tdb2: remove tdb_get()
[ccan] / ccan / tdb2 / free.c
index dca8ff10709c81e3848b0c1fb9e3e4431ed0996f..48ea2b20185d8d6fbbeb737657331d666cffb6dd 100644 (file)
@@ -105,7 +105,7 @@ static tdb_off_t find_free_head(struct tdb_context *tdb,
 /* Remove from free bucket. */
 static int remove_from_list(struct tdb_context *tdb,
                            tdb_off_t b_off, tdb_off_t r_off,
-                           struct tdb_free_record *r)
+                           const struct tdb_free_record *r)
 {
        tdb_off_t off;
 
@@ -262,27 +262,30 @@ static tdb_off_t flist_offset(struct tdb_context *tdb, unsigned int flist)
 static int coalesce(struct tdb_context *tdb,
                    tdb_off_t off, tdb_off_t b_off, tdb_len_t data_len)
 {
-       struct tdb_free_record pad, *r;
        tdb_off_t end;
+       struct tdb_free_record rec;
 
        add_stat(tdb, alloc_coalesce_tried, 1);
        end = off + sizeof(struct tdb_used_record) + data_len;
 
        while (end < tdb->map_size) {
+               const struct tdb_free_record *r;
                tdb_off_t nb_off;
                unsigned flist, bucket;
 
-               /* FIXME: do tdb_get here and below really win? */
-               r = tdb_get(tdb, end, &pad, sizeof(pad));
+               r = tdb_access_read(tdb, end, sizeof(*r), true);
                if (!r)
                        goto err;
 
-               if (frec_magic(r) != TDB_FREE_MAGIC)
+               if (frec_magic(r) != TDB_FREE_MAGIC) {
+                       tdb_access_release(tdb, r);
                        break;
+               }
 
                flist = frec_flist(r);
                bucket = size_to_bucket(frec_len(r));
                nb_off = bucket_off(flist_offset(tdb, flist), bucket);
+               tdb_access_release(tdb, r);
 
                /* We may be violating lock order here, so best effort. */
                if (tdb_lock_free_bucket(tdb, nb_off, TDB_LOCK_NOWAIT) == -1) {
@@ -291,31 +294,30 @@ static int coalesce(struct tdb_context *tdb,
                }
 
                /* Now we have lock, re-check. */
-               r = tdb_get(tdb, end, &pad, sizeof(pad));
-               if (!r) {
+               if (tdb_read_convert(tdb, end, &rec, sizeof(rec))) {
                        tdb_unlock_free_bucket(tdb, nb_off);
                        goto err;
                }
 
-               if (unlikely(frec_magic(r) != TDB_FREE_MAGIC)) {
+               if (unlikely(frec_magic(&rec) != TDB_FREE_MAGIC)) {
                        add_stat(tdb, alloc_coalesce_race, 1);
                        tdb_unlock_free_bucket(tdb, nb_off);
                        break;
                }
 
-               if (unlikely(frec_flist(r) != flist)
-                   || unlikely(size_to_bucket(frec_len(r)) != bucket)) {
+               if (unlikely(frec_flist(&rec) != flist)
+                   || unlikely(size_to_bucket(frec_len(&rec)) != bucket)) {
                        add_stat(tdb, alloc_coalesce_race, 1);
                        tdb_unlock_free_bucket(tdb, nb_off);
                        break;
                }
 
-               if (remove_from_list(tdb, nb_off, end, r) == -1) {
+               if (remove_from_list(tdb, nb_off, end, &rec) == -1) {
                        tdb_unlock_free_bucket(tdb, nb_off);
                        goto err;
                }
 
-               end += sizeof(struct tdb_used_record) + frec_len(r);
+               end += sizeof(struct tdb_used_record) + frec_len(&rec);
                tdb_unlock_free_bucket(tdb, nb_off);
                add_stat(tdb, alloc_coalesce_num_merged, 1);
        }
@@ -324,32 +326,28 @@ static int coalesce(struct tdb_context *tdb,
        if (end == off + sizeof(struct tdb_used_record) + data_len)
                return 0;
 
-       /* OK, expand record */
-       r = tdb_get(tdb, off, &pad, sizeof(pad));
-       if (!r)
+       /* OK, expand initial record */
+       if (tdb_read_convert(tdb, off, &rec, sizeof(rec)))
                goto err;
 
-       if (frec_len(r) != data_len) {
+       if (frec_len(&rec) != data_len) {
                tdb->ecode = TDB_ERR_CORRUPT;
                tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
                         "coalesce: expected data len %llu not %llu\n",
-                        (long long)data_len, (long long)frec_len(r));
+                        (long long)data_len, (long long)frec_len(&rec));
                goto err;
        }
 
-       if (remove_from_list(tdb, b_off, off, r) == -1)
-               goto err;
-
-       r = tdb_access_write(tdb, off, sizeof(*r), true);
-       if (!r)
+       if (remove_from_list(tdb, b_off, off, &rec) == -1)
                goto err;
 
        /* We have to drop this to avoid deadlocks, so make sure record
         * doesn't get coalesced by someone else! */
-       r->magic_and_prev = TDB_COALESCING_MAGIC << (64 - TDB_OFF_UPPER_STEAL);
+       rec.magic_and_prev = TDB_COALESCING_MAGIC
+               << (64 - TDB_OFF_UPPER_STEAL);
        /* FIXME: Use 255 as invalid free list? */
-       r->flist_and_len = end - off - sizeof(struct tdb_used_record);
-       if (tdb_access_commit(tdb, r) != 0)
+       rec.flist_and_len = end - off - sizeof(struct tdb_used_record);
+       if (tdb_write_convert(tdb, off, &rec, sizeof(rec)) != 0)
                goto err;
 
        add_stat(tdb, alloc_coalesce_succeeded, 1);
@@ -374,7 +372,7 @@ static tdb_off_t lock_and_alloc(struct tdb_context *tdb,
                                unsigned hashlow)
 {
        tdb_off_t off, b_off,best_off;
-       struct tdb_free_record pad, best = { 0 }, *r;
+       struct tdb_free_record best = { 0 };
        double multiplier;
        size_t size = adjust_size(keylen, datalen);
 
@@ -404,12 +402,16 @@ again:
                goto unlock_err;
 
        while (off) {
-               /* FIXME: Does tdb_get win anything here? */
-               r = tdb_get(tdb, off, &pad, sizeof(*r));
+               const struct tdb_free_record *r;
+               tdb_len_t len;
+               tdb_off_t next;
+
+               r = tdb_access_read(tdb, off, sizeof(*r), true);
                if (!r)
                        goto unlock_err;
 
                if (frec_magic(r) != TDB_FREE_MAGIC) {
+                       tdb_access_release(tdb, r);
                        tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
                                 "lock_and_alloc: %llu non-free 0x%llx\n",
                                 (long long)off, (long long)r->magic_and_prev);
@@ -421,13 +423,19 @@ again:
                        best = *r;
                }
 
-               if (frec_len(&best) < size * multiplier && best_off)
+               if (frec_len(&best) < size * multiplier && best_off) {
+                       tdb_access_release(tdb, r);
                        break;
+               }
 
                multiplier *= 1.01;
 
+               next = r->next;
+               len = frec_len(r);
+               tdb_access_release(tdb, r);
+
                /* Since we're going slow anyway, try coalescing here. */
-               switch (coalesce(tdb, off, b_off, frec_len(r))) {
+               switch (coalesce(tdb, off, b_off, len)) {
                case -1:
                        /* This has already unlocked on error. */
                        return -1;
@@ -435,7 +443,7 @@ again:
                        /* This has unlocked list, restart. */
                        goto again;
                }
-               off = r->next;
+               off = next;
        }
 
        /* If we found anything at all, use it. */