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Merge branch 'mh/separate-ref-cache'

Browse Source 
The internals of the refs API around the cached refs has been
streamlined.

* mh/separate-ref-cache:
  do_for_each_entry_in_dir(): delete function
  files_pack_refs(): use reference iteration
  commit_packed_refs(): use reference iteration
  cache_ref_iterator_begin(): make function smarter
  get_loose_ref_cache(): new function
  get_loose_ref_dir(): function renamed from get_loose_refs()
  do_for_each_entry_in_dir(): eliminate `offset` argument
  refs: handle "refs/bisect/" in `loose_fill_ref_dir()`
  ref-cache: use a callback function to fill the cache
  refs: record the ref_store in ref_cache, not ref_dir
  ref-cache: introduce a new type, ref_cache
  refs: split `ref_cache` code into separate files
  ref-cache: rename `remove_entry()` to `remove_entry_from_dir()`
  ref-cache: rename `find_ref()` to `find_ref_entry()`
  ref-cache: rename `add_ref()` to `add_ref_entry()`
  refs_verify_refname_available(): use function in more places
  refs_verify_refname_available(): implement once for all backends
  refs_ref_iterator_begin(): new function
  refs_read_raw_ref(): new function
  get_ref_dir(): don't call read_loose_refs() for "refs/bisect"
This commit is contained in:
Junio C Hamano 2017-04-26 15:39:13 +09:00
commit 77b34eaa07
7 changed files with 1066 additions and 1089 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Makefile
View File

@ -817,6 +817,7 @@ LIB_OBJS += reflog-walk.o
LIB_OBJS += refs.o
LIB_OBJS += refs/files-backend.o
LIB_OBJS += refs/iterator.o
LIB_OBJS += refs/ref-cache.o
LIB_OBJS += ref-filter.o
LIB_OBJS += remote.o
LIB_OBJS += replace_object.o

109
refs.c
View File

@ -5,6 +5,7 @@
#include "cache.h"
#include "hashmap.h"
#include "lockfile.h"
#include "iterator.h"
#include "refs.h"
#include "refs/refs-internal.h"
#include "object.h"
@ -1238,6 +1239,18 @@ int head_ref(each_ref_fn fn, void *cb_data)
return head_ref_submodule(NULL, fn, cb_data);
}
struct ref_iterator *refs_ref_iterator_begin(
struct ref_store *refs,
const char *prefix, int trim, int flags)
{
struct ref_iterator *iter;
iter = refs->be->iterator_begin(refs, prefix, flags);
iter = prefix_ref_iterator_begin(iter, prefix, trim);
return iter;
}
/*
* Call fn for each reference in the specified submodule for which the
* refname begins with prefix. If trim is non-zero, then trim that
@ -1255,8 +1268,7 @@ static int do_for_each_ref(struct ref_store *refs, const char *prefix,
if (!refs)
return 0;
iter = refs->be->iterator_begin(refs, prefix, flags);
iter = prefix_ref_iterator_begin(iter, prefix, trim);
iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
return do_for_each_ref_iterator(iter, fn, cb_data);
}
@ -1334,6 +1346,13 @@ int for_each_rawref(each_ref_fn fn, void *cb_data)
return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
}
int refs_read_raw_ref(struct ref_store *ref_store,
const char *refname, unsigned char *sha1,
struct strbuf *referent, unsigned int *type)
{
return ref_store->be->read_raw_ref(ref_store, refname, sha1, referent, type);
}
/* This function needs to return a meaningful errno on failure */
const char *refs_resolve_ref_unsafe(struct ref_store *refs,
const char *refname,
@ -1370,7 +1389,7 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
unsigned int read_flags = 0;
if (refs->be->read_raw_ref(refs, refname,
if (refs_read_raw_ref(refs, refname,
sha1, &sb_refname, &read_flags)) {
*flags |= read_flags;
if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
@ -1654,11 +1673,91 @@ int ref_transaction_commit(struct ref_transaction *transaction,
int refs_verify_refname_available(struct ref_store *refs,
const char *refname,
const struct string_list *extra,
const struct string_list *extras,
const struct string_list *skip,
struct strbuf *err)
{
return refs->be->verify_refname_available(refs, refname, extra, skip, err);
const char *slash;
const char *extra_refname;
struct strbuf dirname = STRBUF_INIT;
struct strbuf referent = STRBUF_INIT;
struct object_id oid;
unsigned int type;
struct ref_iterator *iter;
int ok;
int ret = -1;
/*
* For the sake of comments in this function, suppose that
* refname is "refs/foo/bar".
*/
assert(err);
strbuf_grow(&dirname, strlen(refname) + 1);
for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
/* Expand dirname to the new prefix, not including the trailing slash: */
strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
/*
* We are still at a leading dir of the refname (e.g.,
* "refs/foo"; if there is a reference with that name,
* it is a conflict, *unless* it is in skip.
*/
if (skip && string_list_has_string(skip, dirname.buf))
continue;
if (!refs_read_raw_ref(refs, dirname.buf, oid.hash, &referent, &type)) {
strbuf_addf(err, "'%s' exists; cannot create '%s'",
dirname.buf, refname);
goto cleanup;
}
if (extras && string_list_has_string(extras, dirname.buf)) {
strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
refname, dirname.buf);
goto cleanup;
}
}
/*
* We are at the leaf of our refname (e.g., "refs/foo/bar").
* There is no point in searching for a reference with that
* name, because a refname isn't considered to conflict with
* itself. But we still need to check for references whose
* names are in the "refs/foo/bar/" namespace, because they
* *do* conflict.
*/
strbuf_addstr(&dirname, refname + dirname.len);
strbuf_addch(&dirname, '/');
iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
DO_FOR_EACH_INCLUDE_BROKEN);
while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
if (skip &&
string_list_has_string(skip, iter->refname))
continue;
strbuf_addf(err, "'%s' exists; cannot create '%s'",
iter->refname, refname);
ref_iterator_abort(iter);
goto cleanup;
}
if (ok != ITER_DONE)
die("BUG: error while iterating over references");
extra_refname = find_descendant_ref(dirname.buf, extras, skip);
if (extra_refname)
strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
refname, extra_refname);
else
ret = 0;
cleanup:
strbuf_release(&referent);
strbuf_release(&dirname);
return ret;
}
int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)

2
refs.h
View File

@ -97,7 +97,7 @@ int read_ref(const char *refname, unsigned char *sha1);
int refs_verify_refname_available(struct ref_store *refs,
const char *refname,
const struct string_list *extra,
const struct string_list *extras,
const struct string_list *skip,
struct strbuf *err);

1227
refs/files-backend.c
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File diff suppressed because it is too large Load Diff

523
refs/ref-cache.c Normal file
View File

@ -0,0 +1,523 @@
#include "../cache.h"
#include "../refs.h"
#include "refs-internal.h"
#include "ref-cache.h"
#include "../iterator.h"
void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
{
ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
dir->entries[dir->nr++] = entry;
/* optimize for the case that entries are added in order */
if (dir->nr == 1 ||
(dir->nr == dir->sorted + 1 &&
strcmp(dir->entries[dir->nr - 2]->name,
dir->entries[dir->nr - 1]->name) < 0))
dir->sorted = dir->nr;
}
struct ref_dir *get_ref_dir(struct ref_entry *entry)
{
struct ref_dir *dir;
assert(entry->flag & REF_DIR);
dir = &entry->u.subdir;
if (entry->flag & REF_INCOMPLETE) {
if (!dir->cache->fill_ref_dir)
die("BUG: incomplete ref_store without fill_ref_dir function");
dir->cache->fill_ref_dir(dir->cache->ref_store, dir, entry->name);
entry->flag &= ~REF_INCOMPLETE;
}
return dir;
}
struct ref_entry *create_ref_entry(const char *refname,
const unsigned char *sha1, int flag,
int check_name)
{
struct ref_entry *ref;
if (check_name &&
check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
die("Reference has invalid format: '%s'", refname);
FLEX_ALLOC_STR(ref, name, refname);
hashcpy(ref->u.value.oid.hash, sha1);
oidclr(&ref->u.value.peeled);
ref->flag = flag;
return ref;
}
struct ref_cache *create_ref_cache(struct ref_store *refs,
fill_ref_dir_fn *fill_ref_dir)
{
struct ref_cache *ret = xcalloc(1, sizeof(*ret));
ret->ref_store = refs;
ret->fill_ref_dir = fill_ref_dir;
ret->root = create_dir_entry(ret, "", 0, 1);
return ret;
}
static void clear_ref_dir(struct ref_dir *dir);
static void free_ref_entry(struct ref_entry *entry)
{
if (entry->flag & REF_DIR) {
/*
* Do not use get_ref_dir() here, as that might
* trigger the reading of loose refs.
*/
clear_ref_dir(&entry->u.subdir);
}
free(entry);
}
void free_ref_cache(struct ref_cache *cache)
{
free_ref_entry(cache->root);
free(cache);
}
/*
* Clear and free all entries in dir, recursively.
*/
static void clear_ref_dir(struct ref_dir *dir)
{
int i;
for (i = 0; i < dir->nr; i++)
free_ref_entry(dir->entries[i]);
free(dir->entries);
dir->sorted = dir->nr = dir->alloc = 0;
dir->entries = NULL;
}
struct ref_entry *create_dir_entry(struct ref_cache *cache,
const char *dirname, size_t len,
int incomplete)
{
struct ref_entry *direntry;
FLEX_ALLOC_MEM(direntry, name, dirname, len);
direntry->u.subdir.cache = cache;
direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
return direntry;
}
static int ref_entry_cmp(const void *a, const void *b)
{
struct ref_entry *one = *(struct ref_entry **)a;
struct ref_entry *two = *(struct ref_entry **)b;
return strcmp(one->name, two->name);
}
static void sort_ref_dir(struct ref_dir *dir);
struct string_slice {
size_t len;
const char *str;
};
static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
{
const struct string_slice *key = key_;
const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
int cmp = strncmp(key->str, ent->name, key->len);
if (cmp)
return cmp;
return '\0' - (unsigned char)ent->name[key->len];
}
int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
{
struct ref_entry **r;
struct string_slice key;
if (refname == NULL || !dir->nr)
return -1;
sort_ref_dir(dir);
key.len = len;
key.str = refname;
r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
ref_entry_cmp_sslice);
if (r == NULL)
return -1;
return r - dir->entries;
}
/*
* Search for a directory entry directly within dir (without
* recursing). Sort dir if necessary. subdirname must be a directory
* name (i.e., end in '/'). If mkdir is set, then create the
* directory if it is missing; otherwise, return NULL if the desired
* directory cannot be found. dir must already be complete.
*/
static struct ref_dir *search_for_subdir(struct ref_dir *dir,
const char *subdirname, size_t len,
int mkdir)
{
int entry_index = search_ref_dir(dir, subdirname, len);
struct ref_entry *entry;
if (entry_index == -1) {
if (!mkdir)
return NULL;
/*
* Since dir is complete, the absence of a subdir
* means that the subdir really doesn't exist;
* therefore, create an empty record for it but mark
* the record complete.
*/
entry = create_dir_entry(dir->cache, subdirname, len, 0);
add_entry_to_dir(dir, entry);
} else {
entry = dir->entries[entry_index];
}
return get_ref_dir(entry);
}
/*
* If refname is a reference name, find the ref_dir within the dir
* tree that should hold refname. If refname is a directory name
* (i.e., it ends in '/'), then return that ref_dir itself. dir must
* represent the top-level directory and must already be complete.
* Sort ref_dirs and recurse into subdirectories as necessary. If
* mkdir is set, then create any missing directories; otherwise,
* return NULL if the desired directory cannot be found.
*/
static struct ref_dir *find_containing_dir(struct ref_dir *dir,
const char *refname, int mkdir)
{
const char *slash;
for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
size_t dirnamelen = slash - refname + 1;
struct ref_dir *subdir;
subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
if (!subdir) {
dir = NULL;
break;
}
dir = subdir;
}
return dir;
}
struct ref_entry *find_ref_entry(struct ref_dir *dir, const char *refname)
{
int entry_index;
struct ref_entry *entry;
dir = find_containing_dir(dir, refname, 0);
if (!dir)
return NULL;
entry_index = search_ref_dir(dir, refname, strlen(refname));
if (entry_index == -1)
return NULL;
entry = dir->entries[entry_index];
return (entry->flag & REF_DIR) ? NULL : entry;
}
int remove_entry_from_dir(struct ref_dir *dir, const char *refname)
{
int refname_len = strlen(refname);
int entry_index;
struct ref_entry *entry;
int is_dir = refname[refname_len - 1] == '/';
if (is_dir) {
/*
* refname represents a reference directory. Remove
* the trailing slash; otherwise we will get the
* directory *representing* refname rather than the
* one *containing* it.
*/
char *dirname = xmemdupz(refname, refname_len - 1);
dir = find_containing_dir(dir, dirname, 0);
free(dirname);
} else {
dir = find_containing_dir(dir, refname, 0);
}
if (!dir)
return -1;
entry_index = search_ref_dir(dir, refname, refname_len);
if (entry_index == -1)
return -1;
entry = dir->entries[entry_index];
memmove(&dir->entries[entry_index],
&dir->entries[entry_index + 1],
(dir->nr - entry_index - 1) * sizeof(*dir->entries)
);
dir->nr--;
if (dir->sorted > entry_index)
dir->sorted--;
free_ref_entry(entry);
return dir->nr;
}
int add_ref_entry(struct ref_dir *dir, struct ref_entry *ref)
{
dir = find_containing_dir(dir, ref->name, 1);
if (!dir)
return -1;
add_entry_to_dir(dir, ref);
return 0;
}
/*
* Emit a warning and return true iff ref1 and ref2 have the same name
* and the same sha1. Die if they have the same name but different
* sha1s.
*/
static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
{
if (strcmp(ref1->name, ref2->name))
return 0;
/* Duplicate name; make sure that they don't conflict: */
if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
/* This is impossible by construction */
die("Reference directory conflict: %s", ref1->name);
if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid))
die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
warning("Duplicated ref: %s", ref1->name);
return 1;
}
/*
* Sort the entries in dir non-recursively (if they are not already
* sorted) and remove any duplicate entries.
*/
static void sort_ref_dir(struct ref_dir *dir)
{
int i, j;
struct ref_entry *last = NULL;
/*
* This check also prevents passing a zero-length array to qsort(),
* which is a problem on some platforms.
*/
if (dir->sorted == dir->nr)
return;
QSORT(dir->entries, dir->nr, ref_entry_cmp);
/* Remove any duplicates: */
for (i = 0, j = 0; j < dir->nr; j++) {
struct ref_entry *entry = dir->entries[j];
if (last && is_dup_ref(last, entry))
free_ref_entry(entry);
else
last = dir->entries[i++] = entry;
}
dir->sorted = dir->nr = i;
}
/*
* Load all of the refs from `dir` (recursively) into our in-memory
* cache.
*/
static void prime_ref_dir(struct ref_dir *dir)
{
/*
* The hard work of loading loose refs is done by get_ref_dir(), so we
* just need to recurse through all of the sub-directories. We do not
* even need to care about sorting, as traversal order does not matter
* to us.
*/
int i;
for (i = 0; i < dir->nr; i++) {
struct ref_entry *entry = dir->entries[i];
if (entry->flag & REF_DIR)
prime_ref_dir(get_ref_dir(entry));
}
}
/*
* A level in the reference hierarchy that is currently being iterated
* through.
*/
struct cache_ref_iterator_level {
/*
* The ref_dir being iterated over at this level. The ref_dir
* is sorted before being stored here.
*/
struct ref_dir *dir;
/*
* The index of the current entry within dir (which might
* itself be a directory). If index == -1, then the iteration
* hasn't yet begun. If index == dir->nr, then the iteration
* through this level is over.
*/
int index;
};
/*
* Represent an iteration through a ref_dir in the memory cache. The
* iteration recurses through subdirectories.
*/
struct cache_ref_iterator {
struct ref_iterator base;
/*
* The number of levels currently on the stack. This is always
* at least 1, because when it becomes zero the iteration is
* ended and this struct is freed.
*/
size_t levels_nr;
/* The number of levels that have been allocated on the stack */
size_t levels_alloc;
/*
* A stack of levels. levels[0] is the uppermost level that is
* being iterated over in this iteration. (This is not
* necessary the top level in the references hierarchy. If we
* are iterating through a subtree, then levels[0] will hold
* the ref_dir for that subtree, and subsequent levels will go
* on from there.)
*/
struct cache_ref_iterator_level *levels;
};
static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
{
struct cache_ref_iterator *iter =
(struct cache_ref_iterator *)ref_iterator;
while (1) {
struct cache_ref_iterator_level *level =
&iter->levels[iter->levels_nr - 1];
struct ref_dir *dir = level->dir;
struct ref_entry *entry;
if (level->index == -1)
sort_ref_dir(dir);
if (++level->index == level->dir->nr) {
/* This level is exhausted; pop up a level */
if (--iter->levels_nr == 0)
return ref_iterator_abort(ref_iterator);
continue;
}
entry = dir->entries[level->index];
if (entry->flag & REF_DIR) {
/* push down a level */
ALLOC_GROW(iter->levels, iter->levels_nr + 1,
iter->levels_alloc);
level = &iter->levels[iter->levels_nr++];
level->dir = get_ref_dir(entry);
level->index = -1;
} else {
iter->base.refname = entry->name;
iter->base.oid = &entry->u.value.oid;
iter->base.flags = entry->flag;
return ITER_OK;
}
}
}
enum peel_status peel_entry(struct ref_entry *entry, int repeel)
{
enum peel_status status;
if (entry->flag & REF_KNOWS_PEELED) {
if (repeel) {
entry->flag &= ~REF_KNOWS_PEELED;
oidclr(&entry->u.value.peeled);
} else {
return is_null_oid(&entry->u.value.peeled) ?
PEEL_NON_TAG : PEEL_PEELED;
}
}
if (entry->flag & REF_ISBROKEN)
return PEEL_BROKEN;
if (entry->flag & REF_ISSYMREF)
return PEEL_IS_SYMREF;
status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);
if (status == PEEL_PEELED || status == PEEL_NON_TAG)
entry->flag |= REF_KNOWS_PEELED;
return status;
}
static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
struct object_id *peeled)
{
struct cache_ref_iterator *iter =
(struct cache_ref_iterator *)ref_iterator;
struct cache_ref_iterator_level *level;
struct ref_entry *entry;
level = &iter->levels[iter->levels_nr - 1];
if (level->index == -1)
die("BUG: peel called before advance for cache iterator");
entry = level->dir->entries[level->index];
if (peel_entry(entry, 0))
return -1;
oidcpy(peeled, &entry->u.value.peeled);
return 0;
}
static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
{
struct cache_ref_iterator *iter =
(struct cache_ref_iterator *)ref_iterator;
free(iter->levels);
base_ref_iterator_free(ref_iterator);
return ITER_DONE;
}
static struct ref_iterator_vtable cache_ref_iterator_vtable = {
cache_ref_iterator_advance,
cache_ref_iterator_peel,
cache_ref_iterator_abort
};
struct ref_iterator *cache_ref_iterator_begin(struct ref_cache *cache,
const char *prefix,
int prime_dir)
{
struct ref_dir *dir;
struct cache_ref_iterator *iter;
struct ref_iterator *ref_iterator;
struct cache_ref_iterator_level *level;
dir = get_ref_dir(cache->root);
if (prefix && *prefix)
dir = find_containing_dir(dir, prefix, 0);
if (!dir)
/* There's nothing to iterate over. */
return empty_ref_iterator_begin();
if (prime_dir)
prime_ref_dir(dir);
iter = xcalloc(1, sizeof(*iter));
ref_iterator = &iter->base;
base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable);
ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
iter->levels_nr = 1;
level = &iter->levels[0];
level->index = -1;
level->dir = dir;
if (prefix && *prefix)
ref_iterator = prefix_ref_iterator_begin(ref_iterator,
prefix, 0);
return ref_iterator;
}

267
refs/ref-cache.h Normal file
View File

@ -0,0 +1,267 @@
#ifndef REFS_REF_CACHE_H
#define REFS_REF_CACHE_H
struct ref_dir;
/*
* If this ref_cache is filled lazily, this function is used to load
* information into the specified ref_dir (shallow or deep, at the
* option of the ref_store). dirname includes a trailing slash.
*/
typedef void fill_ref_dir_fn(struct ref_store *ref_store,
struct ref_dir *dir, const char *dirname);
struct ref_cache {
struct ref_entry *root;
/* A pointer to the ref_store whose cache this is: */
struct ref_store *ref_store;
/*
* Function used (if necessary) to lazily-fill cache. May be
* NULL.
*/
fill_ref_dir_fn *fill_ref_dir;
};
/*
* Information used (along with the information in ref_entry) to
* describe a single cached reference. This data structure only
* occurs embedded in a union in struct ref_entry, and only when
* (ref_entry->flag & REF_DIR) is zero.
*/
struct ref_value {
/*
* The name of the object to which this reference resolves
* (which may be a tag object). If REF_ISBROKEN, this is
* null. If REF_ISSYMREF, then this is the name of the object
* referred to by the last reference in the symlink chain.
*/
struct object_id oid;
/*
* If REF_KNOWS_PEELED, then this field holds the peeled value
* of this reference, or null if the reference is known not to
* be peelable. See the documentation for peel_ref() for an
* exact definition of "peelable".
*/
struct object_id peeled;
};
/*
* Information used (along with the information in ref_entry) to
* describe a level in the hierarchy of references. This data
* structure only occurs embedded in a union in struct ref_entry, and
* only when (ref_entry.flag & REF_DIR) is set. In that case,
* (ref_entry.flag & REF_INCOMPLETE) determines whether the references
* in the directory have already been read:
*
* (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
* or packed references, already read.
*
* (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
* references that hasn't been read yet (nor has any of its
* subdirectories).
*
* Entries within a directory are stored within a growable array of
* pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
* sorted are sorted by their component name in strcmp() order and the
* remaining entries are unsorted.
*
* Loose references are read lazily, one directory at a time. When a
* directory of loose references is read, then all of the references
* in that directory are stored, and REF_INCOMPLETE stubs are created
* for any subdirectories, but the subdirectories themselves are not
* read. The reading is triggered by get_ref_dir().
*/
struct ref_dir {
int nr, alloc;
/*
* Entries with index 0 <= i < sorted are sorted by name. New
* entries are appended to the list unsorted, and are sorted
* only when required; thus we avoid the need to sort the list
* after the addition of every reference.
*/
int sorted;
/* The ref_cache containing this entry: */
struct ref_cache *cache;
struct ref_entry **entries;
};
/*
* Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
* REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
* public values; see refs.h.
*/
/*
* The field ref_entry->u.value.peeled of this value entry contains
* the correct peeled value for the reference, which might be
* null_sha1 if the reference is not a tag or if it is broken.
*/
#define REF_KNOWS_PEELED 0x10
/* ref_entry represents a directory of references */
#define REF_DIR 0x20
/*
* Entry has not yet been read from disk (used only for REF_DIR
* entries representing loose references)
*/
#define REF_INCOMPLETE 0x40
/*
* A ref_entry represents either a reference or a "subdirectory" of
* references.
*
* Each directory in the reference namespace is represented by a
* ref_entry with (flags & REF_DIR) set and containing a subdir member
* that holds the entries in that directory that have been read so
* far. If (flags & REF_INCOMPLETE) is set, then the directory and
* its subdirectories haven't been read yet. REF_INCOMPLETE is only
* used for loose reference directories.
*
* References are represented by a ref_entry with (flags & REF_DIR)
* unset and a value member that describes the reference's value. The
* flag member is at the ref_entry level, but it is also needed to
* interpret the contents of the value field (in other words, a
* ref_value object is not very much use without the enclosing
* ref_entry).
*
* Reference names cannot end with slash and directories' names are
* always stored with a trailing slash (except for the top-level
* directory, which is always denoted by ""). This has two nice
* consequences: (1) when the entries in each subdir are sorted
* lexicographically by name (as they usually are), the references in
* a whole tree can be generated in lexicographic order by traversing
* the tree in left-to-right, depth-first order; (2) the names of
* references and subdirectories cannot conflict, and therefore the
* presence of an empty subdirectory does not block the creation of a
* similarly-named reference. (The fact that reference names with the
* same leading components can conflict *with each other* is a
* separate issue that is regulated by refs_verify_refname_available().)
*
* Please note that the name field contains the fully-qualified
* reference (or subdirectory) name. Space could be saved by only
* storing the relative names. But that would require the full names
* to be generated on the fly when iterating in do_for_each_ref(), and
* would break callback functions, who have always been able to assume
* that the name strings that they are passed will not be freed during
* the iteration.
*/
struct ref_entry {
unsigned char flag; /* ISSYMREF? ISPACKED? */
union {
struct ref_value value; /* if not (flags&REF_DIR) */
struct ref_dir subdir; /* if (flags&REF_DIR) */
} u;
/*
* The full name of the reference (e.g., "refs/heads/master")
* or the full name of the directory with a trailing slash
* (e.g., "refs/heads/"):
*/
char name[FLEX_ARRAY];
};
/*
* Return the index of the entry with the given refname from the
* ref_dir (non-recursively), sorting dir if necessary. Return -1 if
* no such entry is found. dir must already be complete.
*/
int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len);
struct ref_dir *get_ref_dir(struct ref_entry *entry);
/*
* Create a struct ref_entry object for the specified dirname.
* dirname is the name of the directory with a trailing slash (e.g.,
* "refs/heads/") or "" for the top-level directory.
*/
struct ref_entry *create_dir_entry(struct ref_cache *cache,
const char *dirname, size_t len,
int incomplete);
struct ref_entry *create_ref_entry(const char *refname,
const unsigned char *sha1, int flag,
int check_name);
/*
* Return a pointer to a new `ref_cache`. Its top-level starts out
* marked incomplete. If `fill_ref_dir` is non-NULL, it is the
* function called to fill in incomplete directories in the
* `ref_cache` when they are accessed. If it is NULL, then the whole
* `ref_cache` must be filled (including clearing its directories'
* `REF_INCOMPLETE` bits) before it is used.
*/
struct ref_cache *create_ref_cache(struct ref_store *refs,
fill_ref_dir_fn *fill_ref_dir);
/*
* Free the `ref_cache` and all of its associated data.
*/
void free_ref_cache(struct ref_cache *cache);
/*
* Add a ref_entry to the end of dir (unsorted). Entry is always
* stored directly in dir; no recursion into subdirectories is
* done.
*/
void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry);
/*
* Remove the entry with the given name from dir, recursing into
* subdirectories as necessary. If refname is the name of a directory
* (i.e., ends with '/'), then remove the directory and its contents.
* If the removal was successful, return the number of entries
* remaining in the directory entry that contained the deleted entry.
* If the name was not found, return -1. Please note that this
* function only deletes the entry from the cache; it does not delete
* it from the filesystem or ensure that other cache entries (which
* might be symbolic references to the removed entry) are updated.
* Nor does it remove any containing dir entries that might be made
* empty by the removal. dir must represent the top-level directory
* and must already be complete.
*/
int remove_entry_from_dir(struct ref_dir *dir, const char *refname);
/*
* Add a ref_entry to the ref_dir (unsorted), recursing into
* subdirectories as necessary. dir must represent the top-level
* directory. Return 0 on success.
*/
int add_ref_entry(struct ref_dir *dir, struct ref_entry *ref);
/*
* Find the value entry with the given name in dir, sorting ref_dirs
* and recursing into subdirectories as necessary. If the name is not
* found or it corresponds to a directory entry, return NULL.
*/
struct ref_entry *find_ref_entry(struct ref_dir *dir, const char *refname);
/*
* Start iterating over references in `cache`. If `prefix` is
* specified, only include references whose names start with that
* prefix. If `prime_dir` is true, then fill any incomplete
* directories before beginning the iteration.
*/
struct ref_iterator *cache_ref_iterator_begin(struct ref_cache *cache,
const char *prefix,
int prime_dir);
/*
* Peel the entry (if possible) and return its new peel_status. If
* repeel is true, re-peel the entry even if there is an old peeled
* value that is already stored in it.
*
* It is OK to call this function with a packed reference entry that
* might be stale and might even refer to an object that has since
* been garbage-collected. In such a case, if the entry has
* REF_KNOWS_PEELED then leave the status unchanged and return
* PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
*/
enum peel_status peel_entry(struct ref_entry *entry, int repeel);
#endif /* REFS_REF_CACHE_H */

22
refs/refs-internal.h
View File

@ -165,6 +165,10 @@ struct ref_update {
const char refname[FLEX_ARRAY];
};
int refs_read_raw_ref(struct ref_store *ref_store,
const char *refname, unsigned char *sha1,
struct strbuf *referent, unsigned int *type);
/*
* Add a ref_update with the specified properties to transaction, and
* return a pointer to the new object. This function does not verify
@ -331,6 +335,17 @@ struct ref_iterator *empty_ref_iterator_begin(void);
*/
int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
/*
* Return an iterator that goes over each reference in `refs` for
* which the refname begins with prefix. If trim is non-zero, then
* trim that many characters off the beginning of each refname. flags
* can be DO_FOR_EACH_INCLUDE_BROKEN to include broken references in
* the iteration.
*/
struct ref_iterator *refs_ref_iterator_begin(
struct ref_store *refs,
const char *prefix, int trim, int flags);
/*
* A callback function used to instruct merge_ref_iterator how to
* interleave the entries from iter0 and iter1. The function should
@ -575,12 +590,6 @@ typedef int read_raw_ref_fn(struct ref_store *ref_store,
const char *refname, unsigned char *sha1,
struct strbuf *referent, unsigned int *type);
typedef int verify_refname_available_fn(struct ref_store *ref_store,
const char *newname,
const struct string_list *extras,
const struct string_list *skip,
struct strbuf *err);
struct ref_storage_be {
struct ref_storage_be *next;
const char *name;
@ -597,7 +606,6 @@ struct ref_storage_be {
ref_iterator_begin_fn *iterator_begin;
read_raw_ref_fn *read_raw_ref;
verify_refname_available_fn *verify_refname_available;
reflog_iterator_begin_fn *reflog_iterator_begin;
for_each_reflog_ent_fn *for_each_reflog_ent;