Python script use to change SVN working copy format

Python script use to change SVN working copy format from 1.4, 1.5, 1.6 to 1.4, 1.5, 1.6:

Example usage:

python change-svn-wc-format.py <working copy path> 1.4 –verbose –force

This will convert the working copy path into 1.4.  This is useful if you are experiencing slow update or generally cannot update or use your subversion installation because its error says that the client is too old.  You might want to convert it to the version your client subversion is using.

#!/usr/bin/env python
#
# change-svn-wc-format.py: Change the format of a Subversion working copy.
#
# ====================================================================
#    Licensed to the Subversion Corporation (SVN Corp.) under one
#    or more contributor license agreements.  See the NOTICE file
#    distributed with this work for additional information
#    regarding copyright ownership.  The SVN Corp. licenses this file
#    to you under the Apache License, Version 2.0 (the
#    "License"); you may not use this file except in compliance
#    with the License.  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing,
#    software distributed under the License is distributed on an
#    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
#    KIND, either express or implied.  See the License for the
#    specific language governing permissions and limitations
#    under the License.
# ====================================================================

import sys
import os
import getopt
try:
 my_getopt = getopt.gnu_getopt
except AttributeError:
 my_getopt = getopt.getopt

### The entries file parser in subversion/tests/cmdline/svntest/entry.py
### handles the XML-based WC entries file format used by Subversion
### 1.3 and lower.  It could be rolled into this script.

LATEST_FORMATS = { "1.4" : 8,
 "1.5" : 9,
 "1.6" : 10,
 # Do NOT add format 11 here.  See comment in must_retain_fields
 # for why.
 }

def usage_and_exit(error_msg=None):
 """Write usage information and exit.  If ERROR_MSG is provide, that
 error message is printed first (to stderr), the usage info goes to
 stderr, and the script exits with a non-zero status.  Otherwise,
 usage info goes to stdout and the script exits with a zero status."""
 progname = os.path.basename(sys.argv[0])

 stream = error_msg and sys.stderr or sys.stdout
 if error_msg:
 stream.write("ERROR: %s\n\n" % error_msg)
 stream.write("""\
usage: %s WC_PATH SVN_VERSION [--verbose] [--force] [--skip-unknown-format]
 %s --help

Change the format of a Subversion working copy to that of SVN_VERSION.

 --skip-unknown-format    : skip directories with unknown working copy
 format and continue the update

""" % (progname, progname))
 stream.flush()
 sys.exit(error_msg and 1 or 0)

def get_adm_dir():
 """Return the name of Subversion's administrative directory,
 adjusted for the SVN_ASP_DOT_NET_HACK environment variable.  See
 <http://svn.collab.net/repos/svn/trunk/notes/asp-dot-net-hack.txt>
 for details."""
 return "SVN_ASP_DOT_NET_HACK" in os.environ and "_svn" or ".svn"

class WCFormatConverter:
 "Performs WC format conversions."
 root_path = None
 error_on_unrecognized = True
 force = False
 verbosity = 0

 def write_dir_format(self, format_nbr, dirname, paths):
 """Attempt to write the WC format FORMAT_NBR to the entries file
 for DIRNAME.  Throws LossyConversionException when not in --force
 mode, and unconvertable WC data is encountered."""

 # Avoid iterating in unversioned directories.
 if not (get_adm_dir() in paths):
 del paths[:]
 return

 # Process the entries file for this versioned directory.
 if self.verbosity:
 print("Processing directory '%s'" % dirname)
 entries = Entries(os.path.join(dirname, get_adm_dir(), "entries"))
 entries_parsed = True
 if self.verbosity:
 print("Parsing file '%s'" % entries.path)
 try:
 entries.parse(self.verbosity)
 except UnrecognizedWCFormatException, e:
 if self.error_on_unrecognized:
 raise
 sys.stderr.write("%s, skipping\n" % e)
 sys.stderr.flush()
 entries_parsed = False

 if entries_parsed:
 format = Format(os.path.join(dirname, get_adm_dir(), "format"))
 if self.verbosity:
 print("Updating file '%s'" % format.path)
 format.write_format(format_nbr, self.verbosity)
 else:
 if self.verbosity:
 print("Skipping file '%s'" % format.path)

 if self.verbosity:
 print("Checking whether WC format can be converted")
 try:
 entries.assert_valid_format(format_nbr, self.verbosity)
 except LossyConversionException, e:
 # In --force mode, ignore complaints about lossy conversion.
 if self.force:
 print("WARNING: WC format conversion will be lossy. Dropping "\
 "field(s) %s " % ", ".join(e.lossy_fields))
 else:
 raise

 if self.verbosity:
 print("Writing WC format")
 entries.write_format(format_nbr)

 def change_wc_format(self, format_nbr):
 """Walk all paths in a WC tree, and change their format to
 FORMAT_NBR.  Throw LossyConversionException or NotImplementedError
 if the WC format should not be converted, or is unrecognized."""
 for dirpath, dirs, files in os.walk(self.root_path):
 self.write_dir_format(format_nbr, dirpath, dirs + files)

class Entries:
 """Represents a .svn/entries file.

 'The entries file' section in subversion/libsvn_wc/README is a
 useful reference."""

 # The name and index of each field composing an entry's record.
 entry_fields = (
 "name",
 "kind",
 "revision",
 "url",
 "repos",
 "schedule",
 "text-time",
 "checksum",
 "committed-date",
 "committed-rev",
 "last-author",
 "has-props",
 "has-prop-mods",
 "cachable-props",
 "present-props",
 "conflict-old",
 "conflict-new",
 "conflict-wrk",
 "prop-reject-file",
 "copied",
 "copyfrom-url",
 "copyfrom-rev",
 "deleted",
 "absent",
 "incomplete",
 "uuid",
 "lock-token",
 "lock-owner",
 "lock-comment",
 "lock-creation-date",
 "changelist",
 "keep-local",
 "working-size",
 "depth",
 "tree-conflicts",
 "file-external",
 )

 # The format number.
 format_nbr = -1

 # How many bytes the format number takes in the file.  (The format number
 # may have leading zeroes after using this script to convert format 10 to
 # format 9 -- which would write the format number as '09'.)
 format_nbr_bytes = -1

 def __init__(self, path):
 self.path = path
 self.entries = []

 def parse(self, verbosity=0):
 """Parse the entries file.  Throw NotImplementedError if the WC
 format is unrecognized."""

 input = open(self.path, "r")

 # Read WC format number from INPUT.  Validate that it
 # is a supported format for conversion.
 format_line = input.readline()
 try:
 self.format_nbr = int(format_line)
 self.format_nbr_bytes = len(format_line.rstrip()) # remove '\n'
 except ValueError:
 self.format_nbr = -1
 self.format_nbr_bytes = -1
 if not self.format_nbr in LATEST_FORMATS.values():
 raise UnrecognizedWCFormatException(self.format_nbr, self.path)

 # Parse file into individual entries, to later inspect for
 # non-convertable data.
 entry = None
 while True:
 entry = self.parse_entry(input, verbosity)
 if entry is None:
 break
 self.entries.append(entry)

 input.close()

 def assert_valid_format(self, format_nbr, verbosity=0):
 if verbosity >= 2:
 print("Validating format for entries file '%s'" % self.path)
 for entry in self.entries:
 if verbosity >= 3:
 print("Validating format for entry '%s'" % entry.get_name())
 try:
 entry.assert_valid_format(format_nbr)
 except LossyConversionException:
 if verbosity >= 3:
 sys.stderr.write("Offending entry:\n%s\n" % entry)
 sys.stderr.flush()
 raise

 def parse_entry(self, input, verbosity=0):
 "Read an individual entry from INPUT stream."
 entry = None

 while True:
 line = input.readline()
 if line in ("", "\x0c\n"):
 # EOF or end of entry terminator encountered.
 break

 if entry is None:
 entry = Entry()

 # Retain the field value, ditching its field terminator ("\x0a").
 entry.fields.append(line[:-1])

 if entry is not None and verbosity >= 3:
 sys.stdout.write(str(entry))
 print("-" * 76)
 return entry

 def write_format(self, format_nbr):
 # Overwrite all bytes of the format number (which are the first bytes in
 # the file).  Overwrite format '10' by format '09', which will be converted
 # to '9' by Subversion when it rewrites the file.  (Subversion 1.4 and later
 # ignore leading zeroes in the format number.)
 assert len(str(format_nbr)) <= self.format_nbr_bytes
 format_string = '%0' + str(self.format_nbr_bytes) + 'd'

 os.chmod(self.path, 0600)
 output = open(self.path, "r+", 0)
 output.write(format_string % format_nbr)
 output.close()
 os.chmod(self.path, 0400)

class Entry:
 "Describes an entry in a WC."

 # Maps format numbers to indices of fields within an entry's record that must
 # be retained when downgrading to that format.
 must_retain_fields = {
 # Not in 1.4: changelist, keep-local, depth, tree-conflicts, file-externals
 8  : (30, 31, 33, 34, 35),
 # Not in 1.5: tree-conflicts, file-externals
 9  : (34, 35),
 10 : (),
 # Downgrading from format 11 (1.7-dev) to format 10 is not possible,
 # because 11 does not use has-props and cachable-props (but 10 does).
 # Naively downgrading in that situation causes properties to disappear
 # from the wc.
 #
 # Downgrading from the 1.7 SQLite-based format to format 10 is not
 # implemented.
 }

 def __init__(self):
 self.fields = []

 def assert_valid_format(self, format_nbr):
 "Assure that conversion will be non-lossy by examining fields."

 # Check whether lossy conversion is being attempted.
 lossy_fields = []
 for field_index in self.must_retain_fields[format_nbr]:
 if len(self.fields) - 1 >= field_index and self.fields[field_index]:
 lossy_fields.append(Entries.entry_fields[field_index])
 if lossy_fields:
 raise LossyConversionException(lossy_fields,
 "Lossy WC format conversion requested for entry '%s'\n"
 "Data for the following field(s) is unsupported by older versions "
 "of\nSubversion, and is likely to be subsequently discarded, and/or "
 "have\nunexpected side-effects: %s\n\n"
 "WC format conversion was cancelled, use the --force option to "
 "override\nthe default behavior."
 % (self.get_name(), ", ".join(lossy_fields)))

 def get_name(self):
 "Return the name of this entry."
 return len(self.fields) > 0 and self.fields[0] or ""

 def __str__(self):
 "Return all fields from this entry as a multi-line string."
 rep = ""
 for i in range(0, len(self.fields)):
 rep += "[%s] %s\n" % (Entries.entry_fields[i], self.fields[i])
 return rep

class Format:
 """Represents a .svn/format file."""

 def __init__(self, path):
 self.path = path

 def write_format(self, format_nbr, verbosity=0):
 format_string = '%d\n'
 if os.path.exists(self.path):
 if verbosity >= 1:
 print("%s will be updated." % self.path)
 os.chmod(self.path,0600)
 else:
 if verbosity >= 1:
 print("%s does not exist, creating it." % self.path)
 format = open(self.path, "w")
 format.write(format_string % format_nbr)
 format.close()
 os.chmod(self.path, 0400)

class LocalException(Exception):
 """Root of local exception class hierarchy."""
 pass

class LossyConversionException(LocalException):
 "Exception thrown when a lossy WC format conversion is requested."
 def __init__(self, lossy_fields, str):
 self.lossy_fields = lossy_fields
 self.str = str
 def __str__(self):
 return self.str

class UnrecognizedWCFormatException(LocalException):
 def __init__(self, format, path):
 self.format = format
 self.path = path
 def __str__(self):
 return ("Unrecognized WC format %d in '%s'; "
 "only formats 8, 9, and 10 can be supported") % (self.format, self.path)

def main():
 try:
 opts, args = my_getopt(sys.argv[1:], "vh?",
 ["debug", "force", "skip-unknown-format",
 "verbose", "help"])
 except:
 usage_and_exit("Unable to process arguments/options")

 converter = WCFormatConverter()

 # Process arguments.
 if len(args) == 2:
 converter.root_path = args[0]
 svn_version = args[1]
 else:
 usage_and_exit()

 # Process options.
 debug = False
 for opt, value in opts:
 if opt in ("--help", "-h", "-?"):
 usage_and_exit()
 elif opt == "--force":
 converter.force = True
 elif opt == "--skip-unknown-format":
 converter.error_on_unrecognized = False
 elif opt in ("--verbose", "-v"):
 converter.verbosity += 1
 elif opt == "--debug":
 debug = True
 else:
 usage_and_exit("Unknown option '%s'" % opt)

 try:
 new_format_nbr = LATEST_FORMATS[svn_version]
 except KeyError:
 usage_and_exit("Unsupported version number '%s'; "
 "only 1.4, 1.5, and 1.6 can be supported" % svn_version)

 try:
 converter.change_wc_format(new_format_nbr)
 except LocalException, e:
 if debug:
 raise
 sys.stderr.write("%s\n" % e)
 sys.stderr.flush()
 sys.exit(1)

 print("Converted WC at '%s' into format %d for Subversion %s" % \
 (converter.root_path, new_format_nbr, svn_version))

if __name__ == "__main__":
 main()
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