# 
# 
# patch "README"
#  from [9f8f3733a57d238f540764b3ad8bd7ed0cf27c10]
#    to [1bfe02c50e6a3cf27edbf7a5f1927a26101beaf4]
# 
# patch "tracvc/mtn/backend.py"
#  from [96c10000b1c2e58cef92cb6efe3563cd92a192b8]
#    to [16047bbc0b40cabc3375d8fa43017c916c23d15b]
# 
# patch "tracvc/mtn/cache.py"
#  from [74ba6b640de58de20e8922c97eda6f77aecc2a27]
#    to [4a30ff0444dffafb15cdab7d65908b41b99692fd]
# 
============================================================
--- README	9f8f3733a57d238f540764b3ad8bd7ed0cf27c10
+++ README	1bfe02c50e6a3cf27edbf7a5f1927a26101beaf4
@@ -40,13 +40,22 @@
 
 Configuration
 
-  Currently, there's not much to configure. All configuration options
-  have to be placed in the [mtn] section of the conf/trac.ini file.
+  All configuration options have to be placed in the [mtn] section of
+  the conf/trac.ini file.
 
   * The full path to the Monotone binary can be specified using the
     'mtn_binary' option.
 
+  * A caching method for Monotone manifests, certs and changesets can
+    be specified using the 'cachespec' option. The format is:
+      cachespec = backend[:opt1[:opt2[...]]]
+    Currently two backends are provided:
+    - 'localmem': (default) uses local memory for caching. Takes no
+      options.
+    - 'dbmshelve:prefix': Persistent, uses Unix DBM databases named
+      prefix*.{pag|dir}. All directories in prefix must exist.
 
+
 Known Problems/Missing Features
 
   * SECURITY: The monotone select functionality is exposed. Selectors
@@ -61,7 +70,7 @@
   * Log on per-file basis is missing, and the browser view shows the
     same revision for all files.
 
-  * Some operations are very slow.
+  * Some operations are somewhat slow.
 
   * Revision and Cert data is cached forever. This will be adjustable
     in the future.
============================================================
--- tracvc/mtn/backend.py	96c10000b1c2e58cef92cb6efe3563cd92a192b8
+++ tracvc/mtn/backend.py	16047bbc0b40cabc3375d8fa43017c916c23d15b
@@ -41,6 +41,9 @@
     mtn_binary = Option('mtn', 'mtn_binary', '/usr/bin/mtn',
                         '''Full path to the monotone binary.''')
 
+    cachespec = Option('mtn', 'cachespec', 'localmem',
+                       '''Select a caching mechanism.''')
+
     # IRepositoryConnector methods
     def __init__(self):
         self.repos = {}
@@ -55,7 +58,8 @@
         # note: we don't use type or authname, therefore we can always
         # return the same Repository object for the same database path
         if not path in self.repos:
-            self.repos[path] = MonotoneRepository(path, self.log, self.mtn_binary)
+            self.repos[path] = MonotoneRepository(path, self.log,
+                                self.mtn_binary, self.cachespec)
         return self.repos[path]
 
     # IWikiSyntaxProvider methods
@@ -96,8 +100,8 @@
 
 class MonotoneRepository(Repository):
 
-    def __init__(self, path, log, binary):
-        cachespec = 'localmem'
+
+    def __init__(self, path, log, binary, cachespec):
         self.mtn = MTN(path, log, binary, cachespec)
         Repository.__init__(self, 'mtn:%s' % path, None, log)
 
============================================================
--- tracvc/mtn/cache.py	74ba6b640de58de20e8922c97eda6f77aecc2a27
+++ tracvc/mtn/cache.py	4a30ff0444dffafb15cdab7d65908b41b99692fd
@@ -26,6 +26,8 @@
     from threading import Lock
 except ImportError:
     from dummy_threading import Lock
+from shelve import Shelf
+import dbm
 
 
 class Cache(object):
@@ -126,7 +128,7 @@
 
     def add(self, key, value):
         self.lock.acquire()
-        if key not in self.cache:
+        if not key in self.cache:
             self.cache[key] = value
         self.lock.release()
 
@@ -142,6 +144,26 @@
 Cache.add_backend('localmem', LocalMem)
 
 
+# Unfortunately, dbash (i.e. bsddb) doesn't work reliably, at least on
+# my system, so we can't simply use anydb, which prefers dbhash.
+
+class DBMShelve(LocalMem):
+    """Using Python's shelve on a DBM database."""
+
+    def __init__(self, realm, prefix):
+        LocalMem.__init__(self, realm)
+        self.dbname = prefix + realm
+        self.cache = Shelf(dbm.open(self.dbname, 'c'))
+
+    def __del__(self):
+        self.cache.close()
+
+    def flush_all(self):
+        self.cache = Shelf(dbm.open(self.dbname, 'n'))
+
+Cache.add_backend('dbmshelve', DBMShelve)
+
+
 def memoize(get_cachespec, realm = None):
     """Decorates a method with the Memoize decorator. get_cachespec is
     a method of the same class which returns the desired cachespec,
@@ -162,12 +184,15 @@
         return self
 
     def __call__(self, *args):
+        # shelve only supports keys of type integer or string
+        key = len(args)==1 and args[0] or args
         try:
-            return self.cache.get(args)
+            return self.cache.get(key)
         except KeyError:
             # not yet in the cache
+            #print "CACHEMISS", self.realm, key
             value = self.function(self.instance, *args)
-            self.cache.add(args, value)
+            self.cache.add(key, value)
             return value
         except AttributeError:
             # oops, no cache yet, get one and restart