Allow updating references if the old value matches the given one.
*/
GIT_EXTERN(int) git_reference_create(git_reference **out, git_repository *repo, const char *name, const git_oid *id, int force, const git_signature *signature, const char *log_message);
+/**
+ * Conditionally create new direct reference
+ *
+ * A direct reference (also called an object id reference) refers directly
+ * to a specific object id (a.k.a. OID or SHA) in the repository. The id
+ * permanently refers to the object (although the reference itself can be
+ * moved). For example, in libgit2 the direct ref "refs/tags/v0.17.0"
+ * refers to OID 5b9fac39d8a76b9139667c26a63e6b3f204b3977.
+ *
+ * The direct reference will be created in the repository and written to
+ * the disk. The generated reference object must be freed by the user.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ * and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything. You must avoid
+ * the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ * sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * This function will return an error if a reference already exists with the
+ * given name unless `force` is true, in which case it will be overwritten.
+ *
+ * The signature and message for the reflog will be ignored if the
+ * reference does not belong in the standard set (HEAD, branches and
+ * remote-tracking branches) and and it does not have a reflog.
+ *
+ * It will also return an error if the reference's value at the time
+ * of updating does not match the one passed.
+ *
+ * @param out Pointer to the newly created reference
+ * @param repo Repository where that reference will live
+ * @param name The name of the reference
+ * @param id The object id pointed to by the reference.
+ * @param force Overwrite existing references
+ * @param force Overwrite existing references
+ * @param signature The identity that will used to populate the reflog entry
+ * @param log_message The one line long message to be appended to the reflog
+ * @param old_id The old value which the reference should have
+ * @return 0 on success, GIT_EEXISTS, GIT_EINVALIDSPEC or an error code
+ */
+GIT_EXTERN(int) git_reference_create_if(git_reference **out, git_repository *repo, const char *name, const git_oid *id, int force, const git_signature *signature, const char *log_message, const git_oid *old_id);
+
/**
* Get the OID pointed to by a direct reference.
*
const char *log_message);
/**
- * Create a new reference with the same name as the given reference but a
+ * Conditionally create a new reference with the same name as the given reference but a
* different OID target. The reference must be a direct reference, otherwise
* this will fail.
*
* The new reference will be written to disk, overwriting the given reference.
*
- * The signature and message for the reflog will be ignored if the
- * reference does not belong in the standard set (HEAD, branches and
- * remote-tracking branches) and and it does not have a reflog.
- *
* @param out Pointer to the newly created reference
* @param ref The reference
* @param id The new target OID for the reference
*/
int (*write)(git_refdb_backend *backend,
const git_reference *ref, int force,
- const git_signature *who, const char *message);
+ const git_signature *who, const char *message,
+ const git_oid *old);
int (*rename)(
git_reference **out, git_refdb_backend *backend,
iter->free(iter);
}
-int git_refdb_write(git_refdb *db, git_reference *ref, int force, const git_signature *who, const char *message)
+int git_refdb_write(git_refdb *db, git_reference *ref, int force, const git_signature *who, const char *message, const git_oid *old)
{
assert(db && db->backend);
GIT_REFCOUNT_INC(db);
ref->db = db;
- return db->backend->write(db->backend, ref, force, who, message);
+ return db->backend->write(db->backend, ref, force, who, message, old);
}
int git_refdb_rename(
int git_refdb_iterator_next_name(const char **out, git_reference_iterator *iter);
void git_refdb_iterator_free(git_reference_iterator *iter);
-int git_refdb_write(git_refdb *refdb, git_reference *ref, int force, const git_signature *who, const char *message);
+int git_refdb_write(git_refdb *refdb, git_reference *ref, int force, const git_signature *who, const char *message, const git_oid *old);
int git_refdb_delete(git_refdb *refdb, const char *ref_name);
int git_refdb_reflog_read(git_reflog **out, git_refdb *db, const char *name);
static int loose_lock(git_filebuf *file, refdb_fs_backend *backend, const git_reference *ref)
{
+ int error;
git_buf ref_path = GIT_BUF_INIT;
+ assert(file && backend && ref);
+
/* Remove a possibly existing empty directory hierarchy
* which name would collide with the reference name
*/
if (git_buf_joinpath(&ref_path, backend->path, ref->name) < 0)
return -1;
- if (git_filebuf_open(file, ref_path.ptr, GIT_FILEBUF_FORCE, GIT_REFS_FILE_MODE) < 0) {
- git_buf_free(&ref_path);
- return -1;
- }
+ error = git_filebuf_open(file, ref_path.ptr, GIT_FILEBUF_FORCE, GIT_REFS_FILE_MODE);
git_buf_free(&ref_path);
- return 0;
+ return error;
}
static int loose_commit(git_filebuf *file, const git_reference *ref)
{
+ assert(file && ref);
+
if (ref->type == GIT_REF_OID) {
char oid[GIT_OID_HEXSZ + 1];
git_oid_nfmt(oid, sizeof(oid), &ref->target.oid);
const git_reference *ref,
int force,
const git_signature *who,
- const char *message)
+ const char *message,
+ const git_oid *old_id)
{
refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
git_filebuf file = GIT_FILEBUF_INIT;
+ git_reference *old_ref;
int error;
assert(backend);
if (error < 0)
return error;
- /* We need to perform the reflog append under the ref's lock */
+ /* We need to perform the reflog append and old value check under the ref's lock */
if ((error = loose_lock(&file, backend, ref)) < 0)
return error;
+ if (old_id) {
+ if ((error = refdb_fs_backend__lookup(&old_ref, _backend, ref->name)) < 0) {
+ git_filebuf_cleanup(&file);
+ return error;
+ }
+
+ if (old_ref->type == GIT_REF_SYMBOLIC) {
+ giterr_set(GITERR_REFERENCE, "cannot compare id to symbolic reference target");
+ goto on_error;
+ }
+
+ /* Finally we can compare the ids */
+ if (git_oid_cmp(old_id, &old_ref->target.oid)) {
+ giterr_set(GITERR_REFERENCE, "old reference value does not match");
+ goto on_error;
+ }
+ }
+
if (should_write_reflog(backend->repo, ref->name) &&
(error = reflog_append(backend, ref, who, message)) < 0) {
git_filebuf_cleanup(&file);
}
return loose_commit(&file, ref);
+
+on_error:
+ git_filebuf_cleanup(&file);
+ git_reference_free(old_ref);
+ return -1;
}
static int refdb_fs_backend__delete(
const char *symbolic,
int force,
const git_signature *signature,
- const char *log_message)
+ const char *log_message,
+ const git_oid *old_id)
{
char normalized[GIT_REFNAME_MAX];
git_refdb *refdb;
GITERR_CHECK_ALLOC(ref);
- if ((error = git_refdb_write(refdb, ref, force, signature, log_message)) < 0) {
+ if ((error = git_refdb_write(refdb, ref, force, signature, log_message, old_id)) < 0) {
git_reference_free(ref);
return error;
}
git_reference **ref_out,
git_repository *repo,
const char *name,
- const git_oid *oid,
+ const git_oid *id,
int force,
const git_signature *signature,
const char *log_message)
+{
+ return git_reference_create_if(ref_out, repo, name, id, force, signature, log_message, NULL);
+}
+
+int git_reference_create_if(
+ git_reference **ref_out,
+ git_repository *repo,
+ const char *name,
+ const git_oid *id,
+ int force,
+ const git_signature *signature,
+ const char *log_message,
+ const git_oid *old_id)
{
int error;
git_signature *who = NULL;
- assert(oid);
+ assert(id);
if (!signature) {
if ((error = log_signature(&who, repo)) < 0)
}
error = reference__create(
- ref_out, repo, name, oid, NULL, force, signature, log_message);
+ ref_out, repo, name, id, NULL, force, signature, log_message, old_id);
git_signature_free(who);
return error;
}
error = reference__create(
- ref_out, repo, name, NULL, target, force, signature, log_message);
+ ref_out, repo, name, NULL, target, force, signature, log_message, NULL);
git_signature_free(who);
return error;
return -1;
}
-int git_reference_set_target(
+int git_reference_set_target_if(
git_reference **out,
git_reference *ref,
const git_oid *id,
const git_signature *signature,
- const char *log_message)
+ const char *log_message,
+ const git_oid *old_id)
{
int error;
+ git_repository *repo;
assert(out && ref && id);
+ repo = ref->db->repo;
+
if ((error = ensure_is_an_updatable_direct_reference(ref)) < 0)
return error;
- return git_reference_create(
- out, ref->db->repo, ref->name, id, 1, signature, log_message);
+ return git_reference_create_if(out, repo, ref->name, id, 1, signature, log_message, old_id);
}
static int ensure_is_an_updatable_symbolic_reference(git_reference *ref)
return -1;
}
+int git_reference_set_target(
+ git_reference **out,
+ git_reference *ref,
+ const git_oid *id,
+ const git_signature *signature,
+ const char *log_message)
+{
+ return git_reference_set_target_if(out, ref, id, signature, log_message, NULL);
+}
+
int git_reference_symbolic_set_target(
git_reference **out,
git_reference *ref,
projects / libgit2.git / commitdiff