Implement step8 Restore

pyredis/__main__.py

@@ -33,6 +33,11 @@ async def amain(args):
 
     datastore = DataStore()
 
+    if args.restore and not AppendOnlyPersister.restore_from_file(
+        "ccdb.aof", datastore
+    ):
+        return -1
+
     loop = asyncio.get_running_loop()
 
     loop.create_task(acheck_expiry_task(datastore))
@@ -76,6 +81,7 @@ def main(args):
     )
     parser.add_argument("--asyncio", action=argparse.BooleanOptionalAction)
     parser.add_argument("--trio", action=argparse.BooleanOptionalAction)
+    parser.add_argument("--restore", action=argparse.BooleanOptionalAction)
     parser.add_argument(
         "-v",
         "--verbose",

pyredis/persistence.py

@@ -1,3 +1,7 @@
+from pyredis.commands import handle_command
+from pyredis.protocol import extract_frame_from_buffer
+
+
 class AppendOnlyPersister:
     def __init__(self, filename):
         self._filename = filename
@@ -8,3 +12,23 @@ def log_command(self, command):
 
         for item in command:
             self._file.write(item.resp_encode())
+
+    @staticmethod
+    def restore_from_file(filename=None, database=None):
+        buffer = bytearray()
+        with open(filename, "rb") as f:
+            while True:
+                data = f.read(1024)
+                if data:
+                    buffer.extend(data)
+                else:
+                    break
+                while True:
+                    frame, frame_size = extract_frame_from_buffer(buffer)
+
+                    if frame:
+                        buffer = buffer[frame_size:]
+                        handle_command(frame, database, None)
+                    else:
+                        break
+        return True