/*
* Copyright (C) 2009-2012 the libgit2 contributors
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "refs.h"
#include "hash.h"
#include "repository.h"
#include "fileops.h"
#include "pack.h"
#include "reflog.h"
#include <git2/tag.h>
#include <git2/object.h>
#include <git2/oid.h>
GIT__USE_STRMAP;
#define DEFAULT_NESTING_LEVEL 5
#define MAX_NESTING_LEVEL 10
enum {
GIT_PACKREF_HAS_PEEL = 1,
GIT_PACKREF_WAS_LOOSE = 2
};
struct packref {
git_oid oid;
git_oid peel;
char flags;
char name[GIT_FLEX_ARRAY];
};
static int reference_read(
git_buf *file_content,
time_t *mtime,
const char *repo_path,
const char *ref_name,
int *updated);
/* loose refs */
static int loose_parse_symbolic(git_reference *ref, git_buf *file_content);
static int loose_parse_oid(git_oid *ref, git_buf *file_content);
static int loose_lookup(git_reference *ref);
static int loose_lookup_to_packfile(struct packref **ref_out,
git_repository *repo, const char *name);
static int loose_write(git_reference *ref);
/* packed refs */
static int packed_parse_peel(struct packref *tag_ref,
const char **buffer_out, const char *buffer_end);
static int packed_parse_oid(struct packref **ref_out,
const char **buffer_out, const char *buffer_end);
static int packed_load(git_repository *repo);
static int packed_loadloose(git_repository *repository);
static int packed_write_ref(struct packref *ref, git_filebuf *file);
static int packed_find_peel(git_repository *repo, struct packref *ref);
static int packed_remove_loose(git_repository *repo, git_vector *packing_list);
static int packed_sort(const void *a, const void *b);
static int packed_lookup(git_reference *ref);
static int packed_write(git_repository *repo);
/* internal helpers */
static int reference_path_available(git_repository *repo,
const char *ref, const char *old_ref);
static int reference_delete(git_reference *ref);
static int reference_lookup(git_reference *ref);
void git_reference_free(git_reference *reference)
{
if (reference == NULL)
return;
git__free(reference->name);
reference->name = NULL;
if (reference->flags & GIT_REF_SYMBOLIC) {
git__free(reference->target.symbolic);
reference->target.symbolic = NULL;
}
git__free(reference);
}
static int reference_alloc(
git_reference **ref_out,
git_repository *repo,
const char *name)
{
git_reference *reference = NULL;
assert(ref_out && repo && name);
reference = git__malloc(sizeof(git_reference));
GITERR_CHECK_ALLOC(reference);
memset(reference, 0x0, sizeof(git_reference));
reference->owner = repo;
reference->name = git__strdup(name);
GITERR_CHECK_ALLOC(reference->name);
*ref_out = reference;
return 0;
}
static int reference_read(
git_buf *file_content,
time_t *mtime,
const char *repo_path,
const char *ref_name,
int *updated)
{
git_buf path = GIT_BUF_INIT;
int result;
assert(file_content && repo_path && ref_name);
/* Determine the full path of the file */
if (git_buf_joinpath(&path, repo_path, ref_name) < 0)
return -1;
result = git_futils_readbuffer_updated(file_content, path.ptr, mtime, updated);
git_buf_free(&path);
return result;
}
static int loose_parse_symbolic(git_reference *ref, git_buf *file_content)
{
const unsigned int header_len = (unsigned int)strlen(GIT_SYMREF);
const char *refname_start;
refname_start = (const char *)file_content->ptr;
if (git_buf_len(file_content) < header_len + 1) {
giterr_set(GITERR_REFERENCE, "Corrupted loose reference file");
return -1;
}
/*
* Assume we have already checked for the header
* before calling this function
*/
refname_start += header_len;
ref->target.symbolic = git__strdup(refname_start);
GITERR_CHECK_ALLOC(ref->target.symbolic);
return 0;
}
static int loose_parse_oid(git_oid *oid, git_buf *file_content)
{
/* File format: 40 chars (OID) */
if (git_buf_len(file_content) == GIT_OID_HEXSZ &&
git_oid_fromstr(oid, git_buf_cstr(file_content)) == 0)
return 0;
giterr_set(GITERR_REFERENCE, "Corrupted loose reference file");
return -1;
}
static git_ref_t loose_guess_rtype(const git_buf *full_path)
{
git_buf ref_file = GIT_BUF_INIT;
git_ref_t type;
type = GIT_REF_INVALID;
if (git_futils_readbuffer(&ref_file, full_path->ptr) == 0) {
if (git__prefixcmp((const char *)(ref_file.ptr), GIT_SYMREF) == 0)
type = GIT_REF_SYMBOLIC;
else
type = GIT_REF_OID;
}
git_buf_free(&ref_file);
return type;
}
static int loose_lookup(git_reference *ref)
{
int result, updated;
git_buf ref_file = GIT_BUF_INIT;
result = reference_read(&ref_file, &ref->mtime,
ref->owner->path_repository, ref->name, &updated);
if (result < 0)
return result;
if (!updated)
return 0;
git_buf_rtrim(&ref_file);
if (ref->flags & GIT_REF_SYMBOLIC) {
git__free(ref->target.symbolic);
ref->target.symbolic = NULL;
}
ref->flags = 0;
if (git__prefixcmp((const char *)(ref_file.ptr), GIT_SYMREF) == 0) {
ref->flags |= GIT_REF_SYMBOLIC;
result = loose_parse_symbolic(ref, &ref_file);
} else {
ref->flags |= GIT_REF_OID;
result = loose_parse_oid(&ref->target.oid, &ref_file);
}
git_buf_free(&ref_file);
return result;
}
static int loose_lookup_to_packfile(
struct packref **ref_out,
git_repository *repo,
const char *name)
{
git_buf ref_file = GIT_BUF_INIT;
struct packref *ref = NULL;
size_t name_len;
*ref_out = NULL;
if (reference_read(&ref_file, NULL, repo->path_repository, name, NULL) < 0)
return -1;
git_buf_rtrim(&ref_file);
name_len = strlen(name);
ref = git__malloc(sizeof(struct packref) + name_len + 1);
GITERR_CHECK_ALLOC(ref);
memcpy(ref->name, name, name_len);
ref->name[name_len] = 0;
if (loose_parse_oid(&ref->oid, &ref_file) < 0) {
git_buf_free(&ref_file);
git__free(ref);
return -1;
}
ref->flags = GIT_PACKREF_WAS_LOOSE;
*ref_out = ref;
git_buf_free(&ref_file);
return 0;
}
static int loose_write(git_reference *ref)
{
git_filebuf file = GIT_FILEBUF_INIT;
git_buf ref_path = GIT_BUF_INIT;
struct stat st;
if (git_buf_joinpath(&ref_path, ref->owner->path_repository, ref->name) < 0)
return -1;
/* Remove a possibly existing empty directory hierarchy
* which name would collide with the reference name
*/
if (git_path_isdir(git_buf_cstr(&ref_path)) &&
(git_futils_rmdir_r(git_buf_cstr(&ref_path), GIT_DIRREMOVAL_ONLY_EMPTY_DIRS) < 0)) {
git_buf_free(&ref_path);
return -1;
}
if (git_filebuf_open(&file, ref_path.ptr, GIT_FILEBUF_FORCE) < 0) {
git_buf_free(&ref_path);
return -1;
}
git_buf_free(&ref_path);
if (ref->flags & GIT_REF_OID) {
char oid[GIT_OID_HEXSZ + 1];
git_oid_fmt(oid, &ref->target.oid);
oid[GIT_OID_HEXSZ] = '\0';
git_filebuf_printf(&file, "%s\n", oid);
} else if (ref->flags & GIT_REF_SYMBOLIC) {
git_filebuf_printf(&file, GIT_SYMREF "%s\n", ref->target.symbolic);
} else {
assert(0); /* don't let this happen */
}
if (p_stat(ref_path.ptr, &st) == 0)
ref->mtime = st.st_mtime;
return git_filebuf_commit(&file, GIT_REFS_FILE_MODE);
}
static int packed_parse_peel(
struct packref *tag_ref,
const char **buffer_out,
const char *buffer_end)
{
const char *buffer = *buffer_out + 1;
assert(buffer[-1] == '^');
/* Ensure it's not the first entry of the file */
if (tag_ref == NULL)
goto corrupt;
/* Ensure reference is a tag */
if (git__prefixcmp(tag_ref->name, GIT_REFS_TAGS_DIR) != 0)
goto corrupt;
if (buffer + GIT_OID_HEXSZ >= buffer_end)
goto corrupt;
/* Is this a valid object id? */
if (git_oid_fromstr(&tag_ref->peel, buffer) < 0)
goto corrupt;
buffer = buffer + GIT_OID_HEXSZ;
if (*buffer == '\r')
buffer++;
if (*buffer != '\n')
goto corrupt;
*buffer_out = buffer + 1;
return 0;
corrupt:
giterr_set(GITERR_REFERENCE, "The packed references file is corrupted");
return -1;
}
static int packed_parse_oid(
struct packref **ref_out,
const char **buffer_out,
const char *buffer_end)
{
struct packref *ref = NULL;
const char *buffer = *buffer_out;
const char *refname_begin, *refname_end;
size_t refname_len;
git_oid id;
refname_begin = (buffer + GIT_OID_HEXSZ + 1);
if (refname_begin >= buffer_end || refname_begin[-1] != ' ')
goto corrupt;
/* Is this a valid object id? */
if (git_oid_fromstr(&id, buffer) < 0)
goto corrupt;
refname_end = memchr(refname_begin, '\n', buffer_end - refname_begin);
if (refname_end == NULL)
goto corrupt;
if (refname_end[-1] == '\r')
refname_end--;
refname_len = refname_end - refname_begin;
ref = git__malloc(sizeof(struct packref) + refname_len + 1);
GITERR_CHECK_ALLOC(ref);
memcpy(ref->name, refname_begin, refname_len);
ref->name[refname_len] = 0;
git_oid_cpy(&ref->oid, &id);
ref->flags = 0;
*ref_out = ref;
*buffer_out = refname_end + 1;
return 0;
corrupt:
git__free(ref);
giterr_set(GITERR_REFERENCE, "The packed references file is corrupted");
return -1;
}
static int packed_load(git_repository *repo)
{
int result, updated;
git_buf packfile = GIT_BUF_INIT;
const char *buffer_start, *buffer_end;
git_refcache *ref_cache = &repo->references;
/* First we make sure we have allocated the hash table */
if (ref_cache->packfile == NULL) {
ref_cache->packfile = git_strmap_alloc();
GITERR_CHECK_ALLOC(ref_cache->packfile);
}
result = reference_read(&packfile, &ref_cache->packfile_time,
repo->path_repository, GIT_PACKEDREFS_FILE, &updated);
/*
* If we couldn't find the file, we need to clear the table and
* return. On any other error, we return that error. If everything
* went fine and the file wasn't updated, then there's nothing new
* for us here, so just return. Anything else means we need to
* refresh the packed refs.
*/
if (result == GIT_ENOTFOUND) {
git_strmap_clear(ref_cache->packfile);
return 0;
}
if (result < 0)
return -1;
if (!updated)
return 0;
/*
* At this point, we want to refresh the packed refs. We already
* have the contents in our buffer.
*/
git_strmap_clear(ref_cache->packfile);
buffer_start = (const char *)packfile.ptr;
buffer_end = (const char *)(buffer_start) + packfile.size;
while (buffer_start < buffer_end && buffer_start[0] == '#') {
buffer_start = strchr(buffer_start, '\n');
if (buffer_start == NULL)
goto parse_failed;
buffer_start++;
}
while (buffer_start < buffer_end) {
int err;
struct packref *ref = NULL;
if (packed_parse_oid(&ref, &buffer_start, buffer_end) < 0)
goto parse_failed;
if (buffer_start[0] == '^') {
if (packed_parse_peel(ref, &buffer_start, buffer_end) < 0)
goto parse_failed;
}
git_strmap_insert(ref_cache->packfile, ref->name, ref, err);
if (err < 0)
goto parse_failed;
}
git_buf_free(&packfile);
return 0;
parse_failed:
git_strmap_free(ref_cache->packfile);
ref_cache->packfile = NULL;
git_buf_free(&packfile);
return -1;
}
struct dirent_list_data {
git_repository *repo;
size_t repo_path_len;
unsigned int list_flags;
int (*callback)(const char *, void *);
void *callback_payload;
int callback_error;
};
static int _dirent_loose_listall(void *_data, git_buf *full_path)
{
struct dirent_list_data *data = (struct dirent_list_data *)_data;
const char *file_path = full_path->ptr + data->repo_path_len;
if (git_path_isdir(full_path->ptr) == true)
return git_path_direach(full_path, _dirent_loose_listall, _data);
/* do not add twice a reference that exists already in the packfile */
if ((data->list_flags & GIT_REF_PACKED) != 0 &&
git_strmap_exists(data->repo->references.packfile, file_path))
return 0;
if (data->list_flags != GIT_REF_LISTALL) {
if ((data->list_flags & loose_guess_rtype(full_path)) == 0)
return 0; /* we are filtering out this reference */
}
if (data->callback(file_path, data->callback_payload))
data->callback_error = GIT_EUSER;
return data->callback_error;
}
static int _dirent_loose_load(void *data, git_buf *full_path)
{
git_repository *repository = (git_repository *)data;
void *old_ref = NULL;
struct packref *ref;
const char *file_path;
int err;
if (git_path_isdir(full_path->ptr) == true)
return git_path_direach(full_path, _dirent_loose_load, repository);
file_path = full_path->ptr + strlen(repository->path_repository);
if (loose_lookup_to_packfile(&ref, repository, file_path) < 0)
return -1;
git_strmap_insert2(
repository->references.packfile, ref->name, ref, old_ref, err);
if (err < 0) {
git__free(ref);
return -1;
}
git__free(old_ref);
return 0;
}
/*
* Load all the loose references from the repository
* into the in-memory Packfile, and build a vector with
* all the references so it can be written back to
* disk.
*/
static int packed_loadloose(git_repository *repository)
{
git_buf refs_path = GIT_BUF_INIT;
int result;
/* the packfile must have been previously loaded! */
assert(repository->references.packfile);
if (git_buf_joinpath(&refs_path, repository->path_repository, GIT_REFS_DIR) < 0)
return -1;
/*
* Load all the loose files from disk into the Packfile table.
* This will overwrite any old packed entries with their
* updated loose versions
*/
result = git_path_direach(&refs_path, _dirent_loose_load, repository);
git_buf_free(&refs_path);
return result;
}
/*
* Write a single reference into a packfile
*/
static int packed_write_ref(struct packref *ref, git_filebuf *file)
{
char oid[GIT_OID_HEXSZ + 1];
git_oid_fmt(oid, &ref->oid);
oid[GIT_OID_HEXSZ] = 0;
/*
* For references that peel to an object in the repo, we must
* write the resulting peel on a separate line, e.g.
*
* 6fa8a902cc1d18527e1355773c86721945475d37 refs/tags/libgit2-0.4
* ^2ec0cb7959b0bf965d54f95453f5b4b34e8d3100
*
* This obviously only applies to tags.
* The required peels have already been loaded into `ref->peel_target`.
*/
if (ref->flags & GIT_PACKREF_HAS_PEEL) {
char peel[GIT_OID_HEXSZ + 1];
git_oid_fmt(peel, &ref->peel);
peel[GIT_OID_HEXSZ] = 0;
if (git_filebuf_printf(file, "%s %s\n^%s\n", oid, ref->name, peel) < 0)
return -1;
} else {
if (git_filebuf_printf(file, "%s %s\n", oid, ref->name) < 0)
return -1;
}
return 0;
}
/*
* Find out what object this reference resolves to.
*
* For references that point to a 'big' tag (e.g. an
* actual tag object on the repository), we need to
* cache on the packfile the OID of the object to
* which that 'big tag' is pointing to.
*/
static int packed_find_peel(git_repository *repo, struct packref *ref)
{
git_object *object;
if (ref->flags & GIT_PACKREF_HAS_PEEL)
return 0;
/*
* Only applies to tags, i.e. references
* in the /refs/tags folder
*/
if (git__prefixcmp(ref->name, GIT_REFS_TAGS_DIR) != 0)
return 0;
/*
* Find the tagged object in the repository
*/
if (git_object_lookup(&object, repo, &ref->oid, GIT_OBJ_ANY) < 0)
return -1;
/*
* If the tagged object is a Tag object, we need to resolve it;
* if the ref is actually a 'weak' ref, we don't need to resolve
* anything.
*/
if (git_object_type(object) == GIT_OBJ_TAG) {
git_tag *tag = (git_tag *)object;
/*
* Find the object pointed at by this tag
*/
git_oid_cpy(&ref->peel, git_tag_target_oid(tag));
ref->flags |= GIT_PACKREF_HAS_PEEL;
/*
* The reference has now cached the resolved OID, and is
* marked at such. When written to the packfile, it'll be
* accompanied by this resolved oid
*/
}
git_object_free(object);
return 0;
}
/*
* Remove all loose references
*
* Once we have successfully written a packfile,
* all the loose references that were packed must be
* removed from disk.
*
* This is a dangerous method; make sure the packfile
* is well-written, because we are destructing references
* here otherwise.
*/
static int packed_remove_loose(git_repository *repo, git_vector *packing_list)
{
unsigned int i;
git_buf full_path = GIT_BUF_INIT;
int failed = 0;
for (i = 0; i < packing_list->length; ++i) {
struct packref *ref = git_vector_get(packing_list, i);
if ((ref->flags & GIT_PACKREF_WAS_LOOSE) == 0)
continue;
if (git_buf_joinpath(&full_path, repo->path_repository, ref->name) < 0)
return -1; /* critical; do not try to recover on oom */
if (git_path_exists(full_path.ptr) == true && p_unlink(full_path.ptr) < 0) {
if (failed)
continue;
giterr_set(GITERR_REFERENCE,
"Failed to remove loose reference '%s' after packing: %s",
full_path.ptr, strerror(errno));
failed = 1;
}
/*
* if we fail to remove a single file, this is *not* good,
* but we should keep going and remove as many as possible.
* After we've removed as many files as possible, we return
* the error code anyway.
*/
}
git_buf_free(&full_path);
return failed ? -1 : 0;
}
static int packed_sort(const void *a, const void *b)
{
const struct packref *ref_a = (const struct packref *)a;
const struct packref *ref_b = (const struct packref *)b;
return strcmp(ref_a->name, ref_b->name);
}
/*
* Write all the contents in the in-memory packfile to disk.
*/
static int packed_write(git_repository *repo)
{
git_filebuf pack_file = GIT_FILEBUF_INIT;
unsigned int i;
git_buf pack_file_path = GIT_BUF_INIT;
git_vector packing_list;
unsigned int total_refs;
assert(repo && repo->references.packfile);
total_refs =
(unsigned int)git_strmap_num_entries(repo->references.packfile);
if (git_vector_init(&packing_list, total_refs, packed_sort) < 0)
return -1;
/* Load all the packfile into a vector */
{
struct packref *reference;
/* cannot fail: vector already has the right size */
git_strmap_foreach_value(repo->references.packfile, reference, {
git_vector_insert(&packing_list, reference);
});
}
/* sort the vector so the entries appear sorted on the packfile */
git_vector_sort(&packing_list);
/* Now we can open the file! */
if (git_buf_joinpath(&pack_file_path, repo->path_repository, GIT_PACKEDREFS_FILE) < 0)
goto cleanup_memory;
if (git_filebuf_open(&pack_file, pack_file_path.ptr, 0) < 0)
goto cleanup_packfile;
/* Packfiles have a header... apparently
* This is in fact not required, but we might as well print it
* just for kicks */
if (git_filebuf_printf(&pack_file, "%s\n", GIT_PACKEDREFS_HEADER) < 0)
goto cleanup_packfile;
for (i = 0; i < packing_list.length; ++i) {
struct packref *ref = (struct packref *)git_vector_get(&packing_list, i);
if (packed_find_peel(repo, ref) < 0)
goto cleanup_packfile;
if (packed_write_ref(ref, &pack_file) < 0)
goto cleanup_packfile;
}
/* if we've written all the references properly, we can commit
* the packfile to make the changes effective */
if (git_filebuf_commit(&pack_file, GIT_PACKEDREFS_FILE_MODE) < 0)
goto cleanup_memory;
/* when and only when the packfile has been properly written,
* we can go ahead and remove the loose refs */
if (packed_remove_loose(repo, &packing_list) < 0)
goto cleanup_memory;
{
struct stat st;
if (p_stat(pack_file_path.ptr, &st) == 0)
repo->references.packfile_time = st.st_mtime;
}
git_vector_free(&packing_list);
git_buf_free(&pack_file_path);
/* we're good now */
return 0;
cleanup_packfile:
git_filebuf_cleanup(&pack_file);
cleanup_memory:
git_vector_free(&packing_list);
git_buf_free(&pack_file_path);
return -1;
}
struct reference_available_t {
const char *new_ref;
const char *old_ref;
int available;
};
static int _reference_available_cb(const char *ref, void *data)
{
struct reference_available_t *d;
assert(ref && data);
d = (struct reference_available_t *)data;
if (!d->old_ref || strcmp(d->old_ref, ref)) {
size_t reflen = strlen(ref);
size_t newlen = strlen(d->new_ref);
size_t cmplen = reflen < newlen ? reflen : newlen;
const char *lead = reflen < newlen ? d->new_ref : ref;
if (!strncmp(d->new_ref, ref, cmplen) && lead[cmplen] == '/') {
d->available = 0;
return -1;
}
}
return 0;
}
static int reference_path_available(
git_repository *repo,
const char *ref,
const char* old_ref)
{
int error;
struct reference_available_t data;
data.new_ref = ref;
data.old_ref = old_ref;
data.available = 1;
error = git_reference_foreach(
repo, GIT_REF_LISTALL, _reference_available_cb, (void *)&data);
if (error < 0)
return error;
if (!data.available) {
giterr_set(GITERR_REFERENCE,
"The path to reference '%s' collides with an existing one", ref);
return -1;
}
return 0;
}
static int reference_exists(int *exists, git_repository *repo, const char *ref_name)
{
git_buf ref_path = GIT_BUF_INIT;
if (packed_load(repo) < 0)
return -1;
if (git_buf_joinpath(&ref_path, repo->path_repository, ref_name) < 0)
return -1;
if (git_path_isfile(ref_path.ptr) == true ||
git_strmap_exists(repo->references.packfile, ref_path.ptr))
{
*exists = 1;
} else {
*exists = 0;
}
git_buf_free(&ref_path);
return 0;
}
/*
* Check if a reference could be written to disk, based on:
*
* - Whether a reference with the same name already exists,
* and we are allowing or disallowing overwrites
*
* - Whether the name of the reference would collide with
* an existing path
*/
static int reference_can_write(
git_repository *repo,
const char *refname,
const char *previous_name,
int force)
{
/* see if the reference shares a path with an existing reference;
* if a path is shared, we cannot create the reference, even when forcing */
if (reference_path_available(repo, refname, previous_name) < 0)
return -1;
/* check if the reference actually exists, but only if we are not forcing
* the rename. If we are forcing, it's OK to overwrite */
if (!force) {
int exists;
if (reference_exists(&exists, repo, refname) < 0)
return -1;
/* We cannot proceed if the reference already exists and we're not forcing
* the rename; the existing one would be overwritten */
if (exists) {
giterr_set(GITERR_REFERENCE,
"A reference with that name (%s) already exists", refname);
return GIT_EEXISTS;
}
}
/* FIXME: if the reference exists and we are forcing, do we really need to
* remove the reference first?
*
* Two cases:
*
* - the reference already exists and is loose: not a problem, the file
* gets overwritten on disk
*
* - the reference already exists and is packed: we write a new one as
* loose, which by all means renders the packed one useless
*/
return 0;
}
static int packed_lookup(git_reference *ref)
{
struct packref *pack_ref = NULL;
git_strmap *packfile_refs;
khiter_t pos;
if (packed_load(ref->owner) < 0)
return -1;
/* maybe the packfile hasn't changed at all, so we don't
* have to re-lookup the reference */
if ((ref->flags & GIT_REF_PACKED) &&
ref->mtime == ref->owner->references.packfile_time)
return 0;
if (ref->flags & GIT_REF_SYMBOLIC) {
git__free(ref->target.symbolic);
ref->target.symbolic = NULL;
}
/* Look up on the packfile */
packfile_refs = ref->owner->references.packfile;
pos = git_strmap_lookup_index(packfile_refs, ref->name);
if (!git_strmap_valid_index(packfile_refs, pos)) {
giterr_set(GITERR_REFERENCE, "Reference '%s' not found", ref->name);
return GIT_ENOTFOUND;
}
pack_ref = git_strmap_value_at(packfile_refs, pos);
ref->flags = GIT_REF_OID | GIT_REF_PACKED;
ref->mtime = ref->owner->references.packfile_time;
git_oid_cpy(&ref->target.oid, &pack_ref->oid);
return 0;
}
static int reference_lookup(git_reference *ref)
{
int result;
result = loose_lookup(ref);
if (result == 0)
return 0;
/* only try to lookup this reference on the packfile if it
* wasn't found on the loose refs; not if there was a critical error */
if (result == GIT_ENOTFOUND) {
giterr_clear();
result = packed_lookup(ref);
if (result == 0)
return 0;
}
/* unexpected error; free the reference */
git_reference_free(ref);
return result;
}
/*
* Delete a reference.
* This is an internal method; the reference is removed
* from disk or the packfile, but the pointer is not freed
*/
static int reference_delete(git_reference *ref)
{
int result;
assert(ref);
/* If the reference is packed, this is an expensive operation.
* We need to reload the packfile, remove the reference from the
* packing list, and repack */
if (ref->flags & GIT_REF_PACKED) {
git_strmap *packfile_refs;
struct packref *packref;
khiter_t pos;
/* load the existing packfile */
if (packed_load(ref->owner) < 0)
return -1;
packfile_refs = ref->owner->references.packfile;
pos = git_strmap_lookup_index(packfile_refs, ref->name);
if (!git_strmap_valid_index(packfile_refs, pos)) {
giterr_set(GITERR_REFERENCE,
"Reference %s stopped existing in the packfile", ref->name);
return -1;
}
packref = git_strmap_value_at(packfile_refs, pos);
git_strmap_delete_at(packfile_refs, pos);
git__free(packref);
if (packed_write(ref->owner) < 0)
return -1;
/* If the reference is loose, we can just remove the reference
* from the filesystem */
} else {
git_reference *ref_in_pack;
git_buf full_path = GIT_BUF_INIT;
if (git_buf_joinpath(&full_path, ref->owner->path_repository, ref->name) < 0)
return -1;
result = p_unlink(full_path.ptr);
git_buf_free(&full_path); /* done with path at this point */
if (result < 0) {
giterr_set(GITERR_OS, "Failed to unlink '%s'", full_path.ptr);
return -1;
}
/* When deleting a loose reference, we have to ensure that an older
* packed version of it doesn't exist */
if (git_reference_lookup(&ref_in_pack, ref->owner, ref->name) == 0) {
assert((ref_in_pack->flags & GIT_REF_PACKED) != 0);
return git_reference_delete(ref_in_pack);
}
giterr_clear();
}
return 0;
}
int git_reference_delete(git_reference *ref)
{
int result = reference_delete(ref);
git_reference_free(ref);
return result;
}
int git_reference_lookup(git_reference **ref_out,
git_repository *repo, const char *name)
{
return git_reference_lookup_resolved(ref_out, repo, name, 0);
}
int git_reference_name_to_oid(
git_oid *out, git_repository *repo, const char *name)
{
int error;
git_reference *ref;
if ((error = git_reference_lookup_resolved(&ref, repo, name, -1)) < 0)
return error;
git_oid_cpy(out, git_reference_oid(ref));
git_reference_free(ref);
return 0;
}
int git_reference_lookup_resolved(
git_reference **ref_out,
git_repository *repo,
const char *name,
int max_nesting)
{
git_reference *scan;
int result, nesting;
assert(ref_out && repo && name);
*ref_out = NULL;
if (max_nesting > MAX_NESTING_LEVEL)
max_nesting = MAX_NESTING_LEVEL;
else if (max_nesting < 0)
max_nesting = DEFAULT_NESTING_LEVEL;
scan = git__calloc(1, sizeof(git_reference));
GITERR_CHECK_ALLOC(scan);
scan->name = git__calloc(GIT_REFNAME_MAX + 1, sizeof(char));
GITERR_CHECK_ALLOC(scan->name);
if ((result = git_reference__normalize_name(
scan->name,
GIT_REFNAME_MAX,
name)) < 0) {
git_reference_free(scan);
return result;
}
scan->target.symbolic = git__strdup(scan->name);
GITERR_CHECK_ALLOC(scan->target.symbolic);
scan->owner = repo;
scan->flags = GIT_REF_SYMBOLIC;
for (nesting = max_nesting;
nesting >= 0 && (scan->flags & GIT_REF_SYMBOLIC) != 0;
nesting--)
{
if (nesting != max_nesting)
strncpy(scan->name, scan->target.symbolic, GIT_REFNAME_MAX);
scan->mtime = 0;
if ((result = reference_lookup(scan)) < 0)
return result; /* lookup git_reference_free on scan already */
}
if ((scan->flags & GIT_REF_OID) == 0 && max_nesting != 0) {
giterr_set(GITERR_REFERENCE,
"Cannot resolve reference (>%u levels deep)", max_nesting);
git_reference_free(scan);
return -1;
}
*ref_out = scan;
return 0;
}
/**
* Getters
*/
git_ref_t git_reference_type(git_reference *ref)
{
assert(ref);
if (ref->flags & GIT_REF_OID)
return GIT_REF_OID;
if (ref->flags & GIT_REF_SYMBOLIC)
return GIT_REF_SYMBOLIC;
return GIT_REF_INVALID;
}
int git_reference_is_packed(git_reference *ref)
{
assert(ref);
return !!(ref->flags & GIT_REF_PACKED);
}
const char *git_reference_name(git_reference *ref)
{
assert(ref);
return ref->name;
}
git_repository *git_reference_owner(git_reference *ref)
{
assert(ref);
return ref->owner;
}
const git_oid *git_reference_oid(git_reference *ref)
{
assert(ref);
if ((ref->flags & GIT_REF_OID) == 0)
return NULL;
return &ref->target.oid;
}
const char *git_reference_target(git_reference *ref)
{
assert(ref);
if ((ref->flags & GIT_REF_SYMBOLIC) == 0)
return NULL;
return ref->target.symbolic;
}
int git_reference_create_symbolic(
git_reference **ref_out,
git_repository *repo,
const char *name,
const char *target,
int force)
{
char normalized[GIT_REFNAME_MAX];
git_reference *ref = NULL;
if (git_reference__normalize_name(
normalized,
sizeof(normalized),
name) < 0)
return -1;
if (reference_can_write(repo, normalized, NULL, force) < 0)
return -1;
if (reference_alloc(&ref, repo, normalized) < 0)
return -1;
ref->flags |= GIT_REF_SYMBOLIC;
/* set the target; this will normalize the name automatically
* and write the reference on disk */
if (git_reference_set_target(ref, target) < 0) {
git_reference_free(ref);
return -1;
}
if (ref_out == NULL) {
git_reference_free(ref);
} else {
*ref_out = ref;
}
return 0;
}
int git_reference_create_oid(
git_reference **ref_out,
git_repository *repo,
const char *name,
const git_oid *id,
int force)
{
git_reference *ref = NULL;
char normalized[GIT_REFNAME_MAX];
if (git_reference__normalize_name_oid(
normalized,
sizeof(normalized),
name) < 0)
return -1;
if (reference_can_write(repo, normalized, NULL, force) < 0)
return -1;
if (reference_alloc(&ref, repo, name) < 0)
return -1;
ref->flags |= GIT_REF_OID;
/* set the oid; this will write the reference on disk */
if (git_reference_set_oid(ref, id) < 0) {
git_reference_free(ref);
return -1;
}
if (ref_out == NULL) {
git_reference_free(ref);
} else {
*ref_out = ref;
}
return 0;
}
/*
* Change the OID target of a reference.
*
* For both loose and packed references, just change
* the oid in memory and (over)write the file in disk.
*
* We do not repack packed references because of performance
* reasons.
*/
int git_reference_set_oid(git_reference *ref, const git_oid *id)
{
git_odb *odb = NULL;
if ((ref->flags & GIT_REF_OID) == 0) {
giterr_set(GITERR_REFERENCE, "Cannot set OID on symbolic reference");
return -1;
}
assert(ref->owner);
if (git_repository_odb__weakptr(&odb, ref->owner) < 0)
return -1;
/* Don't let the user create references to OIDs that
* don't exist in the ODB */
if (!git_odb_exists(odb, id)) {
giterr_set(GITERR_REFERENCE,
"Target OID for the reference doesn't exist on the repository");
return -1;
}
/* Update the OID value on `ref` */
git_oid_cpy(&ref->target.oid, id);
/* Write back to disk */
return loose_write(ref);
}
/*
* Change the target of a symbolic reference.
*
* This is easy because symrefs cannot be inside
* a pack. We just change the target in memory
* and overwrite the file on disk.
*/
int git_reference_set_target(git_reference *ref, const char *target)
{
char normalized[GIT_REFNAME_MAX];
if ((ref->flags & GIT_REF_SYMBOLIC) == 0) {
giterr_set(GITERR_REFERENCE,
"Cannot set symbolic target on a direct reference");
return -1;
}
if (git_reference__normalize_name(
normalized,
sizeof(normalized),
target))
return -1;
git__free(ref->target.symbolic);
ref->target.symbolic = git__strdup(normalized);
GITERR_CHECK_ALLOC(ref->target.symbolic);
return loose_write(ref);
}
int git_reference_rename(git_reference *ref, const char *new_name, int force)
{
int result;
unsigned int normalization_flags;
git_buf aux_path = GIT_BUF_INIT;
char normalized[GIT_REFNAME_MAX];
const char *head_target = NULL;
git_reference *head = NULL;
normalization_flags = ref->flags & GIT_REF_SYMBOLIC ?
GIT_REF_FORMAT_ALLOW_ONELEVEL
: GIT_REF_FORMAT_NORMAL;
if (git_reference_normalize_name(
normalized,
sizeof(normalized),
new_name,
normalization_flags) < 0)
return -1;
if (reference_can_write(ref->owner, normalized, ref->name, force) < 0)
return -1;
/* Initialize path now so we won't get an allocation failure once
* we actually start removing things. */
if (git_buf_joinpath(&aux_path, ref->owner->path_repository, new_name) < 0)
return -1;
/*
* Now delete the old ref and remove an possibly existing directory
* named `new_name`. Note that using the internal `reference_delete`
* method deletes the ref from disk but doesn't free the pointer, so
* we can still access the ref's attributes for creating the new one
*/
if (reference_delete(ref) < 0)
goto cleanup;
/*
* Finally we can create the new reference.
*/
if (ref->flags & GIT_REF_SYMBOLIC) {
result = git_reference_create_symbolic(
NULL, ref->owner, new_name, ref->target.symbolic, force);
} else {
result = git_reference_create_oid(
NULL, ref->owner, new_name, &ref->target.oid, force);
}
if (result < 0)
goto rollback;
/*
* Check if we have to update HEAD.
*/
if (git_reference_lookup(&head, ref->owner, GIT_HEAD_FILE) < 0) {
giterr_set(GITERR_REFERENCE,
"Failed to update HEAD after renaming reference");
goto cleanup;
}
head_target = git_reference_target(head);
if (head_target && !strcmp(head_target, ref->name)) {
git_reference_free(head);
head = NULL;
if (git_reference_create_symbolic(&head, ref->owner, "HEAD", new_name, 1) < 0) {
giterr_set(GITERR_REFERENCE,
"Failed to update HEAD after renaming reference");
goto cleanup;
}
}
/*
* Rename the reflog file, if it exists.
*/
if ((git_reference_has_log(ref)) && (git_reflog_rename(ref, new_name) < 0))
goto cleanup;
/*
* Change the name of the reference given by the user.
*/
git__free(ref->name);
ref->name = git__strdup(new_name);
/* The reference is no longer packed */
ref->flags &= ~GIT_REF_PACKED;
git_reference_free(head);
git_buf_free(&aux_path);
return 0;
cleanup:
git_reference_free(head);
git_buf_free(&aux_path);
return -1;
rollback:
/*
* Try to create the old reference again, ignore failures
*/
if (ref->flags & GIT_REF_SYMBOLIC)
git_reference_create_symbolic(
NULL, ref->owner, ref->name, ref->target.symbolic, 0);
else
git_reference_create_oid(
NULL, ref->owner, ref->name, &ref->target.oid, 0);
/* The reference is no longer packed */
ref->flags &= ~GIT_REF_PACKED;
git_buf_free(&aux_path);
return -1;
}
int git_reference_resolve(git_reference **ref_out, git_reference *ref)
{
if (ref->flags & GIT_REF_OID)
return git_reference_lookup(ref_out, ref->owner, ref->name);
else
return git_reference_lookup_resolved(ref_out, ref->owner, ref->target.symbolic, -1);
}
int git_reference_packall(git_repository *repo)
{
if (packed_load(repo) < 0 || /* load the existing packfile */
packed_loadloose(repo) < 0 || /* add all the loose refs */
packed_write(repo) < 0) /* write back to disk */
return -1;
return 0;
}
int git_reference_foreach(
git_repository *repo,
unsigned int list_flags,
int (*callback)(const char *, void *),
void *payload)
{
int result;
struct dirent_list_data data;
git_buf refs_path = GIT_BUF_INIT;
/* list all the packed references first */
if (list_flags & GIT_REF_PACKED) {
const char *ref_name;
void *ref;
GIT_UNUSED(ref);
if (packed_load(repo) < 0)
return -1;
git_strmap_foreach(repo->references.packfile, ref_name, ref, {
if (callback(ref_name, payload))
return GIT_EUSER;
});
}
/* now list the loose references, trying not to
* duplicate the ref names already in the packed-refs file */
data.repo_path_len = strlen(repo->path_repository);
data.list_flags = list_flags;
data.repo = repo;
data.callback = callback;
data.callback_payload = payload;
data.callback_error = 0;
if (git_buf_joinpath(&refs_path, repo->path_repository, GIT_REFS_DIR) < 0)
return -1;
result = git_path_direach(&refs_path, _dirent_loose_listall, &data);
git_buf_free(&refs_path);
return data.callback_error ? GIT_EUSER : result;
}
static int cb__reflist_add(const char *ref, void *data)
{
return git_vector_insert((git_vector *)data, git__strdup(ref));
}
int git_reference_list(
git_strarray *array,
git_repository *repo,
unsigned int list_flags)
{
git_vector ref_list;
assert(array && repo);
array->strings = NULL;
array->count = 0;
if (git_vector_init(&ref_list, 8, NULL) < 0)
return -1;
if (git_reference_foreach(
repo, list_flags, &cb__reflist_add, (void *)&ref_list) < 0) {
git_vector_free(&ref_list);
return -1;
}
array->strings = (char **)ref_list.contents;
array->count = ref_list.length;
return 0;
}
int git_reference_reload(git_reference *ref)
{
return reference_lookup(ref);
}
void git_repository__refcache_free(git_refcache *refs)
{
assert(refs);
if (refs->packfile) {
struct packref *reference;
git_strmap_foreach_value(refs->packfile, reference, {
git__free(reference);
});
git_strmap_free(refs->packfile);
}
}
static int is_valid_ref_char(char ch)
{
if ((unsigned) ch <= ' ')
return 0;
switch (ch) {
case '~':
case '^':
case ':':
case '\\':
case '?':
case '[':
case '*':
return 0;
default:
return 1;
}
}
int git_reference_normalize_name(
char *buffer_out,
size_t buffer_size,
const char *name,
unsigned int flags)
{
const char *name_end, *buffer_out_start;
const char *current;
int contains_a_slash = 0;
assert(name && buffer_out);
if (flags & GIT_REF_FORMAT_REFSPEC_PATTERN) {
giterr_set(GITERR_INVALID, "Unimplemented");
return -1;
}
buffer_out_start = buffer_out;
current = name;
name_end = name + strlen(name);
/* Terminating null byte */
buffer_size--;
/* A refname can not be empty */
if (name_end == name)
goto invalid_name;
/* A refname can not end with a dot or a slash */
if (*(name_end - 1) == '.' || *(name_end - 1) == '/')
goto invalid_name;
while (current < name_end && buffer_size > 0) {
if (!is_valid_ref_char(*current))
goto invalid_name;
if (buffer_out > buffer_out_start) {
char prev = *(buffer_out - 1);
/* A refname can not start with a dot nor contain a double dot */
if (*current == '.' && ((prev == '.') || (prev == '/')))
goto invalid_name;
/* '@{' is forbidden within a refname */
if (*current == '{' && prev == '@')
goto invalid_name;
/* Prevent multiple slashes from being added to the output */
if (*current == '/' && prev == '/') {
current++;
continue;
}
}
if (*current == '/') {
if (buffer_out > buffer_out_start)
contains_a_slash = 1;
else {
current++;
continue;
}
}
*buffer_out++ = *current++;
buffer_size--;
}
if (current < name_end) {
giterr_set(
GITERR_REFERENCE,
"The provided buffer is too short to hold the normalization of '%s'", name);
return GIT_EBUFS;
}
/* Object id refname have to contain at least one slash, except
* for HEAD in a detached state or MERGE_HEAD if we're in the
* middle of a merge */
if (!(flags & GIT_REF_FORMAT_ALLOW_ONELEVEL) &&
!contains_a_slash &&
strcmp(name, GIT_HEAD_FILE) != 0 &&
strcmp(name, GIT_MERGE_HEAD_FILE) != 0 &&
strcmp(name, GIT_FETCH_HEAD_FILE) != 0)
goto invalid_name;
/* A refname can not end with ".lock" */
if (!git__suffixcmp(name, GIT_FILELOCK_EXTENSION))
goto invalid_name;
*buffer_out = '\0';
return 0;
invalid_name:
giterr_set(
GITERR_REFERENCE,
"The given reference name '%s' is not valid", name);
return -1;
}
int git_reference__normalize_name(
char *buffer_out,
size_t out_size,
const char *name)
{
return git_reference_normalize_name(
buffer_out,
out_size,
name,
GIT_REF_FORMAT_ALLOW_ONELEVEL);
}
int git_reference__normalize_name_oid(
char *buffer_out,
size_t out_size,
const char *name)
{
return git_reference_normalize_name(
buffer_out,
out_size,
name,
GIT_REF_FORMAT_NORMAL);
}
#define GIT_REF_TYPEMASK (GIT_REF_OID | GIT_REF_SYMBOLIC)
int git_reference_cmp(git_reference *ref1, git_reference *ref2)
{
assert(ref1 && ref2);
/* let's put symbolic refs before OIDs */
if ((ref1->flags & GIT_REF_TYPEMASK) != (ref2->flags & GIT_REF_TYPEMASK))
return (ref1->flags & GIT_REF_SYMBOLIC) ? -1 : 1;
if (ref1->flags & GIT_REF_SYMBOLIC)
return strcmp(ref1->target.symbolic, ref2->target.symbolic);
return git_oid_cmp(&ref1->target.oid, &ref2->target.oid);
}
/* Update the reference named `ref_name` so it points to `oid` */
int git_reference__update(git_repository *repo, const git_oid *oid, const char *ref_name)
{
git_reference *ref;
int res;
res = git_reference_lookup(&ref, repo, ref_name);
/* If we haven't found the reference at all, we assume we need to create
* a new reference and that's it */
if (res == GIT_ENOTFOUND) {
giterr_clear();
return git_reference_create_oid(NULL, repo, ref_name, oid, 1);
}
if (res < 0)
return -1;
/* If we have found a reference, but it's symbolic, we need to update
* the direct reference it points to */
if (git_reference_type(ref) == GIT_REF_SYMBOLIC) {
git_reference *aux;
const char *sym_target;
/* The target pointed at by this reference */
sym_target = git_reference_target(ref);
/* resolve the reference to the target it points to */
res = git_reference_resolve(&aux, ref);
/*
* if the symbolic reference pointed to an inexisting ref,
* this is means we're creating a new branch, for example.
* We need to create a new direct reference with that name
*/
if (res == GIT_ENOTFOUND) {
giterr_clear();
res = git_reference_create_oid(NULL, repo, sym_target, oid, 1);
git_reference_free(ref);
return res;
}
/* free the original symbolic reference now; not before because
* we're using the `sym_target` pointer */
git_reference_free(ref);
if (res < 0)
return -1;
/* store the newly found direct reference in its place */
ref = aux;
}
/* ref is made to point to `oid`: ref is either the original reference,
* or the target of the symbolic reference we've looked up */
res = git_reference_set_oid(ref, oid);
git_reference_free(ref);
return res;
}
struct glob_cb_data {
const char *glob;
int (*callback)(const char *, void *);
void *payload;
};
static int fromglob_cb(const char *reference_name, void *payload)
{
struct glob_cb_data *data = (struct glob_cb_data *)payload;
if (!p_fnmatch(data->glob, reference_name, 0))
return data->callback(reference_name, data->payload);
return 0;
}
int git_reference_foreach_glob(
git_repository *repo,
const char *glob,
unsigned int list_flags,
int (*callback)(
const char *reference_name,
void *payload),
void *payload)
{
struct glob_cb_data data;
assert(repo && glob && callback);
data.glob = glob;
data.callback = callback;
data.payload = payload;
return git_reference_foreach(
repo, list_flags, fromglob_cb, &data);
}
int git_reference_has_log(
git_reference *ref)
{
git_buf path = GIT_BUF_INIT;
int result;
assert(ref);
if (git_buf_join_n(&path, '/', 3, ref->owner->path_repository, GIT_REFLOG_DIR, ref->name) < 0)
return -1;
result = git_path_isfile(git_buf_cstr(&path));
git_buf_free(&path);
return result;
}
int git_reference_is_branch(git_reference *ref)
{
assert(ref);
return git__prefixcmp(ref->name, GIT_REFS_HEADS_DIR) == 0;
}
int git_reference_is_remote(git_reference *ref)
{
assert(ref);
return git__prefixcmp(ref->name, GIT_REFS_REMOTES_DIR) == 0;
}
