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git-commit-vandalism/sha1_file.c
Stefan Beller 7663cdc86c hashmap.h: compare function has access to a data field 
When using the hashmap a common need is to have access to caller provided
data in the compare function. A couple of times we abuse the keydata field
to pass in the data needed. This happens for example in patch-ids.c.

This patch changes the function signature of the compare function
to have one more void pointer available. The pointer given for each
invocation of the compare function must be defined in the init function
of the hashmap and is just passed through.

Documentation of this new feature is deferred to a later patch.
This is a rather mechanical conversion, just adding the new pass-through
parameter.  However while at it improve the naming of the fields of all
compare functions used by hashmaps by ensuring unused parameters are
prefixed with 'unused_' and naming the parameters what they are (instead
of 'unused' make it 'unused_keydata').

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 12:49:28 -07:00

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/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*
* This handles basic git sha1 object files - packing, unpacking,
* creation etc.
*/
#include "cache.h"
#include "config.h"
#include "string-list.h"
#include "lockfile.h"
#include "delta.h"
#include "pack.h"
#include "blob.h"
#include "commit.h"
#include "run-command.h"
#include "tag.h"
#include "tree.h"
#include "tree-walk.h"
#include "refs.h"
#include "pack-revindex.h"
#include "sha1-lookup.h"
#include "bulk-checkin.h"
#include "streaming.h"
#include "dir.h"
#include "mru.h"
#include "list.h"
#include "mergesort.h"
#include "quote.h"
#define SZ_FMT PRIuMAX
static inline uintmax_t sz_fmt(size_t s) { return s; }
const unsigned char null_sha1[20];
const struct object_id null_oid;
const struct object_id empty_tree_oid = {
EMPTY_TREE_SHA1_BIN_LITERAL
};
const struct object_id empty_blob_oid = {
EMPTY_BLOB_SHA1_BIN_LITERAL
};
/*
* This is meant to hold a *small* number of objects that you would
* want read_sha1_file() to be able to return, but yet you do not want
* to write them into the object store (e.g. a browse-only
* application).
*/
static struct cached_object {
unsigned char sha1[20];
enum object_type type;
void *buf;
unsigned long size;
} *cached_objects;
static int cached_object_nr, cached_object_alloc;
static struct cached_object empty_tree = {
EMPTY_TREE_SHA1_BIN_LITERAL,
OBJ_TREE,
"",
0
};
static struct cached_object *find_cached_object(const unsigned char *sha1)
{
int i;
struct cached_object *co = cached_objects;
for (i = 0; i < cached_object_nr; i++, co++) {
if (!hashcmp(co->sha1, sha1))
return co;
}
if (!hashcmp(sha1, empty_tree.sha1))
return &empty_tree;
return NULL;
}
int mkdir_in_gitdir(const char *path)
{
if (mkdir(path, 0777)) {
int saved_errno = errno;
struct stat st;
struct strbuf sb = STRBUF_INIT;
if (errno != EEXIST)
return -1;
/*
* Are we looking at a path in a symlinked worktree
* whose original repository does not yet have it?
* e.g. .git/rr-cache pointing at its original
* repository in which the user hasn't performed any
* conflict resolution yet?
*/
if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
strbuf_readlink(&sb, path, st.st_size) ||
!is_absolute_path(sb.buf) ||
mkdir(sb.buf, 0777)) {
strbuf_release(&sb);
errno = saved_errno;
return -1;
}
strbuf_release(&sb);
}
return adjust_shared_perm(path);
}
enum scld_error safe_create_leading_directories(char *path)
{
char *next_component = path + offset_1st_component(path);
enum scld_error ret = SCLD_OK;
while (ret == SCLD_OK && next_component) {
struct stat st;
char *slash = next_component, slash_character;
while (*slash && !is_dir_sep(*slash))
slash++;
if (!*slash)
break;
next_component = slash + 1;
while (is_dir_sep(*next_component))
next_component++;
if (!*next_component)
break;
slash_character = *slash;
*slash = '\0';
if (!stat(path, &st)) {
/* path exists */
if (!S_ISDIR(st.st_mode)) {
errno = ENOTDIR;
ret = SCLD_EXISTS;
}
} else if (mkdir(path, 0777)) {
if (errno == EEXIST &&
!stat(path, &st) && S_ISDIR(st.st_mode))
; /* somebody created it since we checked */
else if (errno == ENOENT)
/*
* Either mkdir() failed because
* somebody just pruned the containing
* directory, or stat() failed because
* the file that was in our way was
* just removed. Either way, inform
* the caller that it might be worth
* trying again:
*/
ret = SCLD_VANISHED;
else
ret = SCLD_FAILED;
} else if (adjust_shared_perm(path)) {
ret = SCLD_PERMS;
}
*slash = slash_character;
}
return ret;
}
enum scld_error safe_create_leading_directories_const(const char *path)
{
int save_errno;
/* path points to cache entries, so xstrdup before messing with it */
char *buf = xstrdup(path);
enum scld_error result = safe_create_leading_directories(buf);
save_errno = errno;
free(buf);
errno = save_errno;
return result;
}
int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
{
/*
* The number of times we will try to remove empty directories
* in the way of path. This is only 1 because if another
* process is racily creating directories that conflict with
* us, we don't want to fight against them.
*/
int remove_directories_remaining = 1;
/*
* The number of times that we will try to create the
* directories containing path. We are willing to attempt this
* more than once, because another process could be trying to
* clean up empty directories at the same time as we are
* trying to create them.
*/
int create_directories_remaining = 3;
/* A scratch copy of path, filled lazily if we need it: */
struct strbuf path_copy = STRBUF_INIT;
int ret, save_errno;
/* Sanity check: */
assert(*path);
retry_fn:
ret = fn(path, cb);
save_errno = errno;
if (!ret)
goto out;
if (errno == EISDIR && remove_directories_remaining-- > 0) {
/*
* A directory is in the way. Maybe it is empty; try
* to remove it:
*/
if (!path_copy.len)
strbuf_addstr(&path_copy, path);
if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
goto retry_fn;
} else if (errno == ENOENT && create_directories_remaining-- > 0) {
/*
* Maybe the containing directory didn't exist, or
* maybe it was just deleted by a process that is
* racing with us to clean up empty directories. Try
* to create it:
*/
enum scld_error scld_result;
if (!path_copy.len)
strbuf_addstr(&path_copy, path);
do {
scld_result = safe_create_leading_directories(path_copy.buf);
if (scld_result == SCLD_OK)
goto retry_fn;
} while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
}
out:
strbuf_release(&path_copy);
errno = save_errno;
return ret;
}
static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
{
int i;
for (i = 0; i < 20; i++) {
static char hex[] = "0123456789abcdef";
unsigned int val = sha1[i];
strbuf_addch(buf, hex[val >> 4]);
strbuf_addch(buf, hex[val & 0xf]);
if (!i)
strbuf_addch(buf, '/');
}
}
const char *sha1_file_name(const unsigned char *sha1)
{
static struct strbuf buf = STRBUF_INIT;
strbuf_reset(&buf);
strbuf_addf(&buf, "%s/", get_object_directory());
fill_sha1_path(&buf, sha1);
return buf.buf;
}
struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
{
strbuf_setlen(&alt->scratch, alt->base_len);
return &alt->scratch;
}
static const char *alt_sha1_path(struct alternate_object_database *alt,
const unsigned char *sha1)
{
struct strbuf *buf = alt_scratch_buf(alt);
fill_sha1_path(buf, sha1);
return buf->buf;
}
char *odb_pack_name(struct strbuf *buf,
const unsigned char *sha1,
const char *ext)
{
strbuf_reset(buf);
strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
sha1_to_hex(sha1), ext);
return buf->buf;
}
char *sha1_pack_name(const unsigned char *sha1)
{
static struct strbuf buf = STRBUF_INIT;
return odb_pack_name(&buf, sha1, "pack");
}
char *sha1_pack_index_name(const unsigned char *sha1)
{
static struct strbuf buf = STRBUF_INIT;
return odb_pack_name(&buf, sha1, "idx");
}
struct alternate_object_database *alt_odb_list;
static struct alternate_object_database **alt_odb_tail;
/*
* Return non-zero iff the path is usable as an alternate object database.
*/
static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
{
struct alternate_object_database *alt;
/* Detect cases where alternate disappeared */
if (!is_directory(path->buf)) {
error("object directory %s does not exist; "
"check .git/objects/info/alternates.",
path->buf);
return 0;
}
/*
* Prevent the common mistake of listing the same
* thing twice, or object directory itself.
*/
for (alt = alt_odb_list; alt; alt = alt->next) {
if (!fspathcmp(path->buf, alt->path))
return 0;
}
if (!fspathcmp(path->buf, normalized_objdir))
return 0;
return 1;
}
/*
* Prepare alternate object database registry.
*
* The variable alt_odb_list points at the list of struct
* alternate_object_database. The elements on this list come from
* non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
* environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
* whose contents is similar to that environment variable but can be
* LF separated. Its base points at a statically allocated buffer that
* contains "/the/directory/corresponding/to/.git/objects/...", while
* its name points just after the slash at the end of ".git/objects/"
* in the example above, and has enough space to hold 40-byte hex
* SHA1, an extra slash for the first level indirection, and the
* terminating NUL.
*/
static int link_alt_odb_entry(const char *entry, const char *relative_base,
int depth, const char *normalized_objdir)
{
struct alternate_object_database *ent;
struct strbuf pathbuf = STRBUF_INIT;
if (!is_absolute_path(entry) && relative_base) {
strbuf_realpath(&pathbuf, relative_base, 1);
strbuf_addch(&pathbuf, '/');
}
strbuf_addstr(&pathbuf, entry);
if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
error("unable to normalize alternate object path: %s",
pathbuf.buf);
strbuf_release(&pathbuf);
return -1;
}
/*
* The trailing slash after the directory name is given by
* this function at the end. Remove duplicates.
*/
while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
strbuf_setlen(&pathbuf, pathbuf.len - 1);
if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
strbuf_release(&pathbuf);
return -1;
}
ent = alloc_alt_odb(pathbuf.buf);
/* add the alternate entry */
*alt_odb_tail = ent;
alt_odb_tail = &(ent->next);
ent->next = NULL;
/* recursively add alternates */
read_info_alternates(pathbuf.buf, depth + 1);
strbuf_release(&pathbuf);
return 0;
}
static const char *parse_alt_odb_entry(const char *string,
int sep,
struct strbuf *out)
{
const char *end;
strbuf_reset(out);
if (*string == '#') {
/* comment; consume up to next separator */
end = strchrnul(string, sep);
} else if (*string == '"' && !unquote_c_style(out, string, &end)) {
/*
* quoted path; unquote_c_style has copied the
* data for us and set "end". Broken quoting (e.g.,
* an entry that doesn't end with a quote) falls
* back to the unquoted case below.
*/
} else {
/* normal, unquoted path */
end = strchrnul(string, sep);
strbuf_add(out, string, end - string);
}
if (*end)
end++;
return end;
}
static void link_alt_odb_entries(const char *alt, int len, int sep,
const char *relative_base, int depth)
{
struct strbuf objdirbuf = STRBUF_INIT;
struct strbuf entry = STRBUF_INIT;
if (depth > 5) {
error("%s: ignoring alternate object stores, nesting too deep.",
relative_base);
return;
}
strbuf_add_absolute_path(&objdirbuf, get_object_directory());
if (strbuf_normalize_path(&objdirbuf) < 0)
die("unable to normalize object directory: %s",
objdirbuf.buf);
while (*alt) {
alt = parse_alt_odb_entry(alt, sep, &entry);
if (!entry.len)
continue;
link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
}
strbuf_release(&entry);
strbuf_release(&objdirbuf);
}
void read_info_alternates(const char * relative_base, int depth)
{
char *map;
size_t mapsz;
struct stat st;
char *path;
int fd;
path = xstrfmt("%s/info/alternates", relative_base);
fd = git_open(path);
free(path);
if (fd < 0)
return;
if (fstat(fd, &st) || (st.st_size == 0)) {
close(fd);
return;
}
mapsz = xsize_t(st.st_size);
map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
munmap(map, mapsz);
}
struct alternate_object_database *alloc_alt_odb(const char *dir)
{
struct alternate_object_database *ent;
FLEX_ALLOC_STR(ent, path, dir);
strbuf_init(&ent->scratch, 0);
strbuf_addf(&ent->scratch, "%s/", dir);
ent->base_len = ent->scratch.len;
return ent;
}
void add_to_alternates_file(const char *reference)
{
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
char *alts = git_pathdup("objects/info/alternates");
FILE *in, *out;
hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
out = fdopen_lock_file(lock, "w");
if (!out)
die_errno("unable to fdopen alternates lockfile");
in = fopen(alts, "r");
if (in) {
struct strbuf line = STRBUF_INIT;
int found = 0;
while (strbuf_getline(&line, in) != EOF) {
if (!strcmp(reference, line.buf)) {
found = 1;
break;
}
fprintf_or_die(out, "%s\n", line.buf);
}
strbuf_release(&line);
fclose(in);
if (found) {
rollback_lock_file(lock);
lock = NULL;
}
}
else if (errno != ENOENT)
die_errno("unable to read alternates file");
if (lock) {
fprintf_or_die(out, "%s\n", reference);
if (commit_lock_file(lock))
die_errno("unable to move new alternates file into place");
if (alt_odb_tail)
link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
}
free(alts);
}
void add_to_alternates_memory(const char *reference)
{
/*
* Make sure alternates are initialized, or else our entry may be
* overwritten when they are.
*/
prepare_alt_odb();
link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
}
/*
* Compute the exact path an alternate is at and returns it. In case of
* error NULL is returned and the human readable error is added to `err`
* `path` may be relative and should point to $GITDIR.
* `err` must not be null.
*/
char *compute_alternate_path(const char *path, struct strbuf *err)
{
char *ref_git = NULL;
const char *repo, *ref_git_s;
int seen_error = 0;
ref_git_s = real_path_if_valid(path);
if (!ref_git_s) {
seen_error = 1;
strbuf_addf(err, _("path '%s' does not exist"), path);
goto out;
} else
/*
* Beware: read_gitfile(), real_path() and mkpath()
* return static buffer
*/
ref_git = xstrdup(ref_git_s);
repo = read_gitfile(ref_git);
if (!repo)
repo = read_gitfile(mkpath("%s/.git", ref_git));
if (repo) {
free(ref_git);
ref_git = xstrdup(repo);
}
if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
char *ref_git_git = mkpathdup("%s/.git", ref_git);
free(ref_git);
ref_git = ref_git_git;
} else if (!is_directory(mkpath("%s/objects", ref_git))) {
struct strbuf sb = STRBUF_INIT;
seen_error = 1;
if (get_common_dir(&sb, ref_git)) {
strbuf_addf(err,
_("reference repository '%s' as a linked "
"checkout is not supported yet."),
path);
goto out;
}
strbuf_addf(err, _("reference repository '%s' is not a "
"local repository."), path);
goto out;
}
if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
strbuf_addf(err, _("reference repository '%s' is shallow"),
path);
seen_error = 1;
goto out;
}
if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
strbuf_addf(err,
_("reference repository '%s' is grafted"),
path);
seen_error = 1;
goto out;
}
out:
if (seen_error) {
FREE_AND_NULL(ref_git);
}
return ref_git;
}
int foreach_alt_odb(alt_odb_fn fn, void *cb)
{
struct alternate_object_database *ent;
int r = 0;
prepare_alt_odb();
for (ent = alt_odb_list; ent; ent = ent->next) {
r = fn(ent, cb);
if (r)
break;
}
return r;
}
void prepare_alt_odb(void)
{
const char *alt;
if (alt_odb_tail)
return;
alt = getenv(ALTERNATE_DB_ENVIRONMENT);
if (!alt) alt = "";
alt_odb_tail = &alt_odb_list;
link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
read_info_alternates(get_object_directory(), 0);
}
/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
static int freshen_file(const char *fn)
{
struct utimbuf t;
t.actime = t.modtime = time(NULL);
return !utime(fn, &t);
}
/*
* All of the check_and_freshen functions return 1 if the file exists and was
* freshened (if freshening was requested), 0 otherwise. If they return
* 0, you should not assume that it is safe to skip a write of the object (it
* either does not exist on disk, or has a stale mtime and may be subject to
* pruning).
*/
int check_and_freshen_file(const char *fn, int freshen)
{
if (access(fn, F_OK))
return 0;
if (freshen && !freshen_file(fn))
return 0;
return 1;
}
static int check_and_freshen_local(const unsigned char *sha1, int freshen)
{
return check_and_freshen_file(sha1_file_name(sha1), freshen);
}
static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
{
struct alternate_object_database *alt;
prepare_alt_odb();
for (alt = alt_odb_list; alt; alt = alt->next) {
const char *path = alt_sha1_path(alt, sha1);
if (check_and_freshen_file(path, freshen))
return 1;
}
return 0;
}
static int check_and_freshen(const unsigned char *sha1, int freshen)
{
return check_and_freshen_local(sha1, freshen) ||
check_and_freshen_nonlocal(sha1, freshen);
}
int has_loose_object_nonlocal(const unsigned char *sha1)
{
return check_and_freshen_nonlocal(sha1, 0);
}
static int has_loose_object(const unsigned char *sha1)
{
return check_and_freshen(sha1, 0);
}
static unsigned int pack_used_ctr;
static unsigned int pack_mmap_calls;
static unsigned int peak_pack_open_windows;
static unsigned int pack_open_windows;
static unsigned int pack_open_fds;
static unsigned int pack_max_fds;
static size_t peak_pack_mapped;
static size_t pack_mapped;
struct packed_git *packed_git;
static struct mru packed_git_mru_storage;
struct mru *packed_git_mru = &packed_git_mru_storage;
void pack_report(void)
{
fprintf(stderr,
"pack_report: getpagesize() = %10" SZ_FMT "\n"
"pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
"pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
sz_fmt(getpagesize()),
sz_fmt(packed_git_window_size),
sz_fmt(packed_git_limit));
fprintf(stderr,
"pack_report: pack_used_ctr = %10u\n"
"pack_report: pack_mmap_calls = %10u\n"
"pack_report: pack_open_windows = %10u / %10u\n"
"pack_report: pack_mapped = "
"%10" SZ_FMT " / %10" SZ_FMT "\n",
pack_used_ctr,
pack_mmap_calls,
pack_open_windows, peak_pack_open_windows,
sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
}
/*
* Open and mmap the index file at path, perform a couple of
* consistency checks, then record its information to p. Return 0 on
* success.
*/
static int check_packed_git_idx(const char *path, struct packed_git *p)
{
void *idx_map;
struct pack_idx_header *hdr;
size_t idx_size;
uint32_t version, nr, i, *index;
int fd = git_open(path);
struct stat st;
if (fd < 0)
return -1;
if (fstat(fd, &st)) {
close(fd);
return -1;
}
idx_size = xsize_t(st.st_size);
if (idx_size < 4 * 256 + 20 + 20) {
close(fd);
return error("index file %s is too small", path);
}
idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
hdr = idx_map;
if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
version = ntohl(hdr->idx_version);
if (version < 2 || version > 2) {
munmap(idx_map, idx_size);
return error("index file %s is version %"PRIu32
" and is not supported by this binary"
" (try upgrading GIT to a newer version)",
path, version);
}
} else
version = 1;
nr = 0;
index = idx_map;
if (version > 1)
index += 2; /* skip index header */
for (i = 0; i < 256; i++) {
uint32_t n = ntohl(index[i]);
if (n < nr) {
munmap(idx_map, idx_size);
return error("non-monotonic index %s", path);
}
nr = n;
}
if (version == 1) {
/*
* Total size:
* - 256 index entries 4 bytes each
* - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
* - 20-byte SHA1 of the packfile
* - 20-byte SHA1 file checksum
*/
if (idx_size != 4*256 + nr * 24 + 20 + 20) {
munmap(idx_map, idx_size);
return error("wrong index v1 file size in %s", path);
}
} else if (version == 2) {
/*
* Minimum size:
* - 8 bytes of header
* - 256 index entries 4 bytes each
* - 20-byte sha1 entry * nr
* - 4-byte crc entry * nr
* - 4-byte offset entry * nr
* - 20-byte SHA1 of the packfile
* - 20-byte SHA1 file checksum
* And after the 4-byte offset table might be a
* variable sized table containing 8-byte entries
* for offsets larger than 2^31.
*/
unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
unsigned long max_size = min_size;
if (nr)
max_size += (nr - 1)*8;
if (idx_size < min_size || idx_size > max_size) {
munmap(idx_map, idx_size);
return error("wrong index v2 file size in %s", path);
}
if (idx_size != min_size &&
/*
* make sure we can deal with large pack offsets.
* 31-bit signed offset won't be enough, neither
* 32-bit unsigned one will be.
*/
(sizeof(off_t) <= 4)) {
munmap(idx_map, idx_size);
return error("pack too large for current definition of off_t in %s", path);
}
}
p->index_version = version;
p->index_data = idx_map;
p->index_size = idx_size;
p->num_objects = nr;
return 0;
}
int open_pack_index(struct packed_git *p)
{
char *idx_name;
size_t len;
int ret;
if (p->index_data)
return 0;
if (!strip_suffix(p->pack_name, ".pack", &len))
die("BUG: pack_name does not end in .pack");
idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
ret = check_packed_git_idx(idx_name, p);
free(idx_name);
return ret;
}
static void scan_windows(struct packed_git *p,
struct packed_git **lru_p,
struct pack_window **lru_w,
struct pack_window **lru_l)
{
struct pack_window *w, *w_l;
for (w_l = NULL, w = p->windows; w; w = w->next) {
if (!w->inuse_cnt) {
if (!*lru_w || w->last_used < (*lru_w)->last_used) {
*lru_p = p;
*lru_w = w;
*lru_l = w_l;
}
}
w_l = w;
}
}
static int unuse_one_window(struct packed_git *current)
{
struct packed_git *p, *lru_p = NULL;
struct pack_window *lru_w = NULL, *lru_l = NULL;
if (current)
scan_windows(current, &lru_p, &lru_w, &lru_l);
for (p = packed_git; p; p = p->next)
scan_windows(p, &lru_p, &lru_w, &lru_l);
if (lru_p) {
munmap(lru_w->base, lru_w->len);
pack_mapped -= lru_w->len;
if (lru_l)
lru_l->next = lru_w->next;
else
lru_p->windows = lru_w->next;
free(lru_w);
pack_open_windows--;
return 1;
}
return 0;
}
void release_pack_memory(size_t need)
{
size_t cur = pack_mapped;
while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
; /* nothing */
}
static void mmap_limit_check(size_t length)
{
static size_t limit = 0;
if (!limit) {
limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
if (!limit)
limit = SIZE_MAX;
}
if (length > limit)
die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
(uintmax_t)length, (uintmax_t)limit);
}
void *xmmap_gently(void *start, size_t length,
int prot, int flags, int fd, off_t offset)
{
void *ret;
mmap_limit_check(length);
ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED) {
if (!length)
return NULL;
release_pack_memory(length);
ret = mmap(start, length, prot, flags, fd, offset);
}
return ret;
}
void *xmmap(void *start, size_t length,
int prot, int flags, int fd, off_t offset)
{
void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED)
die_errno("mmap failed");
return ret;
}
void close_pack_windows(struct packed_git *p)
{
while (p->windows) {
struct pack_window *w = p->windows;
if (w->inuse_cnt)
die("pack '%s' still has open windows to it",
p->pack_name);
munmap(w->base, w->len);
pack_mapped -= w->len;
pack_open_windows--;
p->windows = w->next;
free(w);
}
}
static int close_pack_fd(struct packed_git *p)
{
if (p->pack_fd < 0)
return 0;
close(p->pack_fd);
pack_open_fds--;
p->pack_fd = -1;
return 1;
}
static void close_pack(struct packed_git *p)
{
close_pack_windows(p);
close_pack_fd(p);
close_pack_index(p);
}
void close_all_packs(void)
{
struct packed_git *p;
for (p = packed_git; p; p = p->next)
if (p->do_not_close)
die("BUG: want to close pack marked 'do-not-close'");
else
close_pack(p);
}
/*
* The LRU pack is the one with the oldest MRU window, preferring packs
* with no used windows, or the oldest mtime if it has no windows allocated.
*/
static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
{
struct pack_window *w, *this_mru_w;
int has_windows_inuse = 0;
/*
* Reject this pack if it has windows and the previously selected
* one does not. If this pack does not have windows, reject
* it if the pack file is newer than the previously selected one.
*/
if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
return;
for (w = this_mru_w = p->windows; w; w = w->next) {
/*
* Reject this pack if any of its windows are in use,
* but the previously selected pack did not have any
* inuse windows. Otherwise, record that this pack
* has windows in use.
*/
if (w->inuse_cnt) {
if (*accept_windows_inuse)
has_windows_inuse = 1;
else
return;
}
if (w->last_used > this_mru_w->last_used)
this_mru_w = w;
/*
* Reject this pack if it has windows that have been
* used more recently than the previously selected pack.
* If the previously selected pack had windows inuse and
* we have not encountered a window in this pack that is
* inuse, skip this check since we prefer a pack with no
* inuse windows to one that has inuse windows.
*/
if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
this_mru_w->last_used > (*mru_w)->last_used)
return;
}
/*
* Select this pack.
*/
*mru_w = this_mru_w;
*lru_p = p;
*accept_windows_inuse = has_windows_inuse;
}
static int close_one_pack(void)
{
struct packed_git *p, *lru_p = NULL;
struct pack_window *mru_w = NULL;
int accept_windows_inuse = 1;
for (p = packed_git; p; p = p->next) {
if (p->pack_fd == -1)
continue;
find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
}
if (lru_p)
return close_pack_fd(lru_p);
return 0;
}
void unuse_pack(struct pack_window **w_cursor)
{
struct pack_window *w = *w_cursor;
if (w) {
w->inuse_cnt--;
*w_cursor = NULL;
}
}
void close_pack_index(struct packed_git *p)
{
if (p->index_data) {
munmap((void *)p->index_data, p->index_size);
p->index_data = NULL;
}
}
static unsigned int get_max_fd_limit(void)
{
#ifdef RLIMIT_NOFILE
{
struct rlimit lim;
if (!getrlimit(RLIMIT_NOFILE, &lim))
return lim.rlim_cur;
}
#endif
#ifdef _SC_OPEN_MAX
{
long open_max = sysconf(_SC_OPEN_MAX);
if (0 < open_max)
return open_max;
/*
* Otherwise, we got -1 for one of the two
* reasons:
*
* (1) sysconf() did not understand _SC_OPEN_MAX
* and signaled an error with -1; or
* (2) sysconf() said there is no limit.
*
* We _could_ clear errno before calling sysconf() to
* tell these two cases apart and return a huge number
* in the latter case to let the caller cap it to a
* value that is not so selfish, but letting the
* fallback OPEN_MAX codepath take care of these cases
* is a lot simpler.
*/
}
#endif
#ifdef OPEN_MAX
return OPEN_MAX;
#else
return 1; /* see the caller ;-) */
#endif
}
/*
* Do not call this directly as this leaks p->pack_fd on error return;
* call open_packed_git() instead.
*/
static int open_packed_git_1(struct packed_git *p)
{
struct stat st;
struct pack_header hdr;
unsigned char sha1[20];
unsigned char *idx_sha1;
long fd_flag;
if (!p->index_data && open_pack_index(p))
return error("packfile %s index unavailable", p->pack_name);
if (!pack_max_fds) {
unsigned int max_fds = get_max_fd_limit();
/* Save 3 for stdin/stdout/stderr, 22 for work */
if (25 < max_fds)
pack_max_fds = max_fds - 25;
else
pack_max_fds = 1;
}
while (pack_max_fds <= pack_open_fds && close_one_pack())
; /* nothing */
p->pack_fd = git_open(p->pack_name);
if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
return -1;
pack_open_fds++;
/* If we created the struct before we had the pack we lack size. */
if (!p->pack_size) {
if (!S_ISREG(st.st_mode))
return error("packfile %s not a regular file", p->pack_name);
p->pack_size = st.st_size;
} else if (p->pack_size != st.st_size)
return error("packfile %s size changed", p->pack_name);
/* We leave these file descriptors open with sliding mmap;
* there is no point keeping them open across exec(), though.
*/
fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
if (fd_flag < 0)
return error("cannot determine file descriptor flags");
fd_flag |= FD_CLOEXEC;
if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
return error("cannot set FD_CLOEXEC");
/* Verify we recognize this pack file format. */
if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
return error("file %s is far too short to be a packfile", p->pack_name);
if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
return error("file %s is not a GIT packfile", p->pack_name);
if (!pack_version_ok(hdr.hdr_version))
return error("packfile %s is version %"PRIu32" and not"
" supported (try upgrading GIT to a newer version)",
p->pack_name, ntohl(hdr.hdr_version));
/* Verify the pack matches its index. */
if (p->num_objects != ntohl(hdr.hdr_entries))
return error("packfile %s claims to have %"PRIu32" objects"
" while index indicates %"PRIu32" objects",
p->pack_name, ntohl(hdr.hdr_entries),
p->num_objects);
if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
return error("end of packfile %s is unavailable", p->pack_name);
if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
return error("packfile %s signature is unavailable", p->pack_name);
idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
if (hashcmp(sha1, idx_sha1))
return error("packfile %s does not match index", p->pack_name);
return 0;
}
static int open_packed_git(struct packed_git *p)
{
if (!open_packed_git_1(p))
return 0;
close_pack_fd(p);
return -1;
}
static int in_window(struct pack_window *win, off_t offset)
{
/* We must promise at least 20 bytes (one hash) after the
* offset is available from this window, otherwise the offset
* is not actually in this window and a different window (which
* has that one hash excess) must be used. This is to support
* the object header and delta base parsing routines below.
*/
off_t win_off = win->offset;
return win_off <= offset
&& (offset + 20) <= (win_off + win->len);
}
unsigned char *use_pack(struct packed_git *p,
struct pack_window **w_cursor,
off_t offset,
unsigned long *left)
{
struct pack_window *win = *w_cursor;
/* Since packfiles end in a hash of their content and it's
* pointless to ask for an offset into the middle of that
* hash, and the in_window function above wouldn't match
* don't allow an offset too close to the end of the file.
*/
if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
die("packfile %s cannot be accessed", p->pack_name);
if (offset > (p->pack_size - 20))
die("offset beyond end of packfile (truncated pack?)");
if (offset < 0)
die(_("offset before end of packfile (broken .idx?)"));
if (!win || !in_window(win, offset)) {
if (win)
win->inuse_cnt--;
for (win = p->windows; win; win = win->next) {
if (in_window(win, offset))
break;
}
if (!win) {
size_t window_align = packed_git_window_size / 2;
off_t len;
if (p->pack_fd == -1 && open_packed_git(p))
die("packfile %s cannot be accessed", p->pack_name);
win = xcalloc(1, sizeof(*win));
win->offset = (offset / window_align) * window_align;
len = p->pack_size - win->offset;
if (len > packed_git_window_size)
len = packed_git_window_size;
win->len = (size_t)len;
pack_mapped += win->len;
while (packed_git_limit < pack_mapped
&& unuse_one_window(p))
; /* nothing */
win->base = xmmap(NULL, win->len,
PROT_READ, MAP_PRIVATE,
p->pack_fd, win->offset);
if (win->base == MAP_FAILED)
die_errno("packfile %s cannot be mapped",
p->pack_name);
if (!win->offset && win->len == p->pack_size
&& !p->do_not_close)
close_pack_fd(p);
pack_mmap_calls++;
pack_open_windows++;
if (pack_mapped > peak_pack_mapped)
peak_pack_mapped = pack_mapped;
if (pack_open_windows > peak_pack_open_windows)
peak_pack_open_windows = pack_open_windows;
win->next = p->windows;
p->windows = win;
}
}
if (win != *w_cursor) {
win->last_used = pack_used_ctr++;
win->inuse_cnt++;
*w_cursor = win;
}
offset -= win->offset;
if (left)
*left = win->len - xsize_t(offset);
return win->base + offset;
}
static struct packed_git *alloc_packed_git(int extra)
{
struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
memset(p, 0, sizeof(*p));
p->pack_fd = -1;
return p;
}
static void try_to_free_pack_memory(size_t size)
{
release_pack_memory(size);
}
struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
{
static int have_set_try_to_free_routine;
struct stat st;
size_t alloc;
struct packed_git *p;
if (!have_set_try_to_free_routine) {
have_set_try_to_free_routine = 1;
set_try_to_free_routine(try_to_free_pack_memory);
}
/*
* Make sure a corresponding .pack file exists and that
* the index looks sane.
*/
if (!strip_suffix_mem(path, &path_len, ".idx"))
return NULL;
/*
* ".pack" is long enough to hold any suffix we're adding (and
* the use xsnprintf double-checks that)
*/
alloc = st_add3(path_len, strlen(".pack"), 1);
p = alloc_packed_git(alloc);
memcpy(p->pack_name, path, path_len);
xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
if (!access(p->pack_name, F_OK))
p->pack_keep = 1;
xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
free(p);
return NULL;
}
/* ok, it looks sane as far as we can check without
* actually mapping the pack file.
*/
p->pack_size = st.st_size;
p->pack_local = local;
p->mtime = st.st_mtime;
if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
hashclr(p->sha1);
return p;
}
struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
{
const char *path = sha1_pack_name(sha1);
size_t alloc = st_add(strlen(path), 1);
struct packed_git *p = alloc_packed_git(alloc);
memcpy(p->pack_name, path, alloc); /* includes NUL */
hashcpy(p->sha1, sha1);
if (check_packed_git_idx(idx_path, p)) {
free(p);
return NULL;
}
return p;
}
void install_packed_git(struct packed_git *pack)
{
if (pack->pack_fd != -1)
pack_open_fds++;
pack->next = packed_git;
packed_git = pack;
}
void (*report_garbage)(unsigned seen_bits, const char *path);
static void report_helper(const struct string_list *list,
int seen_bits, int first, int last)
{
if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
return;
for (; first < last; first++)
report_garbage(seen_bits, list->items[first].string);
}
static void report_pack_garbage(struct string_list *list)
{
int i, baselen = -1, first = 0, seen_bits = 0;
if (!report_garbage)
return;
string_list_sort(list);
for (i = 0; i < list->nr; i++) {
const char *path = list->items[i].string;
if (baselen != -1 &&
strncmp(path, list->items[first].string, baselen)) {
report_helper(list, seen_bits, first, i);
baselen = -1;
seen_bits = 0;
}
if (baselen == -1) {
const char *dot = strrchr(path, '.');
if (!dot) {
report_garbage(PACKDIR_FILE_GARBAGE, path);
continue;
}
baselen = dot - path + 1;
first = i;
}
if (!strcmp(path + baselen, "pack"))
seen_bits |= 1;
else if (!strcmp(path + baselen, "idx"))
seen_bits |= 2;
}
report_helper(list, seen_bits, first, list->nr);
}
static void prepare_packed_git_one(char *objdir, int local)
{
struct strbuf path = STRBUF_INIT;
size_t dirnamelen;
DIR *dir;
struct dirent *de;
struct string_list garbage = STRING_LIST_INIT_DUP;
strbuf_addstr(&path, objdir);
strbuf_addstr(&path, "/pack");
dir = opendir(path.buf);
if (!dir) {
if (errno != ENOENT)
error_errno("unable to open object pack directory: %s",
path.buf);
strbuf_release(&path);
return;
}
strbuf_addch(&path, '/');
dirnamelen = path.len;
while ((de = readdir(dir)) != NULL) {
struct packed_git *p;
size_t base_len;
if (is_dot_or_dotdot(de->d_name))
continue;
strbuf_setlen(&path, dirnamelen);
strbuf_addstr(&path, de->d_name);
base_len = path.len;
if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
/* Don't reopen a pack we already have. */
for (p = packed_git; p; p = p->next) {
size_t len;
if (strip_suffix(p->pack_name, ".pack", &len) &&
len == base_len &&
!memcmp(p->pack_name, path.buf, len))
break;
}
if (p == NULL &&
/*
* See if it really is a valid .idx file with
* corresponding .pack file that we can map.
*/
(p = add_packed_git(path.buf, path.len, local)) != NULL)
install_packed_git(p);
}
if (!report_garbage)
continue;
if (ends_with(de->d_name, ".idx") ||
ends_with(de->d_name, ".pack") ||
ends_with(de->d_name, ".bitmap") ||
ends_with(de->d_name, ".keep"))
string_list_append(&garbage, path.buf);
else
report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
}
closedir(dir);
report_pack_garbage(&garbage);
string_list_clear(&garbage, 0);
strbuf_release(&path);
}
static int approximate_object_count_valid;
/*
* Give a fast, rough count of the number of objects in the repository. This
* ignores loose objects completely. If you have a lot of them, then either
* you should repack because your performance will be awful, or they are
* all unreachable objects about to be pruned, in which case they're not really
* interesting as a measure of repo size in the first place.
*/
unsigned long approximate_object_count(void)
{
static unsigned long count;
if (!approximate_object_count_valid) {
struct packed_git *p;
prepare_packed_git();
count = 0;
for (p = packed_git; p; p = p->next) {
if (open_pack_index(p))
continue;
count += p->num_objects;
}
}
return count;
}
static void *get_next_packed_git(const void *p)
{
return ((const struct packed_git *)p)->next;
}
static void set_next_packed_git(void *p, void *next)
{
((struct packed_git *)p)->next = next;
}
static int sort_pack(const void *a_, const void *b_)
{
const struct packed_git *a = a_;
const struct packed_git *b = b_;
int st;
/*
* Local packs tend to contain objects specific to our
* variant of the project than remote ones. In addition,
* remote ones could be on a network mounted filesystem.
* Favor local ones for these reasons.
*/
st = a->pack_local - b->pack_local;
if (st)
return -st;
/*
* Younger packs tend to contain more recent objects,
* and more recent objects tend to get accessed more
* often.
*/
if (a->mtime < b->mtime)
return 1;
else if (a->mtime == b->mtime)
return 0;
return -1;
}
static void rearrange_packed_git(void)
{
packed_git = llist_mergesort(packed_git, get_next_packed_git,
set_next_packed_git, sort_pack);
}
static void prepare_packed_git_mru(void)
{
struct packed_git *p;
mru_clear(packed_git_mru);
for (p = packed_git; p; p = p->next)
mru_append(packed_git_mru, p);
}
static int prepare_packed_git_run_once = 0;
void prepare_packed_git(void)
{
struct alternate_object_database *alt;
if (prepare_packed_git_run_once)
return;
prepare_packed_git_one(get_object_directory(), 1);
prepare_alt_odb();
for (alt = alt_odb_list; alt; alt = alt->next)
prepare_packed_git_one(alt->path, 0);
rearrange_packed_git();
prepare_packed_git_mru();
prepare_packed_git_run_once = 1;
}
void reprepare_packed_git(void)
{
approximate_object_count_valid = 0;
prepare_packed_git_run_once = 0;
prepare_packed_git();
}
static void mark_bad_packed_object(struct packed_git *p,
const unsigned char *sha1)
{
unsigned i;
for (i = 0; i < p->num_bad_objects; i++)
if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
return;
p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
st_mult(GIT_MAX_RAWSZ,
st_add(p->num_bad_objects, 1)));
hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
p->num_bad_objects++;
}
static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
{
struct packed_git *p;
unsigned i;
for (p = packed_git; p; p = p->next)
for (i = 0; i < p->num_bad_objects; i++)
if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
return p;
return NULL;
}
/*
* With an in-core object data in "map", rehash it to make sure the
* object name actually matches "sha1" to detect object corruption.
* With "map" == NULL, try reading the object named with "sha1" using
* the streaming interface and rehash it to do the same.
*/
int check_sha1_signature(const unsigned char *sha1, void *map,
unsigned long size, const char *type)
{
unsigned char real_sha1[20];
enum object_type obj_type;
struct git_istream *st;
git_SHA_CTX c;
char hdr[32];
int hdrlen;
if (map) {
hash_sha1_file(map, size, type, real_sha1);
return hashcmp(sha1, real_sha1) ? -1 : 0;
}
st = open_istream(sha1, &obj_type, &size, NULL);
if (!st)
return -1;
/* Generate the header */
hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
/* Sha1.. */
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, hdrlen);
for (;;) {
char buf[1024 * 16];
ssize_t readlen = read_istream(st, buf, sizeof(buf));
if (readlen < 0) {
close_istream(st);
return -1;
}
if (!readlen)
break;
git_SHA1_Update(&c, buf, readlen);
}
git_SHA1_Final(real_sha1, &c);
close_istream(st);
return hashcmp(sha1, real_sha1) ? -1 : 0;
}
int git_open_cloexec(const char *name, int flags)
{
int fd;
static int o_cloexec = O_CLOEXEC;
fd = open(name, flags | o_cloexec);
if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
/* Try again w/o O_CLOEXEC: the kernel might not support it */
o_cloexec &= ~O_CLOEXEC;
fd = open(name, flags | o_cloexec);
}
#if defined(F_GETFL) && defined(F_SETFL) && defined(FD_CLOEXEC)
{
static int fd_cloexec = FD_CLOEXEC;
if (!o_cloexec && 0 <= fd && fd_cloexec) {
/* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
int flags = fcntl(fd, F_GETFL);
if (fcntl(fd, F_SETFL, flags | fd_cloexec))
fd_cloexec = 0;
}
}
#endif
return fd;
}
/*
* Find "sha1" as a loose object in the local repository or in an alternate.
* Returns 0 on success, negative on failure.
*
* The "path" out-parameter will give the path of the object we found (if any).
* Note that it may point to static storage and is only valid until another
* call to sha1_file_name(), etc.
*/
static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
const char **path)
{
struct alternate_object_database *alt;
*path = sha1_file_name(sha1);
if (!lstat(*path, st))
return 0;
prepare_alt_odb();
errno = ENOENT;
for (alt = alt_odb_list; alt; alt = alt->next) {
*path = alt_sha1_path(alt, sha1);
if (!lstat(*path, st))
return 0;
}
return -1;
}
/*
* Like stat_sha1_file(), but actually open the object and return the
* descriptor. See the caveats on the "path" parameter above.
*/
static int open_sha1_file(const unsigned char *sha1, const char **path)
{
int fd;
struct alternate_object_database *alt;
int most_interesting_errno;
*path = sha1_file_name(sha1);
fd = git_open(*path);
if (fd >= 0)
return fd;
most_interesting_errno = errno;
prepare_alt_odb();
for (alt = alt_odb_list; alt; alt = alt->next) {
*path = alt_sha1_path(alt, sha1);
fd = git_open(*path);
if (fd >= 0)
return fd;
if (most_interesting_errno == ENOENT)
most_interesting_errno = errno;
}
errno = most_interesting_errno;
return -1;
}
/*
* Map the loose object at "path" if it is not NULL, or the path found by
* searching for a loose object named "sha1".
*/
static void *map_sha1_file_1(const char *path,
const unsigned char *sha1,
unsigned long *size)
{
void *map;
int fd;
if (path)
fd = git_open(path);
else
fd = open_sha1_file(sha1, &path);
map = NULL;
if (fd >= 0) {
struct stat st;
if (!fstat(fd, &st)) {
*size = xsize_t(st.st_size);
if (!*size) {
/* mmap() is forbidden on empty files */
error("object file %s is empty", path);
return NULL;
}
map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
}
close(fd);
}
return map;
}
void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
{
return map_sha1_file_1(NULL, sha1, size);
}
unsigned long unpack_object_header_buffer(const unsigned char *buf,
unsigned long len, enum object_type *type, unsigned long *sizep)
{
unsigned shift;
unsigned long size, c;
unsigned long used = 0;
c = buf[used++];
*type = (c >> 4) & 7;
size = c & 15;
shift = 4;
while (c & 0x80) {
if (len <= used || bitsizeof(long) <= shift) {
error("bad object header");
size = used = 0;
break;
}
c = buf[used++];
size += (c & 0x7f) << shift;
shift += 7;
}
*sizep = size;
return used;
}
static int unpack_sha1_short_header(git_zstream *stream,
unsigned char *map, unsigned long mapsize,
void *buffer, unsigned long bufsiz)
{
/* Get the data stream */
memset(stream, 0, sizeof(*stream));
stream->next_in = map;
stream->avail_in = mapsize;
stream->next_out = buffer;
stream->avail_out = bufsiz;
git_inflate_init(stream);
return git_inflate(stream, 0);
}
int unpack_sha1_header(git_zstream *stream,
unsigned char *map, unsigned long mapsize,
void *buffer, unsigned long bufsiz)
{
int status = unpack_sha1_short_header(stream, map, mapsize,
buffer, bufsiz);
if (status < Z_OK)
return status;
/* Make sure we have the terminating NUL */
if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
return -1;
return 0;
}
static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
unsigned long mapsize, void *buffer,
unsigned long bufsiz, struct strbuf *header)
{
int status;
status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
if (status < Z_OK)
return -1;
/*
* Check if entire header is unpacked in the first iteration.
*/
if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
return 0;
/*
* buffer[0..bufsiz] was not large enough. Copy the partial
* result out to header, and then append the result of further
* reading the stream.
*/
strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
stream->next_out = buffer;
stream->avail_out = bufsiz;
do {
status = git_inflate(stream, 0);
strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
return 0;
stream->next_out = buffer;
stream->avail_out = bufsiz;
} while (status != Z_STREAM_END);
return -1;
}
static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
{
int bytes = strlen(buffer) + 1;
unsigned char *buf = xmallocz(size);
unsigned long n;
int status = Z_OK;
n = stream->total_out - bytes;
if (n > size)
n = size;
memcpy(buf, (char *) buffer + bytes, n);
bytes = n;
if (bytes <= size) {
/*
* The above condition must be (bytes <= size), not
* (bytes < size). In other words, even though we
* expect no more output and set avail_out to zero,
* the input zlib stream may have bytes that express
* "this concludes the stream", and we *do* want to
* eat that input.
*
* Otherwise we would not be able to test that we
* consumed all the input to reach the expected size;
* we also want to check that zlib tells us that all
* went well with status == Z_STREAM_END at the end.
*/
stream->next_out = buf + bytes;
stream->avail_out = size - bytes;
while (status == Z_OK)
status = git_inflate(stream, Z_FINISH);
}
if (status == Z_STREAM_END && !stream->avail_in) {
git_inflate_end(stream);
return buf;
}
if (status < 0)
error("corrupt loose object '%s'", sha1_to_hex(sha1));
else if (stream->avail_in)
error("garbage at end of loose object '%s'",
sha1_to_hex(sha1));
free(buf);
return NULL;
}
/*
* We used to just use "sscanf()", but that's actually way
* too permissive for what we want to check. So do an anal
* object header parse by hand.
*/
static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
unsigned int flags)
{
const char *type_buf = hdr;
unsigned long size;
int type, type_len = 0;
/*
* The type can be of any size but is followed by
* a space.
*/
for (;;) {
char c = *hdr++;
if (!c)
return -1;
if (c == ' ')
break;
type_len++;
}
type = type_from_string_gently(type_buf, type_len, 1);
if (oi->typename)
strbuf_add(oi->typename, type_buf, type_len);
/*
* Set type to 0 if its an unknown object and
* we're obtaining the type using '--allow-unknown-type'
* option.
*/
if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
type = 0;
else if (type < 0)
die("invalid object type");
if (oi->typep)
*oi->typep = type;
/*
* The length must follow immediately, and be in canonical
* decimal format (ie "010" is not valid).
*/
size = *hdr++ - '0';
if (size > 9)
return -1;
if (size) {
for (;;) {
unsigned long c = *hdr - '0';
if (c > 9)
break;
hdr++;
size = size * 10 + c;
}
}
if (oi->sizep)
*oi->sizep = size;
/*
* The length must be followed by a zero byte
*/
return *hdr ? -1 : type;
}
int parse_sha1_header(const char *hdr, unsigned long *sizep)
{
struct object_info oi = OBJECT_INFO_INIT;
oi.sizep = sizep;
return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
}
static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
{
int ret;
git_zstream stream;
char hdr[8192];
ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
return NULL;
return unpack_sha1_rest(&stream, hdr, *size, sha1);
}
unsigned long get_size_from_delta(struct packed_git *p,
struct pack_window **w_curs,
off_t curpos)
{
const unsigned char *data;
unsigned char delta_head[20], *in;
git_zstream stream;
int st;
memset(&stream, 0, sizeof(stream));
stream.next_out = delta_head;
stream.avail_out = sizeof(delta_head);
git_inflate_init(&stream);
do {
in = use_pack(p, w_curs, curpos, &stream.avail_in);
stream.next_in = in;
st = git_inflate(&stream, Z_FINISH);
curpos += stream.next_in - in;
} while ((st == Z_OK || st == Z_BUF_ERROR) &&
stream.total_out < sizeof(delta_head));
git_inflate_end(&stream);
if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
error("delta data unpack-initial failed");
return 0;
}
/* Examine the initial part of the delta to figure out
* the result size.
*/
data = delta_head;
/* ignore base size */
get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
/* Read the result size */
return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
}
static off_t get_delta_base(struct packed_git *p,
struct pack_window **w_curs,
off_t *curpos,
enum object_type type,
off_t delta_obj_offset)
{
unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
off_t base_offset;
/* use_pack() assured us we have [base_info, base_info + 20)
* as a range that we can look at without walking off the
* end of the mapped window. Its actually the hash size
* that is assured. An OFS_DELTA longer than the hash size
* is stupid, as then a REF_DELTA would be smaller to store.
*/
if (type == OBJ_OFS_DELTA) {
unsigned used = 0;
unsigned char c = base_info[used++];
base_offset = c & 127;
while (c & 128) {
base_offset += 1;
if (!base_offset || MSB(base_offset, 7))
return 0; /* overflow */
c = base_info[used++];
base_offset = (base_offset << 7) + (c & 127);
}
base_offset = delta_obj_offset - base_offset;
if (base_offset <= 0 || base_offset >= delta_obj_offset)
return 0; /* out of bound */
*curpos += used;
} else if (type == OBJ_REF_DELTA) {
/* The base entry _must_ be in the same pack */
base_offset = find_pack_entry_one(base_info, p);
*curpos += 20;
} else
die("I am totally screwed");
return base_offset;
}
/*
* Like get_delta_base above, but we return the sha1 instead of the pack
* offset. This means it is cheaper for REF deltas (we do not have to do
* the final object lookup), but more expensive for OFS deltas (we
* have to load the revidx to convert the offset back into a sha1).
*/
static const unsigned char *get_delta_base_sha1(struct packed_git *p,
struct pack_window **w_curs,
off_t curpos,
enum object_type type,
off_t delta_obj_offset)
{
if (type == OBJ_REF_DELTA) {
unsigned char *base = use_pack(p, w_curs, curpos, NULL);
return base;
} else if (type == OBJ_OFS_DELTA) {
struct revindex_entry *revidx;
off_t base_offset = get_delta_base(p, w_curs, &curpos,
type, delta_obj_offset);
if (!base_offset)
return NULL;
revidx = find_pack_revindex(p, base_offset);
if (!revidx)
return NULL;
return nth_packed_object_sha1(p, revidx->nr);
} else
return NULL;
}
int unpack_object_header(struct packed_git *p,
struct pack_window **w_curs,
off_t *curpos,
unsigned long *sizep)
{
unsigned char *base;
unsigned long left;
unsigned long used;
enum object_type type;
/* use_pack() assures us we have [base, base + 20) available
* as a range that we can look at. (Its actually the hash
* size that is assured.) With our object header encoding
* the maximum deflated object size is 2^137, which is just
* insane, so we know won't exceed what we have been given.
*/
base = use_pack(p, w_curs, *curpos, &left);
used = unpack_object_header_buffer(base, left, &type, sizep);
if (!used) {
type = OBJ_BAD;
} else
*curpos += used;
return type;
}
static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
{
int type;
struct revindex_entry *revidx;
const unsigned char *sha1;
revidx = find_pack_revindex(p, obj_offset);
if (!revidx)
return OBJ_BAD;
sha1 = nth_packed_object_sha1(p, revidx->nr);
mark_bad_packed_object(p, sha1);
type = sha1_object_info(sha1, NULL);
if (type <= OBJ_NONE)
return OBJ_BAD;
return type;
}
#define POI_STACK_PREALLOC 64
static enum object_type packed_to_object_type(struct packed_git *p,
off_t obj_offset,
enum object_type type,
struct pack_window **w_curs,
off_t curpos)
{
off_t small_poi_stack[POI_STACK_PREALLOC];
off_t *poi_stack = small_poi_stack;
int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
off_t base_offset;
unsigned long size;
/* Push the object we're going to leave behind */
if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
poi_stack_alloc = alloc_nr(poi_stack_nr);
ALLOC_ARRAY(poi_stack, poi_stack_alloc);
memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
} else {
ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
}
poi_stack[poi_stack_nr++] = obj_offset;
/* If parsing the base offset fails, just unwind */
base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
if (!base_offset)
goto unwind;
curpos = obj_offset = base_offset;
type = unpack_object_header(p, w_curs, &curpos, &size);
if (type <= OBJ_NONE) {
/* If getting the base itself fails, we first
* retry the base, otherwise unwind */
type = retry_bad_packed_offset(p, base_offset);
if (type > OBJ_NONE)
goto out;
goto unwind;
}
}
switch (type) {
case OBJ_BAD:
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
break;
default:
error("unknown object type %i at offset %"PRIuMAX" in %s",
type, (uintmax_t)obj_offset, p->pack_name);
type = OBJ_BAD;
}
out:
if (poi_stack != small_poi_stack)
free(poi_stack);
return type;
unwind:
while (poi_stack_nr) {
obj_offset = poi_stack[--poi_stack_nr];
type = retry_bad_packed_offset(p, obj_offset);
if (type > OBJ_NONE)
goto out;
}
type = OBJ_BAD;
goto out;
}
int packed_object_info(struct packed_git *p, off_t obj_offset,
struct object_info *oi)
{
struct pack_window *w_curs = NULL;
unsigned long size;
off_t curpos = obj_offset;
enum object_type type;
/*
* We always get the representation type, but only convert it to
* a "real" type later if the caller is interested.
*/
type = unpack_object_header(p, &w_curs, &curpos, &size);
if (oi->sizep) {
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
off_t tmp_pos = curpos;
off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
type, obj_offset);
if (!base_offset) {
type = OBJ_BAD;
goto out;
}
*oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
if (*oi->sizep == 0) {
type = OBJ_BAD;
goto out;
}
} else {
*oi->sizep = size;
}
}
if (oi->disk_sizep) {
struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
*oi->disk_sizep = revidx[1].offset - obj_offset;
}
if (oi->typep) {
*oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
if (*oi->typep < 0) {
type = OBJ_BAD;
goto out;
}
}
if (oi->delta_base_sha1) {
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
const unsigned char *base;
base = get_delta_base_sha1(p, &w_curs, curpos,
type, obj_offset);
if (!base) {
type = OBJ_BAD;
goto out;
}
hashcpy(oi->delta_base_sha1, base);
} else
hashclr(oi->delta_base_sha1);
}
out:
unuse_pack(&w_curs);
return type;
}
static void *unpack_compressed_entry(struct packed_git *p,
struct pack_window **w_curs,
off_t curpos,
unsigned long size)
{
int st;
git_zstream stream;
unsigned char *buffer, *in;
buffer = xmallocz_gently(size);
if (!buffer)
return NULL;
memset(&stream, 0, sizeof(stream));
stream.next_out = buffer;
stream.avail_out = size + 1;
git_inflate_init(&stream);
do {
in = use_pack(p, w_curs, curpos, &stream.avail_in);
stream.next_in = in;
st = git_inflate(&stream, Z_FINISH);
if (!stream.avail_out)
break; /* the payload is larger than it should be */
curpos += stream.next_in - in;
} while (st == Z_OK || st == Z_BUF_ERROR);
git_inflate_end(&stream);
if ((st != Z_STREAM_END) || stream.total_out != size) {
free(buffer);
return NULL;
}
return buffer;
}
static struct hashmap delta_base_cache;
static size_t delta_base_cached;
static LIST_HEAD(delta_base_cache_lru);
struct delta_base_cache_key {
struct packed_git *p;
off_t base_offset;
};
struct delta_base_cache_entry {
struct hashmap hash;
struct delta_base_cache_key key;
struct list_head lru;
void *data;
unsigned long size;
enum object_type type;
};
static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
{
unsigned int hash;
hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
hash += (hash >> 8) + (hash >> 16);
return hash;
}
static struct delta_base_cache_entry *
get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
{
struct hashmap_entry entry;
struct delta_base_cache_key key;
if (!delta_base_cache.cmpfn)
return NULL;
hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
key.p = p;
key.base_offset = base_offset;
return hashmap_get(&delta_base_cache, &entry, &key);
}
static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
const struct delta_base_cache_key *b)
{
return a->p == b->p && a->base_offset == b->base_offset;
}
static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
const void *va, const void *vb,
const void *vkey)
{
const struct delta_base_cache_entry *a = va, *b = vb;
const struct delta_base_cache_key *key = vkey;
if (key)
return !delta_base_cache_key_eq(&a->key, key);
else
return !delta_base_cache_key_eq(&a->key, &b->key);
}
static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
{
return !!get_delta_base_cache_entry(p, base_offset);
}
/*
* Remove the entry from the cache, but do _not_ free the associated
* entry data. The caller takes ownership of the "data" buffer, and
* should copy out any fields it wants before detaching.
*/
static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
{
hashmap_remove(&delta_base_cache, ent, &ent->key);
list_del(&ent->lru);
delta_base_cached -= ent->size;
free(ent);
}
static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
unsigned long *base_size, enum object_type *type)
{
struct delta_base_cache_entry *ent;
ent = get_delta_base_cache_entry(p, base_offset);
if (!ent)
return unpack_entry(p, base_offset, type, base_size);
*type = ent->type;
*base_size = ent->size;
return xmemdupz(ent->data, ent->size);
}
static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
{
free(ent->data);
detach_delta_base_cache_entry(ent);
}
void clear_delta_base_cache(void)
{
struct list_head *lru, *tmp;
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
struct delta_base_cache_entry *entry =
list_entry(lru, struct delta_base_cache_entry, lru);
release_delta_base_cache(entry);
}
}
static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
void *base, unsigned long base_size, enum object_type type)
{
struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
struct list_head *lru, *tmp;
delta_base_cached += base_size;
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
struct delta_base_cache_entry *f =
list_entry(lru, struct delta_base_cache_entry, lru);
if (delta_base_cached <= delta_base_cache_limit)
break;
release_delta_base_cache(f);
}
ent->key.p = p;
ent->key.base_offset = base_offset;
ent->type = type;
ent->data = base;
ent->size = base_size;
list_add_tail(&ent->lru, &delta_base_cache_lru);
if (!delta_base_cache.cmpfn)
hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
hashmap_add(&delta_base_cache, ent);
}
static void *read_object(const unsigned char *sha1, enum object_type *type,
unsigned long *size);
static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
{
static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
p->pack_name, (uintmax_t)obj_offset);
}
int do_check_packed_object_crc;
#define UNPACK_ENTRY_STACK_PREALLOC 64
struct unpack_entry_stack_ent {
off_t obj_offset;
off_t curpos;
unsigned long size;
};
void *unpack_entry(struct packed_git *p, off_t obj_offset,
enum object_type *final_type, unsigned long *final_size)
{
struct pack_window *w_curs = NULL;
off_t curpos = obj_offset;
void *data = NULL;
unsigned long size;
enum object_type type;
struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
int base_from_cache = 0;
write_pack_access_log(p, obj_offset);
/* PHASE 1: drill down to the innermost base object */
for (;;) {
off_t base_offset;
int i;
struct delta_base_cache_entry *ent;
ent = get_delta_base_cache_entry(p, curpos);
if (ent) {
type = ent->type;
data = ent->data;
size = ent->size;
detach_delta_base_cache_entry(ent);
base_from_cache = 1;
break;
}
if (do_check_packed_object_crc && p->index_version > 1) {
struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
off_t len = revidx[1].offset - obj_offset;
if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
const unsigned char *sha1 =
nth_packed_object_sha1(p, revidx->nr);
error("bad packed object CRC for %s",
sha1_to_hex(sha1));
mark_bad_packed_object(p, sha1);
unuse_pack(&w_curs);
return NULL;
}
}
type = unpack_object_header(p, &w_curs, &curpos, &size);
if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
break;
base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
if (!base_offset) {
error("failed to validate delta base reference "
"at offset %"PRIuMAX" from %s",
(uintmax_t)curpos, p->pack_name);
/* bail to phase 2, in hopes of recovery */
data = NULL;
break;
}
/* push object, proceed to base */
if (delta_stack_nr >= delta_stack_alloc
&& delta_stack == small_delta_stack) {
delta_stack_alloc = alloc_nr(delta_stack_nr);
ALLOC_ARRAY(delta_stack, delta_stack_alloc);
memcpy(delta_stack, small_delta_stack,
sizeof(*delta_stack)*delta_stack_nr);
} else {
ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
}
i = delta_stack_nr++;
delta_stack[i].obj_offset = obj_offset;
delta_stack[i].curpos = curpos;
delta_stack[i].size = size;
curpos = obj_offset = base_offset;
}
/* PHASE 2: handle the base */
switch (type) {
case OBJ_OFS_DELTA:
case OBJ_REF_DELTA:
if (data)
die("BUG: unpack_entry: left loop at a valid delta");
break;
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
if (!base_from_cache)
data = unpack_compressed_entry(p, &w_curs, curpos, size);
break;
default:
data = NULL;
error("unknown object type %i at offset %"PRIuMAX" in %s",
type, (uintmax_t)obj_offset, p->pack_name);
}
/* PHASE 3: apply deltas in order */
/* invariants:
* 'data' holds the base data, or NULL if there was corruption
*/
while (delta_stack_nr) {
void *delta_data;
void *base = data;
void *external_base = NULL;
unsigned long delta_size, base_size = size;
int i;
data = NULL;
if (base)
add_delta_base_cache(p, obj_offset, base, base_size, type);
if (!base) {
/*
* We're probably in deep shit, but let's try to fetch
* the required base anyway from another pack or loose.
* This is costly but should happen only in the presence
* of a corrupted pack, and is better than failing outright.
*/
struct revindex_entry *revidx;
const unsigned char *base_sha1;
revidx = find_pack_revindex(p, obj_offset);
if (revidx) {
base_sha1 = nth_packed_object_sha1(p, revidx->nr);
error("failed to read delta base object %s"
" at offset %"PRIuMAX" from %s",
sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
p->pack_name);
mark_bad_packed_object(p, base_sha1);
base = read_object(base_sha1, &type, &base_size);
external_base = base;
}
}
i = --delta_stack_nr;
obj_offset = delta_stack[i].obj_offset;
curpos = delta_stack[i].curpos;
delta_size = delta_stack[i].size;
if (!base)
continue;
delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
if (!delta_data) {
error("failed to unpack compressed delta "
"at offset %"PRIuMAX" from %s",
(uintmax_t)curpos, p->pack_name);
data = NULL;
free(external_base);
continue;
}
data = patch_delta(base, base_size,
delta_data, delta_size,
&size);
/*
* We could not apply the delta; warn the user, but keep going.
* Our failure will be noticed either in the next iteration of
* the loop, or if this is the final delta, in the caller when
* we return NULL. Those code paths will take care of making
* a more explicit warning and retrying with another copy of
* the object.
*/
if (!data)
error("failed to apply delta");
free(delta_data);
free(external_base);
}
*final_type = type;
*final_size = size;
unuse_pack(&w_curs);
if (delta_stack != small_delta_stack)
free(delta_stack);
return data;
}
const unsigned char *nth_packed_object_sha1(struct packed_git *p,
uint32_t n)
{
const unsigned char *index = p->index_data;
if (!index) {
if (open_pack_index(p))
return NULL;
index = p->index_data;
}
if (n >= p->num_objects)
return NULL;
index += 4 * 256;
if (p->index_version == 1) {
return index + 24 * n + 4;
} else {
index += 8;
return index + 20 * n;
}
}
const struct object_id *nth_packed_object_oid(struct object_id *oid,
struct packed_git *p,
uint32_t n)
{
const unsigned char *hash = nth_packed_object_sha1(p, n);
if (!hash)
return NULL;
hashcpy(oid->hash, hash);
return oid;
}
void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
{
const unsigned char *ptr = vptr;
const unsigned char *start = p->index_data;
const unsigned char *end = start + p->index_size;
if (ptr < start)
die(_("offset before start of pack index for %s (corrupt index?)"),
p->pack_name);
/* No need to check for underflow; .idx files must be at least 8 bytes */
if (ptr >= end - 8)
die(_("offset beyond end of pack index for %s (truncated index?)"),
p->pack_name);
}
off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
{
const unsigned char *index = p->index_data;
index += 4 * 256;
if (p->index_version == 1) {
return ntohl(*((uint32_t *)(index + 24 * n)));
} else {
uint32_t off;
index += 8 + p->num_objects * (20 + 4);
off = ntohl(*((uint32_t *)(index + 4 * n)));
if (!(off & 0x80000000))
return off;
index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
check_pack_index_ptr(p, index);
return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
ntohl(*((uint32_t *)(index + 4)));
}
}
off_t find_pack_entry_one(const unsigned char *sha1,
struct packed_git *p)
{
const uint32_t *level1_ofs = p->index_data;
const unsigned char *index = p->index_data;
unsigned hi, lo, stride;
static int use_lookup = -1;
static int debug_lookup = -1;
if (debug_lookup < 0)
debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
if (!index) {
if (open_pack_index(p))
return 0;
level1_ofs = p->index_data;
index = p->index_data;
}
if (p->index_version > 1) {
level1_ofs += 2;
index += 8;
}
index += 4 * 256;
hi = ntohl(level1_ofs[*sha1]);
lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
if (p->index_version > 1) {
stride = 20;
} else {
stride = 24;
index += 4;
}
if (debug_lookup)
printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
if (use_lookup < 0)
use_lookup = !!getenv("GIT_USE_LOOKUP");
if (use_lookup) {
int pos = sha1_entry_pos(index, stride, 0,
lo, hi, p->num_objects, sha1);
if (pos < 0)
return 0;
return nth_packed_object_offset(p, pos);
}
do {
unsigned mi = (lo + hi) / 2;
int cmp = hashcmp(index + mi * stride, sha1);
if (debug_lookup)
printf("lo %u hi %u rg %u mi %u\n",
lo, hi, hi - lo, mi);
if (!cmp)
return nth_packed_object_offset(p, mi);
if (cmp > 0)
hi = mi;
else
lo = mi+1;
} while (lo < hi);
return 0;
}
int is_pack_valid(struct packed_git *p)
{
/* An already open pack is known to be valid. */
if (p->pack_fd != -1)
return 1;
/* If the pack has one window completely covering the
* file size, the pack is known to be valid even if
* the descriptor is not currently open.
*/
if (p->windows) {
struct pack_window *w = p->windows;
if (!w->offset && w->len == p->pack_size)
return 1;
}
/* Force the pack to open to prove its valid. */
return !open_packed_git(p);
}
static int fill_pack_entry(const unsigned char *sha1,
struct pack_entry *e,
struct packed_git *p)
{
off_t offset;
if (p->num_bad_objects) {
unsigned i;
for (i = 0; i < p->num_bad_objects; i++)
if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
return 0;
}
offset = find_pack_entry_one(sha1, p);
if (!offset)
return 0;
/*
* We are about to tell the caller where they can locate the
* requested object. We better make sure the packfile is
* still here and can be accessed before supplying that
* answer, as it may have been deleted since the index was
* loaded!
*/
if (!is_pack_valid(p))
return 0;
e->offset = offset;
e->p = p;
hashcpy(e->sha1, sha1);
return 1;
}
/*
* Iff a pack file contains the object named by sha1, return true and
* store its location to e.
*/
static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
{
struct mru_entry *p;
prepare_packed_git();
if (!packed_git)
return 0;
for (p = packed_git_mru->head; p; p = p->next) {
if (fill_pack_entry(sha1, e, p->item)) {
mru_mark(packed_git_mru, p);
return 1;
}
}
return 0;
}
struct packed_git *find_sha1_pack(const unsigned char *sha1,
struct packed_git *packs)
{
struct packed_git *p;
for (p = packs; p; p = p->next) {
if (find_pack_entry_one(sha1, p))
return p;
}
return NULL;
}
static int sha1_loose_object_info(const unsigned char *sha1,
struct object_info *oi,
int flags)
{
int status = 0;
unsigned long mapsize;
void *map;
git_zstream stream;
char hdr[32];
struct strbuf hdrbuf = STRBUF_INIT;
if (oi->delta_base_sha1)
hashclr(oi->delta_base_sha1);
/*
* If we don't care about type or size, then we don't
* need to look inside the object at all. Note that we
* do not optimize out the stat call, even if the
* caller doesn't care about the disk-size, since our
* return value implicitly indicates whether the
* object even exists.
*/
if (!oi->typep && !oi->typename && !oi->sizep) {
const char *path;
struct stat st;
if (stat_sha1_file(sha1, &st, &path) < 0)
return -1;
if (oi->disk_sizep)
*oi->disk_sizep = st.st_size;
return 0;
}
map = map_sha1_file(sha1, &mapsize);
if (!map)
return -1;
if (oi->disk_sizep)
*oi->disk_sizep = mapsize;
if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
status = error("unable to unpack %s header with --allow-unknown-type",
sha1_to_hex(sha1));
} else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
status = error("unable to unpack %s header",
sha1_to_hex(sha1));
if (status < 0)
; /* Do nothing */
else if (hdrbuf.len) {
if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
status = error("unable to parse %s header with --allow-unknown-type",
sha1_to_hex(sha1));
} else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
status = error("unable to parse %s header", sha1_to_hex(sha1));
git_inflate_end(&stream);
munmap(map, mapsize);
if (status && oi->typep)
*oi->typep = status;
strbuf_release(&hdrbuf);
return (status < 0) ? status : 0;
}
int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
{
struct cached_object *co;
struct pack_entry e;
int rtype;
enum object_type real_type;
const unsigned char *real = lookup_replace_object_extended(sha1, flags);
co = find_cached_object(real);
if (co) {
if (oi->typep)
*(oi->typep) = co->type;
if (oi->sizep)
*(oi->sizep) = co->size;
if (oi->disk_sizep)
*(oi->disk_sizep) = 0;
if (oi->delta_base_sha1)
hashclr(oi->delta_base_sha1);
if (oi->typename)
strbuf_addstr(oi->typename, typename(co->type));
oi->whence = OI_CACHED;
return 0;
}
if (!find_pack_entry(real, &e)) {
/* Most likely it's a loose object. */
if (!sha1_loose_object_info(real, oi, flags)) {
oi->whence = OI_LOOSE;
return 0;
}
/* Not a loose object; someone else may have just packed it. */
reprepare_packed_git();
if (!find_pack_entry(real, &e))
return -1;
}
/*
* packed_object_info() does not follow the delta chain to
* find out the real type, unless it is given oi->typep.
*/
if (oi->typename && !oi->typep)
oi->typep = &real_type;
rtype = packed_object_info(e.p, e.offset, oi);
if (rtype < 0) {
mark_bad_packed_object(e.p, real);
if (oi->typep == &real_type)
oi->typep = NULL;
return sha1_object_info_extended(real, oi, 0);
} else if (in_delta_base_cache(e.p, e.offset)) {
oi->whence = OI_DBCACHED;
} else {
oi->whence = OI_PACKED;
oi->u.packed.offset = e.offset;
oi->u.packed.pack = e.p;
oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
rtype == OBJ_OFS_DELTA);
}
if (oi->typename)
strbuf_addstr(oi->typename, typename(*oi->typep));
if (oi->typep == &real_type)
oi->typep = NULL;
return 0;
}
/* returns enum object_type or negative */
int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
{
enum object_type type;
struct object_info oi = OBJECT_INFO_INIT;
oi.typep = &type;
oi.sizep = sizep;
if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
return -1;
return type;
}
static void *read_packed_sha1(const unsigned char *sha1,
enum object_type *type, unsigned long *size)
{
struct pack_entry e;
void *data;
if (!find_pack_entry(sha1, &e))
return NULL;
data = cache_or_unpack_entry(e.p, e.offset, size, type);
if (!data) {
/*
* We're probably in deep shit, but let's try to fetch
* the required object anyway from another pack or loose.
* This should happen only in the presence of a corrupted
* pack, and is better than failing outright.
*/
error("failed to read object %s at offset %"PRIuMAX" from %s",
sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
mark_bad_packed_object(e.p, sha1);
data = read_object(sha1, type, size);
}
return data;
}
int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
unsigned char *sha1)
{
struct cached_object *co;
hash_sha1_file(buf, len, typename(type), sha1);
if (has_sha1_file(sha1) || find_cached_object(sha1))
return 0;
ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
co = &cached_objects[cached_object_nr++];
co->size = len;
co->type = type;
co->buf = xmalloc(len);
memcpy(co->buf, buf, len);
hashcpy(co->sha1, sha1);
return 0;
}
static void *read_object(const unsigned char *sha1, enum object_type *type,
unsigned long *size)
{
unsigned long mapsize;
void *map, *buf;
struct cached_object *co;
co = find_cached_object(sha1);
if (co) {
*type = co->type;
*size = co->size;
return xmemdupz(co->buf, co->size);
}
buf = read_packed_sha1(sha1, type, size);
if (buf)
return buf;
map = map_sha1_file(sha1, &mapsize);
if (map) {
buf = unpack_sha1_file(map, mapsize, type, size, sha1);
munmap(map, mapsize);
return buf;
}
reprepare_packed_git();
return read_packed_sha1(sha1, type, size);
}
/*
* This function dies on corrupt objects; the callers who want to
* deal with them should arrange to call read_object() and give error
* messages themselves.
*/
void *read_sha1_file_extended(const unsigned char *sha1,
enum object_type *type,
unsigned long *size,
unsigned flag)
{
void *data;
const struct packed_git *p;
const char *path;
struct stat st;
const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
errno = 0;
data = read_object(repl, type, size);
if (data)
return data;
if (errno && errno != ENOENT)
die_errno("failed to read object %s", sha1_to_hex(sha1));
/* die if we replaced an object with one that does not exist */
if (repl != sha1)
die("replacement %s not found for %s",
sha1_to_hex(repl), sha1_to_hex(sha1));
if (!stat_sha1_file(repl, &st, &path))
die("loose object %s (stored in %s) is corrupt",
sha1_to_hex(repl), path);
if ((p = has_packed_and_bad(repl)) != NULL)
die("packed object %s (stored in %s) is corrupt",
sha1_to_hex(repl), p->pack_name);
return NULL;
}
void *read_object_with_reference(const unsigned char *sha1,
const char *required_type_name,
unsigned long *size,
unsigned char *actual_sha1_return)
{
enum object_type type, required_type;
void *buffer;
unsigned long isize;
unsigned char actual_sha1[20];
required_type = type_from_string(required_type_name);
hashcpy(actual_sha1, sha1);
while (1) {
int ref_length = -1;
const char *ref_type = NULL;
buffer = read_sha1_file(actual_sha1, &type, &isize);
if (!buffer)
return NULL;
if (type == required_type) {
*size = isize;
if (actual_sha1_return)
hashcpy(actual_sha1_return, actual_sha1);
return buffer;
}
/* Handle references */
else if (type == OBJ_COMMIT)
ref_type = "tree ";
else if (type == OBJ_TAG)
ref_type = "object ";
else {
free(buffer);
return NULL;
}
ref_length = strlen(ref_type);
if (ref_length + 40 > isize ||
memcmp(buffer, ref_type, ref_length) ||
get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
free(buffer);
return NULL;
}
free(buffer);
/* Now we have the ID of the referred-to object in
* actual_sha1. Check again. */
}
}
static void write_sha1_file_prepare(const void *buf, unsigned long len,
const char *type, unsigned char *sha1,
char *hdr, int *hdrlen)
{
git_SHA_CTX c;
/* Generate the header */
*hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
/* Sha1.. */
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, *hdrlen);
git_SHA1_Update(&c, buf, len);
git_SHA1_Final(sha1, &c);
}
/*
* Move the just written object into its final resting place.
*/
int finalize_object_file(const char *tmpfile, const char *filename)
{
int ret = 0;
if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
goto try_rename;
else if (link(tmpfile, filename))
ret = errno;
/*
* Coda hack - coda doesn't like cross-directory links,
* so we fall back to a rename, which will mean that it
* won't be able to check collisions, but that's not a
* big deal.
*
* The same holds for FAT formatted media.
*
* When this succeeds, we just return. We have nothing
* left to unlink.
*/
if (ret && ret != EEXIST) {
try_rename:
if (!rename(tmpfile, filename))
goto out;
ret = errno;
}
unlink_or_warn(tmpfile);
if (ret) {
if (ret != EEXIST) {
return error_errno("unable to write sha1 filename %s", filename);
}
/* FIXME!!! Collision check here ? */
}
out:
if (adjust_shared_perm(filename))
return error("unable to set permission to '%s'", filename);
return 0;
}
static int write_buffer(int fd, const void *buf, size_t len)
{
if (write_in_full(fd, buf, len) < 0)
return error_errno("file write error");
return 0;
}
int hash_sha1_file(const void *buf, unsigned long len, const char *type,
unsigned char *sha1)
{
char hdr[32];
int hdrlen = sizeof(hdr);
write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
return 0;
}
/* Finalize a file on disk, and close it. */
static void close_sha1_file(int fd)
{
if (fsync_object_files)
fsync_or_die(fd, "sha1 file");
if (close(fd) != 0)
die_errno("error when closing sha1 file");
}
/* Size of directory component, including the ending '/' */
static inline int directory_size(const char *filename)
{
const char *s = strrchr(filename, '/');
if (!s)
return 0;
return s - filename + 1;
}
/*
* This creates a temporary file in the same directory as the final
* 'filename'
*
* We want to avoid cross-directory filename renames, because those
* can have problems on various filesystems (FAT, NFS, Coda).
*/
static int create_tmpfile(struct strbuf *tmp, const char *filename)
{
int fd, dirlen = directory_size(filename);
strbuf_reset(tmp);
strbuf_add(tmp, filename, dirlen);
strbuf_addstr(tmp, "tmp_obj_XXXXXX");
fd = git_mkstemp_mode(tmp->buf, 0444);
if (fd < 0 && dirlen && errno == ENOENT) {
/*
* Make sure the directory exists; note that the contents
* of the buffer are undefined after mkstemp returns an
* error, so we have to rewrite the whole buffer from
* scratch.
*/
strbuf_reset(tmp);
strbuf_add(tmp, filename, dirlen - 1);
if (mkdir(tmp->buf, 0777) && errno != EEXIST)
return -1;
if (adjust_shared_perm(tmp->buf))
return -1;
/* Try again */
strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
fd = git_mkstemp_mode(tmp->buf, 0444);
}
return fd;
}
static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
const void *buf, unsigned long len, time_t mtime)
{
int fd, ret;
unsigned char compressed[4096];
git_zstream stream;
git_SHA_CTX c;
unsigned char parano_sha1[20];
static struct strbuf tmp_file = STRBUF_INIT;
const char *filename = sha1_file_name(sha1);
fd = create_tmpfile(&tmp_file, filename);
if (fd < 0) {
if (errno == EACCES)
return error("insufficient permission for adding an object to repository database %s", get_object_directory());
else
return error_errno("unable to create temporary file");
}
/* Set it up */
git_deflate_init(&stream, zlib_compression_level);
stream.next_out = compressed;
stream.avail_out = sizeof(compressed);
git_SHA1_Init(&c);
/* First header.. */
stream.next_in = (unsigned char *)hdr;
stream.avail_in = hdrlen;
while (git_deflate(&stream, 0) == Z_OK)
; /* nothing */
git_SHA1_Update(&c, hdr, hdrlen);
/* Then the data itself.. */
stream.next_in = (void *)buf;
stream.avail_in = len;
do {
unsigned char *in0 = stream.next_in;
ret = git_deflate(&stream, Z_FINISH);
git_SHA1_Update(&c, in0, stream.next_in - in0);
if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
die("unable to write sha1 file");
stream.next_out = compressed;
stream.avail_out = sizeof(compressed);
} while (ret == Z_OK);
if (ret != Z_STREAM_END)
die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
ret = git_deflate_end_gently(&stream);
if (ret != Z_OK)
die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
git_SHA1_Final(parano_sha1, &c);
if (hashcmp(sha1, parano_sha1) != 0)
die("confused by unstable object source data for %s", sha1_to_hex(sha1));
close_sha1_file(fd);
if (mtime) {
struct utimbuf utb;
utb.actime = mtime;
utb.modtime = mtime;
if (utime(tmp_file.buf, &utb) < 0)
warning_errno("failed utime() on %s", tmp_file.buf);
}
return finalize_object_file(tmp_file.buf, filename);
}
static int freshen_loose_object(const unsigned char *sha1)
{
return check_and_freshen(sha1, 1);
}
static int freshen_packed_object(const unsigned char *sha1)
{
struct pack_entry e;
if (!find_pack_entry(sha1, &e))
return 0;
if (e.p->freshened)
return 1;
if (!freshen_file(e.p->pack_name))
return 0;
e.p->freshened = 1;
return 1;
}
int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
{
char hdr[32];
int hdrlen = sizeof(hdr);
/* Normally if we have it in the pack then we do not bother writing
* it out into .git/objects/??/?{38} file.
*/
write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
return 0;
return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
}
int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
unsigned char *sha1, unsigned flags)
{
char *header;
int hdrlen, status = 0;
/* type string, SP, %lu of the length plus NUL must fit this */
hdrlen = strlen(type) + 32;
header = xmalloc(hdrlen);
write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
if (!(flags & HASH_WRITE_OBJECT))
goto cleanup;
if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
goto cleanup;
status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
cleanup:
free(header);
return status;
}
int force_object_loose(const unsigned char *sha1, time_t mtime)
{
void *buf;
unsigned long len;
enum object_type type;
char hdr[32];
int hdrlen;
int ret;
if (has_loose_object(sha1))
return 0;
buf = read_packed_sha1(sha1, &type, &len);
if (!buf)
return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
free(buf);
return ret;
}
int has_pack_index(const unsigned char *sha1)
{
struct stat st;
if (stat(sha1_pack_index_name(sha1), &st))
return 0;
return 1;
}
int has_sha1_pack(const unsigned char *sha1)
{
struct pack_entry e;
return find_pack_entry(sha1, &e);
}
int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
{
struct pack_entry e;
if (!startup_info->have_repository)
return 0;
if (find_pack_entry(sha1, &e))
return 1;
if (has_loose_object(sha1))
return 1;
if (flags & HAS_SHA1_QUICK)
return 0;
reprepare_packed_git();
return find_pack_entry(sha1, &e);
}
int has_object_file(const struct object_id *oid)
{
return has_sha1_file(oid->hash);
}
int has_object_file_with_flags(const struct object_id *oid, int flags)
{
return has_sha1_file_with_flags(oid->hash, flags);
}
static void check_tree(const void *buf, size_t size)
{
struct tree_desc desc;
struct name_entry entry;
init_tree_desc(&desc, buf, size);
while (tree_entry(&desc, &entry))
/* do nothing
* tree_entry() will die() on malformed entries */
;
}
static void check_commit(const void *buf, size_t size)
{
struct commit c;
memset(&c, 0, sizeof(c));
if (parse_commit_buffer(&c, buf, size))
die("corrupt commit");
}
static void check_tag(const void *buf, size_t size)
{
struct tag t;
memset(&t, 0, sizeof(t));
if (parse_tag_buffer(&t, buf, size))
die("corrupt tag");
}
static int index_mem(unsigned char *sha1, void *buf, size_t size,
enum object_type type,
const char *path, unsigned flags)
{
int ret, re_allocated = 0;
int write_object = flags & HASH_WRITE_OBJECT;
if (!type)
type = OBJ_BLOB;
/*
* Convert blobs to git internal format
*/
if ((type == OBJ_BLOB) && path) {
struct strbuf nbuf = STRBUF_INIT;
if (convert_to_git(&the_index, path, buf, size, &nbuf,
write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
buf = strbuf_detach(&nbuf, &size);
re_allocated = 1;
}
}
if (flags & HASH_FORMAT_CHECK) {
if (type == OBJ_TREE)
check_tree(buf, size);
if (type == OBJ_COMMIT)
check_commit(buf, size);
if (type == OBJ_TAG)
check_tag(buf, size);
}
if (write_object)
ret = write_sha1_file(buf, size, typename(type), sha1);
else
ret = hash_sha1_file(buf, size, typename(type), sha1);
if (re_allocated)
free(buf);
return ret;
}
static int index_stream_convert_blob(unsigned char *sha1, int fd,
const char *path, unsigned flags)
{
int ret;
const int write_object = flags & HASH_WRITE_OBJECT;
struct strbuf sbuf = STRBUF_INIT;
assert(path);
assert(would_convert_to_git_filter_fd(path));
convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
write_object ? safe_crlf : SAFE_CRLF_FALSE);
if (write_object)
ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
sha1);
else
ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
sha1);
strbuf_release(&sbuf);
return ret;
}
static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
const char *path, unsigned flags)
{
struct strbuf sbuf = STRBUF_INIT;
int ret;
if (strbuf_read(&sbuf, fd, 4096) >= 0)
ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
else
ret = -1;
strbuf_release(&sbuf);
return ret;
}
#define SMALL_FILE_SIZE (32*1024)
static int index_core(unsigned char *sha1, int fd, size_t size,
enum object_type type, const char *path,
unsigned flags)
{
int ret;
if (!size) {
ret = index_mem(sha1, "", size, type, path, flags);
} else if (size <= SMALL_FILE_SIZE) {
char *buf = xmalloc(size);
if (size == read_in_full(fd, buf, size))
ret = index_mem(sha1, buf, size, type, path, flags);
else
ret = error_errno("short read");
free(buf);
} else {
void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
ret = index_mem(sha1, buf, size, type, path, flags);
munmap(buf, size);
}
return ret;
}
/*
* This creates one packfile per large blob unless bulk-checkin
* machinery is "plugged".
*
* This also bypasses the usual "convert-to-git" dance, and that is on
* purpose. We could write a streaming version of the converting
* functions and insert that before feeding the data to fast-import
* (or equivalent in-core API described above). However, that is
* somewhat complicated, as we do not know the size of the filter
* result, which we need to know beforehand when writing a git object.
* Since the primary motivation for trying to stream from the working
* tree file and to avoid mmaping it in core is to deal with large
* binary blobs, they generally do not want to get any conversion, and
* callers should avoid this code path when filters are requested.
*/
static int index_stream(unsigned char *sha1, int fd, size_t size,
enum object_type type, const char *path,
unsigned flags)
{
return index_bulk_checkin(sha1, fd, size, type, path, flags);
}
int index_fd(unsigned char *sha1, int fd, struct stat *st,
enum object_type type, const char *path, unsigned flags)
{
int ret;
/*
* Call xsize_t() only when needed to avoid potentially unnecessary
* die() for large files.
*/
if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
ret = index_stream_convert_blob(sha1, fd, path, flags);
else if (!S_ISREG(st->st_mode))
ret = index_pipe(sha1, fd, type, path, flags);
else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
(path && would_convert_to_git(&the_index, path)))
ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
flags);
else
ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
flags);
close(fd);
return ret;
}
int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
{
int fd;
struct strbuf sb = STRBUF_INIT;
switch (st->st_mode & S_IFMT) {
case S_IFREG:
fd = open(path, O_RDONLY);
if (fd < 0)
return error_errno("open(\"%s\")", path);
if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
return error("%s: failed to insert into database",
path);
break;
case S_IFLNK:
if (strbuf_readlink(&sb, path, st->st_size))
return error_errno("readlink(\"%s\")", path);
if (!(flags & HASH_WRITE_OBJECT))
hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
return error("%s: failed to insert into database",
path);
strbuf_release(&sb);
break;
case S_IFDIR:
return resolve_gitlink_ref(path, "HEAD", sha1);
default:
return error("%s: unsupported file type", path);
}
return 0;
}
int read_pack_header(int fd, struct pack_header *header)
{
if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
/* "eof before pack header was fully read" */
return PH_ERROR_EOF;
if (header->hdr_signature != htonl(PACK_SIGNATURE))
/* "protocol error (pack signature mismatch detected)" */
return PH_ERROR_PACK_SIGNATURE;
if (!pack_version_ok(header->hdr_version))
/* "protocol error (pack version unsupported)" */
return PH_ERROR_PROTOCOL;
return 0;
}
void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
{
enum object_type type = sha1_object_info(sha1, NULL);
if (type < 0)
die("%s is not a valid object", sha1_to_hex(sha1));
if (type != expect)
die("%s is not a valid '%s' object", sha1_to_hex(sha1),
typename(expect));
}
static int for_each_file_in_obj_subdir(int subdir_nr,
struct strbuf *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data)
{
size_t baselen = path->len;
DIR *dir = opendir(path->buf);
struct dirent *de;
int r = 0;
if (!dir) {
if (errno == ENOENT)
return 0;
return error_errno("unable to open %s", path->buf);
}
while ((de = readdir(dir))) {
if (is_dot_or_dotdot(de->d_name))
continue;
strbuf_setlen(path, baselen);
strbuf_addf(path, "/%s", de->d_name);
if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2) {
char hex[GIT_MAX_HEXSZ+1];
struct object_id oid;
xsnprintf(hex, sizeof(hex), "%02x%s",
subdir_nr, de->d_name);
if (!get_oid_hex(hex, &oid)) {
if (obj_cb) {
r = obj_cb(&oid, path->buf, data);
if (r)
break;
}
continue;
}
}
if (cruft_cb) {
r = cruft_cb(de->d_name, path->buf, data);
if (r)
break;
}
}
closedir(dir);
strbuf_setlen(path, baselen);
if (!r && subdir_cb)
r = subdir_cb(subdir_nr, path->buf, data);
return r;
}
int for_each_loose_file_in_objdir_buf(struct strbuf *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data)
{
size_t baselen = path->len;
int r = 0;
int i;
for (i = 0; i < 256; i++) {
strbuf_addf(path, "/%02x", i);
r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
subdir_cb, data);
strbuf_setlen(path, baselen);
if (r)
break;
}
return r;
}
int for_each_loose_file_in_objdir(const char *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data)
{
struct strbuf buf = STRBUF_INIT;
int r;
strbuf_addstr(&buf, path);
r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
subdir_cb, data);
strbuf_release(&buf);
return r;
}
struct loose_alt_odb_data {
each_loose_object_fn *cb;
void *data;
};
static int loose_from_alt_odb(struct alternate_object_database *alt,
void *vdata)
{
struct loose_alt_odb_data *data = vdata;
struct strbuf buf = STRBUF_INIT;
int r;
strbuf_addstr(&buf, alt->path);
r = for_each_loose_file_in_objdir_buf(&buf,
data->cb, NULL, NULL,
data->data);
strbuf_release(&buf);
return r;
}
int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
{
struct loose_alt_odb_data alt;
int r;
r = for_each_loose_file_in_objdir(get_object_directory(),
cb, NULL, NULL, data);
if (r)
return r;
if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
return 0;
alt.cb = cb;
alt.data = data;
return foreach_alt_odb(loose_from_alt_odb, &alt);
}
static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
{
uint32_t i;
int r = 0;
for (i = 0; i < p->num_objects; i++) {
struct object_id oid;
if (!nth_packed_object_oid(&oid, p, i))
return error("unable to get sha1 of object %u in %s",
i, p->pack_name);
r = cb(&oid, p, i, data);
if (r)
break;
}
return r;
}
int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
{
struct packed_git *p;
int r = 0;
int pack_errors = 0;
prepare_packed_git();
for (p = packed_git; p; p = p->next) {
if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
continue;
if (open_pack_index(p)) {
pack_errors = 1;
continue;
}
r = for_each_object_in_pack(p, cb, data);
if (r)
break;
}
return r ? r : pack_errors;
}
static int check_stream_sha1(git_zstream *stream,
const char *hdr,
unsigned long size,
const char *path,
const unsigned char *expected_sha1)
{
git_SHA_CTX c;
unsigned char real_sha1[GIT_MAX_RAWSZ];
unsigned char buf[4096];
unsigned long total_read;
int status = Z_OK;
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, stream->total_out);
/*
* We already read some bytes into hdr, but the ones up to the NUL
* do not count against the object's content size.
*/
total_read = stream->total_out - strlen(hdr) - 1;
/*
* This size comparison must be "<=" to read the final zlib packets;
* see the comment in unpack_sha1_rest for details.
*/
while (total_read <= size &&
(status == Z_OK || status == Z_BUF_ERROR)) {
stream->next_out = buf;
stream->avail_out = sizeof(buf);
if (size - total_read < stream->avail_out)
stream->avail_out = size - total_read;
status = git_inflate(stream, Z_FINISH);
git_SHA1_Update(&c, buf, stream->next_out - buf);
total_read += stream->next_out - buf;
}
git_inflate_end(stream);
if (status != Z_STREAM_END) {
error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
return -1;
}
if (stream->avail_in) {
error("garbage at end of loose object '%s'",
sha1_to_hex(expected_sha1));
return -1;
}
git_SHA1_Final(real_sha1, &c);
if (hashcmp(expected_sha1, real_sha1)) {
error("sha1 mismatch for %s (expected %s)", path,
sha1_to_hex(expected_sha1));
return -1;
}
return 0;
}
int read_loose_object(const char *path,
const unsigned char *expected_sha1,
enum object_type *type,
unsigned long *size,
void **contents)
{
int ret = -1;
void *map = NULL;
unsigned long mapsize;
git_zstream stream;
char hdr[32];
*contents = NULL;
map = map_sha1_file_1(path, NULL, &mapsize);
if (!map) {
error_errno("unable to mmap %s", path);
goto out;
}
if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
error("unable to unpack header of %s", path);
goto out;
}
*type = parse_sha1_header(hdr, size);
if (*type < 0) {
error("unable to parse header of %s", path);
git_inflate_end(&stream);
goto out;
}
if (*type == OBJ_BLOB) {
if (check_stream_sha1(&stream, hdr, *size, path, expected_sha1) < 0)
goto out;
} else {
*contents = unpack_sha1_rest(&stream, hdr, *size, expected_sha1);
if (!*contents) {
error("unable to unpack contents of %s", path);
git_inflate_end(&stream);
goto out;
}
if (check_sha1_signature(expected_sha1, *contents,
*size, typename(*type))) {
error("sha1 mismatch for %s (expected %s)", path,
sha1_to_hex(expected_sha1));
free(*contents);
goto out;
}
}
ret = 0; /* everything checks out */
out:
if (map)
munmap(map, mapsize);
return ret;
}
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