Include hashes of previous pdus when referencing them

4 files changed, 77 insertions, 12 deletions

diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index b2a3f0b56c..af05b47932 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -177,6 +177,14 @@ class DataStore(RoomMemberStore, RoomStore,
                 txn, pdu.pdu_id, pdu.origin, key_id, signature_bytes,
             )
 
+        for prev_pdu_id, prev_origin, prev_hashes in pdu.prev_pdus:
+            for alg, hash_base64 in prev_hashes.items():
+                hash_bytes = decode_base64(hash_base64)
+                self._store_prev_pdu_hash_txn(
+                    txn, pdu.pdu_id, pdu.origin, prev_pdu_id, prev_origin, alg,
+                    hash_bytes
+                )
+
         if pdu.is_state:
             self._persist_state_txn(txn, pdu.prev_pdus, cols)
         else:
@@ -352,6 +360,7 @@ class DataStore(RoomMemberStore, RoomStore,
             prev_pdus = self._get_latest_pdus_in_context(
                 txn, room_id
             )
+
             if state_type is not None and state_key is not None:
                 prev_state_pdu = self._get_current_state_pdu(
                     txn, room_id, state_type, state_key
@@ -401,17 +410,16 @@ class Snapshot(object):
         self.prev_state_pdu = prev_state_pdu
 
     def fill_out_prev_events(self, event):
-        if hasattr(event, "prev_events"):
+        if hasattr(event, "prev_pdus"):
             return
 
-        es = [
-            "%s@%s" % (p_id, origin) for p_id, origin, _ in self.prev_pdus
+        event.prev_pdus = [
+            (p_id, origin, hashes)
+            for p_id, origin, hashes, _ in self.prev_pdus
         ]
 
-        event.prev_events = [e for e in es if e != event.event_id]
-
         if self.prev_pdus:
-            event.depth = max([int(v) for _, _, v in self.prev_pdus]) + 1
+            event.depth = max([int(v) for _, _, _, v in self.prev_pdus]) + 1
         else:
             event.depth = 0
 
diff --git a/synapse/storage/pdu.py b/synapse/storage/pdu.py
index 9d624429b7..a423b42dbd 100644
--- a/synapse/storage/pdu.py
+++ b/synapse/storage/pdu.py
@@ -20,10 +20,13 @@ from ._base import SQLBaseStore, Table, JoinHelper
 from synapse.federation.units import Pdu
 from synapse.util.logutils import log_function
 
+from syutil.base64util import encode_base64
+
 from collections import namedtuple
 
 import logging
 
+
 logger = logging.getLogger(__name__)
 
 
@@ -64,6 +67,8 @@ class PduStore(SQLBaseStore):
                 for r in PduEdgesTable.decode_results(txn.fetchall())
             ]
 
+            edge_hashes = self._get_prev_pdu_hashes_txn(txn, pdu_id, origin)
+
             hashes = self._get_pdu_hashes_txn(txn, pdu_id, origin)
             signatures = self._get_pdu_origin_signatures_txn(
                 txn, pdu_id, origin
@@ -86,7 +91,7 @@ class PduStore(SQLBaseStore):
             row = txn.fetchone()
             if row:
                 results.append(PduTuple(
-                    PduEntry(*row), edges, hashes, signatures
+                    PduEntry(*row), edges, hashes, signatures, edge_hashes
                 ))
 
         return results
@@ -310,9 +315,14 @@ class PduStore(SQLBaseStore):
             (context, )
         )
 
-        results = txn.fetchall()
+        results = []
+        for pdu_id, origin, depth in txn.fetchall():
+            hashes = self._get_pdu_hashes_txn(txn, pdu_id, origin)
+            sha256_bytes = hashes["sha256"]
+            prev_hashes = {"sha256": encode_base64(sha256_bytes)}
+            results.append((pdu_id, origin, prev_hashes, depth))
 
-        return [(row[0], row[1], row[2]) for row in results]
+        return results
 
     @defer.inlineCallbacks
     def get_oldest_pdus_in_context(self, context):
@@ -431,7 +441,7 @@ class PduStore(SQLBaseStore):
                 "DELETE FROM %s WHERE pdu_id = ? AND origin = ?"
                 % PduForwardExtremitiesTable.table_name
             )
-            txn.executemany(query, prev_pdus)
+            txn.executemany(query, list(p[:2] for p in prev_pdus))
 
             # We only insert as a forward extremety the new pdu if there are no
             # other pdus that reference it as a prev pdu
@@ -454,7 +464,7 @@ class PduStore(SQLBaseStore):
             # deleted in a second if they're incorrect anyway.
             txn.executemany(
                 PduBackwardExtremitiesTable.insert_statement(),
-                [(i, o, context) for i, o in prev_pdus]
+                [(i, o, context) for i, o, _ in prev_pdus]
             )
 
             # Also delete from the backwards extremities table all ones that
@@ -915,7 +925,7 @@ This does not include a prev_pdus key.
 
 PduTuple = namedtuple(
     "PduTuple",
-    ("pdu_entry", "prev_pdu_list", "hashes", "signatures")
+    ("pdu_entry", "prev_pdu_list", "hashes", "signatures", "edge_hashes")
 )
 """ This is a tuple of a `PduEntry` and a list of `PduIdTuple` that represent
 the `prev_pdus` key of a PDU.
diff --git a/synapse/storage/schema/signatures.sql b/synapse/storage/schema/signatures.sql
index 86ee0f2377..a72c4dc35f 100644
--- a/synapse/storage/schema/signatures.sql
+++ b/synapse/storage/schema/signatures.sql
@@ -34,3 +34,19 @@ CREATE TABLE IF NOT EXISTS pdu_origin_signatures (
 CREATE INDEX IF NOT EXISTS pdu_origin_signatures_id ON pdu_origin_signatures (
     pdu_id, origin
 );
+
+CREATE TABLE IF NOT EXISTS pdu_edge_hashes(
+    pdu_id TEXT,
+    origin TEXT,
+    prev_pdu_id TEXT,
+    prev_origin TEXT,
+    algorithm TEXT,
+    hash BLOB,
+    CONSTRAINT uniqueness UNIQUE (
+        pdu_id, origin, prev_pdu_id, prev_origin, algorithm
+    )
+);
+
+CREATE INDEX IF NOT EXISTS pdu_edge_hashes_id ON pdu_edge_hashes(
+    pdu_id, origin
+);
diff --git a/synapse/storage/signatures.py b/synapse/storage/signatures.py
index 1f0a680500..1147102489 100644
--- a/synapse/storage/signatures.py
+++ b/synapse/storage/signatures.py
@@ -88,3 +88,34 @@ class SignatureStore(SQLBaseStore):
             "signature": buffer(signature_bytes),
         })
 
+    def _get_prev_pdu_hashes_txn(self, txn, pdu_id, origin):
+        """Get all the hashes for previous PDUs of a PDU
+        Args:
+            txn (cursor):
+            pdu_id (str): Id of the PDU.
+            origin (str): Origin of the PDU.
+        Returns:
+            dict of (pdu_id, origin) -> dict of algorithm -> hash_bytes.
+        """
+        query = (
+            "SELECT prev_pdu_id, prev_origin, algorithm, hash"
+            " FROM pdu_edge_hashes"
+            " WHERE pdu_id = ? and origin = ?"
+        )
+        txn.execute(query, (pdu_id, origin))
+        results = {}
+        for prev_pdu_id, prev_origin, algorithm, hash_bytes in txn.fetchall():
+            hashes = results.setdefault((prev_pdu_id, prev_origin), {})
+            hashes[algorithm] = hash_bytes
+        return results
+
+    def _store_prev_pdu_hash_txn(self, txn, pdu_id, origin, prev_pdu_id,
+                             prev_origin, algorithm, hash_bytes):
+        self._simple_insert_txn(txn, "pdu_edge_hashes", {
+            "pdu_id": pdu_id,
+            "origin": origin,
+            "prev_pdu_id": prev_pdu_id,
+            "prev_origin": prev_origin,
+            "algorithm": algorithm,
+            "hash": buffer(hash_bytes),
+        })