tdb2: change API to return the error value.
[ccan] / ccan / tdb2 / tdb.c
index 8bebe2af206b2a361734a687f062722fc2c8a626..c087aad25ea9c9e782f722de6bcacec720cac239 100644 (file)
@@ -197,7 +197,6 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        tdb->direct_access = 0;
        tdb->fd = -1;
        tdb->map_size = sizeof(struct tdb_header);
-       tdb->ecode = TDB_SUCCESS;
        tdb->flags = tdb_flags;
        tdb->logfn = NULL;
        tdb->transaction = NULL;
@@ -227,17 +226,20 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                                tdb->stats->size = sizeof(attr->stats);
                        break;
                default:
-                       tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                                  "tdb_open: unknown attribute type %u",
-                                  attr->base.attr);
+                       ecode = tdb_logerr(tdb, TDB_ERR_EINVAL,
+                                          TDB_LOG_USE_ERROR,
+                                          "tdb_open:"
+                                          " unknown attribute type %u",
+                                          attr->base.attr);
                        goto fail;
                }
                attr = attr->base.next;
        }
 
        if ((open_flags & O_ACCMODE) == O_WRONLY) {
-               tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                          "tdb_open: can't open tdb %s write-only", name);
+               ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+                                  "tdb_open: can't open tdb %s write-only",
+                                  name);
                goto fail;
        }
 
@@ -254,7 +256,8 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        /* internal databases don't need any of the rest. */
        if (tdb->flags & TDB_INTERNAL) {
                tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
-               if (tdb_new_database(tdb, seed, &hdr) != 0) {
+               ecode = tdb_new_database(tdb, seed, &hdr);
+               if (ecode != TDB_SUCCESS) {
                        goto fail;
                }
                tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
@@ -266,9 +269,9 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        if ((tdb->fd = open(name, open_flags, mode)) == -1) {
                /* errno set by open(2) */
                saved_errno = errno;
-               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                          "tdb_open: could not open file %s: %s",
-                          name, strerror(errno));
+               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                  "tdb_open: could not open file %s: %s",
+                                  name, strerror(errno));
                goto fail;
        }
 
@@ -277,26 +280,27 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
         fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
 
        /* ensure there is only one process initialising at once */
-       tdb->ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
-       if (tdb->ecode != TDB_SUCCESS) {
+       ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
+       if (ecode != TDB_SUCCESS) {
                goto fail;
        }
 
        /* If they used O_TRUNC, read will return 0. */
        rlen = read(tdb->fd, &hdr, sizeof(hdr));
        if (rlen == 0 && (open_flags & O_CREAT)) {
-               if (tdb_new_database(tdb, seed, &hdr) == -1) {
+               ecode = tdb_new_database(tdb, seed, &hdr);
+               if (ecode != TDB_SUCCESS) {
                        goto fail;
                }
        } else if (rlen < 0) {
-               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                          "tdb_open: error %s reading %s",
-                          strerror(errno), name);
+               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                  "tdb_open: error %s reading %s",
+                                  strerror(errno), name);
                goto fail;
        } else if (rlen < sizeof(hdr)
                   || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
-               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                          "tdb_open: %s is not a tdb file", name);
+               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                  "tdb_open: %s is not a tdb file", name);
                goto fail;
        }
 
@@ -305,9 +309,10 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                        tdb->flags |= TDB_CONVERT;
                else {
                        /* wrong version */
-                       tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                                  "tdb_open: %s is unknown version 0x%llx",
-                                  name, (long long)hdr.version);
+                       ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                          "tdb_open:"
+                                          " %s is unknown version 0x%llx",
+                                          name, (long long)hdr.version);
                        goto fail;
                }
        }
@@ -318,34 +323,35 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
        if (hdr.hash_test != hash_test) {
                /* wrong hash variant */
-               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                          "tdb_open: %s uses a different hash function",
-                          name);
+               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                  "tdb_open:"
+                                  " %s uses a different hash function",
+                                  name);
                goto fail;
        }
 
        if (fstat(tdb->fd, &st) == -1) {
                saved_errno = errno;
-               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                          "tdb_open: could not stat open %s: %s",
-                          name, strerror(errno));
+               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                  "tdb_open: could not stat open %s: %s",
+                                  name, strerror(errno));
                goto fail;
        }
 
        /* Is it already in the open list?  If so, fail. */
        if (tdb_already_open(st.st_dev, st.st_ino)) {
                /* FIXME */
-               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
-                          "tdb_open: %s (%d,%d) is already open in this"
-                          " process",
-                          name, (int)st.st_dev, (int)st.st_ino);
+               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
+                                  "tdb_open: %s (%d,%d) is already open"
+                                  " in this process",
+                                  name, (int)st.st_dev, (int)st.st_ino);
                goto fail;
        }
 
        tdb->name = strdup(name);
        if (!tdb->name) {
-               tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
-                          "tdb_open: failed to allocate name");
+               ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+                                  "tdb_open: failed to allocate name");
                goto fail;
        }
 
@@ -365,13 +371,12 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                }
                ecode = tdb_lock_and_recover(tdb);
                if (ecode != TDB_SUCCESS) {
-                       tdb->ecode = ecode;
                        goto fail;
                }
        }
 
-       tdb->ecode = tdb_ftable_init(tdb);
-       if (tdb->ecode != TDB_SUCCESS) {
+       ecode = tdb_ftable_init(tdb);
+       if (ecode != TDB_SUCCESS) {
                goto fail;
        }
 
@@ -382,7 +387,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
  fail:
        /* Map ecode to some logical errno. */
        if (!saved_errno) {
-               switch (tdb->ecode) {
+               switch (ecode) {
                case TDB_ERR_CORRUPT:
                case TDB_ERR_IO:
                        saved_errno = EIO;
@@ -488,8 +493,8 @@ static enum TDB_ERROR replace_data(struct tdb_context *tdb,
        return TDB_SUCCESS;
 }
 
-int tdb_store(struct tdb_context *tdb,
-             struct tdb_data key, struct tdb_data dbuf, int flag)
+enum TDB_ERROR tdb_store(struct tdb_context *tdb,
+                        struct tdb_data key, struct tdb_data dbuf, int flag)
 {
        struct hash_info h;
        tdb_off_t off;
@@ -499,15 +504,14 @@ int tdb_store(struct tdb_context *tdb,
 
        off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               tdb->ecode = off;
-               return -1;
+               return off;
        }
 
        /* Now we have lock on this hash bucket. */
        if (flag == TDB_INSERT) {
                if (off) {
-                       tdb->ecode = TDB_ERR_EXISTS;
-                       goto fail;
+                       ecode = TDB_ERR_EXISTS;
+                       goto out;
                }
        } else {
                if (off) {
@@ -519,8 +523,7 @@ int tdb_store(struct tdb_context *tdb,
                                                       key.dsize, dbuf.dsize,
                                                       &rec, h.h);
                                if (ecode != TDB_SUCCESS) {
-                                       tdb->ecode = ecode;
-                                       goto fail;
+                                       goto out;
                                }
                                ecode = tdb->methods->twrite(tdb,
                                                             off + sizeof(rec)
@@ -528,40 +531,32 @@ int tdb_store(struct tdb_context *tdb,
                                                             dbuf.dptr,
                                                             dbuf.dsize);
                                if (ecode != TDB_SUCCESS) {
-                                       tdb->ecode = ecode;
-                                       goto fail;
+                                       goto out;
                                }
                                tdb_unlock_hashes(tdb, h.hlock_start,
                                                  h.hlock_range, F_WRLCK);
-                               return 0;
+                               return TDB_SUCCESS;
                        }
                } else {
                        if (flag == TDB_MODIFY) {
                                /* if the record doesn't exist and we
                                   are in TDB_MODIFY mode then we should fail
                                   the store */
-                               tdb->ecode = TDB_ERR_NOEXIST;
-                               goto fail;
+                               ecode = TDB_ERR_NOEXIST;
+                               goto out;
                        }
                }
        }
 
        /* If we didn't use the old record, this implies we're growing. */
        ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
+out:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       if (ecode != TDB_SUCCESS) {
-               tdb->ecode = ecode;
-               return -1;
-       }
-       return 0;
-
-fail:
-       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return -1;
+       return ecode;
 }
 
-int tdb_append(struct tdb_context *tdb,
-              struct tdb_data key, struct tdb_data dbuf)
+enum TDB_ERROR tdb_append(struct tdb_context *tdb,
+                         struct tdb_data key, struct tdb_data dbuf)
 {
        struct hash_info h;
        tdb_off_t off;
@@ -573,8 +568,7 @@ int tdb_append(struct tdb_context *tdb,
 
        off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               tdb->ecode = off;
-               return -1;
+               return off;
        }
 
        if (off) {
@@ -587,38 +581,29 @@ int tdb_append(struct tdb_context *tdb,
                                               old_dlen + dbuf.dsize, &rec,
                                               h.h);
                        if (ecode != TDB_SUCCESS) {
-                               tdb->ecode = ecode;
-                               goto fail;
+                               goto out;
                        }
 
                        off += sizeof(rec) + key.dsize + old_dlen;
                        ecode = tdb->methods->twrite(tdb, off, dbuf.dptr,
                                                     dbuf.dsize);
-                       if (ecode != TDB_SUCCESS) {
-                               tdb->ecode = ecode;
-                               goto fail;
-                       }
-
-                       /* FIXME: tdb_increment_seqnum(tdb); */
-                       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range,
-                                         F_WRLCK);
-                       return 0;
+                       goto out;
                }
 
                /* Slow path. */
                newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
                if (!newdata) {
-                       tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
-                                  "tdb_append: failed to allocate %zu bytes",
-                                  (size_t)(key.dsize+old_dlen+dbuf.dsize));
-                       goto fail;
+                       ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+                                          "tdb_append:"
+                                          " failed to allocate %zu bytes",
+                                          (size_t)(key.dsize + old_dlen
+                                                   + dbuf.dsize));
+                       goto out;
                }
                ecode = tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
                                            newdata, old_dlen);
                if (ecode != TDB_SUCCESS) {
-                       tdb->ecode = ecode;
-                       free(newdata);
-                       goto fail;
+                       goto out_free_newdata;
                }
                memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
                new_dbuf.dptr = newdata;
@@ -630,51 +615,44 @@ int tdb_append(struct tdb_context *tdb,
 
        /* If they're using tdb_append(), it implies they're growing record. */
        ecode = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
-       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       free(newdata);
 
-       if (ecode != TDB_SUCCESS) {
-               tdb->ecode = ecode;
-               return -1;
-       }
-       return 0;
-
-fail:
+out_free_newdata:
+       free(newdata);
+out:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return -1;
+       return ecode;
 }
 
-struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
+enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
+                        struct tdb_data *data)
 {
        tdb_off_t off;
        struct tdb_used_record rec;
        struct hash_info h;
-       struct tdb_data ret;
+       enum TDB_ERROR ecode;
 
        off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               tdb->ecode = off;
-               return tdb_null;
+               return off;
        }
 
        if (!off) {
-               tdb->ecode = TDB_ERR_NOEXIST;
-               ret = tdb_null;
+               ecode = TDB_ERR_NOEXIST;
        } else {
-               ret.dsize = rec_data_length(&rec);
-               ret.dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
-                                         ret.dsize);
-               if (TDB_PTR_IS_ERR(ret.dptr)) {
-                       tdb->ecode = TDB_PTR_ERR(ret.dptr);
-                       ret = tdb_null;
-               }
+               data->dsize = rec_data_length(&rec);
+               data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
+                                           data->dsize);
+               if (TDB_PTR_IS_ERR(data->dptr)) {
+                       ecode = TDB_PTR_ERR(data->dptr);
+               } else
+                       ecode = TDB_SUCCESS;
        }
 
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
-       return ret;
+       return ecode;
 }
 
-int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
+enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 {
        tdb_off_t off;
        struct tdb_used_record rec;
@@ -683,20 +661,17 @@ int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 
        off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               tdb->ecode = off;
-               return -1;
+               return off;
        }
 
        if (!off) {
-               tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-               tdb->ecode = TDB_ERR_NOEXIST;
-               return -1;
+               ecode = TDB_ERR_NOEXIST;
+               goto unlock;
        }
 
        ecode = delete_from_hash(tdb, &h);
        if (ecode != TDB_SUCCESS) {
-               tdb->ecode = ecode;
-               goto unlock_err;
+               goto unlock;
        }
 
        /* Free the deleted entry. */
@@ -706,17 +681,10 @@ int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
                                + rec_key_length(&rec)
                                + rec_data_length(&rec)
                                + rec_extra_padding(&rec));
-       if (ecode != TDB_SUCCESS) {
-               tdb->ecode = ecode;
-               goto unlock_err;
-       }
 
+unlock:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return 0;
-
-unlock_err:
-       tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return -1;
+       return ecode;
 }
 
 int tdb_close(struct tdb_context *tdb)
@@ -759,15 +727,10 @@ int tdb_close(struct tdb_context *tdb)
        return ret;
 }
 
-enum TDB_ERROR tdb_error(const struct tdb_context *tdb)
-{
-       return tdb->ecode;
-}
-
-const char *tdb_errorstr(const struct tdb_context *tdb)
+const char *tdb_errorstr(enum TDB_ERROR ecode)
 {
        /* Gcc warns if you miss a case in the switch, so use that. */
-       switch (tdb->ecode) {
+       switch (ecode) {
        case TDB_SUCCESS: return "Success";
        case TDB_ERR_CORRUPT: return "Corrupt database";
        case TDB_ERR_IO: return "IO Error";
@@ -792,8 +755,6 @@ enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
        /* tdb_open paths care about errno, so save it. */
        int saved_errno = errno;
 
-       tdb->ecode = ecode;
-
        if (!tdb->logfn)
                return ecode;