Implement PUT chunk uploads, 16MiB chunk size for faster transfers with resilient retries and smoother progress

cista/fileio.py

@@ -1,5 +1,6 @@
 import asyncio
 import os
+import threading
 
 from cista import config
 from cista.util import filename
@@ -69,6 +70,8 @@ class FileServer:
             self.alink.to_sync,
         )
         self.cache = LRUCache(File, capacity=10, maxage=5.0)
+        self.cache_lock = threading.Lock()
+        self.file_locks: dict[str, threading.Lock] = {}
 
     async def stop(self):
         await self.alink.stop()
@@ -80,6 +83,8 @@ class FileServer:
                 with req as (command, *args):
                     if command == "upload":
                         req.set_result(self.upload(*args))
+                    elif command == "upload_info":
+                        req.set_result(self.upload_info(*args))
                     elif command == "download":
                         req.set_result(self.download(*args))
                     else:
@@ -87,13 +92,42 @@ class FileServer:
         finally:
             self.cache.close()
 
+    @staticmethod
+    def _stat_size(path):
+        try:
+            return os.stat(path).st_size
+        except FileNotFoundError:
+            return None
+
     def upload(self, name, pos, data, file_size):
         name = filename.sanitize(name)
-        f = self.cache[name]
-        f.write(pos, data, file_size=file_size)
+        with self.cache_lock:
+            f = self.cache[name]
+            lock = self.file_locks.setdefault(name, threading.Lock())
+        with lock:
+            f.write(pos, data, file_size=file_size)
         return len(data)
 
+    def upload_info(self, name, pos, data, file_size):
+        name = filename.sanitize(name)
+        with self.cache_lock:
+            f = self.cache[name]
+            lock = self.file_locks.setdefault(name, threading.Lock())
+        with lock:
+            size_before = self._stat_size(f.path)
+            f.write(pos, data, file_size=file_size)
+            size_after = self._stat_size(f.path)
+        return {
+            "written": len(data),
+            "created": size_before is None,
+            "size_before": size_before,
+            "size_after": size_after,
+        }
+
     def download(self, name, start, end):
         name = filename.sanitize(name)
-        f = self.cache[name]
-        return f[start:end]
+        with self.cache_lock:
+            f = self.cache[name]
+            lock = self.file_locks.setdefault(name, threading.Lock())
+        with lock:
+            return f[start:end]