- Add change-svn-wc-format.py utility from http://svn.collab.net/repos/svn/tr...

change-svn-wc-format.py

Index: change-svn-wc-format.py
===================================================================
--- change-svn-wc-format.py	(revision 0)
+++ change-svn-wc-format.py	(revision 0)
@@ -0,0 +1,414 @@
+#!/usr/bin/env python
+#
+# change-svn-wc-format.py: Change the format of a Subversion working copy.
+#
+# ====================================================================
+# Copyright (c) 2007-2009 CollabNet.  All rights reserved.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution.  The terms
+# are also available at http://subversion.tigris.org/license-1.html.
+# If newer versions of this license are posted there, you may use a
+# newer version instead, at your option.
+#
+# This software consists of voluntary contributions made by many
+# individuals.  For exact contribution history, see the revision
+# history and logs, available at http://subversion.tigris.org/.
+# ====================================================================
+
+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()