From 963a0cd98366ecd6b72c9c824f87f876796536c2 Mon Sep 17 00:00:00 2001
From: Steve Slaven <bpk@hoopajoo.net>
Date: Mon, 27 Jul 2009 22:44:41 -0700
Subject: Modified to open a fh at the init using the mode requested, and just
 shuttling the pickle data in and out of this fh so the cp -a on files with
 perm of 444 should work correctly


diff --git a/fusearchive.py b/fusearchive.py
index 13d56dd..f8cce35 100755
--- a/fusearchive.py
+++ b/fusearchive.py
@@ -24,7 +24,7 @@ fuse.feature_assert('stateful_files', 'has_init')
 magic_profiling = False
 enable_stats = False
 enable_psyco = False
-debug_level = 0
+debug_level = 3
 
 # These control some of the file output
 magic_blocksize = 1024 * 128
@@ -39,6 +39,15 @@ dirty_size = 1024 * 1024 * 1;
 # This is the number of actualy blocks in that size
 dirty_flush = int( dirty_size / magic_blocksize )
 
+def flag2mode(flags):
+    md = {os.O_RDONLY: 'r', os.O_WRONLY: 'w', os.O_RDWR: 'w+'}
+    m = md[flags & (os.O_RDONLY | os.O_WRONLY | os.O_RDWR)]
+
+    if flags | os.O_APPEND:
+        m = m.replace('w', 'a', 1)
+
+    return m
+
 def dmsg(level,message):
     if level <= debug_level:
         print str(level) + ": " + str(message)
@@ -257,25 +266,7 @@ class FuseArchiveStream:
     """This just allows switching out writer classes easily"""
     @staticmethod
     def open( path, mode = 'r' ):
-        # This was added to fix the case of copying a read-only file, cp
-        # will create the new file then it gets chmod or something but we
-        # don't keep an fh around to write to later, we open and close it
-        # every time we need to update the file info.  We should keep an fh
-        # around from creation time and use that instead though and allow
-        # passing an fh here instead of a filename
-        if os.path.exists( path ):
-            st = os.stat( path )
-            # Make it writable
-            os.chmod( path, stat.S_IWUSR )
-        else:
-            st = None
-
         fh = gzip.open( path, mode, gzip_compress_level )
-
-        if st:
-            # Reset permissions
-            os.chmod( path, st.st_mode )
-
         #fh = open( path, mode )
         return fh
 
@@ -284,20 +275,36 @@ class FuseArchiveSerializer:
     @staticmethod
     def dump( file, obj ):
         out = FuseArchiveStream.open( file, "wb" )
-        if not magic_profiling:
-            cPickle.dump( obj, out, -1 ) # new file format
+        FuseArchiveSerializer.dumpfh( obj, out, -1 ) # new file format
         out.close()
 
     @staticmethod
+    def dumpfh( fh, obj ):
+        fh.truncate( 0 )
+        file = gzip.GzipFile( None, "wb", gzip_compress_level, fh )
+        #file = fh
+        cPickle.dump( obj, file, -1 ) # new file format
+        file.flush()
+
+    @staticmethod
     def load( file ):
         if magic_profiling:
             return { 'size': 0, 'chunks': 0, 'chunk_size': 0 }
 
         inp = FuseArchiveStream.open( file, "rb" )
-        magic = cPickle.load( inp )
+        magic = FuseArchiveSerialize.loadfh( inp )
         inp.close()
         return magic
 
+    @staticmethod
+    def loadfh( fh ):
+        fh.seek( 0 )
+        file = gzip.GzipFile( None, "rb", gzip_compress_level, fh )
+        #file = fh
+        #pdb.set_trace()
+        magic = cPickle.load( file )
+        return( magic )
+
 class FuseArchiveStat(fuse.Stat):
     def __init__(self, stat):
         self.st_mode = stat.st_mode
@@ -483,11 +490,22 @@ class FuseArchive(Fuse):
                 self.offset = -1
 
             if os.path.exists( "./tree" + self.orig_path ):
+                preexist = True
+            else:
+                preexist = False
+
+            # Open the file now and keep the fh around so that cp -a on r/o
+            # files works (in the create a read-only file for writing case)
+            src = "./tree" + path
+            dmsg( 3, "Saving fh for " + src )
+            self.file = os.fdopen( os.open( src, flags, *mode ),
+                flag2mode( flags ) )
+
+            if preexist:
                 # Read in file info table
-                src = "./tree" + self.orig_path
-                dmsg( 3, "Unpickling: " + src )
+                dmsg( 3, "Unpickling: " + str( self.file ) )
                 # TODO: return an IO error if inflating fails
-                magic = FuseArchiveSerializer.load( src )
+                magic = FuseArchiveSerializer.loadfh( self.file )
                 dmsg( 3, "Got data: " + str( magic ) )
                 self.size = magic[ 'size' ]
                 self.chunks = magic[ 'chunks' ]
@@ -679,6 +697,7 @@ class FuseArchive(Fuse):
             # Deflate the file
             dmsg( 2, "Release: " + self.orig_path )
             self.flush()
+            self.file.close()
 
         def _fflush(self):
             if self.wr and self.modified:
@@ -704,7 +723,7 @@ class FuseArchive(Fuse):
 
                 dmsg( 3, "Size calculated is: " + str( self.size ) )
 
-                FuseArchiveSerializer.dump( "./tree" + self.orig_path, {
+                FuseArchiveSerializer.dumpfh( self.file, {
                     'size': self.size,
                     'chunks': self.chunks,
                     'chunk_size': self.chunk_size
-- 
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