Queue scans rather than rejecting them

supysonic/cli.py

@@ -17,7 +17,7 @@ from pony.orm import db_session
 from pony.orm import ObjectNotFound
 
 from .daemon.client import DaemonClient
-from .daemon.exceptions import DaemonUnavailableError, ScannerAlreadyRunningError
+from .daemon.exceptions import DaemonUnavailableError
 from .db import Folder, User
 from .managers.folder import FolderManager
 from .managers.user import UserManager
@@ -180,10 +180,7 @@ class SupysonicCLI(cmd.Cmd):
             self.__folder_scan_foreground(folders, force)
 
     def __folder_scan_background(self, folders, force):
-        try:
         self.__daemon.scan(folders, force)
-        except ScannerAlreadyRunningError:
-            self.write_error_line('The daemon is already scanning, please try again later')
 
     def __folder_scan_foreground(self, folders, force):
         try:

supysonic/daemon/__init__.py

@@ -8,13 +8,16 @@
 # Distributed under terms of the GNU AGPLv3 license.
 
 import logging
+try:
+    from queue import Queue, Empty
+except ImportError:
+    from Queue import Queue, Empty
 
 from multiprocessing.connection import Listener
-from pony.orm import db_session
+from pony.orm import db_session, select
 from threading import Thread
 
 from .client import DaemonCommand
-from .exceptions import ScannerAlreadyRunningError
 from ..db import Folder
 from ..scanner import Scanner
 from ..utils import get_secret_key
@@ -55,14 +58,23 @@ class Daemon(object):
             self.__handle_connection(conn)
 
     def start_scan(self, folders = [], force = False):
+        if not folders:
+            with db_session:
+                folders = select(f.name for f in Folder if f.root)[:]
+
         if self.__scanner is not None and self.__scanner.is_alive():
-            raise ScannerAlreadyRunningError()
+            for f in folders:
+                self.__scanner.queue_folder(f)
+            return
 
         extensions = self.__config.BASE['scanner_extensions']
         if extensions:
             extensions = extensions.split(' ')
 
-        self.__scanner = ScannerThread(self.__watcher, folders, kwargs = { 'force': force, 'extensions': extensions, 'notify_watcher': False })
+        self.__scanner = ScannerThread(self.__watcher, kwargs = { 'force': force, 'extensions': extensions, 'notify_watcher': False })
+        for f in folders:
+            self.__scanner.queue_folder(f)
+
         self.__scanner.start()
 
     def terminate(self):
@@ -70,32 +82,50 @@ class Daemon(object):
         if self.__watcher is not None:
             self.__watcher.stop()
 
+class ScanQueue(Queue):
+    def _init(self, maxsize):
+        self.queue = set()
+        self.__last_got = None
+
+    def _put(self, item):
+        if self.__last_got != item:
+            self.queue.add(item)
+
+    def _get(self):
+        self.__last_got = self.queue.pop()
+        return self.__last_got
+
 class ScannerThread(Thread):
-    def __init__(self, watcher, folders, *args, **kwargs):
+    def __init__(self, watcher, *args, **kwargs):
         super(ScannerThread, self).__init__(*args, **kwargs)
         self.__watcher = watcher
-        self.__folders = folders
         self.__scanned = {}
+        self.__queue = ScanQueue()
+
+    def queue_folder(self, folder):
+        self.__queue.put(folder)
 
     def run(self):
         s = Scanner(*self._args, **self._kwargs)
 
         with db_session:
-            if self.__folders:
-                folders = Folder.select(lambda f: f.root and f.name in self.__folders)
-            else:
-                folders = Folder.select(lambda f: f.root)
+            try:
+                while True:
+                    name = self.__queue.get(False)
+                    folder = Folder.get(root = True, name = name)
+                    if folder is None:
+                        continue
 
-            for f in folders:
-                name = f.name
                     if self.__watcher is not None:
-                    self.__watcher.remove_folder(f)
+                        self.__watcher.remove_folder(folder)
                     try:
                         logger.info('Scanning %s', name)
-                    s.scan(f, lambda x: self.__scanned.update({ name: x }))
+                        s.scan(folder, lambda x: self.__scanned.update({ name: x }))
                     finally:
                         if self.__watcher is not None:
-                        self.__watcher.add_folder(f)
+                            self.__watcher.add_folder(folder)
+            except Empty:
+                pass
 
             s.finish()
 

supysonic/daemon/client.py

@@ -9,7 +9,7 @@
 
 from multiprocessing.connection import Client
 
-from .exceptions import DaemonUnavailableError, ScannerAlreadyRunningError
+from .exceptions import DaemonUnavailableError
 from ..config import get_current_config
 from ..py23 import strtype
 from ..utils import get_secret_key
@@ -49,11 +49,7 @@ class ScannerStartCommand(ScannerCommand):
         self.__force = force
 
     def apply(self, connection, daemon):
-        try:
         daemon.start_scan(self.__folders, self.__force)
-            connection.send(ScannerStartResult(None))
-        except ScannerAlreadyRunningError as e:
-            connection.send(ScannerStartResult(e))
 
 class DaemonCommandResult(object):
     pass
@@ -64,12 +60,6 @@ class ScannerProgressResult(DaemonCommandResult):
 
     scanned = property(lambda self: self.__scanned)
 
-class ScannerStartResult(DaemonCommandResult):
-    def __init__(self, exception):
-        self.__exception = exception
-
-    exception = property(lambda self: self.__exception)
-
 class DaemonClient(object):
     def __init__(self, address = None):
         self.__address = address or get_current_config().DAEMON['socket']
@@ -105,6 +95,3 @@ class DaemonClient(object):
             raise TypeError('Expecting list, got ' + str(type(folders)))
         with self.__get_connection() as c:
             c.send(ScannerStartCommand(folders, force))
-            rv = c.recv()
-            if rv.exception is not None:
-                raise rv.exception

supysonic/daemon/exceptions.py

@@ -9,6 +9,3 @@
 
 class DaemonUnavailableError(Exception):
     pass
-
-class ScannerAlreadyRunningError(Exception):
-    pass