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authorSteve Slaven <bpk@hoopajoo.net>2009-07-23 20:41:08 (GMT)
committerSteve Slaven <bpk@hoopajoo.net>2009-07-23 20:41:08 (GMT)
commitea8e86da16ed863858dd1b3d4ede9e087c8d8a0c (patch)
tree5c1f61b151746fe357e7b809a7d006d334742dad
parent5b74584e1b732603564f95560fdb304010a21404 (diff)
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Modified to do chunking on demand, runs but file writing not working
-rwxr-xr-xfusearchive.py201
1 files changed, 145 insertions, 56 deletions
diff --git a/fusearchive.py b/fusearchive.py
index 9b6364f..92717cf 100755
--- a/fusearchive.py
+++ b/fusearchive.py
@@ -26,7 +26,7 @@ fuse.feature_assert('stateful_files', 'has_init')
magic_blocksize = 1024 * 32
magic_depth = 5
-debug_level = 2
+debug_level = 4
def dmsg(level,message):
if level <= debug_level:
@@ -187,7 +187,7 @@ def deflate( src, dest ):
out.close()
class FuseArchiveStat(fuse.Stat):
- def __init__(self, stat, overstat):
+ def __init__(self, stat):
self.st_mode = stat.st_mode
self.st_ino = stat.st_ino
self.st_dev = stat.st_dev
@@ -195,13 +195,17 @@ class FuseArchiveStat(fuse.Stat):
self.st_nlink = stat.st_nlink
self.st_uid = stat.st_uid
self.st_gid = stat.st_gid
- self.st_size = overstat.st_size
+ self.st_size = stat.st_size
self.st_atime = stat.st_atime
self.st_mtime = stat.st_mtime
self.st_ctime = stat.st_mtime
+ self.st_blocks = stat.st_blocks
+ self.st_blksize = stat.st_blksize
+
+ def overstat( self, size ):
+ self.st_size = size
# Yeah we shouldn't always just add 1
self.st_blocks = int( self.st_size / 512 ) + 1
- self.st_blksize = stat.st_blksize
class FuseArchive(Fuse):
@@ -226,7 +230,8 @@ class FuseArchive(Fuse):
inp.close()
dmsg( 3, "Overridding getattr" )
- stats = FuseArchiveStat( stats, magic[ 'stat' ] )
+ stats = FuseArchiveStat( stats )
+ stats.overstat( magic[ 'size' ] )
return stats
@@ -335,47 +340,124 @@ class FuseArchive(Fuse):
# Inflate the file
dmsg( 1, "Init file: " + path )
self.orig_path = path;
- ( fdnum, self.tmp_name ) = tempfile.mkstemp();
- #os.close( fdnum );
+
+ # init rw and offset
+ self.offset = 0
+ self.read = False
+ self.write = False
+ self.size = 0
+
+ # This is the current in-memory chunk and offset in to data[]
+ self.chunk = None
+ self.chunk_index = 0
+ self.chunk_modified = False
+ self.chunk_size = magic_blocksize
+
+ # The chunk table
+ self.chunks = []
+
+ # TODO: Better flag handling here?
+ md = flag2mode( flags )
+ if re.match( '^r', md ):
+ self.read = True
+ elif re.match( '^w', md ):
+ self.write = True
+ elif re.match( '^a', md ):
+ self.write = True
+ self.offset = -1
if os.path.exists( "./tree" + self.orig_path ):
- inflate( "./tree" + path, self.tmp_name )
+ # Read in file info table
+ src = "./tree" + self.orig_path
+ dmsg( 3, "Unpickling: " + src )
+ # TODO: return an IO error if inflating fails
+ inp = gzip.open( src, "r" )
+ magic = pickle.load( inp )
+ inp.close()
+ dmsg( 3, "Got data: " + str( magic ) )
+ self.size = magic[ 'size' ]
+ self.chunks = magic[ 'chunks' ]
+ self.chunk_size = magic[ 'chunk_size' ]
else:
if re.match( '(a|w)', flag2mode( flags ) ):
dmsg( 2, "File doesn't exist and we're going to write, creating temp empty file" )
- deflate( "/dev/null", "./tree" + path )
+ self.flush()
- dmsg( 2, "Shadow file: " + self.tmp_name + " for " + self.orig_path )
- dmsg( 3, "Going to open shadow file with flags: " + str(flags) + " mode " + str(mode) )
- # pdb.set_trace()
- dmsg( 3, "Flag2mode is: " + str( flag2mode( flags ) ) )
+ self.direct_io = False
+ self.keep_cache = False
- # Just use the fdnum they gave us instead of reopening it,
- # since that might fail
- # fdnum = os.open( self.tmp_name, flags, *mode )
- #print "Got fdnum: " + str(fdnum)
- self.file = os.fdopen( fdnum, flag2mode( flags ) )
- dmsg( 3, "Open" )
+ dmsg( 3, str(self) + " init complete" )
- self.fd = self.file.fileno()
+ def _load_chunk( self, index ):
+ # Save this chunk if modified
+ if self.chunk_modified:
+ self._save_chunk()
- self.direct_io = False
- self.keep_cache = False
+ dmsg( 3, "Loading chunk " + str(index) )
+ key = None
- self.modified = False
+ try:
+ key = self.chunks[ index ]
+ except IndexError:
+ dmsg( 3, "Index doesn't exist" )
- dmsg( 3, str(self) + " init complete" )
+ if key:
+ dmsg( 3, "Index: " + str( key ) )
+ self.chunk = load_chunk( key )
+ else:
+ dmsg( 3, "No chunk at this index, loading nothing" )
+ self.chunk = None
+
+ self.chunk_index = index
+ self.chunk_modified = False
+
+ def _save_chunk():
+ dmsg( 3, "Saving chunk " + self.chunk_index )
+ key = save_chunk( self.chunk )
+ self.chunks[ index ] = key
+ dmsg( 3, "Key was " + str( key ) )
def read(self, length, offset):
- dmsg( 3, "Reading from " + self.orig_path )
- self.file.seek(offset)
- return self.file.read(length)
+ dmsg( 3, "Reading from " + self.orig_path + " offset: " + str( offset )
+ + " length: " + str( length ) )
+
+ data_read = 0
+ data = None
+ index = int( offset / self.chunk_size )
+ rest = offset % self.chunk_size
+
+ # Keep reading chunks until we have at least this much data
+ while data_read < length:
+ dmsg( 3, "Pulling chunk data" )
+ self._load_chunk( index )
+ chunk_remaining = self.chunk_size - rest
+ data += substr( self.chunk[ rest:chunk_remaining ] )
+ data_read = len( data )
+ index += 1
+ rest = 0
+
+ return data[ :length ]
def write(self, buf, offset):
- dmsg( 3, "Writing to " + self.orig_path )
- self.file.seek(offset)
- self.file.write(buf)
- self.modified = True
+ dmsg( 3, "Writing to " + self.orig_path + " offset: " + str( offset ) )
+
+ index = int( offset / self.chunk_size )
+ rest = offset % self.chunk_size
+
+ buf_offset = 0
+ buf_len = len(buf)
+
+ dmg( 3, "Length: " + str( buf_len ) )
+ while( buf_offset < buf_len ):
+ dmsg( 3, "Pulling in chunk for writing" )
+ self._load_chunk( index )
+ buf_remain = buf_len - buf_offset
+ if rest < buf_remain:
+ dmsg( 3, "Writing " + str( rest ) + " bytes, buffer boundry" )
+ else:
+ dmsg( 3, "Writing final " + str( buf_remain ) + " bytes" )
+
+ self.chunk_modified = True
return len(buf)
# BUG: If you cp -a a file then quickly ls -l sometimes it doesn't show
@@ -384,44 +466,51 @@ class FuseArchive(Fuse):
def release(self, flags):
# Deflate the file
dmsg( 2, "Release: " + self.orig_path )
- self.file.close()
-
- if self.modified:
- dmsg( 2, "Copying working file back to storage: " + \
- self.tmp_name + " -> " + self.orig_path )
-
- #pdb.set_trace()
- deflate( self.tmp_name, "./tree" + self.orig_path )
- else:
- dmsg( 2, "File not modified, not copying back" )
-
- dmsg( 2, "Deleting old file: " + self.tmp_name )
- os.unlink( self.tmp_name );
+ self.flush()
def _fflush(self):
- if 'w' in self.file.mode or 'a' in self.file.mode:
- self.file.flush()
-
+ if self.write:
+ dmsg( 3, "_fflush!" )
+ # Save our main data
+ out = gzip.open( "./tree" + self.orig_path, "w" )
+ pickle.dump( {
+ 'size': self.size,
+ 'chunks': self.chunks,
+ 'chunk_size': self.chunk_size
+ }, out )
+ out.close()
+
+
+ # Currently we treat fsync as flush since we don't keep any data
+ # hanging around anyway in fh stuff
def fsync(self, isfsyncfile):
+ dmsg( 2, "fsync " + self.orig_path )
self._fflush()
- if isfsyncfile and hasattr(os, 'fdatasync'):
- os.fdatasync(self.fd)
- else:
- os.fsync(self.fd)
+ #if isfsyncfile and hasattr(os, 'fdatasync'):
+ # os.fdatasync(self.fd)
+ #else:
+ # os.fsync(self.fd)
def flush(self):
+ dmsg( 2, "flush " + self.orig_path )
self._fflush()
- # cf. xmp_flush() in fusexmp_fh.c
- os.close(os.dup(self.fd))
def fgetattr(self):
- return os.fstat(self.fd)
+ print "WARNING: fgetattr is broken!!!!"
+ return os.lstat( "./tree" + self.orig_path )
def ftruncate(self, len):
- self.modified = True
- self.file.truncate(len)
+ self.chunks = []
+ self._load_chunk( 0 )
+ self._fflush()
+
+ if len > 0:
+ print "WARNING: ftruncate is broken!!!"
def lock(self, cmd, owner, **kw):
+ dmsg( 3, "WARNING: locking unsupported" )
+ return
+
# The code here is much rather just a demonstration of the locking
# API than something which actually was seen to be useful.