update the history cache in place instead of clearing/rebuilding

hub/db/db.py

@@ -1173,7 +1173,7 @@ class HubDB:
             raise DBError(f'only got {len(self.headers) - height:,d} headers starting at {height:,d}, not {count:,d}')
         return [self.coin.header_hash(header) for header in self.headers[height:height + count]]
 
-    def _read_history(self, hashX: bytes, limit: int = 1000) -> List[int]:
+    def _read_history(self, hashX: bytes, limit: Optional[int] = 1000) -> List[int]:
         txs = []
         txs_extend = txs.extend
         for hist in self.prefix_db.hashX_history.iterate(prefix=(hashX,), include_key=False):
@@ -1182,7 +1182,7 @@ class HubDB:
                 break
         return txs
 
-    async def read_history(self, hashX: bytes, limit: int = 1000) -> List[int]:
+    async def read_history(self, hashX: bytes, limit: Optional[int] = 1000) -> List[int]:
         return await asyncio.get_event_loop().run_in_executor(self._executor, self._read_history, hashX, limit)
 
     async def limited_history(self, hashX, *, limit=1000):

hub/herald/service.py

@@ -46,9 +46,12 @@ class HubServerService(BlockchainReaderService):
     def advance(self, height: int):
         super().advance(height)
         touched_hashXs = self.db.prefix_db.touched_hashX.get(height).touched_hashXs
+        self.session_manager.update_history_caches(touched_hashXs)
         self.notifications_to_send.append((set(touched_hashXs), height))
 
     def unwind(self):
+        self.session_manager.hashX_raw_history_cache.clear()
+        self.session_manager.hashX_history_cache.clear()
         prev_count = self.db.tx_counts.pop()
         tx_count = self.db.tx_counts[-1]
         self.db.headers.pop()

hub/herald/session.py

@@ -1,5 +1,5 @@
 import os
-import ssl
+import sys
 import math
 import time
 import codecs
@@ -23,7 +23,7 @@ from hub.build_info import BUILD, COMMIT_HASH, DOCKER_TAG
 from hub.herald.search import SearchIndex
 from hub.common import sha256, hash_to_hex_str, hex_str_to_hash, HASHX_LEN, version_string, formatted_time, SIZE_BUCKETS
 from hub.common import protocol_version, RPCError, DaemonError, TaskGroup, HISTOGRAM_BUCKETS
-from hub.common import LRUCache, LRUCacheWithMetrics, asyncify_for_loop
+from hub.common import LRUCacheWithMetrics
 from hub.herald.jsonrpc import JSONRPCAutoDetect, JSONRPCConnection, JSONRPCv2, JSONRPC
 from hub.herald.common import BatchRequest, ProtocolError, Request, Batch, Notification
 from hub.herald.framer import NewlineFramer
@@ -33,6 +33,8 @@ if typing.TYPE_CHECKING:
     from hub.scribe.daemon import LBCDaemon
     from hub.herald.mempool import HubMemPool
 
+PYTHON_VERSION = sys.version_info.major, sys.version_info.minor
+TypedDict = dict if PYTHON_VERSION < (3, 8) else typing.TypedDict
 BAD_REQUEST = 1
 DAEMON_ERROR = 2
 
@@ -43,6 +45,11 @@ SignatureInfo = namedtuple('SignatureInfo', 'min_args max_args '
                            'required_names other_names')
 
 
+class CachedAddressHistoryItem(TypedDict):
+    tx_hash: str
+    height: int
+
+
 def scripthash_to_hashX(scripthash: str) -> bytes:
     try:
         bin_hash = hex_str_to_hash(scripthash)
@@ -205,16 +212,50 @@ class SessionManager:
             elastic_host=env.elastic_host, elastic_port=env.elastic_port
         )
         self.running = False
-        self.hashX_history_cache = LRUCacheWithMetrics(2 ** 14, metric_name='raw_history', namespace=NAMESPACE)
+        # hashX: List[int]
-        self.hashX_full_cache = LRUCacheWithMetrics(2 ** 12, metric_name='full_history', namespace=NAMESPACE)
+        self.hashX_raw_history_cache = LRUCacheWithMetrics(2 ** 16, metric_name='raw_history', namespace=NAMESPACE)
-        self.history_tx_info_cache = LRUCacheWithMetrics(2 ** 18, metric_name='history_tx', namespace=NAMESPACE)
+        # hashX: List[CachedAddressHistoryItem]
+        self.hashX_history_cache = LRUCacheWithMetrics(2 ** 14, metric_name='full_history', namespace=NAMESPACE)
+        # tx_num: Tuple[txid, height]
+        self.history_tx_info_cache = LRUCacheWithMetrics(2 ** 19, metric_name='history_tx', namespace=NAMESPACE)
 
     def clear_caches(self):
-        self.hashX_history_cache.clear()
-        self.hashX_full_cache.clear()
         self.resolve_outputs_cache.clear()
         self.resolve_cache.clear()
 
+    def update_history_caches(self, touched_hashXs: typing.List[bytes]):
+        update_history_cache = {}
+        for hashX in set(touched_hashXs):
+            history_tx_nums = None
+            # if the history is the raw_history_cache, update it
+            # TODO: use a reversed iterator for this instead of rescanning it all
+            if hashX in self.hashX_raw_history_cache:
+                self.hashX_raw_history_cache[hashX] = history_tx_nums = self.db._read_history(hashX, None)
+            # if it's in hashX_history_cache, prepare to update it in a batch
+            if hashX in self.hashX_history_cache:
+                full_cached = self.hashX_history_cache[hashX]
+                if history_tx_nums is None:
+                    history_tx_nums = self.db._read_history(hashX, None)
+                new_txs = history_tx_nums[len(full_cached):]
+                update_history_cache[hashX] = full_cached, new_txs
+        if update_history_cache:
+            # get the set of new tx nums that were touched in all of the new histories to be cached
+            total_tx_nums = set()
+            for _, new_txs in update_history_cache.values():
+                total_tx_nums.update(new_txs)
+            total_tx_nums = list(total_tx_nums)
+            # collect the total new tx infos
+            referenced_new_txs = {
+                tx_num: (CachedAddressHistoryItem(tx_hash=tx_hash[::-1].hex(), height=bisect_right(self.db.tx_counts, tx_num)))
+                for tx_num, tx_hash in zip(total_tx_nums, self.db._get_tx_hashes(total_tx_nums))
+            }
+            # update the cached history lists
+            get_referenced = referenced_new_txs.__getitem__
+            for hashX, (full, new_txs) in update_history_cache.items():
+                append_to_full = full.append
+                for tx_num in new_txs:
+                    append_to_full(get_referenced(tx_num))
+
     async def _start_server(self, kind, *args, **kw_args):
         loop = asyncio.get_event_loop()
 
@@ -603,45 +644,47 @@ class SessionManager:
         self.txs_sent += 1
         return hex_hash
 
-    async def limited_history(self, hashX: bytes) -> typing.List[typing.Tuple[str, int]]:
+    async def _cached_raw_history(self, hashX: bytes, limit: typing.Optional[int] = None):
-        cached_full_history = self.hashX_full_cache.get(hashX)
+        tx_nums = self.hashX_raw_history_cache.get(hashX)
+        if tx_nums is None:
+            self.hashX_raw_history_cache[hashX] = tx_nums = await self.db.read_history(hashX, limit)
+        return tx_nums
+
+    async def cached_confirmed_history(self, hashX: bytes,
+                                       limit: typing.Optional[int] = None) -> typing.List[CachedAddressHistoryItem]:
+        cached_full_history = self.hashX_history_cache.get(hashX)
+        # return the cached history
         if cached_full_history is not None:
             self.address_history_size_metric.observe(len(cached_full_history))
             return cached_full_history
-        if hashX not in self.hashX_history_cache:
+        # return the history and update the caches
-            limit = self.env.max_send // 97
+        tx_nums = await self._cached_raw_history(hashX, limit)
-            self.hashX_history_cache[hashX] = tx_nums = await self.db.read_history(hashX, limit)
-        else:
-            tx_nums = self.hashX_history_cache[hashX]
-        self.address_history_size_metric.observe(len(tx_nums))
         needed_tx_infos = []
         append_needed_tx_info = needed_tx_infos.append
         tx_infos = {}
-        cnt = 0
+        for cnt, tx_num in enumerate(tx_nums):  # determine which tx_hashes are cached and which we need to look up
-        for tx_num in tx_nums:
             cached = self.history_tx_info_cache.get(tx_num)
             if cached is not None:
                 tx_infos[tx_num] = cached
             else:
                 append_needed_tx_info(tx_num)
-            cnt += 1
             if cnt % 1000 == 0:
                 await asyncio.sleep(0)
-        if needed_tx_infos:
+        if needed_tx_infos:  # request all the needed tx hashes in one batch, cache the txids and heights
-            for tx_num, tx_hash in zip(needed_tx_infos, await self.db.get_tx_hashes(needed_tx_infos)):
+            for cnt, (tx_num, tx_hash) in enumerate(zip(needed_tx_infos, await self.db.get_tx_hashes(needed_tx_infos))):
-                hist = tx_hash[::-1].hex(), bisect_right(self.db.tx_counts, tx_num)
+                hist = CachedAddressHistoryItem(tx_hash=tx_hash[::-1].hex(), height=bisect_right(self.db.tx_counts, tx_num))
                 tx_infos[tx_num] = self.history_tx_info_cache[tx_num] = hist
-                cnt += 1
                 if cnt % 1000 == 0:
                     await asyncio.sleep(0)
+        # ensure the ordering of the txs
         history = []
         history_append = history.append
-        for tx_num in tx_nums:
+        for cnt, tx_num in enumerate(tx_nums):
             history_append(tx_infos[tx_num])
-            self.hashX_full_cache[hashX] = history
-            cnt += 1
             if cnt % 1000 == 0:
                 await asyncio.sleep(0)
+        self.hashX_history_cache[hashX] = history
+        self.address_history_size_metric.observe(len(history))
         return history
 
     def _notify_peer(self, peer):
@@ -1463,13 +1506,8 @@ class LBRYElectrumX(asyncio.Protocol):
 
     async def confirmed_and_unconfirmed_history(self, hashX):
         # Note history is ordered but unconfirmed is unordered in e-s
-        history = await self.session_manager.limited_history(hashX)
+        history = await self.session_manager.cached_confirmed_history(hashX)
-        conf = [
+        return history + self.unconfirmed_history(hashX)
-            item async for item in asyncify_for_loop(
-                ({'tx_hash': txid, 'height': height} for txid, height in history), 1000
-            )
-        ]
-        return conf + self.unconfirmed_history(hashX)
 
     async def scripthash_get_history(self, scripthash):
         """Return the confirmed and unconfirmed history of a scripthash."""