tdb2: allow multiple chain locks.
[ccan] / ccan / tdb2 / tdb.c
index 79ccd0f1c260cb476b35c146f15a9438f843a673..18cf2e93a598ea7c3f742bcb3e445a5985686d55 100644 (file)
@@ -38,7 +38,7 @@ static enum TDB_ERROR replace_data(struct tdb_context *tdb,
 
        /* We didn't like the existing one: remove it. */
        if (old_off) {
-               add_stat(tdb, frees, 1);
+               tdb->stats.frees++;
                ecode = add_free_record(tdb, old_off,
                                        sizeof(struct tdb_used_record)
                                        + key.dsize + old_room);
@@ -63,7 +63,9 @@ static enum TDB_ERROR replace_data(struct tdb_context *tdb,
                return ecode;
        }
 
-       /* FIXME: tdb_increment_seqnum(tdb); */
+       if (tdb->flags & TDB_SEQNUM)
+               tdb_inc_seqnum(tdb);
+
        return TDB_SUCCESS;
 }
 
@@ -79,6 +81,9 @@ static enum TDB_ERROR update_data(struct tdb_context *tdb,
                /* Put a zero in; future versions may append other data. */
                ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
        }
+       if (tdb->flags & TDB_SEQNUM)
+               tdb_inc_seqnum(tdb);
+
        return ecode;
 }
 
@@ -93,7 +98,7 @@ enum TDB_ERROR tdb_store(struct tdb_context *tdb,
 
        off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               return off;
+               return tdb->last_error = off;
        }
 
        /* Now we have lock on this hash bucket. */
@@ -123,7 +128,7 @@ enum TDB_ERROR tdb_store(struct tdb_context *tdb,
                                }
                                tdb_unlock_hashes(tdb, h.hlock_start,
                                                  h.hlock_range, F_WRLCK);
-                               return TDB_SUCCESS;
+                               return tdb->last_error = TDB_SUCCESS;
                        }
                } else {
                        if (flag == TDB_MODIFY) {
@@ -140,7 +145,7 @@ enum TDB_ERROR tdb_store(struct tdb_context *tdb,
        ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
 out:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return ecode;
+       return tdb->last_error = ecode;
 }
 
 enum TDB_ERROR tdb_append(struct tdb_context *tdb,
@@ -156,7 +161,7 @@ enum TDB_ERROR tdb_append(struct tdb_context *tdb,
 
        off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               return off;
+               return tdb->last_error = off;
        }
 
        if (off) {
@@ -208,7 +213,7 @@ out_free_newdata:
        free(newdata);
 out:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return ecode;
+       return tdb->last_error = ecode;
 }
 
 enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
@@ -221,7 +226,7 @@ enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
 
        off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               return off;
+               return tdb->last_error = off;
        }
 
        if (!off) {
@@ -237,7 +242,7 @@ enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
        }
 
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
-       return ecode;
+       return tdb->last_error = ecode;
 }
 
 bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
@@ -248,10 +253,12 @@ bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
 
        off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
+               tdb->last_error = off;
                return false;
        }
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 
+       tdb->last_error = TDB_SUCCESS;
        return off ? true : false;
 }
 
@@ -264,7 +271,7 @@ enum TDB_ERROR 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)) {
-               return off;
+               return tdb->last_error = off;
        }
 
        if (!off) {
@@ -278,16 +285,19 @@ enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
        }
 
        /* Free the deleted entry. */
-       add_stat(tdb, frees, 1);
+       tdb->stats.frees++;
        ecode = add_free_record(tdb, off,
                                sizeof(struct tdb_used_record)
                                + rec_key_length(&rec)
                                + rec_data_length(&rec)
                                + rec_extra_padding(&rec));
 
+       if (tdb->flags & TDB_SEQNUM)
+               tdb_inc_seqnum(tdb);
+
 unlock:
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
-       return ecode;
+       return tdb->last_error = ecode;
 }
 
 unsigned int tdb_get_flags(struct tdb_context *tdb)
@@ -298,8 +308,9 @@ unsigned int tdb_get_flags(struct tdb_context *tdb)
 void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
 {
        if (tdb->flags & TDB_INTERNAL) {
-               tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                          "tdb_add_flag: internal db");
+               tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+                                            TDB_LOG_USE_ERROR,
+                                            "tdb_add_flag: internal db");
                return;
        }
        switch (flag) {
@@ -313,17 +324,23 @@ void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
        case TDB_NOSYNC:
                tdb->flags |= TDB_NOSYNC;
                break;
+       case TDB_SEQNUM:
+               tdb->flags |= TDB_SEQNUM;
+               break;
        default:
-               tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                          "tdb_add_flag: Unknown flag %u", flag);
+               tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+                                            TDB_LOG_USE_ERROR,
+                                            "tdb_add_flag: Unknown flag %u",
+                                            flag);
        }
 }
 
 void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
 {
        if (tdb->flags & TDB_INTERNAL) {
-               tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                          "tdb_remove_flag: internal db");
+               tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+                                            TDB_LOG_USE_ERROR,
+                                            "tdb_remove_flag: internal db");
                return;
        }
        switch (flag) {
@@ -337,9 +354,14 @@ void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
        case TDB_NOSYNC:
                tdb->flags &= ~TDB_NOSYNC;
                break;
+       case TDB_SEQNUM:
+               tdb->flags &= ~TDB_SEQNUM;
+               break;
        default:
-               tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                          "tdb_remove_flag: Unknown flag %u", flag);
+               tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+                                            TDB_LOG_USE_ERROR,
+                                            "tdb_remove_flag: Unknown flag %u",
+                                            flag);
        }
 }
 
@@ -360,6 +382,11 @@ const char *tdb_errorstr(enum TDB_ERROR ecode)
        return "Invalid error code";
 }
 
+enum TDB_ERROR tdb_error(struct tdb_context *tdb)
+{
+       return tdb->last_error;
+}
+
 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
                               enum TDB_ERROR ecode,
                               enum tdb_log_level level,
@@ -371,7 +398,7 @@ enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
        /* tdb_open paths care about errno, so save it. */
        int saved_errno = errno;
 
-       if (!tdb->logfn)
+       if (!tdb->log_fn)
                return ecode;
 
        va_start(ap, fmt);
@@ -379,11 +406,11 @@ enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
        va_end(ap);
 
        if (len < 0) {
-               tdb->logfn(tdb, TDB_LOG_ERROR, tdb->log_private,
-                          "out of memory formatting message:");
-               tdb->logfn(tdb, level, tdb->log_private, fmt);
+               tdb->log_fn(tdb, TDB_LOG_ERROR,
+                           "out of memory formatting message:", tdb->log_data);
+               tdb->log_fn(tdb, level, fmt, tdb->log_data);
        } else {
-               tdb->logfn(tdb, level, tdb->log_private, message);
+               tdb->log_fn(tdb, level, message, tdb->log_data);
                free(message);
        }
        errno = saved_errno;
@@ -392,40 +419,39 @@ enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
 
 enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
                                 TDB_DATA key,
-                                enum TDB_ERROR (*parse)(TDB_DATA key,
-                                                        TDB_DATA data,
-                                                        void *p),
-                                void *p)
+                                enum TDB_ERROR (*parse)(TDB_DATA k,
+                                                        TDB_DATA d,
+                                                        void *data),
+                                void *data)
 {
        tdb_off_t off;
        struct tdb_used_record rec;
        struct hash_info h;
-       TDB_DATA data;
        enum TDB_ERROR ecode;
 
        off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
        if (TDB_OFF_IS_ERR(off)) {
-               return off;
+               return tdb->last_error = off;
        }
 
        if (!off) {
                ecode = TDB_ERR_NOEXIST;
        } else {
-               data.dsize = rec_data_length(&rec);
-               data.dptr = (void *)tdb_access_read(tdb,
-                                                   off + sizeof(rec)
-                                                   + key.dsize,
-                                                   data.dsize, false);
-               if (TDB_PTR_IS_ERR(data.dptr)) {
-                       ecode = TDB_PTR_ERR(data.dptr);
+               const void *dptr;
+               dptr = tdb_access_read(tdb, off + sizeof(rec) + key.dsize,
+                                      rec_data_length(&rec), false);
+               if (TDB_PTR_IS_ERR(dptr)) {
+                       ecode = TDB_PTR_ERR(dptr);
                } else {
-                       ecode = parse(key, data, p);
-                       tdb_access_release(tdb, data.dptr);
+                       TDB_DATA d = tdb_mkdata(dptr, rec_data_length(&rec));
+
+                       ecode = parse(key, d, data);
+                       tdb_access_release(tdb, dptr);
                }
        }
 
        tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
-       return ecode;
+       return tdb->last_error = ecode;
 }
 
 const char *tdb_name(const struct tdb_context *tdb)
@@ -433,6 +459,17 @@ const char *tdb_name(const struct tdb_context *tdb)
        return tdb->name;
 }
 
+int64_t tdb_get_seqnum(struct tdb_context *tdb)
+{
+       tdb_off_t off = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+       if (TDB_OFF_IS_ERR(off))
+               tdb->last_error = off;
+       else
+               tdb->last_error = TDB_SUCCESS;
+       return off;
+}
+       
+
 int tdb_fd(const struct tdb_context *tdb)
 {
        return tdb->file->fd;