Reset the main transaction after a term insert instead of opening RW all times.

lakesuperior/store/ldp_rs/lmdb_triplestore.pyx

@@ -1238,36 +1238,31 @@ cdef class LmdbTriplestore(BaseLmdbStore):
         key_v.mv_data = thash
         key_v.mv_size = HLEN
 
-        # Unfortunately, we have to open a RW transaction even if the term is
-        # found and we don't have write to the store. Because if we have to,
-        # the term is not found outside of the RW txn until the *parent* RO
-        # txn is committed.
-
-        if self.is_txn_rw:
-            # Use existing R/W transaction.
-            logger.info('Working in existing RW transaction.')
-            _txn = self.txn
-        else:
-            # Open new R/W transaction.
-            logger.info('Opening a temporary RW transaction.')
-            _check(lmdb.mdb_txn_begin(self.dbenv, NULL, 0, &_txn))
-
         try:
-            try:
-                logger.info(
-                    f'Check {buffer_dump(&pk_t)} with hash '
-                    f'{(<unsigned char*>thash)[:HLEN]} in store before adding.'
-                )
-                logger.info(f'Store path: {self.env_path}')
-                _check(lmdb.mdb_get(
-                    _txn, self.get_dbi(b'th:t'), &key_v, &data_v)
-                )
+            logger.info(
+                f'Check {buffer_dump(&pk_t)} with hash '
+                f'{(<unsigned char*>thash)[:HLEN]} in store before adding.'
+            )
+            logger.info(f'Store path: {self.env_path}')
+            _check(lmdb.mdb_get(
+                self.txn, self.get_dbi(b'th:t'), &key_v, &data_v)
+            )
 
-                tk = (<Key*>data_v.mv_data)[0]
+            return (<Key*>data_v.mv_data)[0]
 
-            except KeyNotFoundError:
-                logger.info(f'Adding term {term} to store.')
-                # If key is not in the store, add it.
+        except KeyNotFoundError:
+            logger.info(f'Adding term {term} to store.')
+            # If key is not in the store, add it.
+            if self.is_txn_rw:
+                # Use existing R/W transaction.
+                logger.info('Working in existing RW transaction.')
+                _txn = self.txn
+            else:
+                # Open new R/W transaction.
+                logger.info('Opening a temporary RW transaction.')
+                _check(lmdb.mdb_txn_begin(self.dbenv, NULL, 0, &_txn))
+
+            try:
                 # Main entry.
                 tk = self._append(&pk_t, b't:st', txn=_txn)
 
@@ -1277,16 +1272,17 @@ cdef class LmdbTriplestore(BaseLmdbStore):
                 _check(lmdb.mdb_put(
                     _txn, self.get_dbi(b'th:t'), &key_v, &data_v, 0
                 ))
+                if not self.is_txn_rw:
+                    _check(lmdb.mdb_txn_commit(_txn))
+                    # Kick the main transaction to see the new terms.
+                    lmdb.mdb_txn_reset(self.txn)
+                    _check(lmdb.mdb_txn_renew(self.txn))
 
-            if not self.is_txn_rw:
-                _check(lmdb.mdb_txn_commit(_txn))
-
-            return tk
-
-        except:
-            if not self.is_txn_rw:
-                lmdb.mdb_txn_abort(_txn)
-            raise
+                return tk
+            except:
+                if not self.is_txn_rw:
+                    lmdb.mdb_txn_abort(_txn)
+                raise
 
 
     cdef Key _append(