From 0a833f5f8325bab1b68e44a78931d000276ae0e7 Mon Sep 17 00:00:00 2001
From: Jack Robison <jackrobison@lbry.io>
Date: Fri, 19 Feb 2021 13:22:07 -0500
Subject: [PATCH] transaction_num_mapping

---
 lbry/wallet/server/block_processor.py | 2 +-
 lbry/wallet/server/leveldb.py         | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/lbry/wallet/server/block_processor.py b/lbry/wallet/server/block_processor.py
index 24c53d392..fd304fb92 100644
--- a/lbry/wallet/server/block_processor.py
+++ b/lbry/wallet/server/block_processor.py
@@ -544,7 +544,7 @@ class BlockProcessor:
                 self.utxo_cache[txin.prev_hash + s_pack('<H', txin.prev_idx)] = undo_item
                 self.touched.add(undo_item[:-12])
 
-            self.db.total_transactions.pop()
+            self.db.transaction_num_mapping.pop(self.db.total_transactions.pop())
 
         assert n == 0
         self.tx_count -= len(txs)
diff --git a/lbry/wallet/server/leveldb.py b/lbry/wallet/server/leveldb.py
index 6dc30eaac..f509a14a7 100644
--- a/lbry/wallet/server/leveldb.py
+++ b/lbry/wallet/server/leveldb.py
@@ -111,6 +111,7 @@ class LevelDB:
 
         self._tx_and_merkle_cache = LRUCacheWithMetrics(2 ** 17, metric_name='tx_and_merkle', namespace="wallet_server")
         self.total_transactions = None
+        self.transaction_num_mapping = {}
 
     # def add_unflushed(self, hashXs_by_tx, first_tx_num):
     #     unflushed = self.history.unflushed
@@ -156,6 +157,9 @@ class LevelDB:
         txids = await asyncio.get_event_loop().run_in_executor(self.executor, get_txids)
         assert len(txids) == len(self.tx_counts) == 0 or len(txids) == self.tx_counts[-1]
         self.total_transactions = txids
+        self.transaction_num_mapping = {
+            txid: i for i, txid in enumerate(txids)
+        }
         ts = time.perf_counter() - start
         self.logger.info("loaded %i txids in %ss", len(self.total_transactions), round(ts, 4))