ewah: support platforms that require aligned reads
[gitweb.git] / refs.c
diff --git a/refs.c b/refs.c
index d78860c46d95ea9785c83c08824355275393ed99..3710748ab88d8fa4639c3a0a436ca0e2b0c25552 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -72,6 +72,10 @@ int check_refname_format(const char *refname, int flags)
 {
        int component_len, component_count = 0;
 
+       if (!strcmp(refname, "@"))
+               /* Refname is a single character '@'. */
+               return -1;
+
        while (1) {
                /* We are at the start of a path component. */
                component_len = check_refname_component(refname, flags);
@@ -1951,7 +1955,7 @@ static int remove_empty_directories(const char *file)
 static char *substitute_branch_name(const char **string, int *len)
 {
        struct strbuf buf = STRBUF_INIT;
-       int ret = interpret_branch_name(*string, &buf);
+       int ret = interpret_branch_name(*string, *len, &buf);
 
        if (ret == *len) {
                size_t size;
@@ -2121,11 +2125,12 @@ struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha
 }
 
 struct ref_lock *lock_any_ref_for_update(const char *refname,
-                                        const unsigned char *old_sha1, int flags)
+                                        const unsigned char *old_sha1,
+                                        int flags, int *type_p)
 {
        if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
                return NULL;
-       return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
+       return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
 }
 
 /*
@@ -2413,60 +2418,82 @@ static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
        return 0;
 }
 
-static int repack_without_ref(const char *refname)
+static int repack_without_refs(const char **refnames, int n)
 {
        struct ref_dir *packed;
        struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
        struct string_list_item *ref_to_delete;
+       int i, removed = 0;
+
+       /* Look for a packed ref */
+       for (i = 0; i < n; i++)
+               if (get_packed_ref(refnames[i]))
+                       break;
 
-       if (!get_packed_ref(refname))
-               return 0; /* refname does not exist in packed refs */
+       /* Avoid locking if we have nothing to do */
+       if (i == n)
+               return 0; /* no refname exists in packed refs */
 
        if (lock_packed_refs(0)) {
                unable_to_lock_error(git_path("packed-refs"), errno);
-               return error("cannot delete '%s' from packed refs", refname);
+               return error("cannot delete '%s' from packed refs", refnames[i]);
        }
        packed = get_packed_refs(&ref_cache);
 
-       /* Remove refname from the cache: */
-       if (remove_entry(packed, refname) == -1) {
+       /* Remove refnames from the cache */
+       for (i = 0; i < n; i++)
+               if (remove_entry(packed, refnames[i]) != -1)
+                       removed = 1;
+       if (!removed) {
                /*
-                * The packed entry disappeared while we were
+                * All packed entries disappeared while we were
                 * acquiring the lock.
                 */
                rollback_packed_refs();
                return 0;
        }
 
-       /* Remove any other accumulated cruft: */
+       /* Remove any other accumulated cruft */
        do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
        for_each_string_list_item(ref_to_delete, &refs_to_delete) {
                if (remove_entry(packed, ref_to_delete->string) == -1)
                        die("internal error");
        }
 
-       /* Write what remains: */
+       /* Write what remains */
        return commit_packed_refs();
 }
 
-int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
+static int repack_without_ref(const char *refname)
 {
-       struct ref_lock *lock;
-       int err, i = 0, ret = 0, flag = 0;
+       return repack_without_refs(&refname, 1);
+}
 
-       lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
-       if (!lock)
-               return 1;
+static int delete_ref_loose(struct ref_lock *lock, int flag)
+{
        if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
                /* loose */
-               i = strlen(lock->lk->filename) - 5; /* .lock */
+               int err, i = strlen(lock->lk->filename) - 5; /* .lock */
+
                lock->lk->filename[i] = 0;
                err = unlink_or_warn(lock->lk->filename);
-               if (err && errno != ENOENT)
-                       ret = 1;
-
                lock->lk->filename[i] = '.';
+               if (err && errno != ENOENT)
+                       return 1;
        }
+       return 0;
+}
+
+int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
+{
+       struct ref_lock *lock;
+       int ret = 0, flag = 0;
+
+       lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
+       if (!lock)
+               return 1;
+       ret |= delete_ref_loose(lock, flag);
+
        /* removing the loose one could have resurrected an earlier
         * packed one.  Also, if it was not loose we need to repack
         * without it.
@@ -3169,12 +3196,13 @@ int for_each_reflog(each_ref_fn fn, void *cb_data)
        return retval;
 }
 
-int update_ref(const char *action, const char *refname,
-               const unsigned char *sha1, const unsigned char *oldval,
-               int flags, enum action_on_err onerr)
+static struct ref_lock *update_ref_lock(const char *refname,
+                                       const unsigned char *oldval,
+                                       int flags, int *type_p,
+                                       enum action_on_err onerr)
 {
-       static struct ref_lock *lock;
-       lock = lock_any_ref_for_update(refname, oldval, flags);
+       struct ref_lock *lock;
+       lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
        if (!lock) {
                const char *str = "Cannot lock the ref '%s'.";
                switch (onerr) {
@@ -3182,8 +3210,14 @@ int update_ref(const char *action, const char *refname,
                case DIE_ON_ERR: die(str, refname); break;
                case QUIET_ON_ERR: break;
                }
-               return 1;
        }
+       return lock;
+}
+
+static int update_ref_write(const char *action, const char *refname,
+                           const unsigned char *sha1, struct ref_lock *lock,
+                           enum action_on_err onerr)
+{
        if (write_ref_sha1(lock, sha1, action) < 0) {
                const char *str = "Cannot update the ref '%s'.";
                switch (onerr) {
@@ -3196,6 +3230,117 @@ int update_ref(const char *action, const char *refname,
        return 0;
 }
 
+int update_ref(const char *action, const char *refname,
+              const unsigned char *sha1, const unsigned char *oldval,
+              int flags, enum action_on_err onerr)
+{
+       struct ref_lock *lock;
+       lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
+       if (!lock)
+               return 1;
+       return update_ref_write(action, refname, sha1, lock, onerr);
+}
+
+static int ref_update_compare(const void *r1, const void *r2)
+{
+       const struct ref_update * const *u1 = r1;
+       const struct ref_update * const *u2 = r2;
+       return strcmp((*u1)->ref_name, (*u2)->ref_name);
+}
+
+static int ref_update_reject_duplicates(struct ref_update **updates, int n,
+                                       enum action_on_err onerr)
+{
+       int i;
+       for (i = 1; i < n; i++)
+               if (!strcmp(updates[i - 1]->ref_name, updates[i]->ref_name)) {
+                       const char *str =
+                               "Multiple updates for ref '%s' not allowed.";
+                       switch (onerr) {
+                       case MSG_ON_ERR:
+                               error(str, updates[i]->ref_name); break;
+                       case DIE_ON_ERR:
+                               die(str, updates[i]->ref_name); break;
+                       case QUIET_ON_ERR:
+                               break;
+                       }
+                       return 1;
+               }
+       return 0;
+}
+
+int update_refs(const char *action, const struct ref_update **updates_orig,
+               int n, enum action_on_err onerr)
+{
+       int ret = 0, delnum = 0, i;
+       struct ref_update **updates;
+       int *types;
+       struct ref_lock **locks;
+       const char **delnames;
+
+       if (!updates_orig || !n)
+               return 0;
+
+       /* Allocate work space */
+       updates = xmalloc(sizeof(*updates) * n);
+       types = xmalloc(sizeof(*types) * n);
+       locks = xcalloc(n, sizeof(*locks));
+       delnames = xmalloc(sizeof(*delnames) * n);
+
+       /* Copy, sort, and reject duplicate refs */
+       memcpy(updates, updates_orig, sizeof(*updates) * n);
+       qsort(updates, n, sizeof(*updates), ref_update_compare);
+       ret = ref_update_reject_duplicates(updates, n, onerr);
+       if (ret)
+               goto cleanup;
+
+       /* Acquire all locks while verifying old values */
+       for (i = 0; i < n; i++) {
+               locks[i] = update_ref_lock(updates[i]->ref_name,
+                                          (updates[i]->have_old ?
+                                           updates[i]->old_sha1 : NULL),
+                                          updates[i]->flags,
+                                          &types[i], onerr);
+               if (!locks[i]) {
+                       ret = 1;
+                       goto cleanup;
+               }
+       }
+
+       /* Perform updates first so live commits remain referenced */
+       for (i = 0; i < n; i++)
+               if (!is_null_sha1(updates[i]->new_sha1)) {
+                       ret = update_ref_write(action,
+                                              updates[i]->ref_name,
+                                              updates[i]->new_sha1,
+                                              locks[i], onerr);
+                       locks[i] = NULL; /* freed by update_ref_write */
+                       if (ret)
+                               goto cleanup;
+               }
+
+       /* Perform deletes now that updates are safely completed */
+       for (i = 0; i < n; i++)
+               if (locks[i]) {
+                       delnames[delnum++] = locks[i]->ref_name;
+                       ret |= delete_ref_loose(locks[i], types[i]);
+               }
+       ret |= repack_without_refs(delnames, delnum);
+       for (i = 0; i < delnum; i++)
+               unlink_or_warn(git_path("logs/%s", delnames[i]));
+       clear_loose_ref_cache(&ref_cache);
+
+cleanup:
+       for (i = 0; i < n; i++)
+               if (locks[i])
+                       unlock_ref(locks[i]);
+       free(updates);
+       free(types);
+       free(locks);
+       free(delnames);
+       return ret;
+}
+
 /*
  * generate a format suitable for scanf from a ref_rev_parse_rules
  * rule, that is replace the "%.*s" spec with a "%s" spec