but this version uses Linus's idea to use a new "initialized" bit, which is conceptually much cleaner. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-23 21:57:30 +02:00
unsigned name_hash_initialized : 1,
initialized : 1;
Create pathname-based hash-table lookup into index This creates a hash index of every single file added to the index. Right now that hash index isn't actually used for much: I implemented a "cache_name_exists()" function that uses it to efficiently look up a filename in the index without having to do the O(logn) binary search, but quite frankly, that's not why this patch is interesting. No, the whole and only reason to create the hash of the filenames in the index is that by modifying the hash function, you can fairly easily do things like making it always hash equivalent names into the same bucket. That, in turn, means that suddenly questions like "does this name exist in the index under an _equivalent_ name?" becomes much much cheaper. Guiding principles behind this patch: - it shouldn't be too costly. In fact, my primary goal here was to actually speed up "git commit" with a fully populated kernel tree, by being faster at checking whether a file already existed in the index. I did succeed, but only barely: Best before: [torvalds@woody linux]$ time git commit > /dev/null real 0m0.255s user 0m0.168s sys 0m0.088s Best after: [torvalds@woody linux]$ time ~/git/git commit > /dev/null real 0m0.233s user 0m0.144s sys 0m0.088s so some things are actually faster (~8%). Caveat: that's really the best case. Other things are invariably going to be slightly slower, since we populate that index cache, and quite frankly, few things really use it to look things up. That said, the cost is really quite small. The worst case is probably doing a "git ls-files", which will do very little except puopulate the index, and never actually looks anything up in it, just lists it. Before: [torvalds@woody linux]$ time git ls-files > /dev/null real 0m0.016s user 0m0.016s sys 0m0.000s After: [torvalds@woody linux]$ time ~/git/git ls-files > /dev/null real 0m0.021s user 0m0.012s sys 0m0.008s and while the thing has really gotten relatively much slower, we're still talking about something almost unmeasurable (eg 5ms). And that really should be pretty much the worst case. So we lose 5ms on one "benchmark", but win 22ms on another. Pick your poison - this patch has the advantage that it will _likely_ speed up the cases that are complex and expensive more than it slows down the cases that are already so fast that nobody cares. But if you look at relative speedups/slowdowns, it doesn't look so good. - It should be simple and clean The code may be a bit subtle (the reasons I do hash removal the way I do etc), but it re-uses the existing hash.c files, so it really is fairly small and straightforward apart from a few odd details. Now, this patch on its own doesn't really do much, but I think it's worth looking at, if only because if done correctly, the name hashing really can make an improvement to the whole issue of "do we have a filename that looks like this in the index already". And at least it gets real testing by being used even by default (ie there is a real use-case for it even without any insane filesystems). NOTE NOTE NOTE! The current hash is a joke. I'm ashamed of it, I'm just not ashamed of it enough to really care. I took all the numbers out of my nether regions - I'm sure it's good enough that it works in practice, but the whole point was that you can make a really much fancier hash that hashes characters not directly, but by their upper-case value or something like that, and thus you get a case-insensitive hash, while still keeping the name and the index itself totally case sensitive. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-23 03:41:14 +01:00
struct hash_table name_hash;
};
extern struct index_state the_index;
/* Name hashing */
extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
/*
* We don't actually *remove* it, we can just mark it invalid so that
* we won't find it in lookups.
*
* Not only would we have to search the lists (simple enough), but
* we'd also have to rehash other hash buckets in case this makes the
* hash bucket empty (common). So it's much better to just mark
* it.
*/
static inline void remove_name_hash(struct cache_entry *ce)
{
ce->ce_flags |= CE_UNHASHED;
}
#ifndef NO_THE_INDEX_COMPATIBILITY_MACROS
#define active_cache (the_index.cache)
#define active_nr (the_index.cache_nr)
#define active_alloc (the_index.cache_alloc)
#define active_cache_changed (the_index.cache_changed)
#define active_cache_tree (the_index.cache_tree)
#define read_cache() read_index(&the_index)
#define read_cache_from(path) read_index_from(&the_index, (path))
#define read_cache_preload(pathspec) read_index_preload(&the_index, (pathspec))
#define is_cache_unborn() is_index_unborn(&the_index)
#define read_cache_unmerged() read_index_unmerged(&the_index)
#define write_cache(newfd, cache, entries) write_index(&the_index, (newfd))
#define discard_cache() discard_index(&the_index)
#define unmerged_cache() unmerged_index(&the_index)
#define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
#define add_cache_entry(ce, option) add_index_entry(&the_index, (ce), (option))
#define rename_cache_entry_at(pos, new_name) rename_index_entry_at(&the_index, (pos), (new_name))
#define remove_cache_entry_at(pos) remove_index_entry_at(&the_index, (pos))
#define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
#define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags))
#define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags))
#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
#define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
#define cache_name_exists(name, namelen, igncase) index_name_exists(&the_index, (name), (namelen), (igncase))
#define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen))
#define resolve_undo_clear() resolve_undo_clear_index(&the_index)
#define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
#define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
#endif
enum object_type {
OBJ_BAD = -1,
OBJ_NONE = 0,
OBJ_COMMIT = 1,
OBJ_TREE = 2,
OBJ_BLOB = 3,
OBJ_TAG = 4,
/* 5 for future expansion */
OBJ_OFS_DELTA = 6,
OBJ_REF_DELTA = 7,
OBJ_ANY,
OBJ_MAX
};
static inline enum object_type object_type(unsigned int mode)
{
return S_ISDIR(mode) ? OBJ_TREE :
S_ISGITLINK(mode) ? OBJ_COMMIT :
OBJ_BLOB;
}
#define GIT_DIR_ENVIRONMENT "GIT_DIR"
introduce GIT_WORK_TREE to specify the work tree setup_gdg is used as abbreviation for setup_git_directory_gently. The work tree can be specified using the environment variable GIT_WORK_TREE and the config option core.worktree (the environment variable has precendence over the config option). Additionally there is a command line option --work-tree which sets the environment variable. setup_gdg does the following now: GIT_DIR unspecified repository in .git directory parent directory of the .git directory is used as work tree, GIT_WORK_TREE is ignored GIT_DIR unspecified repository in cwd GIT_DIR is set to cwd see the cases with GIT_DIR specified what happens next and also see the note below GIT_DIR specified GIT_WORK_TREE/core.worktree unspecified cwd is used as work tree GIT_DIR specified GIT_WORK_TREE/core.worktree specified the specified work tree is used Note on the case where GIT_DIR is unspecified and repository is in cwd: GIT_WORK_TREE is used but is_inside_git_dir is always true. I did it this way because setup_gdg might be called multiple times (e.g. when doing alias expansion) and in successive calls setup_gdg should do the same thing every time. Meaning of is_bare/is_inside_work_tree/is_inside_git_dir: (1) is_bare_repository A repository is bare if core.bare is true or core.bare is unspecified and the name suggests it is bare (directory not named .git). The bare option disables a few protective checks which are useful with a working tree. Currently this changes if a repository is bare: updates of HEAD are allowed git gc packs the refs the reflog is disabled by default (2) is_inside_work_tree True if the cwd is inside the associated working tree (if there is one), false otherwise. (3) is_inside_git_dir True if the cwd is inside the git directory, false otherwise. Before this patch is_inside_git_dir was always true for bare repositories. When setup_gdg finds a repository git_config(git_default_config) is always called. This ensure that is_bare_repository makes use of core.bare and does not guess even though core.bare is specified. inside_work_tree and inside_git_dir are set if setup_gdg finds a repository. The is_inside_work_tree and is_inside_git_dir functions will die if they are called before a successful call to setup_gdg. Signed-off-by: Matthias Lederhofer <matled@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-06 09:10:42 +02:00
#define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
Rename environment variables. H. Peter Anvin mentioned that using SHA1_whatever as an environment variable name is not nice and we should instead use names starting with "GIT_" prefix to avoid conflicts. Here is what this patch does: * Renames the following environment variables: New name Old Name GIT_AUTHOR_DATE AUTHOR_DATE GIT_AUTHOR_EMAIL AUTHOR_EMAIL GIT_AUTHOR_NAME AUTHOR_NAME GIT_COMMITTER_EMAIL COMMIT_AUTHOR_EMAIL GIT_COMMITTER_NAME COMMIT_AUTHOR_NAME GIT_ALTERNATE_OBJECT_DIRECTORIES SHA1_FILE_DIRECTORIES GIT_OBJECT_DIRECTORY SHA1_FILE_DIRECTORY * Introduces a compatibility macro, gitenv(), which does an getenv() and if it fails calls gitenv_bc(), which in turn picks up the value from old name while giving a warning about using an old name. * Changes all users of the environment variable to fetch environment variable with the new name using gitenv(). * Updates the documentation and scripts shipped with Linus GIT distribution. The transition plan is as follows: * We will keep the backward compatibility list used by gitenv() for now, so the current scripts and user environments continue to work as before. The users will get warnings when they have old name but not new name in their environment to the stderr. * The Porcelain layers should start using new names. However, just in case it ends up calling old Plumbing layer implementation, they should also export old names, taking values from the corresponding new names, during the transition period. * After a transition period, we would drop the compatibility support and drop gitenv(). Revert the callers to directly call getenv() but keep using the new names. The last part is probably optional and the transition duration needs to be set to a reasonable value. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-05-10 02:57:56 +02:00
#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
#define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
#define CONFIG_ENVIRONMENT "GIT_CONFIG"
#define CONFIG_DATA_ENVIRONMENT "GIT_CONFIG_PARAMETERS"
#define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
#define CEILING_DIRECTORIES_ENVIRONMENT "GIT_CEILING_DIRECTORIES"
#define NO_REPLACE_OBJECTS_ENVIRONMENT "GIT_NO_REPLACE_OBJECTS"
Add basic infrastructure to assign attributes to paths This adds the basic infrastructure to assign attributes to paths, in a way similar to what the exclusion mechanism does based on $GIT_DIR/info/exclude and .gitignore files. An attribute is just a simple string that does not contain any whitespace. They can be specified in $GIT_DIR/info/attributes file, and .gitattributes file in each directory. Each line in these files defines a pattern matching rule. Similar to the exclusion mechanism, a later match overrides an earlier match in the same file, and entries from .gitattributes file in the same directory takes precedence over the ones from parent directories. Lines in $GIT_DIR/info/attributes file are used as the lowest precedence default rules. A line is either a comment (an empty line, or a line that begins with a '#'), or a rule, which is a whitespace separated list of tokens. The first token on the line is a shell glob pattern. The rest are names of attributes, each of which can optionally be prefixed with '!'. Such a line means "if a path matches this glob, this attribute is set (or unset -- if the attribute name is prefixed with '!'). For glob matching, the same "if the pattern does not have a slash in it, the basename of the path is matched with fnmatch(3) against the pattern, otherwise, the path is matched with the pattern with FNM_PATHNAME" rule as the exclusion mechanism is used. This does not define what an attribute means. Tying an attribute to various effects it has on git operation for paths that have it will be specified separately. Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-12 10:07:32 +02:00
#define GITATTRIBUTES_FILE ".gitattributes"
#define INFOATTRIBUTES_FILE "info/attributes"
attribute macro support This adds "attribute macros" (for lack of better name). So far, we have low-level attributes such as crlf and diff, which are defined in operational terms --- setting or unsetting them on a particular path directly affects what is done to the path. For example, in order to decline diffs or crlf conversions on a binary blob, no diffs on PostScript files, and treat all other files normally, you would have something like these: * diff crlf *.ps !diff proprietary.o !diff !crlf That is fine as the operation goes, but gets unwieldy rather rapidly, when we start adding more low-level attributes that are defined in operational terms. A near-term example of such an attribute would be 'merge-3way' which would control if git should attempt the usual 3-way file-level merge internally, or leave merging to a specialized external program of user's choice. When it is added, we do _not_ want to force the users to update the above to: * diff crlf merge-3way *.ps !diff proprietary.o !diff !crlf !merge-3way The way this patch solves this issue is to realize that the attributes the user is assigning to paths are not defined in terms of operations but in terms of what they are. All of the three low-level attributes usually make sense for most of the files that sane SCM users have git operate on (these files are typically called "text'). Only a few cases, such as binary blob, need exception to decline the "usual treatment given to text files" -- and people mark them as "binary". So this allows the $GIT_DIR/info/alternates and .gitattributes at the toplevel of the project to also specify attributes that assigns other attributes. The syntax is '[attr]' followed by an attribute name followed by a list of attribute names: [attr] binary !diff !crlf !merge-3way When "binary" attribute is set to a path, if the path has not got diff/crlf/merge-3way attribute set or unset by other rules, this rule unsets the three low-level attributes. It is expected that the user level .gitattributes will be expressed mostly in terms of attributes based on what the files are, and the above sample would become like this: (built-in attribute configuration) [attr] binary !diff !crlf !merge-3way * diff crlf merge-3way (project specific .gitattributes) proprietary.o binary (user preference $GIT_DIR/info/attributes) *.ps !diff There are a few caveats. * As described above, you can define these macros only in $GIT_DIR/info/attributes and toplevel .gitattributes. * There is no attempt to detect circular definition of macro attributes, and definitions are evaluated from bottom to top as usual to fill in other attributes that have not yet got values. The following would work as expected: [attr] text diff crlf [attr] ps text !diff *.ps ps while this would most likely not (I haven't tried): [attr] ps text !diff [attr] text diff crlf *.ps ps * When a macro says "[attr] A B !C", saying that a path does not have attribute A does not let you tell anything about attributes B or C. That is, given this: [attr] text diff crlf [attr] ps text !diff *.txt !ps path hello.txt, which would match "*.txt" pattern, would have "ps" attribute set to zero, but that does not make text attribute of hello.txt set to false (nor diff attribute set to true). Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-14 17:54:37 +02:00
#define ATTRIBUTE_MACRO_PREFIX "[attr]"
#define GIT_NOTES_REF_ENVIRONMENT "GIT_NOTES_REF"
#define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
#define GIT_NOTES_DISPLAY_REF_ENVIRONMENT "GIT_NOTES_DISPLAY_REF"
#define GIT_NOTES_REWRITE_REF_ENVIRONMENT "GIT_NOTES_REWRITE_REF"
#define GIT_NOTES_REWRITE_MODE_ENVIRONMENT "GIT_NOTES_REWRITE_MODE"
/*
* Repository-local GIT_* environment variables
* The array is NULL-terminated to simplify its usage in contexts such
* environment creation or simple walk of the list.
* The number of non-NULL entries is available as a macro.
*/
#define LOCAL_REPO_ENV_SIZE 9
extern const char *const local_repo_env[LOCAL_REPO_ENV_SIZE + 1];
extern int is_bare_repository_cfg;
extern int is_bare_repository(void);
extern int is_inside_git_dir(void);
Clean up work-tree handling The old version of work-tree support was an unholy mess, barely readable, and not to the point. For example, why do you have to provide a worktree, when it is not used? As in "git status". Now it works. Another riddle was: if you can have work trees inside the git dir, why are some programs complaining that they need a work tree? IOW it is allowed to call $ git --git-dir=../ --work-tree=. bla when you really want to. In this case, you are both in the git directory and in the working tree. So, programs have to actually test for the right thing, namely if they are inside a working tree, and not if they are inside a git directory. Also, GIT_DIR=../.git should behave the same as if no GIT_DIR was specified, unless there is a repository in the current working directory. It does now. The logic to determine if a repository is bare, or has a work tree (tertium non datur), is this: --work-tree=bla overrides GIT_WORK_TREE, which overrides core.bare = true, which overrides core.worktree, which overrides GIT_DIR/.. when GIT_DIR ends in /.git, which overrides the directory in which .git/ was found. In related news, a long standing bug was fixed: when in .git/bla/x.git/, which is a bare repository, git formerly assumed ../.. to be the appropriate git dir. This problem was reported by Shawn Pearce to have caused much pain, where a colleague mistakenly ran "git init" in "/" a long time ago, and bare repositories just would not work. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-01 02:30:14 +02:00
extern char *git_work_tree_cfg;
introduce GIT_WORK_TREE to specify the work tree setup_gdg is used as abbreviation for setup_git_directory_gently. The work tree can be specified using the environment variable GIT_WORK_TREE and the config option core.worktree (the environment variable has precendence over the config option). Additionally there is a command line option --work-tree which sets the environment variable. setup_gdg does the following now: GIT_DIR unspecified repository in .git directory parent directory of the .git directory is used as work tree, GIT_WORK_TREE is ignored GIT_DIR unspecified repository in cwd GIT_DIR is set to cwd see the cases with GIT_DIR specified what happens next and also see the note below GIT_DIR specified GIT_WORK_TREE/core.worktree unspecified cwd is used as work tree GIT_DIR specified GIT_WORK_TREE/core.worktree specified the specified work tree is used Note on the case where GIT_DIR is unspecified and repository is in cwd: GIT_WORK_TREE is used but is_inside_git_dir is always true. I did it this way because setup_gdg might be called multiple times (e.g. when doing alias expansion) and in successive calls setup_gdg should do the same thing every time. Meaning of is_bare/is_inside_work_tree/is_inside_git_dir: (1) is_bare_repository A repository is bare if core.bare is true or core.bare is unspecified and the name suggests it is bare (directory not named .git). The bare option disables a few protective checks which are useful with a working tree. Currently this changes if a repository is bare: updates of HEAD are allowed git gc packs the refs the reflog is disabled by default (2) is_inside_work_tree True if the cwd is inside the associated working tree (if there is one), false otherwise. (3) is_inside_git_dir True if the cwd is inside the git directory, false otherwise. Before this patch is_inside_git_dir was always true for bare repositories. When setup_gdg finds a repository git_config(git_default_config) is always called. This ensure that is_bare_repository makes use of core.bare and does not guess even though core.bare is specified. inside_work_tree and inside_git_dir are set if setup_gdg finds a repository. The is_inside_work_tree and is_inside_git_dir functions will die if they are called before a successful call to setup_gdg. Signed-off-by: Matthias Lederhofer <matled@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-06 09:10:42 +02:00
extern int is_inside_work_tree(void);
extern int have_git_dir(void);
extern const char *get_git_dir(void);
extern char *get_object_directory(void);
extern char *get_index_file(void);
extern char *get_graft_file(void);
extern int set_git_dir(const char *path);
Clean up work-tree handling The old version of work-tree support was an unholy mess, barely readable, and not to the point. For example, why do you have to provide a worktree, when it is not used? As in "git status". Now it works. Another riddle was: if you can have work trees inside the git dir, why are some programs complaining that they need a work tree? IOW it is allowed to call $ git --git-dir=../ --work-tree=. bla when you really want to. In this case, you are both in the git directory and in the working tree. So, programs have to actually test for the right thing, namely if they are inside a working tree, and not if they are inside a git directory. Also, GIT_DIR=../.git should behave the same as if no GIT_DIR was specified, unless there is a repository in the current working directory. It does now. The logic to determine if a repository is bare, or has a work tree (tertium non datur), is this: --work-tree=bla overrides GIT_WORK_TREE, which overrides core.bare = true, which overrides core.worktree, which overrides GIT_DIR/.. when GIT_DIR ends in /.git, which overrides the directory in which .git/ was found. In related news, a long standing bug was fixed: when in .git/bla/x.git/, which is a bare repository, git formerly assumed ../.. to be the appropriate git dir. This problem was reported by Shawn Pearce to have caused much pain, where a colleague mistakenly ran "git init" in "/" a long time ago, and bare repositories just would not work. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-01 02:30:14 +02:00
extern const char *get_git_work_tree(void);
extern const char *read_gitfile_gently(const char *path);
extern void set_git_work_tree(const char *tree);
#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
extern const char **get_pathspec(const char *prefix, const char **pathspec);
extern void setup_work_tree(void);
extern const char *setup_git_directory_gently(int *);
extern const char *setup_git_directory(void);
extern const char *prefix_path(const char *prefix, int len, const char *path);
extern const char *prefix_filename(const char *prefix, int len, const char *path);
extern int check_filename(const char *prefix, const char *name);
extern void verify_filename(const char *prefix, const char *name);
extern void verify_non_filename(const char *prefix, const char *name);
#define INIT_DB_QUIET 0x0001
extern int init_db(const char *template_dir, unsigned int flags);
#define alloc_nr(x) (((x)+16)*3/2)
/*
* Realloc the buffer pointed at by variable 'x' so that it can hold
* at least 'nr' entries; the number of entries currently allocated
* is 'alloc', using the standard growing factor alloc_nr() macro.
*
* DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
*/
#define ALLOC_GROW(x, nr, alloc) \
do { \
if ((nr) > alloc) { \
if (alloc_nr(alloc) < (nr)) \
alloc = (nr); \
else \
alloc = alloc_nr(alloc); \
x = xrealloc((x), alloc * sizeof(*(x))); \
} \
} while (0)
/* Initialize and use the cache information */
extern int read_index(struct index_state *);
extern int read_index_preload(struct index_state *, const char **pathspec);
extern int read_index_from(struct index_state *, const char *path);
extern int is_index_unborn(struct index_state *);
extern int read_index_unmerged(struct index_state *);
extern int write_index(struct index_state *, int newfd);
extern int discard_index(struct index_state *);
extern int unmerged_index(const struct index_state *);
extern int verify_path(const char *path);
extern struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int igncase);
extern int index_name_pos(const struct index_state *, const char *name, int namelen);
#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
#define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
#define ADD_CACHE_SKIP_DFCHECK 4 /* Ok to skip DF conflict checks */
#define ADD_CACHE_JUST_APPEND 8 /* Append only; tree.c::read_tree() */
#define ADD_CACHE_NEW_ONLY 16 /* Do not replace existing ones */
extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
extern int remove_index_entry_at(struct index_state *, int pos);
check_updates(): effective removal of cache entries marked CE_REMOVE Below is oprofile output from GIT command 'git chekcout -q my-v2.6.25' (move from tag v2.6.27 to tag v2.6.25 of the Linux kernel): CPU: Core 2, speed 1999.95 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (Unhalted core cycles) count 20000 Counted INST_RETIRED_ANY_P events (number of instructions retired) with a unit mask of 0x00 (No unit mask) count 20000 CPU_CLK_UNHALT...|INST_RETIRED:2...| samples| %| samples| %| ------------------------------------ 409247 100.000 342878 100.000 git CPU_CLK_UNHALT...|INST_RETIRED:2...| samples| %| samples| %| ------------------------------------ 260476 63.6476 257843 75.1996 libz.so.1.2.3 100876 24.6492 64378 18.7758 kernel-2.6.28.4_2.vmlinux 30850 7.5382 7874 2.2964 libc-2.9.so 14775 3.6103 8390 2.4469 git 2020 0.4936 4325 1.2614 libcrypto.so.0.9.8 191 0.0467 32 0.0093 libpthread-2.9.so 58 0.0142 36 0.0105 ld-2.9.so 1 2.4e-04 0 0 libldap-2.3.so.0.2.31 Detail list of the top 20 function entries (libz counted in one blob): CPU_CLK_UNHALTED INST_RETIRED_ANY_P samples % samples % image name symbol name 260476 63.6862 257843 75.2725 libz.so.1.2.3 /lib/libz.so.1.2.3 16587 4.0555 3636 1.0615 libc-2.9.so memcpy 7710 1.8851 277 0.0809 libc-2.9.so memmove 3679 0.8995 1108 0.3235 kernel-2.6.28.4_2.vmlinux d_validate 3546 0.8670 2607 0.7611 kernel-2.6.28.4_2.vmlinux __getblk 3174 0.7760 1813 0.5293 libc-2.9.so _int_malloc 2396 0.5858 3681 1.0746 kernel-2.6.28.4_2.vmlinux copy_to_user 2270 0.5550 2528 0.7380 kernel-2.6.28.4_2.vmlinux __link_path_walk 2205 0.5391 1797 0.5246 kernel-2.6.28.4_2.vmlinux ext4_mark_iloc_dirty 2103 0.5142 1203 0.3512 kernel-2.6.28.4_2.vmlinux find_first_zero_bit 2077 0.5078 997 0.2911 kernel-2.6.28.4_2.vmlinux do_get_write_access 2070 0.5061 514 0.1501 git cache_name_compare 2043 0.4995 1501 0.4382 kernel-2.6.28.4_2.vmlinux rcu_irq_exit 2022 0.4944 1732 0.5056 kernel-2.6.28.4_2.vmlinux __ext4_get_inode_loc 2020 0.4939 4325 1.2626 libcrypto.so.0.9.8 /usr/lib/libcrypto.so.0.9.8 1965 0.4804 1384 0.4040 git patch_delta 1708 0.4176 984 0.2873 kernel-2.6.28.4_2.vmlinux rcu_sched_grace_period 1682 0.4112 727 0.2122 kernel-2.6.28.4_2.vmlinux sysfs_slab_alias 1659 0.4056 290 0.0847 git find_pack_entry_one 1480 0.3619 1307 0.3816 kernel-2.6.28.4_2.vmlinux ext4_writepage_trans_blocks Notice the memmove line, where the CPU did 7710 / 277 = 27.8 cycles per instruction, and compared to the total cycles spent inside the source code of GIT for this command, all the memmove() calls translates to (7710 * 100) / 14775 = 52.2% of this. Retesting with a GIT program compiled for gcov usage, I found out that the memmove() calls came from remove_index_entry_at() in read-cache.c, where we have: memmove(istate->cache + pos, istate->cache + pos + 1, (istate->cache_nr - pos) * sizeof(struct cache_entry *)); remove_index_entry_at() is called 4902 times from check_updates() in unpack-trees.c, and each time called we move each cache_entry pointers (from the removed one) one step to the left. Since we have 28828 entries in the cache this time, and if we on average move half of them each time, we in total move approximately 4902 * 0.5 * 28828 * 4 = 282 629 712 bytes, or twice this amount if each pointer is 8 bytes (64 bit). OK, is seems that the function check_updates() is called 28 times, so the estimated guess above had been more correct if check_updates() had been called only once, but the point is: we get lots of bytes moved. To fix this, and use an O(N) algorithm instead, where N is the number of cache_entries, we delete/remove all entries in one loop through all entries. From a retest, the new remove_marked_cache_entries() from the patch below, ended up with the following output line from oprofile: 46 0.0105 15 0.0041 git remove_marked_cache_entries If we can trust the numbers from oprofile in this case, we saved approximately ((7710 - 46) * 20000) / (2 * 1000 * 1000 * 1000) = 0.077 seconds CPU time with this fix for this particular test. And notice that now the CPU did only 46 / 15 = 3.1 cycles/instruction. Signed-off-by: Kjetil Barvik <barvik@broadpark.no> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-18 23:18:03 +01:00
extern void remove_marked_cache_entries(struct index_state *istate);
extern int remove_file_from_index(struct index_state *, const char *path);
#define ADD_CACHE_VERBOSE 1
#define ADD_CACHE_PRETEND 2
#define ADD_CACHE_IGNORE_ERRORS 4
#define ADD_CACHE_IGNORE_REMOVAL 8
#define ADD_CACHE_INTENT 16
extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
extern int add_file_to_index(struct index_state *, const char *path, int flags);
extern struct cache_entry *make_cache_entry(unsigned int mode, const unsigned char *sha1, const char *path, int stage, int refresh);
extern int ce_same_name(struct cache_entry *a, struct cache_entry *b);
extern int index_name_is_other(const struct index_state *, const char *, int);
/* do stat comparison even if CE_VALID is true */
#define CE_MATCH_IGNORE_VALID 01
/* do not check the contents but report dirty on racily-clean entries */
#define CE_MATCH_RACY_IS_DIRTY 02
/* do stat comparison even if CE_SKIP_WORKTREE is true */
#define CE_MATCH_IGNORE_SKIP_WORKTREE 04
extern int ie_match_stat(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
extern int ie_modified(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
extern int ce_path_match(const struct cache_entry *ce, const char **pathspec);
extern int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, enum object_type type, const char *path);
extern int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object);
extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
#define REFRESH_REALLY 0x0001 /* ignore_valid */
#define REFRESH_UNMERGED 0x0002 /* allow unmerged */
#define REFRESH_QUIET 0x0004 /* be quiet about it */
#define REFRESH_IGNORE_MISSING 0x0008 /* ignore non-existent */
#define REFRESH_IGNORE_SUBMODULES 0x0010 /* ignore submodules */
#define REFRESH_IN_PORCELAIN 0x0020 /* user friendly output, not "needs update" */
extern int refresh_index(struct index_state *, unsigned int flags, const char **pathspec, char *seen, char *header_msg);
struct lock_file {
struct lock_file *next;
int fd;
pid_t owner;
char on_list;
char filename[PATH_MAX];
};
#define LOCK_DIE_ON_ERROR 1
#define LOCK_NODEREF 2
extern int unable_to_lock_error(const char *path, int err);
extern NORETURN void unable_to_lock_index_die(const char *path, int err);
extern int hold_lock_file_for_update(struct lock_file *, const char *path, int);
extern int hold_lock_file_for_append(struct lock_file *, const char *path, int);
extern int commit_lock_file(struct lock_file *);
extern int hold_locked_index(struct lock_file *, int);
extern int commit_locked_index(struct lock_file *);
extern void set_alternate_index_output(const char *);
extern int close_lock_file(struct lock_file *);
extern void rollback_lock_file(struct lock_file *);
extern int delete_ref(const char *, const unsigned char *sha1, int delopt);
/* Environment bits from configuration mechanism */
extern int trust_executable_bit;
extern int trust_ctime;
extern int quote_path_fully;
extern int has_symlinks;
extern int ignore_case;
"Assume unchanged" git This adds "assume unchanged" logic, started by this message in the list discussion recently: <Pine.LNX.4.64.0601311807470.7301@g5.osdl.org> This is a workaround for filesystems that do not have lstat() that is quick enough for the index mechanism to take advantage of. On the paths marked as "assumed to be unchanged", the user needs to explicitly use update-index to register the object name to be in the next commit. You can use two new options to update-index to set and reset the CE_VALID bit: git-update-index --assume-unchanged path... git-update-index --no-assume-unchanged path... These forms manipulate only the CE_VALID bit; it does not change the object name recorded in the index file. Nor they add a new entry to the index. When the configuration variable "core.ignorestat = true" is set, the index entries are marked with CE_VALID bit automatically after: - update-index to explicitly register the current object name to the index file. - when update-index --refresh finds the path to be up-to-date. - when tools like read-tree -u and apply --index update the working tree file and register the current object name to the index file. The flag is dropped upon read-tree that does not check out the index entry. This happens regardless of the core.ignorestat settings. Index entries marked with CE_VALID bit are assumed to be unchanged most of the time. However, there are cases that CE_VALID bit is ignored for the sake of safety and usability: - while "git-read-tree -m" or git-apply need to make sure that the paths involved in the merge do not have local modifications. This sacrifices performance for safety. - when git-checkout-index -f -q -u -a tries to see if it needs to checkout the paths. Otherwise you can never check anything out ;-). - when git-update-index --really-refresh (a new flag) tries to see if the index entry is up to date. You can start with everything marked as CE_VALID and run this once to drop CE_VALID bit for paths that are modified. Most notably, "update-index --refresh" honours CE_VALID and does not actively stat, so after you modified a file in the working tree, update-index --refresh would not notice until you tell the index about it with "git-update-index path" or "git-update-index --no-assume-unchanged path". This version is not expected to be perfect. I think diff between index and/or tree and working files may need some adjustment, and there probably needs other cases we should automatically unmark paths that are marked to be CE_VALID. But the basics seem to work, and ready to be tested by people who asked for this feature. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-09 06:15:24 +01:00
extern int assume_unchanged;
extern int prefer_symlink_refs;
extern int log_all_ref_updates;
extern int warn_ambiguous_refs;
extern int unique_abbrev_extra_length;
extern int shared_repository;
extern const char *apply_default_whitespace;
extern const char *apply_default_ignorewhitespace;
extern int zlib_compression_level;
Custom compression levels for objects and packs Add config variables pack.compression and core.loosecompression , and switch --compression=level to pack-objects. Loose objects will be compressed using core.loosecompression if set, else core.compression if set, else Z_BEST_SPEED. Packed objects will be compressed using --compression=level if seen, else pack.compression if set, else core.compression if set, else Z_DEFAULT_COMPRESSION. This is the "pack compression level". Loose objects added to a pack undeltified will be recompressed to the pack compression level if it is unequal to the current loose compression level by the preceding rules, or if the loose object was written while core.legacyheaders = true. Newly deltified loose objects are always compressed to the current pack compression level. Previously packed objects added to a pack are recompressed to the current pack compression level exactly when their deltification status changes, since the previous pack data cannot be reused. In either case, the --no-reuse-object switch from the first patch below will always force recompression to the current pack compression level, instead of assuming the pack compression level hasn't changed and pack data can be reused when possible. This applies on top of the following patches from Nicolas Pitre: [PATCH] allow for undeltified objects not to be reused [PATCH] make "repack -f" imply "pack-objects --no-reuse-object" Signed-off-by: Dana L. How <danahow@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-09 22:56:50 +02:00
extern int core_compression_level;
extern int core_compression_seen;
Fully activate the sliding window pack access. This finally turns on the sliding window behavior for packfile data access by mapping limited size windows and chaining them under the packed_git->windows list. We consider a given byte offset to be within the window only if there would be at least 20 bytes (one hash worth of data) accessible after the requested offset. This range selection relates to the contract that use_pack() makes with its callers, allowing them to access one hash or one object header without needing to call use_pack() for every byte of data obtained. In the worst case scenario we will map the same page of data twice into memory: once at the end of one window and once again at the start of the next window. This duplicate page mapping will happen only when an object header or a delta base reference is spanned over the end of a window and is always limited to just one page of duplication, as no sane operating system will ever have a page size smaller than a hash. I am assuming that the possible wasted page of virtual address space is going to perform faster than the alternatives, which would be to copy the object header or ref delta into a temporary buffer prior to parsing, or to check the window range on every byte during header parsing. We may decide to revisit this decision in the future since this is just a gut instinct decision and has not actually been proven out by experimental testing. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-23 08:34:28 +01:00
extern size_t packed_git_window_size;
extern size_t packed_git_limit;
extern size_t delta_base_cache_limit;
extern int read_replace_refs;
extern int fsync_object_files;
extern int core_preload_index;
extern int core_apply_sparse_checkout;
safecrlf: Add mechanism to warn about irreversible crlf conversions CRLF conversion bears a slight chance of corrupting data. autocrlf=true will convert CRLF to LF during commit and LF to CRLF during checkout. A file that contains a mixture of LF and CRLF before the commit cannot be recreated by git. For text files this is the right thing to do: it corrects line endings such that we have only LF line endings in the repository. But for binary files that are accidentally classified as text the conversion can corrupt data. If you recognize such corruption early you can easily fix it by setting the conversion type explicitly in .gitattributes. Right after committing you still have the original file in your work tree and this file is not yet corrupted. You can explicitly tell git that this file is binary and git will handle the file appropriately. Unfortunately, the desired effect of cleaning up text files with mixed line endings and the undesired effect of corrupting binary files cannot be distinguished. In both cases CRLFs are removed in an irreversible way. For text files this is the right thing to do because CRLFs are line endings, while for binary files converting CRLFs corrupts data. This patch adds a mechanism that can either warn the user about an irreversible conversion or can even refuse to convert. The mechanism is controlled by the variable core.safecrlf, with the following values: - false: disable safecrlf mechanism - warn: warn about irreversible conversions - true: refuse irreversible conversions The default is to warn. Users are only affected by this default if core.autocrlf is set. But the current default of git is to leave core.autocrlf unset, so users will not see warnings unless they deliberately chose to activate the autocrlf mechanism. The safecrlf mechanism's details depend on the git command. The general principles when safecrlf is active (not false) are: - we warn/error out if files in the work tree can modified in an irreversible way without giving the user a chance to backup the original file. - for read-only operations that do not modify files in the work tree we do not not print annoying warnings. There are exceptions. Even though... - "git add" itself does not touch the files in the work tree, the next checkout would, so the safety triggers; - "git apply" to update a text file with a patch does touch the files in the work tree, but the operation is about text files and CRLF conversion is about fixing the line ending inconsistencies, so the safety does not trigger; - "git diff" itself does not touch the files in the work tree, it is often run to inspect the changes you intend to next "git add". To catch potential problems early, safety triggers. The concept of a safety check was originally proposed in a similar way by Linus Torvalds. Thanks to Dimitry Potapov for insisting on getting the naked LF/autocrlf=true case right. Signed-off-by: Steffen Prohaska <prohaska@zib.de>
2008-02-06 12:25:58 +01:00
enum safe_crlf {
SAFE_CRLF_FALSE = 0,
SAFE_CRLF_FAIL = 1,
SAFE_CRLF_WARN = 2
safecrlf: Add mechanism to warn about irreversible crlf conversions CRLF conversion bears a slight chance of corrupting data. autocrlf=true will convert CRLF to LF during commit and LF to CRLF during checkout. A file that contains a mixture of LF and CRLF before the commit cannot be recreated by git. For text files this is the right thing to do: it corrects line endings such that we have only LF line endings in the repository. But for binary files that are accidentally classified as text the conversion can corrupt data. If you recognize such corruption early you can easily fix it by setting the conversion type explicitly in .gitattributes. Right after committing you still have the original file in your work tree and this file is not yet corrupted. You can explicitly tell git that this file is binary and git will handle the file appropriately. Unfortunately, the desired effect of cleaning up text files with mixed line endings and the undesired effect of corrupting binary files cannot be distinguished. In both cases CRLFs are removed in an irreversible way. For text files this is the right thing to do because CRLFs are line endings, while for binary files converting CRLFs corrupts data. This patch adds a mechanism that can either warn the user about an irreversible conversion or can even refuse to convert. The mechanism is controlled by the variable core.safecrlf, with the following values: - false: disable safecrlf mechanism - warn: warn about irreversible conversions - true: refuse irreversible conversions The default is to warn. Users are only affected by this default if core.autocrlf is set. But the current default of git is to leave core.autocrlf unset, so users will not see warnings unless they deliberately chose to activate the autocrlf mechanism. The safecrlf mechanism's details depend on the git command. The general principles when safecrlf is active (not false) are: - we warn/error out if files in the work tree can modified in an irreversible way without giving the user a chance to backup the original file. - for read-only operations that do not modify files in the work tree we do not not print annoying warnings. There are exceptions. Even though... - "git add" itself does not touch the files in the work tree, the next checkout would, so the safety triggers; - "git apply" to update a text file with a patch does touch the files in the work tree, but the operation is about text files and CRLF conversion is about fixing the line ending inconsistencies, so the safety does not trigger; - "git diff" itself does not touch the files in the work tree, it is often run to inspect the changes you intend to next "git add". To catch potential problems early, safety triggers. The concept of a safety check was originally proposed in a similar way by Linus Torvalds. Thanks to Dimitry Potapov for insisting on getting the naked LF/autocrlf=true case right. Signed-off-by: Steffen Prohaska <prohaska@zib.de>
2008-02-06 12:25:58 +01:00
};
extern enum safe_crlf safe_crlf;
enum auto_crlf {
AUTO_CRLF_FALSE = 0,
AUTO_CRLF_TRUE = 1,
AUTO_CRLF_INPUT = -1,
};
extern enum auto_crlf auto_crlf;
enum eol {
EOL_UNSET,
EOL_CRLF,
EOL_LF,
#ifdef NATIVE_CRLF
EOL_NATIVE = EOL_CRLF
#else
EOL_NATIVE = EOL_LF
#endif
};
extern enum eol eol;
enum branch_track {
BRANCH_TRACK_UNSPECIFIED = -1,
BRANCH_TRACK_NEVER = 0,
BRANCH_TRACK_REMOTE,
BRANCH_TRACK_ALWAYS,
BRANCH_TRACK_EXPLICIT,
BRANCH_TRACK_OVERRIDE
};
enum rebase_setup_type {
AUTOREBASE_NEVER = 0,
AUTOREBASE_LOCAL,
AUTOREBASE_REMOTE,
AUTOREBASE_ALWAYS
};
enum push_default_type {
PUSH_DEFAULT_NOTHING = 0,
PUSH_DEFAULT_MATCHING,
PUSH_DEFAULT_TRACKING,
PUSH_DEFAULT_CURRENT
};
extern enum branch_track git_branch_track;
extern enum rebase_setup_type autorebase;
extern enum push_default_type push_default;
enum object_creation_mode {
OBJECT_CREATION_USES_HARDLINKS = 0,
OBJECT_CREATION_USES_RENAMES = 1
};
extern enum object_creation_mode object_creation_mode;
extern char *notes_ref_name;
extern int grafts_replace_parents;
#define GIT_REPO_VERSION 0
extern int repository_format_version;
extern int check_repository_format(void);
#define MTIME_CHANGED 0x0001
#define CTIME_CHANGED 0x0002
#define OWNER_CHANGED 0x0004
#define MODE_CHANGED 0x0008
#define INODE_CHANGED 0x0010
#define DATA_CHANGED 0x0020
#define TYPE_CHANGED 0x0040
extern char *mksnpath(char *buf, size_t n, const char *fmt, ...)
__attribute__((format (printf, 3, 4)));
extern char *git_snpath(char *buf, size_t n, const char *fmt, ...)
__attribute__((format (printf, 3, 4)));
extern char *git_pathdup(const char *fmt, ...)
__attribute__((format (printf, 1, 2)));
/* Return a statically allocated filename matching the sha1 signature */
extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
extern char *git_path_submodule(const char *path, const char *fmt, ...)
__attribute__((format (printf, 2, 3)));
extern char *sha1_file_name(const unsigned char *sha1);
extern char *sha1_pack_name(const unsigned char *sha1);
extern char *sha1_pack_index_name(const unsigned char *sha1);
extern const char *find_unique_abbrev(const unsigned char *sha1, int);
extern const unsigned char null_sha1[20];
static inline int is_null_sha1(const unsigned char *sha1)
{
return !memcmp(sha1, null_sha1, 20);
}
static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
{
return memcmp(sha1, sha2, 20);
}
static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
{
memcpy(sha_dst, sha_src, 20);
}
static inline void hashclr(unsigned char *hash)
{
memset(hash, 0, 20);
}
#define EMPTY_TREE_SHA1_HEX \
"4b825dc642cb6eb9a060e54bf8d69288fbee4904"
#define EMPTY_TREE_SHA1_BIN \
"\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
"\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
int git_mkstemp(char *path, size_t n, const char *template);
int git_mkstemps(char *path, size_t n, const char *template, int suffix_len);
/* set default permissions by passing mode arguments to open(2) */
int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
int git_mkstemp_mode(char *pattern, int mode);
/*
* NOTE NOTE NOTE!!
*
* PERM_UMASK, OLD_PERM_GROUP and OLD_PERM_EVERYBODY enumerations must
* not be changed. Old repositories have core.sharedrepository written in
* numeric format, and therefore these values are preserved for compatibility
* reasons.
*/
enum sharedrepo {
PERM_UMASK = 0,
OLD_PERM_GROUP = 1,
OLD_PERM_EVERYBODY = 2,
PERM_GROUP = 0660,
PERM_EVERYBODY = 0664
};
int git_config_perm(const char *var, const char *value);
int set_shared_perm(const char *path, int mode);
#define adjust_shared_perm(path) set_shared_perm((path), 0)
int safe_create_leading_directories(char *path);
int safe_create_leading_directories_const(const char *path);
extern char *expand_user_path(const char *path);
char *enter_repo(char *path, int strict);
static inline int is_absolute_path(const char *path)
{
return path[0] == '/' || has_dos_drive_prefix(path);
}
int is_directory(const char *);
const char *make_absolute_path(const char *path);
const char *make_nonrelative_path(const char *path);
Make git_dir a path relative to work_tree in setup_work_tree() Once we find the absolute paths for git_dir and work_tree, we can make git_dir a relative path since we know pwd will be work_tree. This should save the kernel some time traversing the path to work_tree all the time if git_dir is inside work_tree. Daniel's patch didn't apply for me as-is, so I recreated it with some differences, and here are the numbers from ten runs each. There is some IO for me - probably due to more-or-less random flushing of the journal - so the variation is bigger than I'd like, but whatever: Before: real 0m8.135s real 0m7.933s real 0m8.080s real 0m7.954s real 0m7.949s real 0m8.112s real 0m7.934s real 0m8.059s real 0m7.979s real 0m8.038s After: real 0m7.685s real 0m7.968s real 0m7.703s real 0m7.850s real 0m7.995s real 0m7.817s real 0m7.963s real 0m7.955s real 0m7.848s real 0m7.969s Now, going by "best of ten" (on the assumption that the longer numbers are all due to IO), I'm saying a 7.933s -> 7.685s reduction, and it does seem to be outside of the noise (ie the "after" case never broke 8s, while the "before" case did so half the time). So looks like about 3% to me. Doing it for a slightly smaller test-case (just the "arch" subdirectory) gets more stable numbers probably due to not filling the journal with metadata updates, so we have: Before: real 0m1.633s real 0m1.633s real 0m1.633s real 0m1.632s real 0m1.632s real 0m1.630s real 0m1.634s real 0m1.631s real 0m1.632s real 0m1.632s After: real 0m1.610s real 0m1.609s real 0m1.610s real 0m1.608s real 0m1.607s real 0m1.610s real 0m1.609s real 0m1.611s real 0m1.608s real 0m1.611s where I'ld just take the averages and say 1.632 vs 1.610, which is just over 1% peformance improvement. So it's not in the noise, but it's not as big as I initially thought and measured. (That said, it obviously depends on how deep the working directory path is too, and whether it is behind NFS or something else that might need to cause more work to look up). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-19 21:34:06 +02:00
const char *make_relative_path(const char *abs, const char *base);
int normalize_path_copy(char *dst, const char *src);
int longest_ancestor_length(const char *path, const char *prefix_list);
char *strip_path_suffix(const char *path, const char *suffix);
int daemon_avoid_alias(const char *path);
int offset_1st_component(const char *path);
/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
extern int sha1_object_info(const unsigned char *, unsigned long *);
extern void *read_sha1_file_repl(const unsigned char *sha1, enum object_type *type, unsigned long *size, const unsigned char **replacement);
static inline void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
{
return read_sha1_file_repl(sha1, type, size, NULL);
}
extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
extern int force_object_loose(const unsigned char *sha1, time_t mtime);
close another possibility for propagating pack corruption Abstract -------- With index v2 we have a per object CRC to allow quick and safe reuse of pack data when repacking. This, however, doesn't currently prevent a stealth corruption from being propagated into a new pack when _not_ reusing pack data as demonstrated by the modification to t5302 included here. The Context ----------- The Git database is all checksummed with SHA1 hashes. Any kind of corruption can be confirmed by verifying this per object hash against corresponding data. However this can be costly to perform systematically and therefore this check is often not performed at run time when accessing the object database. First, the loose object format is entirely compressed with zlib which already provide a CRC verification of its own when inflating data. Any disk corruption would be caught already in this case. Then, packed objects are also compressed with zlib but only for their actual payload. The object headers and delta base references are not deflated for obvious performance reasons, however this leave them vulnerable to potentially undetected disk corruptions. Object types are often validated against the expected type when they're requested, and deflated size must always match the size recorded in the object header, so those cases are pretty much covered as well. Where corruptions could go unnoticed is in the delta base reference. Of course, in the OBJ_REF_DELTA case, the odds for a SHA1 reference to get corrupted so it actually matches the SHA1 of another object with the same size (the delta header stores the expected size of the base object to apply against) are virtually zero. In the OBJ_OFS_DELTA case, the reference is a pack offset which would have to match the start boundary of a different base object but still with the same size, and although this is relatively much more "probable" than in the OBJ_REF_DELTA case, the probability is also about zero in absolute terms. Still, the possibility exists as demonstrated in t5302 and is certainly greater than a SHA1 collision, especially in the OBJ_OFS_DELTA case which is now the default when repacking. Again, repacking by reusing existing pack data is OK since the per object CRC provided by index v2 guards against any such corruptions. What t5302 failed to test is a full repack in such case. The Solution ------------ As unlikely as this kind of stealth corruption can be in practice, it certainly isn't acceptable to propagate it into a freshly created pack. But, because this is so unlikely, we don't want to pay the run time cost associated with extra validation checks all the time either. Furthermore, consequences of such corruption in anything but repacking should be rather visible, and even if it could be quite unpleasant, it still has far less severe consequences than actively creating bad packs. So the best compromize is to check packed object CRC when unpacking objects, and only during the compression/writing phase of a repack, and only when not streaming the result. The cost of this is minimal (less than 1% CPU time), and visible only with a full repack. Someone with a stats background could provide an objective evaluation of this, but I suspect that it's bad RAM that has more potential for data corruptions at this point, even in those cases where this extra check is not performed. Still, it is best to prevent a known hole for corruption when recreating object data into a new pack. What about the streamed pack case? Well, any client receiving a pack must always consider that pack as untrusty and perform full validation anyway, hence no such stealth corruption could be propagated to remote repositoryes already. It is therefore worthless doing local validation in that case. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-31 16:31:08 +01:00
/* global flag to enable extra checks when accessing packed objects */
extern int do_check_packed_object_crc;
extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
extern int move_temp_to_file(const char *tmpfile, const char *filename);
extern int has_sha1_pack(const unsigned char *sha1);
extern int has_sha1_file(const unsigned char *sha1);
extern int has_loose_object_nonlocal(const unsigned char *sha1);
extern int has_pack_index(const unsigned char *sha1);
extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);
extern const signed char hexval_table[256];
static inline unsigned int hexval(unsigned char c)
{
return hexval_table[c];
}
/* Convert to/from hex/sha1 representation */
#define MINIMUM_ABBREV 4
#define DEFAULT_ABBREV 7
struct object_context {
unsigned char tree[20];
char path[PATH_MAX];
unsigned mode;
};
extern int get_sha1(const char *str, unsigned char *sha1);
extern int get_sha1_with_mode_1(const char *str, unsigned char *sha1, unsigned *mode, int gently, const char *prefix);
static inline int get_sha1_with_mode(const char *str, unsigned char *sha1, unsigned *mode)
{
return get_sha1_with_mode_1(str, sha1, mode, 1, NULL);
}
extern int get_sha1_with_context_1(const char *name, unsigned char *sha1, struct object_context *orc, int gently, const char *prefix);
static inline int get_sha1_with_context(const char *str, unsigned char *sha1, struct object_context *orc)
{
return get_sha1_with_context_1(str, sha1, orc, 1, NULL);
}
extern int get_sha1_hex(const char *hex, unsigned char *sha1);
extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */
extern int read_ref(const char *filename, unsigned char *sha1);
extern const char *resolve_ref(const char *path, unsigned char *sha1, int, int *);
extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
extern int interpret_branch_name(const char *str, struct strbuf *);
extern int get_sha1_mb(const char *str, unsigned char *sha1);
2007-11-11 15:01:46 +01:00
extern int refname_match(const char *abbrev_name, const char *full_name, const char **rules);
extern const char *ref_rev_parse_rules[];
2007-11-11 15:01:48 +01:00
extern const char *ref_fetch_rules[];
2007-11-11 15:01:46 +01:00
extern int create_symref(const char *ref, const char *refs_heads_master, const char *logmsg);
extern int validate_headref(const char *ref);
extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
extern int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);
extern void *read_object_with_reference(const unsigned char *sha1,
const char *required_type,
unsigned long *size,
unsigned char *sha1_ret);
extern struct object *peel_to_type(const char *name, int namelen,
struct object *o, enum object_type);
enum date_mode {
DATE_NORMAL = 0,
DATE_RELATIVE,
DATE_SHORT,
DATE_LOCAL,
DATE_ISO8601,
DATE_RFC2822,
DATE_RAW
};
const char *show_date(unsigned long time, int timezone, enum date_mode mode);
const char *show_date_relative(unsigned long time, int tz,
const struct timeval *now,
char *timebuf,
size_t timebuf_size);
int parse_date(const char *date, char *buf, int bufsize);
int parse_date_basic(const char *date, unsigned long *timestamp, int *offset);
void datestamp(char *buf, int bufsize);
#define approxidate(s) approxidate_careful((s), NULL)
unsigned long approxidate_careful(const char *, int *);
unsigned long approxidate_relative(const char *date, const struct timeval *now);
enum date_mode parse_date_format(const char *format);
Re-fix "builtin-commit: fix --signoff" An earlier fix to the said commit was incomplete; it mixed up the meaning of the flag parameter passed to the internal fmt_ident() function, so this corrects it. git_author_info() and git_committer_info() can be told to issue a warning when no usable user information is found, and optionally can be told to error out. Operations that actually use the information to record a new commit or a tag will still error out, but the caller to leave reflog record will just silently use bogus user information. Not warning on misconfigured user information while writing a reflog entry is somewhat debatable, but it is probably nicer to the users to silently let it pass, because the only information you are losing is who checked out the branch. * git_author_info() and git_committer_info() used to take 1 (positive int) to error out with a warning on misconfiguration; this is now signalled with a symbolic constant IDENT_ERROR_ON_NO_NAME. * These functions used to take -1 (negative int) to warn but continue; this is now signalled with a symbolic constant IDENT_WARN_ON_NO_NAME. * fmt_ident() function implements the above error reporting behaviour common to git_author_info() and git_committer_info(). A symbolic constant IDENT_NO_DATE can be or'ed in to the flag parameter to make it return only the "Name <email@address.xz>". * fmt_name() is a thin wrapper around fmt_ident() that always passes IDENT_ERROR_ON_NO_NAME and IDENT_NO_DATE. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-12-09 02:32:08 +01:00
#define IDENT_WARN_ON_NO_NAME 1
#define IDENT_ERROR_ON_NO_NAME 2
#define IDENT_NO_DATE 4
extern const char *git_author_info(int);
extern const char *git_committer_info(int);
extern const char *fmt_ident(const char *name, const char *email, const char *date_str, int);
extern const char *fmt_name(const char *name, const char *email);
extern const char *git_editor(void);
extern const char *git_pager(int stdout_is_tty);
struct checkout {
const char *base_dir;
int base_dir_len;
unsigned force:1,
quiet:1,
not_new:1,
refresh_cache:1;
};
extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
struct cache_def {
char path[PATH_MAX + 1];
int len;
int flags;
int track_flags;
int prefix_len_stat_func;
};
extern int has_symlink_leading_path(const char *name, int len);
extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
extern int check_leading_path(const char *name, int len);
extern int has_dirs_only_path(const char *name, int len, int prefix_len);
extern void schedule_dir_for_removal(const char *name, int len);
extern void remove_scheduled_dirs(void);
extern struct alternate_object_database {
struct alternate_object_database *next;
char *name;
char base[FLEX_ARRAY]; /* more */
} *alt_odb_list;
extern void prepare_alt_odb(void);
extern void add_to_alternates_file(const char *reference);
typedef int alt_odb_fn(struct alternate_object_database *, void *);
extern void foreach_alt_odb(alt_odb_fn, void*);
struct pack_window {
struct pack_window *next;
unsigned char *base;
off_t offset;
size_t len;
unsigned int last_used;
unsigned int inuse_cnt;
};
extern struct packed_git {
struct packed_git *next;
struct pack_window *windows;
off_t pack_size;
const void *index_data;
size_t index_size;
uint32_t num_objects;
uint32_t num_bad_objects;
unsigned char *bad_object_sha1;
int index_version;
time_t mtime;
int pack_fd;
unsigned pack_local:1,
pack_keep:1;
unsigned char sha1[20];
/* something like ".git/objects/pack/xxxxx.pack" */
char pack_name[FLEX_ARRAY]; /* more */
} *packed_git;
struct pack_entry {
off_t offset;
unsigned char sha1[20];
struct packed_git *p;
};
struct ref {
struct ref *next;
unsigned char old_sha1[20];
unsigned char new_sha1[20];
char *symref;
unsigned int force:1,
merge:1,
nonfastforward:1,
deletion:1;
enum {
REF_STATUS_NONE = 0,
REF_STATUS_OK,
REF_STATUS_REJECT_NONFASTFORWARD,
REF_STATUS_REJECT_NODELETE,
REF_STATUS_UPTODATE,
REF_STATUS_REMOTE_REJECT,
REF_STATUS_EXPECTING_REPORT
} status;
char *remote_status;
Renaming push. This allows git-send-pack to push local refs to a destination repository under different names. Here is the name mapping rules for refs. * If there is no ref mapping on the command line: - if '--all' is specified, it is equivalent to specifying <local> ":" <local> for all the existing local refs on the command line - otherwise, it is equivalent to specifying <ref> ":" <ref> for all the refs that exist on both sides. * <name> is just a shorthand for <name> ":" <name> * <src> ":" <dst> push ref that matches <src> to ref that matches <dst>. - It is an error if <src> does not match exactly one of local refs. - It is an error if <dst> matches more than one remote refs. - If <dst> does not match any remote refs, either - it has to start with "refs/"; <dst> is used as the destination literally in this case. - <src> == <dst> and the ref that matched the <src> must not exist in the set of remote refs; the ref matched <src> locally is used as the name of the destination. For example, - "git-send-pack --all <remote>" works exactly as before; - "git-send-pack <remote> master:upstream" pushes local master to remote ref that matches "upstream". If there is no such ref, it is an error. - "git-send-pack <remote> master:refs/heads/upstream" pushes local master to remote refs/heads/upstream, even when refs/heads/upstream does not exist. - "git-send-pack <remote> master" into an empty remote repository pushes the local ref/heads/master to the remote ref/heads/master. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-08-04 01:35:29 +02:00
struct ref *peer_ref; /* when renaming */
char name[FLEX_ARRAY]; /* more */
};
#define REF_NORMAL (1u << 0)
#define REF_HEADS (1u << 1)
#define REF_TAGS (1u << 2)
extern struct ref *find_ref_by_name(const struct ref *list, const char *name);
#define CONNECT_VERBOSE (1u << 0)
extern char *git_getpass(const char *prompt);
extern struct child_process *git_connect(int fd[2], const char *url, const char *prog, int flags);
extern int finish_connect(struct child_process *conn);
extern int path_match(const char *path, int nr, char **match);
2008-09-09 10:27:09 +02:00
struct extra_have_objects {
int nr, alloc;
unsigned char (*array)[20];
};
extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match, unsigned int flags, struct extra_have_objects *);
extern int server_supports(const char *feature);
extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
extern void prepare_packed_git(void);
extern void reprepare_packed_git(void);
extern void install_packed_git(struct packed_git *pack);
extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
struct packed_git *packs);
extern void pack_report(void);
extern int open_pack_index(struct packed_git *);
extern void close_pack_index(struct packed_git *);
extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned int *);
Fix random fast-import errors when compiled with NO_MMAP fast-import was relying on the fact that on most systems mmap() and write() are synchronized by the filesystem's buffer cache. We were relying on the ability to mmap() 20 bytes beyond the current end of the file, then later fill in those bytes with a future write() call, then read them through the previously obtained mmap() address. This isn't always true with some implementations of NFS, but it is especially not true with our NO_MMAP=YesPlease build time option used on some platforms. If fast-import was built with NO_MMAP=YesPlease we used the malloc()+pread() emulation and the subsequent write() call does not update the trailing 20 bytes of a previously obtained "mmap()" (aka malloc'd) address. Under NO_MMAP that behavior causes unpack_entry() in sha1_file.c to be unable to read an object header (or data) that has been unlucky enough to be written to the packfile at a location such that it is in the trailing 20 bytes of a window previously opened on that same packfile. This bug has gone unnoticed for a very long time as it is highly data dependent. Not only does the object have to be placed at the right position, but it also needs to be positioned behind some other object that has been accessed due to a branch cache invalidation. In other words the stars had to align just right, and if you did run into this bug you probably should also have purchased a lottery ticket. Fortunately the workaround is a lot easier than the bug explanation. Before we allow unpack_entry() to read data from a pack window that has also (possibly) been modified through write() we force all existing windows on that packfile to be closed. By closing the windows we ensure that any new access via the emulated mmap() will reread the packfile, updating to the current file content. This comes at a slight performance degredation as we cannot reuse previously cached windows when we update the packfile. But it is a fairly minor difference as the window closes happen at only two points: - When the packfile is finalized and its .idx is generated: At this stage we are getting ready to update the refs and any data access into the packfile is going to be random, and is going after only the branch tips (to ensure they are valid). Our existing windows (if any) are not likely to be positioned at useful locations to access those final tip commits so we probably were closing them before anyway. - When the branch cache missed and we need to reload: At this point fast-import is getting change commands for the next commit and it needs to go re-read a tree object it previously had written out to the packfile. What windows we had (if any) are not likely to cover the tree in question so we probably were closing them before anyway. We do try to avoid unnecessarily closing windows in the second case by checking to see if the packfile size has increased since the last time we called unpack_entry() on that packfile. If the size has not changed then we have not written additional data, and any existing window is still vaild. This nicely handles the cases where fast-import is going through a branch cache reload and needs to read many trees at once. During such an event we are not likely to be updating the packfile so we do not cycle the windows between reads. With this change in place t9301-fast-export.sh (which was broken by c3b0dec509fe136c5417422f31898b5a4e2d5e02) finally works again. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-18 04:57:00 +01:00
extern void close_pack_windows(struct packed_git *);
Replace use_packed_git with window cursors. Part of the implementation concept of the sliding mmap window for pack access is to permit multiple windows per pack to be mapped independently. Since the inuse_cnt is associated with the mmap and not with the file, this value is in struct pack_window and needs to be incremented/decremented for each pack_window accessed by any code. To faciliate that implementation we need to replace all uses of use_packed_git() and unuse_packed_git() with a different API that follows struct pack_window objects rather than struct packed_git. The way this works is when we need to start accessing a pack for the first time we should setup a new window 'cursor' by declaring a local and setting it to NULL: struct pack_windows *w_curs = NULL; To obtain the memory region which contains a specific section of the pack file we invoke use_pack(), supplying the address of our current window cursor: unsigned int len; unsigned char *addr = use_pack(p, &w_curs, offset, &len); the returned address `addr` will be the first byte at `offset` within the pack file. The optional variable len will also be updated with the number of bytes remaining following the address. Multiple calls to use_pack() with the same window cursor will update the window cursor, moving it from one window to another when necessary. In this way each window cursor variable maintains only one struct pack_window inuse at a time. Finally before exiting the scope which originally declared the window cursor we must invoke unuse_pack() to unuse the current window (which may be different from the one that was first obtained from use_pack): unuse_pack(&w_curs); This implementation is still not complete with regards to multiple windows, as only one window per pack file is supported right now. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-23 08:34:08 +01:00
extern void unuse_pack(struct pack_window **);
extern void free_pack_by_name(const char *);
extern void clear_delta_base_cache(void);
extern struct packed_git *add_packed_git(const char *, int, int);
extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t);
extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t);
extern off_t find_pack_entry_one(const unsigned char *, struct packed_git *);
extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
extern const char *packed_object_info_detail(struct packed_git *, off_t, unsigned long *, unsigned long *, unsigned int *, unsigned char *);
/* Dumb servers support */
extern int update_server_info(int);
typedef int (*config_fn_t)(const char *, const char *, void *);
extern int git_default_config(const char *, const char *, void *);
extern int git_config_from_file(config_fn_t fn, const char *, void *);
extern void git_config_push_parameter(const char *text);
extern int git_config_parse_parameter(const char *text);
extern int git_config_parse_environment(void);
extern int git_config_from_parameters(config_fn_t fn, void *data);
extern int git_config(config_fn_t fn, void *);
extern int git_parse_ulong(const char *, unsigned long *);
extern int git_config_int(const char *, const char *);
extern unsigned long git_config_ulong(const char *, const char *);
extern int git_config_bool_or_int(const char *, const char *, int *);
extern int git_config_bool(const char *, const char *);
extern int git_config_maybe_bool(const char *, const char *);
extern int git_config_string(const char **, const char *, const char *);
extern int git_config_pathname(const char **, const char *, const char *);
extern int git_config_set(const char *, const char *);
extern int git_config_set_multivar(const char *, const char *, const char *, int);
extern int git_config_rename_section(const char *, const char *);
extern const char *git_etc_gitconfig(void);
extern int check_repository_format_version(const char *var, const char *value, void *cb);
extern int git_env_bool(const char *, int);
extern int git_config_system(void);
extern int git_config_global(void);
extern int config_error_nonbool(const char *);
extern const char *get_log_output_encoding(void);
extern const char *get_commit_output_encoding(void);
extern const char *config_exclusive_filename;
#define MAX_GITNAME (1000)
extern char git_default_email[MAX_GITNAME];
extern char git_default_name[MAX_GITNAME];
#define IDENT_NAME_GIVEN 01
#define IDENT_MAIL_GIVEN 02
#define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
extern int user_ident_explicitly_given;
extern int user_ident_sufficiently_given(void);
extern const char *git_commit_encoding;
extern const char *git_log_output_encoding;
extern const char *git_mailmap_file;
/* IO helper functions */
extern void maybe_flush_or_die(FILE *, const char *);
extern int copy_fd(int ifd, int ofd);
extern int copy_file(const char *dst, const char *src, int mode);
extern int copy_file_with_time(const char *dst, const char *src, int mode);
extern void write_or_die(int fd, const void *buf, size_t count);
extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
extern int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg);
extern void fsync_or_die(int fd, const char *);
extern ssize_t read_in_full(int fd, void *buf, size_t count);
extern ssize_t write_in_full(int fd, const void *buf, size_t count);
static inline ssize_t write_str_in_full(int fd, const char *str)
{
return write_in_full(fd, str, strlen(str));
}
/* pager.c */
extern void setup_pager(void);
extern const char *pager_program;
extern int pager_in_use(void);
extern int pager_use_color;
extern const char *editor_program;
extern const char *askpass_program;
extern const char *excludes_file;
binary patch. This adds "binary patch" to the diff output and teaches apply what to do with them. On the diff generation side, traditionally, we said "Binary files differ\n" without giving anything other than the preimage and postimage object name on the index line. This was good enough for applying a patch generated from your own repository (very useful while rebasing), because the postimage would be available in such a case. However, this was not useful when the recipient of such a patch via e-mail were to apply it, even if the preimage was available. This patch allows the diff to generate "binary" patch when operating under --full-index option. The binary patch follows the usual extended git diff headers, and looks like this: "GIT binary patch\n" <length byte><data>"\n" ... "\n" Each line is prefixed with a "length-byte", whose value is upper or lowercase alphabet that encodes number of bytes that the data on the line decodes to (1..52 -- 'A' means 1, 'B' means 2, ..., 'Z' means 26, 'a' means 27, ...). <data> is 1 or more groups of 5-byte sequence, each of which encodes up to 4 bytes in base85 encoding. Because 52 / 4 * 5 = 65 and we have the length byte, an output line is capped to 66 characters. The payload is the same diff-delta as we use in the packfiles. On the consumption side, git-apply now can decode and apply the binary patch when --allow-binary-replacement is given, the diff was generated with --full-index, and the receiving repository has the preimage blob, which is the same condition as it always required when accepting an "Binary files differ\n" patch. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-05 01:51:44 +02:00
/* base85 */
int decode_85(char *dst, const char *line, int linelen);
void encode_85(char *buf, const unsigned char *data, int bytes);
binary patch. This adds "binary patch" to the diff output and teaches apply what to do with them. On the diff generation side, traditionally, we said "Binary files differ\n" without giving anything other than the preimage and postimage object name on the index line. This was good enough for applying a patch generated from your own repository (very useful while rebasing), because the postimage would be available in such a case. However, this was not useful when the recipient of such a patch via e-mail were to apply it, even if the preimage was available. This patch allows the diff to generate "binary" patch when operating under --full-index option. The binary patch follows the usual extended git diff headers, and looks like this: "GIT binary patch\n" <length byte><data>"\n" ... "\n" Each line is prefixed with a "length-byte", whose value is upper or lowercase alphabet that encodes number of bytes that the data on the line decodes to (1..52 -- 'A' means 1, 'B' means 2, ..., 'Z' means 26, 'a' means 27, ...). <data> is 1 or more groups of 5-byte sequence, each of which encodes up to 4 bytes in base85 encoding. Because 52 / 4 * 5 = 65 and we have the length byte, an output line is capped to 66 characters. The payload is the same diff-delta as we use in the packfiles. On the consumption side, git-apply now can decode and apply the binary patch when --allow-binary-replacement is given, the diff was generated with --full-index, and the receiving repository has the preimage blob, which is the same condition as it always required when accepting an "Binary files differ\n" patch. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-05 01:51:44 +02:00
Add specialized object allocator This creates a simple specialized object allocator for basic objects. This avoids wasting space with malloc overhead (metadata and extra alignment), since the specialized allocator knows the alignment, and that objects, once allocated, are never freed. It also allows us to track some basic statistics about object allocations. For example, for the mozilla import, it shows object usage as follows: blobs: 627629 (14710 kB) trees: 1119035 (34969 kB) commits: 196423 (8440 kB) tags: 1336 (46 kB) and the simpler allocator shaves off about 2.5% off the memory footprint off a "git-rev-list --all --objects", and is a bit faster too. [ Side note: this concludes the series of "save memory in object storage". The thing is, there simply isn't much more to be saved on the objects. Doing "git-rev-list --all --objects" on the mozilla archive has a final total RSS of 131498 pages for me: that's about 513MB. Of that, the object overhead is now just 56MB, the rest is going somewhere else (put another way: the fact that this patch shaves off 2.5% of the total memory overhead, considering that objects are now not much more than 10% of the total shows how big the wasted space really was: this makes object allocations much more memory- and time-efficient). I haven't looked at where the rest is, but I suspect the bulk of it is just the pack-file loading. It may be that we should pack the tree objects separately from the blob objects: for git-rev-list --objects, we don't actually ever need to even look at the blobs, but since trees and blobs are interspersed in the pack-file, we end up not being dense in the tree accesses, so we end up looking at more pages than we strictly need to. So with a 535MB pack-file, it's entirely possible - even likely - that most of the remaining RSS is just the mmap of the pack-file itself. We don't need to map in _all_ of it, but we do end up mapping a fair amount. ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-19 19:44:15 +02:00
/* alloc.c */
extern void *alloc_blob_node(void);
extern void *alloc_tree_node(void);
extern void *alloc_commit_node(void);
extern void *alloc_tag_node(void);
extern void *alloc_object_node(void);
Add specialized object allocator This creates a simple specialized object allocator for basic objects. This avoids wasting space with malloc overhead (metadata and extra alignment), since the specialized allocator knows the alignment, and that objects, once allocated, are never freed. It also allows us to track some basic statistics about object allocations. For example, for the mozilla import, it shows object usage as follows: blobs: 627629 (14710 kB) trees: 1119035 (34969 kB) commits: 196423 (8440 kB) tags: 1336 (46 kB) and the simpler allocator shaves off about 2.5% off the memory footprint off a "git-rev-list --all --objects", and is a bit faster too. [ Side note: this concludes the series of "save memory in object storage". The thing is, there simply isn't much more to be saved on the objects. Doing "git-rev-list --all --objects" on the mozilla archive has a final total RSS of 131498 pages for me: that's about 513MB. Of that, the object overhead is now just 56MB, the rest is going somewhere else (put another way: the fact that this patch shaves off 2.5% of the total memory overhead, considering that objects are now not much more than 10% of the total shows how big the wasted space really was: this makes object allocations much more memory- and time-efficient). I haven't looked at where the rest is, but I suspect the bulk of it is just the pack-file loading. It may be that we should pack the tree objects separately from the blob objects: for git-rev-list --objects, we don't actually ever need to even look at the blobs, but since trees and blobs are interspersed in the pack-file, we end up not being dense in the tree accesses, so we end up looking at more pages than we strictly need to. So with a 535MB pack-file, it's entirely possible - even likely - that most of the remaining RSS is just the mmap of the pack-file itself. We don't need to map in _all_ of it, but we do end up mapping a fair amount. ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-19 19:44:15 +02:00
extern void alloc_report(void);
/* trace.c */
__attribute__((format (printf, 1, 2)))
extern void trace_printf(const char *format, ...);
__attribute__((format (printf, 2, 3)))
extern void trace_argv_printf(const char **argv, const char *format, ...);
Lazy man's auto-CRLF It currently does NOT know about file attributes, so it does its conversion purely based on content. Maybe that is more in the "git philosophy" anyway, since content is king, but I think we should try to do the file attributes to turn it off on demand. Anyway, BY DEFAULT it is off regardless, because it requires a [core] AutoCRLF = true in your config file to be enabled. We could make that the default for Windows, of course, the same way we do some other things (filemode etc). But you can actually enable it on UNIX, and it will cause: - "git update-index" will write blobs without CRLF - "git diff" will diff working tree files without CRLF - "git checkout" will write files to the working tree _with_ CRLF and things work fine. Funnily, it actually shows an odd file in git itself: git clone -n git test-crlf cd test-crlf git config core.autocrlf true git checkout git diff shows a diff for "Documentation/docbook-xsl.css". Why? Because we have actually checked in that file *with* CRLF! So when "core.autocrlf" is true, we'll always generate a *different* hash for it in the index, because the index hash will be for the content _without_ CRLF. Is this complete? I dunno. It seems to work for me. It doesn't use the filename at all right now, and that's probably a deficiency (we could certainly make the "is_binary()" heuristics also take standard filename heuristics into account). I don't pass in the filename at all for the "index_fd()" case (git-update-index), so that would need to be passed around, but this actually works fine. NOTE NOTE NOTE! The "is_binary()" heuristics are totally made-up by yours truly. I will not guarantee that they work at all reasonable. Caveat emptor. But it _is_ simple, and it _is_ safe, since it's all off by default. The patch is pretty simple - the biggest part is the new "convert.c" file, but even that is really just basic stuff that anybody can write in "Teaching C 101" as a final project for their first class in programming. Not to say that it's bug-free, of course - but at least we're not talking about rocket surgery here. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-13 20:07:23 +01:00
/* convert.c */
/* returns 1 if *dst was used */
safecrlf: Add mechanism to warn about irreversible crlf conversions CRLF conversion bears a slight chance of corrupting data. autocrlf=true will convert CRLF to LF during commit and LF to CRLF during checkout. A file that contains a mixture of LF and CRLF before the commit cannot be recreated by git. For text files this is the right thing to do: it corrects line endings such that we have only LF line endings in the repository. But for binary files that are accidentally classified as text the conversion can corrupt data. If you recognize such corruption early you can easily fix it by setting the conversion type explicitly in .gitattributes. Right after committing you still have the original file in your work tree and this file is not yet corrupted. You can explicitly tell git that this file is binary and git will handle the file appropriately. Unfortunately, the desired effect of cleaning up text files with mixed line endings and the undesired effect of corrupting binary files cannot be distinguished. In both cases CRLFs are removed in an irreversible way. For text files this is the right thing to do because CRLFs are line endings, while for binary files converting CRLFs corrupts data. This patch adds a mechanism that can either warn the user about an irreversible conversion or can even refuse to convert. The mechanism is controlled by the variable core.safecrlf, with the following values: - false: disable safecrlf mechanism - warn: warn about irreversible conversions - true: refuse irreversible conversions The default is to warn. Users are only affected by this default if core.autocrlf is set. But the current default of git is to leave core.autocrlf unset, so users will not see warnings unless they deliberately chose to activate the autocrlf mechanism. The safecrlf mechanism's details depend on the git command. The general principles when safecrlf is active (not false) are: - we warn/error out if files in the work tree can modified in an irreversible way without giving the user a chance to backup the original file. - for read-only operations that do not modify files in the work tree we do not not print annoying warnings. There are exceptions. Even though... - "git add" itself does not touch the files in the work tree, the next checkout would, so the safety triggers; - "git apply" to update a text file with a patch does touch the files in the work tree, but the operation is about text files and CRLF conversion is about fixing the line ending inconsistencies, so the safety does not trigger; - "git diff" itself does not touch the files in the work tree, it is often run to inspect the changes you intend to next "git add". To catch potential problems early, safety triggers. The concept of a safety check was originally proposed in a similar way by Linus Torvalds. Thanks to Dimitry Potapov for insisting on getting the naked LF/autocrlf=true case right. Signed-off-by: Steffen Prohaska <prohaska@zib.de>
2008-02-06 12:25:58 +01:00
extern int convert_to_git(const char *path, const char *src, size_t len,
struct strbuf *dst, enum safe_crlf checksafe);
extern int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst);
extern int renormalize_buffer(const char *path, const char *src, size_t len, struct strbuf *dst);
Lazy man's auto-CRLF It currently does NOT know about file attributes, so it does its conversion purely based on content. Maybe that is more in the "git philosophy" anyway, since content is king, but I think we should try to do the file attributes to turn it off on demand. Anyway, BY DEFAULT it is off regardless, because it requires a [core] AutoCRLF = true in your config file to be enabled. We could make that the default for Windows, of course, the same way we do some other things (filemode etc). But you can actually enable it on UNIX, and it will cause: - "git update-index" will write blobs without CRLF - "git diff" will diff working tree files without CRLF - "git checkout" will write files to the working tree _with_ CRLF and things work fine. Funnily, it actually shows an odd file in git itself: git clone -n git test-crlf cd test-crlf git config core.autocrlf true git checkout git diff shows a diff for "Documentation/docbook-xsl.css". Why? Because we have actually checked in that file *with* CRLF! So when "core.autocrlf" is true, we'll always generate a *different* hash for it in the index, because the index hash will be for the content _without_ CRLF. Is this complete? I dunno. It seems to work for me. It doesn't use the filename at all right now, and that's probably a deficiency (we could certainly make the "is_binary()" heuristics also take standard filename heuristics into account). I don't pass in the filename at all for the "index_fd()" case (git-update-index), so that would need to be passed around, but this actually works fine. NOTE NOTE NOTE! The "is_binary()" heuristics are totally made-up by yours truly. I will not guarantee that they work at all reasonable. Caveat emptor. But it _is_ simple, and it _is_ safe, since it's all off by default. The patch is pretty simple - the biggest part is the new "convert.c" file, but even that is really just basic stuff that anybody can write in "Teaching C 101" as a final project for their first class in programming. Not to say that it's bug-free, of course - but at least we're not talking about rocket surgery here. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-13 20:07:23 +01:00
/* add */
/*
* return 0 if success, 1 - if addition of a file failed and
* ADD_FILES_IGNORE_ERRORS was specified in flags
*/
int add_files_to_cache(const char *prefix, const char **pathspec, int flags);
/* diff.c */
extern int diff_auto_refresh_index;
/* match-trees.c */
void shift_tree(const unsigned char *, const unsigned char *, unsigned char *, int);
void shift_tree_by(const unsigned char *, const unsigned char *, unsigned char *, const char *);
/*
* whitespace rules.
* used by both diff and apply
*/
#define WS_BLANK_AT_EOL 01
#define WS_SPACE_BEFORE_TAB 02
#define WS_INDENT_WITH_NON_TAB 04
#define WS_CR_AT_EOL 010
#define WS_BLANK_AT_EOF 020
#define WS_TAB_IN_INDENT 040
#define WS_TRAILING_SPACE (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB)
extern unsigned whitespace_rule_cfg;
extern unsigned whitespace_rule(const char *);
extern unsigned parse_whitespace_rule(const char *);
extern unsigned ws_check(const char *line, int len, unsigned ws_rule);
extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
extern char *whitespace_error_string(unsigned ws);
extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
/* ls-files */
int report_path_error(const char *ps_matched, const char **pathspec, int prefix_offset);
void overlay_tree_on_cache(const char *tree_name, const char *prefix);
char *alias_lookup(const char *alias);
int split_cmdline(char *cmdline, const char ***argv);
/* Takes a negative value returned by split_cmdline */
const char *split_cmdline_strerror(int cmdline_errno);
/* git.c */
struct startup_info {
int have_repository;
};
extern struct startup_info *startup_info;
/* builtin/merge.c */
int checkout_fast_forward(const unsigned char *from, const unsigned char *to);
#endif /* CACHE_H */