SvnDumpToolEdit: SVN Dump content editor

SvnDumpToolEdit.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
"""
SvnDumpToolEdit: SVN Dump content editor

SvnDumpToolEdit is a small script that allows to change single file nodes
within an SVN dump file. It automatically updates the Content-length attribute
for nodes and generates a new MD5 checksum when a file is changed. This ensures
that the SVN dump will always remain a valid dump file.

This script is based on SvnDumpTool and the SvnDump package written by Martin
Furter. To run the script, the package needs to be installed. Visit his
website[1] for further details and instructions.

SvnDumpToolEdit is written by Patrick Westerhoff[2] and released in the public
domain. Feel free to modify, improve and redistribute the script.

[1] SvnDumpTool: http://svn.borg.ch/svndumptool
[2] poke on github: http://github.com/poke


Instructions
============
To use this script, you will need to modify the `processFile` function below.
It gets the current revision ID, the full file path, the file name and a file
object. The first three values are just for identification, in case you need
it.

The file object is opened and positioned at the beginning. To modify the text,
you have to save the new text in the *same* file object. See the example below
to get an idea of how you can do this.

"""
import os, re, sys

from svndump.file import SvnDumpFile

# Temporary file name to use
__tmpFileName = '.svndump.nodetext'


# Edit this function to your needs.
def processFile ( revId, filePath, fileName, f ):
	"""
	Process the current file.
	
	Arguments:
	  revId     Current revision ID.
	  filePath  Full file path.
	  fileName  File name.
	  f         Opened file object to be edited.
	"""
	# check if the file should be edited
	if fileName != 'example.py':
		return
	
	# read the content, move to the start and truncate the file
	text = f.read()
	f.seek( 0 )
	f.truncate()
	
	# edit the file content
	text = re.sub( 'Foo', 'Bar', text )
	
	# save the content back
	f.write( text )


def editDump ( srcFile, dstFile ):
	"""
	Edit the source dump using the custom processFile function and store it at
	the destination.
	
	Arguments:
	  srcFile   Filename of the source dump.
	  dstFile	Filename of the destination dump.
	"""
	srcDmp = SvnDumpFile()
	srcDmp.open( srcFile )
	dstDmp = None
	
	# read source dump
	while srcDmp.read_next_rev():
		revId = srcDmp.get_rev_nr()
		
		if dstDmp is None:
			dstDmp = SvnDumpFile()
			dstDmp.create_like( dstFile, srcDmp )
		
		# add revision to destination dump
		dstDmp.add_rev( srcDmp.get_rev_props() )
		
		# load nodes from current revision of source dump
		for node in srcDmp.get_nodes_iter():
			if ( node.has_text() ):
				with open( __tmpFileName, 'wb+' ) as f:
					node.write_text_to_file( f )
					f.seek( 0 )
					
					processFile( revId, node.get_path(), node.get_name(), f )
					
				# update text
				node.set_text_file( __tmpFileName )
				
			# add node to current revision of destination dump
			dstDmp.add_node( node )
	
	srcDmp.close()
	dstDmp.close()
	os.unlink( __tmpFileName )


## Module entry
if __name__ == '__main__':
	if len( sys.argv ) > 2:
		editDump( sys.argv[1], sys.argv[2] )
	else:
		print( 'Usage: %s <source file> <destination file>' % sys.argv[0] )