From 911ca8c37e6dfe413490e2016d4486f0a561d35f Mon Sep 17 00:00:00 2001
From: Victor Shyba <victor1984@riseup.net>
Date: Fri, 19 Apr 2019 17:05:18 -0300
Subject: [PATCH] cache and share txs fetches while validating concurrently on
 batches

---
 lbrynet/wallet/resolve.py | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/lbrynet/wallet/resolve.py b/lbrynet/wallet/resolve.py
index d3f8ebb4b..b0b3108ce 100644
--- a/lbrynet/wallet/resolve.py
+++ b/lbrynet/wallet/resolve.py
@@ -1,5 +1,6 @@
 import logging
 
+import asyncio
 from cryptography.exceptions import InvalidSignature
 from binascii import unhexlify, hexlify
 
@@ -24,14 +25,18 @@ class Resolver:
         self.transaction_class = ledger.transaction_class
         self.network = ledger.network
         self.ledger = ledger
+        self._tx_cache = {}
 
     async def resolve(self, page, page_size, *uris):
+        uris = set(uris)
         try:
             for uri in uris:
                 parsed_uri = parse_lbry_uri(uri)
                 if parsed_uri.claim_id:
                     validate_claim_id(parsed_uri.claim_id)
             resolutions = await self.network.get_values_for_uris(self.header_hash, *uris)
+            if len(uris) > 1:
+                return await self._batch_handle(resolutions, uris, page, page_size)
             return await self._handle_resolutions(resolutions, uris, page, page_size)
         except URIParseError as err:
             return {'error': err.args[0]}
@@ -39,6 +44,17 @@ class Resolver:
             log.exception(e)
             return {'error': str(e)}
 
+    async def _batch_handle(self, resolutions, uris, page, page_size):
+        futs = []
+        for uri in uris:
+            futs.append(asyncio.ensure_future(self._handle_resolutions(resolutions, [uri], page, page_size)))
+        results = await asyncio.gather(*futs)
+        return {uri: results[uri] for uri in results if uri in results}
+
+    def _fetch_tx(self, txid):
+        self._tx_cache[txid] = self._tx_cache.get(txid) or asyncio.ensure_future(self.network.get_transaction(txid))
+        return self._tx_cache[txid]
+
     async def _handle_resolutions(self, resolutions, requested_uris, page, page_size):
         results = {}
         for uri in requested_uris:
@@ -135,13 +151,12 @@ class Resolver:
         if not claim_result or 'value' not in claim_result:
             return claim_result
         claim_result = _decode_claim_result(claim_result)
-        channel_id = None
 
         if claim_result['value']:
             claim_result['has_signature'] = False
             if claim_result['value'].is_signed:
                 claim_result['has_signature'] = True
-                claim_tx = await self.network.get_transaction(claim_result['txid'])
+                claim_tx = await self._fetch_tx(claim_result['txid'])
                 if certificate is None:
                     log.info("fetching certificate to check claim signature")
                     channel_id = claim_result['value'].signing_channel_id
@@ -149,7 +164,7 @@ class Resolver:
                     if not certificate:
                         log.warning('Certificate %s not found', channel_id)
                 claim_result['channel_name'] = certificate['name'] if certificate else None
-                cert_tx = await self.network.get_transaction(certificate['txid']) if certificate else None
+                cert_tx = await self._fetch_tx(certificate['txid']) if certificate else None
                 claim_result['signature_is_valid'] = validate_claim_signature_and_get_channel_name(
                     claim_result, certificate, self.ledger, claim_tx=claim_tx, cert_tx=cert_tx
                 )