#include "../cache.h"
+#include "../config.h"
#include "../refs.h"
#include "refs-internal.h"
#include "ref-cache.h"
if (refs->cache) {
struct packed_ref_cache *cache = refs->cache;
- if (is_lock_file_locked(&refs->lock))
- die("BUG: packed-ref cache cleared while locked");
refs->cache = NULL;
release_packed_ref_cache(cache);
}
const char *refname;
const char *traits;
+ if (!line.len || line.buf[line.len - 1] != '\n')
+ die("unterminated line in %s: %s", packed_refs_file, line.buf);
+
if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
if (strstr(traits, " fully-peeled "))
peeled = PEELED_FULLY;
(peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
last->flag |= REF_KNOWS_PEELED;
add_ref_entry(dir, last);
- continue;
- }
- if (last &&
+ } else if (last &&
line.buf[0] == '^' &&
line.len == PEELED_LINE_LENGTH &&
line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
* reference:
*/
last->flag |= REF_KNOWS_PEELED;
+ } else {
+ strbuf_setlen(&line, line.len - 1);
+ die("unexpected line in %s: %s", packed_refs_file, line.buf);
}
}
/*
* Add or overwrite a reference in the in-memory packed reference
* cache. This may only be called while the packed-refs file is locked
- * (see lock_packed_refs()). To actually write the packed-refs file,
+ * (see packed_refs_lock()). To actually write the packed-refs file,
* call commit_packed_refs().
*/
void add_packed_ref(struct ref_store *ref_store,
return 0;
}
-int lock_packed_refs(struct ref_store *ref_store, int flags)
+int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err)
{
struct packed_ref_store *refs =
packed_downcast(ref_store, REF_STORE_WRITE | REF_STORE_MAIN,
- "lock_packed_refs");
+ "packed_refs_lock");
static int timeout_configured = 0;
static int timeout_value = 1000;
- struct packed_ref_cache *packed_ref_cache;
if (!timeout_configured) {
git_config_get_int("core.packedrefstimeout", &timeout_value);
if (hold_lock_file_for_update_timeout(
&refs->lock,
refs->path,
- flags, timeout_value) < 0 ||
- close_lock_file(&refs->lock))
+ flags, timeout_value) < 0) {
+ unable_to_lock_message(refs->path, errno, err);
return -1;
+ }
+
+ if (close_lock_file(&refs->lock)) {
+ strbuf_addf(err, "unable to close %s: %s", refs->path, strerror(errno));
+ return -1;
+ }
/*
* Now that we hold the `packed-refs` lock, make sure that our
*/
validate_packed_ref_cache(refs);
- packed_ref_cache = get_packed_ref_cache(refs);
- /* Increment the reference count to prevent it from being freed: */
- acquire_packed_ref_cache(packed_ref_cache);
+ /*
+ * Now make sure that the packed-refs file as it exists in the
+ * locked state is loaded into the cache:
+ */
+ get_packed_ref_cache(refs);
return 0;
}
+void packed_refs_unlock(struct ref_store *ref_store)
+{
+ struct packed_ref_store *refs = packed_downcast(
+ ref_store,
+ REF_STORE_READ | REF_STORE_WRITE,
+ "packed_refs_unlock");
+
+ if (!is_lock_file_locked(&refs->lock))
+ die("BUG: packed_refs_unlock() called when not locked");
+ rollback_lock_file(&refs->lock);
+}
+
+int packed_refs_is_locked(struct ref_store *ref_store)
+{
+ struct packed_ref_store *refs = packed_downcast(
+ ref_store,
+ REF_STORE_READ | REF_STORE_WRITE,
+ "packed_refs_is_locked");
+
+ return is_lock_file_locked(&refs->lock);
+}
+
/*
* The packed-refs header line that we write out. Perhaps other
* traits will be added later. The trailing space is required.
/*
* Write the current version of the packed refs cache from memory to
* disk. The packed-refs file must already be locked for writing (see
- * lock_packed_refs()). Return zero on success. On errors, rollback
+ * packed_refs_lock()). Return zero on success. On errors, rollback
* the lockfile, write an error message to `err`, and return a nonzero
* value.
*/
struct strbuf sb = STRBUF_INIT;
FILE *out;
struct ref_iterator *iter;
+ char *packed_refs_path;
if (!is_lock_file_locked(&refs->lock))
die("BUG: commit_packed_refs() called when unlocked");
- strbuf_addf(&sb, "%s.new", refs->path);
+ /*
+ * If packed-refs is a symlink, we want to overwrite the
+ * symlinked-to file, not the symlink itself. Also, put the
+ * staging file next to it:
+ */
+ packed_refs_path = get_locked_file_path(&refs->lock);
+ strbuf_addf(&sb, "%s.new", packed_refs_path);
if (create_tempfile(&refs->tempfile, sb.buf) < 0) {
strbuf_addf(err, "unable to create file %s: %s",
sb.buf, strerror(errno));
goto error;
}
- if (rename_tempfile(&refs->tempfile, refs->path)) {
+ if (rename_tempfile(&refs->tempfile, packed_refs_path)) {
strbuf_addf(err, "error replacing %s: %s",
refs->path, strerror(errno));
goto out;
delete_tempfile(&refs->tempfile);
out:
- rollback_lock_file(&refs->lock);
- release_packed_ref_cache(packed_ref_cache);
+ free(packed_refs_path);
return ret;
}
-/*
- * Rollback the lockfile for the packed-refs file, and discard the
- * in-memory packed reference cache. (The packed-refs file will be
- * read anew if it is needed again after this function is called.)
- */
-static void rollback_packed_refs(struct packed_ref_store *refs)
-{
- struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);
-
- packed_assert_main_repository(refs, "rollback_packed_refs");
-
- if (!is_lock_file_locked(&refs->lock))
- die("BUG: packed-refs not locked");
- rollback_lock_file(&refs->lock);
- release_packed_ref_cache(packed_ref_cache);
- clear_packed_ref_cache(refs);
-}
-
/*
* Rewrite the packed-refs file, omitting any refs listed in
* 'refnames'. On error, leave packed-refs unchanged, write an error
- * message to 'err', and return a nonzero value.
+ * message to 'err', and return a nonzero value. The packed refs lock
+ * must be held when calling this function; it will still be held when
+ * the function returns.
*
* The refs in 'refnames' needn't be sorted. `err` must not be NULL.
*/
packed_assert_main_repository(refs, "repack_without_refs");
assert(err);
+ if (!is_lock_file_locked(&refs->lock))
+ die("BUG: repack_without_refs called without holding lock");
+
/* Look for a packed ref */
for_each_string_list_item(refname, refnames) {
if (get_packed_ref(refs, refname->string)) {
if (!needs_repacking)
return 0; /* no refname exists in packed refs */
- if (lock_packed_refs(&refs->base, 0)) {
- unable_to_lock_message(refs->path, errno, err);
- return -1;
- }
packed = get_packed_refs(refs);
/* Remove refnames from the cache */
* All packed entries disappeared while we were
* acquiring the lock.
*/
- rollback_packed_refs(refs);
+ clear_packed_ref_cache(refs);
return 0;
}
return 0;
}
+/*
+ * Write the packed-refs from the cache to the packed-refs tempfile,
+ * incorporating any changes from `updates`. `updates` must be a
+ * sorted string list whose keys are the refnames and whose util
+ * values are `struct ref_update *`. On error, rollback the tempfile,
+ * write an error message to `err`, and return a nonzero value.
+ *
+ * The packfile must be locked before calling this function and will
+ * remain locked when it is done.
+ */
+static int write_with_updates(struct packed_ref_store *refs,
+ struct string_list *updates,
+ struct strbuf *err)
+{
+ struct ref_iterator *iter = NULL;
+ size_t i;
+ int ok;
+ FILE *out;
+ struct strbuf sb = STRBUF_INIT;
+ char *packed_refs_path;
+
+ if (!is_lock_file_locked(&refs->lock))
+ die("BUG: write_with_updates() called while unlocked");
+
+ /*
+ * If packed-refs is a symlink, we want to overwrite the
+ * symlinked-to file, not the symlink itself. Also, put the
+ * staging file next to it:
+ */
+ packed_refs_path = get_locked_file_path(&refs->lock);
+ strbuf_addf(&sb, "%s.new", packed_refs_path);
+ free(packed_refs_path);
+ if (create_tempfile(&refs->tempfile, sb.buf) < 0) {
+ strbuf_addf(err, "unable to create file %s: %s",
+ sb.buf, strerror(errno));
+ strbuf_release(&sb);
+ return -1;
+ }
+ strbuf_release(&sb);
+
+ out = fdopen_tempfile(&refs->tempfile, "w");
+ if (!out) {
+ strbuf_addf(err, "unable to fdopen packed-refs tempfile: %s",
+ strerror(errno));
+ goto error;
+ }
+
+ if (fprintf(out, "%s", PACKED_REFS_HEADER) < 0)
+ goto write_error;
+
+ /*
+ * We iterate in parallel through the current list of refs and
+ * the list of updates, processing an entry from at least one
+ * of the lists each time through the loop. When the current
+ * list of refs is exhausted, set iter to NULL. When the list
+ * of updates is exhausted, leave i set to updates->nr.
+ */
+ iter = packed_ref_iterator_begin(&refs->base, "",
+ DO_FOR_EACH_INCLUDE_BROKEN);
+ if ((ok = ref_iterator_advance(iter)) != ITER_OK)
+ iter = NULL;
+
+ i = 0;
+
+ while (iter || i < updates->nr) {
+ struct ref_update *update = NULL;
+ int cmp;
+
+ if (i >= updates->nr) {
+ cmp = -1;
+ } else {
+ update = updates->items[i].util;
+
+ if (!iter)
+ cmp = +1;
+ else
+ cmp = strcmp(iter->refname, update->refname);
+ }
+
+ if (!cmp) {
+ /*
+ * There is both an old value and an update
+ * for this reference. Check the old value if
+ * necessary:
+ */
+ if ((update->flags & REF_HAVE_OLD)) {
+ if (is_null_oid(&update->old_oid)) {
+ strbuf_addf(err, "cannot update ref '%s': "
+ "reference already exists",
+ update->refname);
+ goto error;
+ } else if (oidcmp(&update->old_oid, iter->oid)) {
+ strbuf_addf(err, "cannot update ref '%s': "
+ "is at %s but expected %s",
+ update->refname,
+ oid_to_hex(iter->oid),
+ oid_to_hex(&update->old_oid));
+ goto error;
+ }
+ }
+
+ /* Now figure out what to use for the new value: */
+ if ((update->flags & REF_HAVE_NEW)) {
+ /*
+ * The update takes precedence. Skip
+ * the iterator over the unneeded
+ * value.
+ */
+ if ((ok = ref_iterator_advance(iter)) != ITER_OK)
+ iter = NULL;
+ cmp = +1;
+ } else {
+ /*
+ * The update doesn't actually want to
+ * change anything. We're done with it.
+ */
+ i++;
+ cmp = -1;
+ }
+ } else if (cmp > 0) {
+ /*
+ * There is no old value but there is an
+ * update for this reference. Make sure that
+ * the update didn't expect an existing value:
+ */
+ if ((update->flags & REF_HAVE_OLD) &&
+ !is_null_oid(&update->old_oid)) {
+ strbuf_addf(err, "cannot update ref '%s': "
+ "reference is missing but expected %s",
+ update->refname,
+ oid_to_hex(&update->old_oid));
+ goto error;
+ }
+ }
+
+ if (cmp < 0) {
+ /* Pass the old reference through. */
+
+ struct object_id peeled;
+ int peel_error = ref_iterator_peel(iter, &peeled);
+
+ if (write_packed_entry(out, iter->refname,
+ iter->oid->hash,
+ peel_error ? NULL : peeled.hash))
+ goto write_error;
+
+ if ((ok = ref_iterator_advance(iter)) != ITER_OK)
+ iter = NULL;
+ } else if (is_null_oid(&update->new_oid)) {
+ /*
+ * The update wants to delete the reference,
+ * and the reference either didn't exist or we
+ * have already skipped it. So we're done with
+ * the update (and don't have to write
+ * anything).
+ */
+ i++;
+ } else {
+ struct object_id peeled;
+ int peel_error = peel_object(update->new_oid.hash,
+ peeled.hash);
+
+ if (write_packed_entry(out, update->refname,
+ update->new_oid.hash,
+ peel_error ? NULL : peeled.hash))
+ goto write_error;
+
+ i++;
+ }
+ }
+
+ if (ok != ITER_DONE) {
+ strbuf_addf(err, "unable to write packed-refs file: "
+ "error iterating over old contents");
+ goto error;
+ }
+
+ if (close_tempfile(&refs->tempfile)) {
+ strbuf_addf(err, "error closing file %s: %s",
+ get_tempfile_path(&refs->tempfile),
+ strerror(errno));
+ strbuf_release(&sb);
+ return -1;
+ }
+
+ return 0;
+
+write_error:
+ strbuf_addf(err, "error writing to %s: %s",
+ get_tempfile_path(&refs->tempfile), strerror(errno));
+
+error:
+ if (iter)
+ ref_iterator_abort(iter);
+
+ delete_tempfile(&refs->tempfile);
+ return -1;
+}
+
+struct packed_transaction_backend_data {
+ /* True iff the transaction owns the packed-refs lock. */
+ int own_lock;
+
+ struct string_list updates;
+};
+
+static void packed_transaction_cleanup(struct packed_ref_store *refs,
+ struct ref_transaction *transaction)
+{
+ struct packed_transaction_backend_data *data = transaction->backend_data;
+
+ if (data) {
+ string_list_clear(&data->updates, 0);
+
+ if (is_tempfile_active(&refs->tempfile))
+ delete_tempfile(&refs->tempfile);
+
+ if (data->own_lock && is_lock_file_locked(&refs->lock)) {
+ packed_refs_unlock(&refs->base);
+ data->own_lock = 0;
+ }
+
+ free(data);
+ transaction->backend_data = NULL;
+ }
+
+ transaction->state = REF_TRANSACTION_CLOSED;
+}
+
static int packed_transaction_prepare(struct ref_store *ref_store,
struct ref_transaction *transaction,
struct strbuf *err)
{
- die("BUG: not implemented yet");
+ struct packed_ref_store *refs = packed_downcast(
+ ref_store,
+ REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB,
+ "ref_transaction_prepare");
+ struct packed_transaction_backend_data *data;
+ size_t i;
+ int ret = TRANSACTION_GENERIC_ERROR;
+
+ /*
+ * Note that we *don't* skip transactions with zero updates,
+ * because such a transaction might be executed for the side
+ * effect of ensuring that all of the references are peeled.
+ * If the caller wants to optimize away empty transactions, it
+ * should do so itself.
+ */
+
+ data = xcalloc(1, sizeof(*data));
+ string_list_init(&data->updates, 0);
+
+ transaction->backend_data = data;
+
+ /*
+ * Stick the updates in a string list by refname so that we
+ * can sort them:
+ */
+ for (i = 0; i < transaction->nr; i++) {
+ struct ref_update *update = transaction->updates[i];
+ struct string_list_item *item =
+ string_list_append(&data->updates, update->refname);
+
+ /* Store a pointer to update in item->util: */
+ item->util = update;
+ }
+ string_list_sort(&data->updates);
+
+ if (ref_update_reject_duplicates(&data->updates, err))
+ goto failure;
+
+ if (!is_lock_file_locked(&refs->lock)) {
+ if (packed_refs_lock(ref_store, 0, err))
+ goto failure;
+ data->own_lock = 1;
+ }
+
+ if (write_with_updates(refs, &data->updates, err))
+ goto failure;
+
+ transaction->state = REF_TRANSACTION_PREPARED;
+ return 0;
+
+failure:
+ packed_transaction_cleanup(refs, transaction);
+ return ret;
}
static int packed_transaction_abort(struct ref_store *ref_store,
struct ref_transaction *transaction,
struct strbuf *err)
{
- die("BUG: not implemented yet");
+ struct packed_ref_store *refs = packed_downcast(
+ ref_store,
+ REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB,
+ "ref_transaction_abort");
+
+ packed_transaction_cleanup(refs, transaction);
+ return 0;
}
static int packed_transaction_finish(struct ref_store *ref_store,
struct ref_transaction *transaction,
struct strbuf *err)
{
- die("BUG: not implemented yet");
+ struct packed_ref_store *refs = packed_downcast(
+ ref_store,
+ REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB,
+ "ref_transaction_finish");
+ int ret = TRANSACTION_GENERIC_ERROR;
+ char *packed_refs_path;
+
+ packed_refs_path = get_locked_file_path(&refs->lock);
+ if (rename_tempfile(&refs->tempfile, packed_refs_path)) {
+ strbuf_addf(err, "error replacing %s: %s",
+ refs->path, strerror(errno));
+ goto cleanup;
+ }
+
+ clear_packed_ref_cache(refs);
+ ret = 0;
+
+cleanup:
+ free(packed_refs_path);
+ packed_transaction_cleanup(refs, transaction);
+ return ret;
}
static int packed_initial_transaction_commit(struct ref_store *ref_store,
static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
struct string_list *refnames, unsigned int flags)
{
- die("BUG: not implemented yet");
+ struct packed_ref_store *refs =
+ packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
+ struct strbuf err = STRBUF_INIT;
+ struct ref_transaction *transaction;
+ struct string_list_item *item;
+ int ret;
+
+ (void)refs; /* We need the check above, but don't use the variable */
+
+ if (!refnames->nr)
+ return 0;
+
+ /*
+ * Since we don't check the references' old_oids, the
+ * individual updates can't fail, so we can pack all of the
+ * updates into a single transaction.
+ */
+
+ transaction = ref_store_transaction_begin(ref_store, &err);
+ if (!transaction)
+ return -1;
+
+ for_each_string_list_item(item, refnames) {
+ if (ref_transaction_delete(transaction, item->string, NULL,
+ flags, msg, &err)) {
+ warning(_("could not delete reference %s: %s"),
+ item->string, err.buf);
+ strbuf_reset(&err);
+ }
+ }
+
+ ret = ref_transaction_commit(transaction, &err);
+
+ if (ret) {
+ if (refnames->nr == 1)
+ error(_("could not delete reference %s: %s"),
+ refnames->items[0].string, err.buf);
+ else
+ error(_("could not delete references: %s"), err.buf);
+ }
+
+ ref_transaction_free(transaction);
+ strbuf_release(&err);
+ return ret;
}
static int packed_pack_refs(struct ref_store *ref_store, unsigned int flags)