Improved ranking for search results and updated search UI without the artifical delay at the loading screen

src/tribler/core/components/gigachannel/community/sync_strategy.py

@@ -3,15 +3,22 @@
 from ipv8.peerdiscovery.discovery import DiscoveryStrategy
 
 
+TARGET_PEERS_NUMBER = 20
+
+
 class RemovePeers(DiscoveryStrategy):
     """
     Synchronization strategy for remote query community.
 
     Remove a random peer, if we have enough peers to walk to.
     """
 
+    def __init__(self, overlay, target_peers_number=TARGET_PEERS_NUMBER):
+        super().__init__(overlay)
+        self.target_peers_number = target_peers_number
+
     def take_step(self):
         with self.walk_lock:
             peers = self.overlay.get_peers()
-            if peers and len(peers) > 20:
+            if peers and len(peers) > self.target_peers_number:
                 self.overlay.network.remove_peer(choice(peers))

src/tribler/core/components/metadata_store/db/store.py

@@ -10,6 +10,7 @@
 
 from pony import orm
 from pony.orm import db_session, desc, left_join, raw_sql, select
+from pony.orm.dbproviders.sqlite import keep_exception
 
 from tribler.core import notifications
 from tribler.core.components.metadata_store.db.orm_bindings import (
@@ -50,9 +51,11 @@
 from tribler.core.utilities.notifier import Notifier
 from tribler.core.utilities.path_util import Path
 from tribler.core.utilities.pony_utils import get_max, get_or_create
+from tribler.core.utilities.search_utils import torrent_rank
 from tribler.core.utilities.unicode import hexlify
 from tribler.core.utilities.utilities import MEMORY_DB
 
+
 BETA_DB_VERSIONS = [0, 1, 2, 3, 4, 5]
 CURRENT_DB_VERSION = 14
 
@@ -167,7 +170,7 @@ def __init__(
         # with the static analysis.
         # pylint: disable=unused-variable
         @self._db.on_connect(provider='sqlite')
-        def sqlite_disable_sync(_, connection):
+        def on_connect(_, connection):
             cursor = connection.cursor()
             cursor.execute("PRAGMA journal_mode = WAL")
             cursor.execute("PRAGMA synchronous = NORMAL")
@@ -180,6 +183,10 @@ def sqlite_disable_sync(_, connection):
                 # losing power during a write will corrupt the database.
                 cursor.execute("PRAGMA journal_mode = 0")
                 cursor.execute("PRAGMA synchronous = 0")
+
+            sqlite_rank = keep_exception(torrent_rank)
+            connection.create_function('search_rank', 5, sqlite_rank)
+
             # pylint: enable=unused-variable
 
         self.MiscData = misc.define_binding(self._db)
@@ -591,7 +598,7 @@ def torrent_exists_in_personal_channel(self, infohash):
         )
 
     # pylint: disable=unused-argument
-    def search_keyword(self, query, lim=100):
+    def search_keyword(self, query):
         # Requires FTS5 table "FtsIndex" to be generated and populated.
         # FTS table is maintained automatically by SQL triggers.
         # BM25 ranking is embedded in FTS5.
@@ -600,10 +607,11 @@ def search_keyword(self, query, lim=100):
         if not query or query == "*":
             return []
 
-        fts_ids = raw_sql(
-            """SELECT rowid FROM ChannelNode WHERE rowid IN (SELECT rowid FROM FtsIndex WHERE FtsIndex MATCH $query
-            ORDER BY bm25(FtsIndex) LIMIT $lim) GROUP BY coalesce(infohash, rowid)"""
-        )
+        fts_ids = raw_sql("""
+            SELECT rowid FROM ChannelNode
+            WHERE rowid IN (SELECT rowid FROM FtsIndex WHERE FtsIndex MATCH $query)
+            GROUP BY coalesce(infohash, rowid)
+        """)
         return left_join(g for g in self.MetadataNode if g.rowid in fts_ids)  # pylint: disable=E1135
 
     @db_session
@@ -639,7 +647,7 @@ def get_entries_query(
 
         if cls is None:
             cls = self.ChannelNode
-        pony_query = self.search_keyword(txt_filter, lim=1000) if txt_filter else left_join(g for g in cls)
+        pony_query = self.search_keyword(txt_filter) if txt_filter else left_join(g for g in cls)
         infohash_set = infohash_set or ({infohash} if infohash else None)
         if popular:
             if metadata_type != REGULAR_TORRENT:
@@ -728,10 +736,49 @@ def get_entries_query(
 
         if sort_by is None:
             if txt_filter:
+                # pylint: disable=W0105
+                """
+                The following call of `sort_by` produces an ORDER BY expression that looks like this:
+
+                ORDER BY
+                    case when "g"."metadata_type" = $CHANNEL_TORRENT then 1
+                         when "g"."metadata_type" = $COLLECTION_NODE then 2
+                         else 3 end,
+
+                    search_rank(
+                        $QUERY_STRING,
+                        g.title,
+                        torrentstate.seeders,
+                        torrentstate.leechers,
+                        $CURRENT_TIME - strftime('%s', g.torrent_date)
+                    ) DESC,
+
+                    "torrentstate"."last_check" DESC,
+
+                So, the channel torrents and channel folders are always on top if they are not filtered out.
+                Then regular torrents are selected in order of their relevance according to a search_rank() result.
+                If two torrents have the same search rank, they are ordered by the last time they were checked.
+
+                The search_rank() function is called directly from the SQLite query, but is implemented in Python,
+                it is actually the torrent_rank() function from core/utilities/search_utils.py, wrapped with
+                keep_exception() to return possible exception from SQLite to Python.
+
+                The search_rank() function receives the following arguments:
+                  - the current query string (like "Big Buck Bunny");
+                  - the title of the current torrent;
+                  - the number of seeders;
+                  - the number of leechers;
+                  - the number of seconds since the torrent's creation time.
+                """
+
                 pony_query = pony_query.sort_by(
                     f"""
                     (1 if g.metadata_type == {CHANNEL_TORRENT} else 2 if g.metadata_type == {COLLECTION_NODE} else 3),
-                    desc(g.health.seeders), desc(g.health.leechers)
+                    raw_sql('''search_rank(
+                        $txt_filter, g.title, torrentstate.seeders, torrentstate.leechers,
+                        $int(time()) - strftime('%s', g.torrent_date)
+                    ) DESC'''),
+                    desc(g.health.last_check)  # just to trigger the TorrentState table inclusion into the left join
                 """
                 )
             elif popular:

src/tribler/core/components/metadata_store/remote_query_community/remote_query_community.py

@@ -1,8 +1,10 @@
 import json
 import struct
+import time
 from asyncio import Future
 from binascii import unhexlify
-from typing import List, Optional, Set
+from itertools import count
+from typing import Any, Dict, List, Optional, Set
 
 from ipv8.lazy_community import lazy_wrapper
 from ipv8.messaging.lazy_payload import VariablePayload, vp_compile
@@ -26,7 +28,7 @@
 BINARY_FIELDS = ("infohash", "channel_pk")
 
 
-def sanitize_query(query_dict, cap=100):
+def sanitize_query(query_dict: Dict[str, Any], cap=100) -> Dict[str, Any]:
     sanitized_dict = dict(query_dict)
 
     # We impose a cap on max numbers of returned entries to prevent DDOS-like attacks
@@ -151,6 +153,8 @@ def __init__(self, my_peer, endpoint, network,
         self.add_message_handler(SelectResponsePayload, self.on_remote_select_response)
 
         self.eva = EVAProtocol(self, self.on_receive, self.on_send_complete, self.on_error)
+        self.remote_queries_in_progress = 0
+        self.next_remote_query_num = count().__next__  # generator of sequential numbers, for logging & debug purposes
 
     async def on_receive(self, result: TransferResult):
         self.logger.debug(f"EVA data received: peer {hexlify(result.peer.mid)}, info {result.info}")
@@ -183,16 +187,32 @@ def send_remote_select(self, peer, processing_callback=None, force_eva_response=
             self.ez_send(peer, RemoteSelectPayload(*args))
         return request
 
-    async def process_rpc_query(self, json_bytes: bytes):
+    def should_limit_rate_for_query(self, sanitized_parameters: Dict[str, Any]) -> bool:
+        return 'txt_filter' in sanitized_parameters
+
+    async def process_rpc_query_rate_limited(self, sanitized_parameters: Dict[str, Any]) -> List:
+        query_num = self.next_remote_query_num()
+        if self.remote_queries_in_progress and self.should_limit_rate_for_query(sanitized_parameters):
+            self.logger.warning(f'Ignore remote query {query_num} as another one is already processing. '
+                                f'The ignored query: {sanitized_parameters}')
+            return []
+
+        self.logger.info(f'Process remote query {query_num}: {sanitized_parameters}')
+        self.remote_queries_in_progress += 1
+        t = time.time()
+        try:
+            return await self.process_rpc_query(sanitized_parameters)
+        finally:
+            self.remote_queries_in_progress -= 1
+            self.logger.info(f'Remote query {query_num} processed in {time.time()-t} seconds: {sanitized_parameters}')
+
+    async def process_rpc_query(self, sanitized_parameters: Dict[str, Any]) -> List:
         """
         Retrieve the result of a database query from a third party, encoded as raw JSON bytes (through `dumps`).
         :raises TypeError: if the JSON contains invalid keys.
         :raises ValueError: if no JSON could be decoded.
         :raises pony.orm.dbapiprovider.OperationalError: if an illegal query was performed.
         """
-        parameters = json.loads(json_bytes)
-        sanitized_parameters = sanitize_query(parameters, self.rqc_settings.max_response_size)
-
         # tags should be extracted because `get_entries_threaded` doesn't expect them as a parameter
         tags = sanitized_parameters.pop('tags', None)
 
@@ -237,9 +257,14 @@ async def on_remote_select_eva(self, peer, request_payload):
     async def on_remote_select(self, peer, request_payload):
         await self._on_remote_select_basic(peer, request_payload)
 
+    def parse_parameters(self, json_bytes: bytes) -> Dict[str, Any]:
+        parameters = json.loads(json_bytes)
+        return sanitize_query(parameters, self.rqc_settings.max_response_size)
+
     async def _on_remote_select_basic(self, peer, request_payload, force_eva_response=False):
         try:
-            db_results = await self.process_rpc_query(request_payload.json)
+            sanitized_parameters = self.parse_parameters(request_payload.json)
+            db_results = await self.process_rpc_query_rate_limited(sanitized_parameters)
 
             # When we send our response to a host, we open a window of opportunity
             # for it to push back updates

src/tribler/core/components/metadata_store/remote_query_community/settings.py

@@ -5,7 +5,16 @@ class RemoteQueryCommunitySettings(TriblerConfigSection):
     minimal_blob_size: int = 200
     maximum_payload_size: int = 1300
     max_entries: int = maximum_payload_size // minimal_blob_size
-    max_query_peers: int = 5
+
+    # The next option is currently used by GigaChannelCommunity only. We probably should move it to the
+    # GigaChannelCommunity settings or to a dedicated search-related section. The value of the option is corresponding
+    # with the TARGET_PEERS_NUMBER of src/tribler/core/components/gigachannel/community/sync_strategy.py, that is, to
+    # the number of peers that GigaChannelCommunity will have after a long run (initially, the number of peers in
+    # GigaChannelCommunity can rise up to several hundred due to DiscoveryBooster). The number of parallel remote
+    # requests should be not too small (to have various results from remote peers) and not too big (to avoid flooding
+    # the network with exceedingly high number of queries). TARGET_PEERS_NUMBER looks like a good middle ground here.
+    max_query_peers: int = 20
+
     max_response_size: int = 100  # Max number of entries returned by SQL query
     max_channel_query_back: int = 4  # Max number of entries to query back on receiving an unknown channel
     push_updates_back_enabled = True

src/tribler/core/components/metadata_store/remote_query_community/tests/test_remote_query_community.py

@@ -1,11 +1,10 @@
 import random
 import string
+import time
 from asyncio import sleep
 from binascii import unhexlify
-from json import dumps
 from operator import attrgetter
 from os import urandom
-from time import time
 from unittest.mock import Mock, patch
 
 from ipv8.keyvault.crypto import default_eccrypto
@@ -112,7 +111,7 @@ async def test_remote_select(self):
                     channel=channel,
                     seeders=2 * i,
                     leechers=i,
-                    last_check=int(time()) + i,
+                    last_check=int(time.time()) + i,
                 )
 
         kwargs_dict = {"txt_filter": "ubuntu*", "metadata_type": [REGULAR_TORRENT]}
@@ -345,7 +344,7 @@ async def test_process_rpc_query_match_many(self):
             channel = self.channel_metadata(0).create_channel("a channel", "")
             add_random_torrent(self.torrent_metadata(0), name="a torrent", channel=channel)
 
-        results = await self.overlay(0).process_rpc_query(dumps({}))
+        results = await self.overlay(0).process_rpc_query({})
         self.assertEqual(2, len(results))
 
         channel_md, torrent_md = results if isinstance(results[0], self.channel_metadata(0)) else results[::-1]
@@ -359,7 +358,7 @@ async def test_process_rpc_query_match_one(self):
         with db_session:
             self.channel_metadata(0).create_channel("a channel", "")
 
-        results = await self.overlay(0).process_rpc_query(dumps({}))
+        results = await self.overlay(0).process_rpc_query({})
         self.assertEqual(1, len(results))
 
         (channel_md,) = results
@@ -369,22 +368,22 @@ async def test_process_rpc_query_match_none(self):
         """
         Check if a correct query with no match in our database returns no result.
         """
-        results = await self.overlay(0).process_rpc_query(dumps({}))
+        results = await self.overlay(0).process_rpc_query({})
         self.assertEqual(0, len(results))
 
-    async def test_process_rpc_query_match_empty_json(self):
+    def test_parse_parameters_match_empty_json(self):
         """
         Check if processing an empty request causes a ValueError (JSONDecodeError) to be raised.
         """
         with self.assertRaises(ValueError):
-            await self.overlay(0).process_rpc_query(b'')
+            self.overlay(0).parse_parameters(b'')
 
-    async def test_process_rpc_query_match_illegal_json(self):
+    def test_parse_parameters_match_illegal_json(self):
         """
         Check if processing a request with illegal JSON causes a UnicodeDecodeError to be raised.
         """
         with self.assertRaises(UnicodeDecodeError):
-            await self.overlay(0).process_rpc_query(b'{"akey":\x80}')
+            self.overlay(0).parse_parameters(b'{"akey":\x80}')
 
     async def test_process_rpc_query_match_invalid_json(self):
         """
@@ -394,21 +393,24 @@ async def test_process_rpc_query_match_invalid_json(self):
             self.channel_metadata(0).create_channel("a channel", "")
         query = b'{"id_":' + b'\x31' * 200 + b'}'
         with self.assertRaises(ValueError):
-            await self.overlay(0).process_rpc_query(query)
+            parameters = self.overlay(0).parse_parameters(query)
+            await self.overlay(0).process_rpc_query(parameters)
 
     async def test_process_rpc_query_match_invalid_key(self):
         """
         Check if processing a request with invalid flags causes a UnicodeDecodeError to be raised.
         """
         with self.assertRaises(TypeError):
-            await self.overlay(0).process_rpc_query(b'{"bla":":("}')
+            parameters = self.overlay(0).parse_parameters(b'{"bla":":("}')
+            await self.overlay(0).process_rpc_query(parameters)
 
     async def test_process_rpc_query_no_column(self):
         """
         Check if processing a request with no database columns causes an OperationalError.
         """
         with self.assertRaises(OperationalError):
-            await self.overlay(0).process_rpc_query(b'{"txt_filter":{"key":"bla"}}')
+            parameters = self.overlay(0).parse_parameters(b'{"txt_filter":{"key":"bla"}}')
+            await self.overlay(0).process_rpc_query(parameters)
 
     async def test_remote_query_big_response(self):
 
@@ -574,3 +576,45 @@ async def test_remote_select_force_eva(self):
         await self.deliver_messages(timeout=0.5)
 
         self.nodes[1].overlay.eva.send_binary.assert_called_once()
+
+    async def test_multiple_parallel_request(self):
+        peer_a = self.nodes[0].my_peer
+        a = self.nodes[0].overlay
+        b = self.nodes[1].overlay
+
+        # Peer A has two torrents "foo" and "bar"
+        with db_session:
+            add_random_torrent(a.mds.TorrentMetadata, name="foo")
+            add_random_torrent(a.mds.TorrentMetadata, name="bar")
+
+        # Peer B sends two parallel full-text search queries, only one of them should be processed
+        callback1 = Mock()
+        kwargs1 = {"txt_filter": "foo", "metadata_type": [REGULAR_TORRENT]}
+        b.send_remote_select(peer_a, **kwargs1, processing_callback=callback1)
+
+        callback2 = Mock()
+        kwargs2 = {"txt_filter": "bar", "metadata_type": [REGULAR_TORRENT]}
+        b.send_remote_select(peer_a, **kwargs2, processing_callback=callback2)
+
+        original_get_entries = MetadataStore.get_entries
+        # Add a delay to ensure that the first query is still being processed when the second one arrives
+        # (the mds.get_entries() method is a synchronous one and is called from a worker thread)
+
+        def slow_get_entries(self, *args, **kwargs):
+            time.sleep(0.1)
+            return original_get_entries(self, *args, **kwargs)
+
+        with patch.object(a, 'logger') as logger, patch.object(MetadataStore, 'get_entries', slow_get_entries):
+            await self.deliver_messages(timeout=0.5)
+
+        torrents1 = list(b.mds.get_entries(**kwargs1))
+        torrents2 = list(b.mds.get_entries(**kwargs2))
+
+        # Both remote queries should return results to the peer B...
+        assert callback1.called and callback2.called
+        # ...but one of them should return an empty list, as the database query was not actually executed
+        assert bool(torrents1) != bool(torrents2)
+
+        # Check that on peer A there is exactly one warning about an ignored remote query
+        warnings = [call.args[0] for call in logger.warning.call_args_list]
+        assert len([msg for msg in warnings if msg.startswith('Ignore remote query')]) == 1