#include "../iterator.h"
#include "../lockfile.h"
+struct packed_ref_store;
+
struct packed_ref_cache {
+ /*
+ * A back-pointer to the packed_ref_store with which this
+ * cache is associated:
+ */
+ struct packed_ref_store *refs;
+
struct ref_cache *cache;
/*
return ref_store;
}
-/*
- * Die if refs is not the main ref store. caller is used in any
- * necessary error messages.
- */
-static void packed_assert_main_repository(struct packed_ref_store *refs,
- const char *caller)
-{
- if (refs->store_flags & REF_STORE_MAIN)
- return;
-
- die("BUG: operation %s only allowed for main ref store", caller);
-}
-
/*
* Downcast `ref_store` to `packed_ref_store`. Die if `ref_store` is
* not a `packed_ref_store`. Also die if `packed_ref_store` doesn't
return ref;
}
+static NORETURN void die_unterminated_line(const char *path,
+ const char *p, size_t len)
+{
+ if (len < 80)
+ die("unterminated line in %s: %.*s", path, (int)len, p);
+ else
+ die("unterminated line in %s: %.75s...", path, p);
+}
+
+static NORETURN void die_invalid_line(const char *path,
+ const char *p, size_t len)
+{
+ const char *eol = memchr(p, '\n', len);
+
+ if (!eol)
+ die_unterminated_line(path, p, len);
+ else if (eol - p < 80)
+ die("unexpected line in %s: %.*s", path, (int)(eol - p), p);
+ else
+ die("unexpected line in %s: %.75s...", path, p);
+
+}
+
/*
- * Read from `packed_refs_file` into a newly-allocated
+ * Read from the `packed-refs` file into a newly-allocated
* `packed_ref_cache` and return it. The return value will already
* have its reference count incremented.
*
* compatibility with older clients, but we do not require it
* (i.e., "peeled" is a no-op if "fully-peeled" is set).
*/
-static struct packed_ref_cache *read_packed_refs(const char *packed_refs_file)
+static struct packed_ref_cache *read_packed_refs(struct packed_ref_store *refs)
{
- FILE *f;
struct packed_ref_cache *packed_refs = xcalloc(1, sizeof(*packed_refs));
+ int fd;
+ struct stat st;
+ size_t size;
+ char *buf;
+ const char *pos, *eol, *eof;
struct ref_entry *last = NULL;
struct strbuf line = STRBUF_INIT;
enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
struct ref_dir *dir;
+ packed_refs->refs = refs;
acquire_packed_ref_cache(packed_refs);
packed_refs->cache = create_ref_cache(NULL, NULL);
packed_refs->cache->root->flag &= ~REF_INCOMPLETE;
- f = fopen(packed_refs_file, "r");
- if (!f) {
+ fd = open(refs->path, O_RDONLY);
+ if (fd < 0) {
if (errno == ENOENT) {
/*
* This is OK; it just means that no
*/
return packed_refs;
} else {
- die_errno("couldn't read %s", packed_refs_file);
+ die_errno("couldn't read %s", refs->path);
}
}
- stat_validity_update(&packed_refs->validity, fileno(f));
+ stat_validity_update(&packed_refs->validity, fd);
+
+ if (fstat(fd, &st) < 0)
+ die_errno("couldn't stat %s", refs->path);
+
+ size = xsize_t(st.st_size);
+ buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ pos = buf;
+ eof = buf + size;
dir = get_ref_dir(packed_refs->cache->root);
- while (strbuf_getwholeline(&line, f, '\n') != EOF) {
+ while (pos < eof) {
struct object_id oid;
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);
+ eol = memchr(pos, '\n', eof - pos);
+ if (!eol)
+ die_unterminated_line(refs->path, pos, eof - pos);
+
+ strbuf_add(&line, pos, eol + 1 - pos);
if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
if (strstr(traits, " fully-peeled "))
else if (strstr(traits, " peeled "))
peeled = PEELED_TAGS;
/* perhaps other traits later as well */
- continue;
+ goto next_line;
}
refname = parse_ref_line(&line, &oid);
*/
last->flag |= REF_KNOWS_PEELED;
} else {
- strbuf_setlen(&line, line.len - 1);
- die("unexpected line in %s: %s", packed_refs_file, line.buf);
+ die_invalid_line(refs->path, line.buf, line.len);
}
+
+ next_line:
+ /* The "+ 1" is for the LF character. */
+ pos = eol + 1;
+ strbuf_reset(&line);
}
- fclose(f);
- strbuf_release(&line);
+ if (munmap(buf, size))
+ die_errno("error ummapping packed-refs file");
+ close(fd);
+ strbuf_release(&line);
return packed_refs;
}
validate_packed_ref_cache(refs);
if (!refs->cache)
- refs->cache = read_packed_refs(refs->path);
+ refs->cache = read_packed_refs(refs);
return refs->cache;
}
return get_packed_ref_dir(get_packed_ref_cache(refs));
}
-/*
- * 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 packed_refs_lock()). To actually write the packed-refs file,
- * call commit_packed_refs().
- */
-void add_packed_ref(struct ref_store *ref_store,
- const char *refname, const struct object_id *oid)
-{
- struct packed_ref_store *refs =
- packed_downcast(ref_store, REF_STORE_WRITE,
- "add_packed_ref");
- struct ref_dir *packed_refs;
- struct ref_entry *packed_entry;
-
- if (!is_lock_file_locked(&refs->lock))
- die("BUG: packed refs not locked");
-
- if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
- die("Reference has invalid format: '%s'", refname);
-
- packed_refs = get_packed_refs(refs);
- packed_entry = find_ref_entry(packed_refs, refname);
- if (packed_entry) {
- /* Overwrite the existing entry: */
- oidcpy(&packed_entry->u.value.oid, oid);
- packed_entry->flag = REF_ISPACKED;
- oidclr(&packed_entry->u.value.peeled);
- } else {
- packed_entry = create_ref_entry(refname, oid, REF_ISPACKED);
- add_ref_entry(packed_refs, packed_entry);
- }
-}
-
/*
* Return the ref_entry for the given refname from the packed
* references. If it does not exist, return NULL.
iter = xcalloc(1, sizeof(*iter));
ref_iterator = &iter->base;
- base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable);
+ base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1);
/*
* Note that get_packed_ref_cache() internally checks whether
"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);
*/
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;
}
if (!is_lock_file_locked(&refs->lock))
die("BUG: packed_refs_unlock() called when not locked");
rollback_lock_file(&refs->lock);
- release_packed_ref_cache(refs->cache);
}
int packed_refs_is_locked(struct ref_store *ref_store)
static const char PACKED_REFS_HEADER[] =
"# pack-refs with: peeled fully-peeled \n";
+static int packed_init_db(struct ref_store *ref_store, struct strbuf *err)
+{
+ /* Nothing to do. */
+ return 0;
+}
+
/*
- * Write the current version of the packed refs cache from memory to
- * disk. The packed-refs file must already be locked for writing (see
- * packed_refs_lock()). Return zero on success. On errors, rollback
- * the lockfile, write an error message to `err`, and return a nonzero
- * value.
+ * 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.
*/
-int commit_packed_refs(struct ref_store *ref_store, struct strbuf *err)
+static int write_with_updates(struct packed_ref_store *refs,
+ struct string_list *updates,
+ struct strbuf *err)
{
- struct packed_ref_store *refs =
- packed_downcast(ref_store, REF_STORE_WRITE | REF_STORE_MAIN,
- "commit_packed_refs");
- struct packed_ref_cache *packed_ref_cache =
- get_packed_ref_cache(refs);
+ struct ref_iterator *iter = NULL;
+ size_t i;
int ok;
- int ret = -1;
- struct strbuf sb = STRBUF_INIT;
FILE *out;
- struct ref_iterator *iter;
+ struct strbuf sb = STRBUF_INIT;
char *packed_refs_path;
if (!is_lock_file_locked(&refs->lock))
- die("BUG: commit_packed_refs() called when unlocked");
+ die("BUG: write_with_updates() called while unlocked");
/*
* If packed-refs is a symlink, we want to overwrite the
*/
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);
- goto out;
+ return -1;
}
strbuf_release(&sb);
goto error;
}
- if (fprintf(out, "%s", PACKED_REFS_HEADER) < 0) {
- strbuf_addf(err, "error writing to %s: %s",
- get_tempfile_path(&refs->tempfile), strerror(errno));
- goto error;
- }
+ if (fprintf(out, "%s", PACKED_REFS_HEADER) < 0)
+ goto write_error;
- iter = cache_ref_iterator_begin(packed_ref_cache->cache, NULL, 0);
- while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
- 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)) {
- strbuf_addf(err, "error writing to %s: %s",
- get_tempfile_path(&refs->tempfile),
- strerror(errno));
- ref_iterator_abort(iter);
- goto 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 rewrite packed-refs file: "
+ strbuf_addf(err, "unable to write packed-refs file: "
"error iterating over old contents");
goto error;
}
- if (rename_tempfile(&refs->tempfile, packed_refs_path)) {
- strbuf_addf(err, "error replacing %s: %s",
- refs->path, strerror(errno));
- goto out;
+ 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;
}
- ret = 0;
- goto out;
+ return 0;
+
+write_error:
+ strbuf_addf(err, "error writing to %s: %s",
+ get_tempfile_path(&refs->tempfile), strerror(errno));
error:
- delete_tempfile(&refs->tempfile);
+ if (iter)
+ ref_iterator_abort(iter);
-out:
- free(packed_refs_path);
- return ret;
+ delete_tempfile(&refs->tempfile);
+ return -1;
}
-/*
- * 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. 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.
- */
-int repack_without_refs(struct ref_store *ref_store,
- struct string_list *refnames, struct strbuf *err)
+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_ref_store *refs =
- packed_downcast(ref_store, REF_STORE_WRITE | REF_STORE_MAIN,
- "repack_without_refs");
- struct ref_dir *packed;
- struct string_list_item *refname;
- int needs_repacking = 0, removed = 0;
+ struct packed_transaction_backend_data *data = transaction->backend_data;
- packed_assert_main_repository(refs, "repack_without_refs");
- assert(err);
+ if (data) {
+ string_list_clear(&data->updates, 0);
- if (!is_lock_file_locked(&refs->lock))
- die("BUG: repack_without_refs called without holding lock");
+ if (is_tempfile_active(&refs->tempfile))
+ delete_tempfile(&refs->tempfile);
- /* Look for a packed ref */
- for_each_string_list_item(refname, refnames) {
- if (get_packed_ref(refs, refname->string)) {
- needs_repacking = 1;
- break;
+ if (data->own_lock && is_lock_file_locked(&refs->lock)) {
+ packed_refs_unlock(&refs->base);
+ data->own_lock = 0;
}
- }
- /* Avoid locking if we have nothing to do */
- if (!needs_repacking)
- return 0; /* no refname exists in packed refs */
-
- packed = get_packed_refs(refs);
-
- /* Remove refnames from the cache */
- for_each_string_list_item(refname, refnames)
- if (remove_entry_from_dir(packed, refname->string) != -1)
- removed = 1;
- if (!removed) {
- /*
- * All packed entries disappeared while we were
- * acquiring the lock.
- */
- clear_packed_ref_cache(refs);
- return 0;
+ free(data);
+ transaction->backend_data = NULL;
}
- /* Write what remains */
- return commit_packed_refs(&refs->base, err);
-}
-
-static int packed_init_db(struct ref_store *ref_store, struct strbuf *err)
-{
- /* Nothing to do. */
- return 0;
+ 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)