Added caching

4 files changed, 35 insertions, 3 deletions

diff --git a/HISTORY b/HISTORY
index 8e2fcdd..5dd34cc 100644
--- a/HISTORY
+++ b/HISTORY
@@ -4,6 +4,9 @@ version 0.8
   - Fixed license header in source files - it's the BSD licence now!
   - Set mtime of file nodes to recording time (parsed from *.rec)
   - Added homepage http://projects.vdr-developer.org/projects/vdrnfofs
+  - Some micro optimizations
+  - Cache the file system nodes user for get_stat() (nodes used for
+    reading are not cached)
 
 version 0.7
   - Fixed file/dir node permissions
diff --git a/TODO b/TODO
index 4a9b7e0..8796b4d 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,2 @@
 - Add option for translating to samba friendly path names
   (especially ':')
-- Performance improvement - maybe caching the file system somehow
diff --git a/vdrnfofs/nodecache.py b/vdrnfofs/nodecache.py
new file mode 100644
index 0000000..05cfafa
--- /dev/null
+++ b/vdrnfofs/nodecache.py
@@ -0,0 +1,28 @@
+import time
+
+class NodeCache:
+    class CacheEntry:
+        def __init__(self, node):
+            self.time = time.time()
+            self.node = node
+
+    def __init__(self):
+        self.cache = {}
+        self.last_clean = time.time()
+
+    def get(self, path, creator):
+        #
+        # !!! It might be nicer to have a thread for cleaning the cache, but
+        # with the Fuse option multithreaded = False, threading seems to
+        # be totally impossible. Somehow Fuse blocks ALL threads.
+        #
+        now = time.time()
+        if (now - self.last_clean) > 15:
+            self.cache = dict((k, v) for k, v in self.cache.items() if (now - v.time) <= 10)
+            self.last_clean = now
+
+        cache_entry = self.cache.get(path, None)
+        if not cache_entry or (now - cache_entry.time) > 10:
+            cache_entry = NodeCache.CacheEntry(creator(path))
+            self.cache[path] = cache_entry
+        return cache_entry.node
diff --git a/vdrnfofs/vdrnfofs.py b/vdrnfofs/vdrnfofs.py
index f8f3bda..9f62156 100644
--- a/vdrnfofs/vdrnfofs.py
+++ b/vdrnfofs/vdrnfofs.py
@@ -39,6 +39,7 @@ import logging
 from concatenated_file_reader import *
 from vdr import *
 from filesystemnodes import *
+from nodecache import *
 
 fuse.fuse_python_api = (0, 2)
 
@@ -108,10 +109,11 @@ class VdrNfoFs(fuse.Fuse):
         self.video = ''
         self.log = ''
         self.loglevel = 'info'
+        self.cache = NodeCache()
 
     def getattr(self, path):
         try:
-            node = get_node(self.video, path)
+            node = self.cache.get(path, lambda x: get_node(self.video, x))
             if node:
                 return node.get_stat()
             return -errno.ENOENT
@@ -122,7 +124,7 @@ class VdrNfoFs(fuse.Fuse):
         try:
             yield fuse.Direntry('.')
             yield fuse.Direntry('..')
-            node = get_node(self.video, path)
+            node = self.cache.get(path, lambda x: get_node(self.video, x))
             if node:
                 for item in node.content():
                     yield fuse.Direntry(item.file_system_name())