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authorSteve Slaven <bpk@hoopajoo.net>2009-07-23 23:12:46 (GMT)
committerSteve Slaven <bpk@hoopajoo.net>2009-07-23 23:12:46 (GMT)
commit04a1000d48f4bceaa09e96199fb56225a5800f4f (patch)
treeed74a2351b991861b1e2d8defc6f8906113fc8c9
parentd174f0a7e811489375bd489cb6b1da31a73a4074 (diff)
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Added caching some dirty blocks
-rwxr-xr-xfusearchive.py50
1 files changed, 40 insertions, 10 deletions
diff --git a/fusearchive.py b/fusearchive.py
index 891872a..d4e8ebe 100755
--- a/fusearchive.py
+++ b/fusearchive.py
@@ -28,6 +28,11 @@ magic_blocksize = 1024 * 32
magic_depth = 5
debug_level = 0
+# Memory for dirty blocks, per file (1M)
+dirty_size = 1024 * 1024 * 1;
+# This is the number of actualy blocks in that size
+dirty_flush = int( dirty_size / magic_blocksize )
+
def dmsg(level,message):
if level <= debug_level:
print str(level) + ": " + str(message)
@@ -278,10 +283,12 @@ class FuseArchive(Fuse):
self.modified = False
# This is the current in-memory chunk and offset in to data[]
+ self.chunk_cache = {};
self.chunk = ''
self.chunk_index = 0
self.chunk_modified = False
self.chunk_size = magic_blocksize
+ self.dirty_chunks = 0
# The chunk table
self.chunks = []
@@ -339,10 +346,11 @@ class FuseArchive(Fuse):
dmsg( 3, "Loading chunk " + str(index) )
key = None
- try:
- key = self.chunks[ index ]
- except IndexError:
+ size = len( self.chunks )
+ if index >= size:
dmsg( 3, "Index doesn't exist" )
+ else:
+ key = self.chunks[ index ]
if key:
dmsg( 3, "Index: " + str( key ) )
@@ -354,18 +362,37 @@ class FuseArchive(Fuse):
self.chunk_index = index
self.chunk_modified = False
+ # This simply puts the chunk data inside our current chunks at chunk_index
def _save_chunk(self):
if self.chunk_modified:
- dmsg( 3, "Saving chunk " + str( self.chunk_index ) )
- key = save_chunk( self.chunk )
-
# Make sure we have room for this chunk
size = len( self.chunks )
if self.chunk_index >= size:
- self.chunks.extend( [None] * ( self.chunk_index -size + 1 ) )
-
- self.chunks[ self.chunk_index ] = key
- dmsg( 3, "Key was " + str( key ) )
+ self.chunks.extend( [ '' ] * ( self.chunk_index -size + 1 ) )
+
+ # Increment dirty chunks if we had a key here already
+ if isinstance( self.chunks[ self.chunk_index ], list ) or \
+ len( self.chunks[ self.chunk_index ] ) == 0:
+ self.dirty_chunks += 1
+ dmsg( 3, "Dirty chunks is now: " + str( self.dirty_chunks ) )
+ dmsg( 3, "Dirty flush at: " + str( dirty_flush ) )
+
+ # Save the dirty chunk temporarily in memory
+ self.chunks[ self.chunk_index ] = self.chunk
+
+ # Flush if we have too many dirty chunks
+ if self.dirty_chunks > dirty_flush:
+ self._flush_chunks()
+
+ # This flushes any cached chunks
+ def _flush_chunks(self):
+ for index in range( len( self.chunks ) ):
+ if isinstance( self.chunks[ index ], str ):
+ dmsg( 3, "Flushing chunk at " + str( index ) )
+ key = save_chunk( self.chunks[ index ] )
+ self.chunks[ index ] = key
+ dmsg( 3, "Key was " + str( key ) )
+ self.dirty_chunks = 0
def read(self, length, offset):
dmsg( 3, "Reading from " + self.orig_path + " offset: " + str( offset )
@@ -454,6 +481,9 @@ class FuseArchive(Fuse):
# Save our main data
self._save_chunk()
+ # And flush any cached chunks
+ self._flush_chunks()
+
# Figure out our size based on the number of chunks + the
# len of the final chunk
numchunks = len( self.chunks )