From c30db15efac0189e336cecb07ce340f47ffc58ba Mon Sep 17 00:00:00 2001
From: Victor Shyba <victor1984@riseup.net>
Date: Fri, 27 Sep 2019 09:09:17 -0300
Subject: [PATCH] faster header download

---
 torba/torba/client/baseledger.py  | 14 ++++++++++++++
 torba/torba/client/basenetwork.py |  5 +++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/torba/torba/client/baseledger.py b/torba/torba/client/baseledger.py
index 7fd5a09e3..41b4191e7 100644
--- a/torba/torba/client/baseledger.py
+++ b/torba/torba/client/baseledger.py
@@ -285,6 +285,8 @@ class BaseLedger(metaclass=LedgerRegistry):
         first_connection = self.network.on_connected.first
         asyncio.ensure_future(self.network.start())
         await first_connection
+        async with self._header_processing_lock:
+            await self.initial_headers_sync()
         await self.join_network()
         self.network.on_connected.listen(self.join_network)
 
@@ -303,6 +305,18 @@ class BaseLedger(metaclass=LedgerRegistry):
         await self.db.close()
         await self.headers.close()
 
+    async def initial_headers_sync(self):
+        target = self.network.remote_height
+        current = len(self.headers)
+        get_chunk = partial(self.network.retriable_call, self.network.get_headers, count=2000)
+        chunks = [asyncio.ensure_future(get_chunk(height)) for height in range(current, target, 2000)]
+        for chunk in chunks:
+            headers = await chunk
+            if not headers:
+                continue
+            headers = headers['hex']
+            await self.update_headers(height=len(self.headers), headers=headers, subscription_update=True)
+
     async def update_headers(self, height=None, headers=None, subscription_update=False):
         rewound = 0
         while True:
diff --git a/torba/torba/client/basenetwork.py b/torba/torba/client/basenetwork.py
index dfed4d800..cdf33dab2 100644
--- a/torba/torba/client/basenetwork.py
+++ b/torba/torba/client/basenetwork.py
@@ -173,9 +173,9 @@ class BaseNetwork:
                 continue
             self.client = await self.session_pool.wait_for_fastest_session()
             log.info("Switching to SPV wallet server: %s:%d", *self.client.server)
-            self._on_connected_controller.add(True)
             try:
                 self._update_remote_height((await self.subscribe_headers(),))
+                self._on_connected_controller.add(True)
                 log.info("Subscribed to headers: %s:%d", *self.client.server)
             except (asyncio.TimeoutError, ConnectionError):
                 log.info("Switching to %s:%d timed out, closing and retrying.", *self.client.server)
@@ -240,7 +240,8 @@ class BaseNetwork:
         return self.rpc('blockchain.transaction.get_merkle', [tx_hash, height], restricted)
 
     def get_headers(self, height, count=10000):
-        return self.rpc('blockchain.block.headers', [height, count])
+        restricted = height >= self.remote_height - 100
+        return self.rpc('blockchain.block.headers', [height, count], restricted)
 
     #  --- Subscribes, history and broadcasts are always aimed towards the master client directly
     def get_history(self, address):