reposurgeon 3.37-1 / usr / bin / repocutter

#! /usr/bin/python
#
# Hacked together by ESR, October 2009. New BSD license applies.
# The Subversion project is explicitly granted permission to redistribute
# under the prevailing license of their project.
#
"""
repocutter - stream surgery on SVN dump files
general usage: repocutter [-q] [-r SELECTION] SUBCOMMAND

In all commands, the -r (or --range) option limits the selection of revisions
over which an operation will be performed. A selection consists of
one or more comma-separated ranges. A range may consist of an integer
revision number or the special name HEAD for the head revision. Or it
may be a colon-separated pair of integers, or an integer followed by a
colon followed by HEAD.

Normally, each subcommand produces a progress spinner on standard
error; each turn means another revision has been filtered. The -q (or
--quiet) option suppresses this.

Type 'repocutter help <subcommand>' for help on a specific subcommand.

Available subcommands:
   squash
   select
   propdel
   propset
   proprename
   log
   setlog
   strip
   expunge
   pathrename
   renumber
   reduce
"""

# This code runs under both Python 2 and Python 3: preserve this property!
from __future__ import print_function

oneliners = {
    "squash":     "Squashing revisions",
    "select":     "Selecting revisions",
    "propdel":    "Deleting revision properties",
    "propset":    "Setting revision properties",
    "proprename": "Renaming revision properties",
    "log":        "Extracting log entries",
    "setlog":     "Mutating log entries",
    "strip":      "Replace content with unique cookies, preserving structure",
    "expunge":    "Expunge operations by Node-path header",
    "pathrename": "Transform Node-path headers with a regexp replace",
    "renumber":   "Renumber revisions so they're contiguous",
    "reduce":     "Topologically reduce a dump.",
    }

helpdict = {
    "squash": """\
squash: usage: repocutter [-q] [-r SELECTION] [-m mapfile] [-f] [-c] squash

The 'squash' subcommand merges adjacent commits that have the same
author and log text and were made within 5 minutes of each other.
This can be helpful in cleaning up after migrations from file-oriented
revision control systems, or if a developer has been using a pre-2006
version of Emacs VC.

With the -m (or --mapfile) option, squash emits a map to the named
file showing how old revision numbers map into new ones.

With the -e (or --excise) option, the specified set of revisions in
unconditionally removed.  The tool will exit with an error if an
excised remove is part of a clique eligible for squashing.  Note that
repocutter does not perform any checks on whether the repository
history is afterwards valid; if you delete a node using this option,
you won't find out you have a problem until you attempt to load the
resulting dumpfile.

repocutter attempts to fix up references to Subversion revisions in log
entries so they will still be correct after squashing.  It considers
anything that looks like the regular expression \\br[0-9]+\\b to be
a comment reference (this is the same format that Subversion uses
in log headers).

Every revision in the file after the first omitted one gets the property
'repocutter:original' set to the revision number it had before the
squash operation.

The option --f (or --flagrefs) causes repocutter to wrap its revision-reference
substitutions in curly braces ({}).  By doing this, then grepping for 'r{'
in the output of 'repocutter log', you can check for false conversions.

The -c (or --compressmap) option changes the mapfile format to one
that is easier for human browsing, though less well suited for
interpretation by other programs.
""",
    "select": """\
select: usage: repocutter [-q] [-r SELECTION] select

The 'select' subcommand selects a range and permits only revisions in
that range to pass to standard output.  A range beginning with 0
includes the dumpfile header.
""",
    "propdel": """\
propdel: usage: repocutter [-r SELECTION] propdel PROPNAME...

Delete the property PROPNAME. May be restricted by a revision
selection. You may specify multiple properties to be deleted.

""",
    "propset": """\
propset: usage: repocutter [-r SELECTION] propset PROPNAME=PROPVAL...

Set the property PROPNAME to PROPVAL. May be restricted by a revision
selection. You may specify multiple property settings.
""",
    "proprename": """\
proprename: usage: repocutter [-r SELECTION] proprename OLDNAME->NEWNAME...

Rename the property OLDNAME to NEWNAME. May be restricted by a
revision selection. You may specify multiple properties to be renamed.
""",
    "log": """\
log: usage: repocutter [-r SELECTION] log

Generate a log report, same format as the output of svn log on a
repository, to standard output.
""",
    "setlog": """\
setlog: usage: repocutter [-r SELECTION] --logentries=LOGFILE setlog

Replace the log entries in the input dumpfile with the corresponding entries
in the LOGFILE, which should be in the format of an svn log output.
Replacements may be restricted to a specified range.
""",
    "strip": """\
strip: usage: repocutter [-r SELECTION] strip PATTERN...

Replace content with unique generated cookies on all node paths
matching the specified regular expressions; if no expressions are
given, match all paths.  Useful when you need to examine a
particularly complex node structure.
""",
    "expunge": """\
expunge: usage: repocutter [-r SELECTION ] expunge PATTERN...

Delete all operations with Node-path headers matching specified
Python regular expressions.  Any revision left with no Node records
after this filtering has its Revision record removed as well.
""",
    "pathrename": """\
expunge: usage: repocutter [-r SELECTION ] pathrename FROM TO

Modify Node-path headers matching the specified Python regular
expression FROM; replace with TO.  TO may contain Pyton
backreferences to parenthesized portions of FROM.
""",
    "renumber": """\
renumber: usage: repocutter renumber

Renumber all revisions, patching Node-copyfrom headers as required.
Any selection option is ignored. Takes no arguments.
""",
    "reduce": """\
reduce: usage: repocutter reduce INPUT-FILE

Strip revisions out of a dump so the only parts left those likely to
be relevant to a conversion problem. A revision is interesting if it
either (a) contains any operation that is not a plain file
modification - any directory operation, or any add, or any delete, or
any copy, or any operation on properties - or (b) it is referenced by
a later copy operation. Any commit that is neither interesting nor
has interesting neighbors is dropped.

Because the 'interesting' status of a commit is not known for sure
until all future commits have been checked for copy operations, this
command requires an input file.  It cannot operate on standard input.
The reduced dump is emitted to standard output.
""",
    }

import os, sys, calendar, time, getopt, re, io

binary_encoding = 'latin-1'

def make_std_wrapper(stream):
    "Standard input/output wrapper factory function"
    # This ensures that the encoding of standard output and standard
    # error on Python 3 matches the binary encoding we use to turn
    # bytes to Unicode in polystr above; it has no effect on Python 2
    # since the output streams are binary
    if isinstance(stream, io.TextIOWrapper):
        # newline="\n" ensures that Python 3 won't mangle line breaks
        # line_buffering=True ensures that interactive command sessions work as expected
        return io.TextIOWrapper(stream.buffer, encoding=binary_encoding, newline="\n", line_buffering=True)
    return stream

sys.stdin = make_std_wrapper(sys.stdin)
sys.stdout = make_std_wrapper(sys.stdout)
sys.stderr = make_std_wrapper(sys.stderr)

class Baton:
    "Ship progress indications to stderr."
    def __init__(self, prompt, endmsg=None):
        self.stream = sys.stderr
        self.stream.write(prompt + "...")
        if os.isatty(self.stream.fileno()):
            self.stream.write(" \010")
        self.stream.flush()
        self.count = 0
        self.endmsg = endmsg
        self.time = time.time()
        return

    def twirl(self, ch=None):
        if self.stream is None:
            return
        if os.isatty(self.stream.fileno()):
            if ch:
                self.stream.write(ch)
            else:
                self.stream.write("-/|\\"[self.count % 4])
                self.stream.write("\010")
            self.stream.flush()
        self.count = self.count + 1
        return

    def end(self, msg=None):
        if msg is None:
            msg = self.endmsg
        if self.stream:
            self.stream.write(("...(%2.2f sec) %s." % (time.time() - self.time, msg)) + os.linesep)
        return

class LineBufferedSource:
    "Generic class for line-buffered input with pushback."
    def __init__(self, infile):
        self.linebuffer = None
        self.file = infile
        self.linenumber = 0
    def readline(self):
        "Line-buffered readline."
        if self.linebuffer:
            line = self.linebuffer
            self.linebuffer = None
        else:
            line = self.file.readline()
            self.linenumber += 1
        return line
    def require(self, prefix):
        "Read a line, require it to have a specified prefix."
        line = self.readline()
        if not line:
            sys.stderr.write("repocutter: unexpected end of input while requiring '%s' input." % prefix + os.linesep)
            sys.exit(1)
        if isinstance(prefix, str):
            assert(line.startswith(prefix))
        else:
            assert(prefix.match(line))
        return line
    def read(self, rlen):
        "Straight read from underlying file, no buffering."
        assert self.linebuffer is None
        text = self.file.read(rlen)
        self.linenumber += text.count(os.linesep[0])
        return text
    def peek(self):
        "Peek at the next line in the source."
        assert(self.linebuffer is None)
        self.linebuffer = self.file.readline()
        return self.linebuffer
    def flush(self):
        "Get the contents of the line buffer, clearing it."
        assert(self.linebuffer is not None)
        line = self.linebuffer
        self.linebuffer = None
        return line
    def push(self, line):
        "Push a line back to the line buffer."
        assert(self.linebuffer is None)
        self.linebuffer = line
    def has_line_buffered(self):
        return self.linebuffer is not None

class Properties:
    def __init__(self, source):
        self.properties = {}
        self.propkeys = []
        while not source.peek().startswith("PROPS-END"):
            source.require("K")
            keyhd = source.readline()
            key = keyhd.strip()
            valhd = source.require("V")
            vlen = int(valhd.split()[1])
            value = source.read(vlen)
            source.require(os.linesep)
            self.properties[key] = value
            self.propkeys.append(key)
        source.flush()
    def __str__(self):
        st = ""
        for key in self.propkeys:
            if key in self.properties:
                st += "K %d%s" % (len(key), os.linesep)
                st += "%s%s" % (key, os.linesep)
                st += "V %d%s" % (len(self.properties[key]), os.linesep)
                st += "%s%s" % (self.properties[key], os.linesep)
        st += "PROPS-END\n"
        return st

class DumpfileSource(LineBufferedSource):
    "This class knows about dumpfile format."
    NodeLeader = re.compile("Node-")
    def __init__(self, infile, baton=None):
        LineBufferedSource.__init__(self, infile)
        self.baton = baton
        self.revision = None
        self.emitted_revisions = set()
    @staticmethod
    def set_length(header, line, val):
        return re.sub("(?<=" + header + "-length: )[0-9]+", str(val), line)
    def read_revision_header(self, property_hook=None):
        "Read a revision header, parsing its properties."
        stash = self.require("Revision-number:")
        self.revision = int(stash.split()[1])
        stash += self.require("Prop-content-length:")
        stash += self.require("Content-length:")
        stash += self.require(os.linesep)
        props = Properties(self)
        if property_hook:
            (props.propkeys, props.properties) = property_hook(props.propkeys, props.properties)
            stash = DumpfileSource.set_length("Prop-content", stash, len(str(props)))
            stash = DumpfileSource.set_length("Content", stash, len(str(props)))
        stash += str(props)
        while self.peek() == '\n':
            stash += self.readline()
        if self.baton:
            self.baton.twirl()
        return (stash, props.properties)
    def read_node(self, property_hook=None):
        "Read a node header and body."
        #print("READ NODE BEGINS")
        header = self.require(DumpfileSource.NodeLeader)
        while True:
            line = self.readline()
            #sys.stderr.write("I see header line %s\n" % repr(line))
            if not line:
                sys.stderr.write('unexpected EOF in node header' + os.linesep)
                sys.exit(1)
            m = re.search(r"Node-copyfrom-rev: ([1-9][0-9]*)", line)
            if m and int(m.group(1)) not in self.emitted_revisions:
                self.require("Node-copyfrom-path")
                continue
            header += line
            if line == '\n':
                break
        properties = ""
        if "Prop-content-length" in header:
            props = Properties(self)
            if property_hook:
                (props.propkeys, props.properties) = property_hook(props.propkeys, props.properties)
            properties = str(props)
        # use a list since extending the string gets slow
        content_list = []
        if "Text-content-length" in header:
            while True:
                line = self.readline()
                #print("I see contents line", repr(line))
                if not line:
                    break
                if line.startswith(("Node-", "Revision-number")):
                    self.push(line)
                    break
                content_list.append(line)
        content = "".join(content_list)
        del content_list
        #print("READ NODE ENDS")
        if property_hook:
            header = DumpfileSource.set_length("Prop-content", header,
                                               len(properties))
            header = DumpfileSource.set_length("Content", header,
                                               len(properties) + len(content))
        return (header, properties, content)
    def read_until_next(self, prefix, revmap=None):
        "Accumulate lines until the next matches a specified prefix."
        stash = ""
        while True:
            line = self.readline()
            if not line:
                return stash
            elif line.startswith(prefix):
                self.push(line)
                return stash
            else:
                # Hack the revision levels in copy-from headers.
                # We're actually modifying the dumpfile contents
                # (rather than selectively omitting parts of it).
                # Note: this will break on a dumpfile that has dumpfiles
                # in its nodes!
                if revmap and line.startswith("Node-copyfrom-rev:"):
                    oldrev = line.split()[1]
                    line = line.replace(oldrev, repr(revmap[int(oldrev)]))
                stash += line
    def __say(self, text):
        m = re.search(r"Revision-number: \([0-9]\)", text)
        if m:
            self.emitted_revisions.add(int(m.group(1)))
        sys.stdout.write(text)
    def report(self, selection, nodehook, prophook=None, passthrough=True):
        "Report a filtered portion of content."
        emit = passthrough and 0 in selection
        stash = self.read_until_next("Revision-number:")
        if emit:
            sys.stdout.write(stash)
        if not self.has_line_buffered():
            return
        while True:
            nodecount = 0
            (stash, properties) = self.read_revision_header(prophook)
            if self.revision in selection:
                pass
            elif self.revision == selection.upperbound()+1:
                return
            else:
                self.read_until_next("Revision-number:")
                continue
            while True:
                line = self.readline()
                if not line:
                    return
                elif line == '\n':
                    if passthrough:
                        self.__say(line)
                    continue
                elif line.startswith("Revision-number:"):
                    self.push(line)
                    if stash and nodecount == 0:
                        if passthrough:
                            self.__say(stash)
                    break
                elif line.startswith("Node-"):
                    nodecount += 1
                    self.push(line)
                    (header, properties, content) = self.read_node(prophook)
                    emit = nodehook(header, properties, content)
                    if emit and stash:
                        emit = stash + emit
                        stash = ""
                    if passthrough and isinstance(emit, str):
                        self.__say(emit)
                    continue
                else:
                    sys.stderr.write("repocutter: parse at %s doesn't look right (%s), aborting!\n" % (self.revision, repr(line)))
                    sys.exit(1)

    def __del__(self):
        if self.baton:
            self.baton.end()

class SubversionRange:
    def __init__(self, txt):
        self.txt = txt
        self.intervals = []
        for (_, item) in enumerate(txt.split(",")):
            if ':' in item:
                (lower, upper) = item.split(':')
            else:
                lower = upper = item
            if lower.isdigit():
                lower = int(lower)
            if upper.isdigit():
                upper = int(upper)
            self.intervals.append((lower, upper))
    def __contains__(self, rev):
        for (lower, upper) in self.intervals:
            if lower == "HEAD":
                sys.stderr.write("repocutter: can't accept HEAD as lower bound of a range.\n")
                sys.exit(1)
            elif upper == "HEAD":
                upper = 9223372036854775807	# Python 2 maxint
            if rev >= lower and rev <= upper:
                return True
        return False
    def upperbound(self):
        "What is the uppermost revision in the spec?"
        if self.intervals[-1][1] == "HEAD":
            return sys.maxint
        else:
            return self.intervals[-1][1]
    def __repr__(self):
        return self.txt

class Logfile:
    "Represent the state of a logfile"
    def __init__(self, readable, restriction=None):
        self.comments = {}
        self.source = LineBufferedSource(readable)
        state = 'awaiting_header'
        author = date = None
        logentry = ""
        lineno = 0
        rev = None
        while True:
            lineno += 1
            line = readable.readline()
            if state == 'in_logentry':
                if not line or line.startswith("-----------"):
                    if rev:
                        logentry = logentry.strip()
                        if restriction is None or rev in restriction:
                            self.comments[rev] = (author, date, logentry)
                        rev = None
                        logentry = ""
                    if line:
                        state = 'awaiting_header'
                    else:
                        break
                else:
                    logentry += line
            elif state == 'awaiting_header':
                if not line:
                    break
                elif line.startswith("-----------"):
                    continue
                else:
                    m = re.match("r[0-9]+", line)
                    if not m:
                        sys.stderr.write('"%s", line %d: repocutter did not see a comment header where one was expected\n' % (readable.name, lineno))
                        sys.exit(1)
                    else:
                        fields = line.split("|")
                        (rev, author, date, _linecount) = map(lambda x: x.strip(), fields)
                        rev = rev[1:]	# strip off leaing 'r'
                        state = 'in_logentry'

    def __contains__(self, key):
        return str(key) in self.comments
    def __getitem__(self, key):
        "Emulate dictionary, for new-style interface."
        return self.comments[str(key)]

def isotime(s):
    "ISO 8601 to local clock time."
    if s[-1] == "Z":
        s = s[:-1]
    if "." in s:
        (date, msec) = s.split(".")
    else:
        date = s
        msec = "0"
    # Note: no leap-second correction!
    return calendar.timegm(time.strptime(date, "%Y-%m-%dT%H:%M:%S")) + float("0." + msec)

def reference_mapper(value, mutator, flagrefs=False):
    "Apply a mutator function to revision references."
    revrefs = []
    for matchobj in re.finditer(r'\br([0-9]+)\b', value):
        revrefs.append(matchobj)
    if revrefs:
        revrefs.reverse()
        for m in revrefs:
            new = mutator(m.group(1))
            if flagrefs:
                new = "{" + new + "}"
            if new != m.group(1):
                value = value[:m.start(1)] + new + value[m.end(1):]
    return value

# Generic machinery ends here, actual command implementations begin

def squash(source, timefuzz,
           mapto=None, selection=None, excise=None,
           flagrefs=False, compressmap=False):
    "Coalesce adjacent commits with same author+log and close timestamps."
    dupes = []
    # The tricky bit is rewriting the revision numbers in node headers
    # associated with copy actions.
    clique_map = {}	# Map revisions to the base reves of their cliques
    squash_map = {}	# Map clique bases revs to their squashed numbers
    skipcount = numbered = clique_base = 0
    outmap = []
    def hacklog(propkeys, propdict, _revision):
        # Hack references to revision levels in comments.
        for (key, value) in propdict.items():
            if key == "svn:log":
                propdict[key] = reference_mapper(value, lambda old: str(squash_map[clique_map[int(old)]]), flagrefs)
        return (propkeys, propdict)
    prevprops = {"svn:log":"", "svn:author":"", "svn:date":0}
    omit = excise is not None and 0 in excise
    while True:
        stash = source.read_until_next("Revision-number:", clique_map)
        if not omit:
            sys.stdout.write(stash)
        if not source.has_line_buffered():
            if excise is not None and dupes and dupes[0] in excise:
                outmap.append((None, dupes))
            elif numbered >= 1:
                outmap.append((numbered-1, dupes))
            break
        else:
            (stash, properties) = source.read_revision_header(hacklog)
            # We have all properties of this revision.
            # Compute whether to merge it with the previous one.
            skip = "svn:log" in properties and "svn:author" in properties \
                   and properties["svn:log"] == prevprops.get("svn:log") \
                   and properties["svn:author"] == prevprops.get("svn:author") \
                   and (selection is None or source.revision in selection) \
                   and abs(isotime(properties["svn:date"]) - isotime(prevprops.get("svn:date"))) < timefuzz
            # Did user request an unconditional omission?
            omit = excise is not None and source.revision in excise
            if skip and omit:
                sys.stderr.write("squash: can't omit a revision about to be squashed.\n")
                sys.exit(1)
            # Treat spans of omitted commits as cliques for reporting
            if omit and excise is not None and source.revision-1 in excise:
                skip = True
            # The magic moment
            if skip:
                skipcount += 1
                clique_map[source.revision] = clique_base
            else:
                clique_base = source.revision
                clique_map[clique_base] = clique_base
                squash_map[clique_base] = source.revision - skipcount
                if excise is not None and dupes and dupes[0] in excise:
                    outmap.append((None, dupes))
                elif numbered >= 1:
                    outmap.append((numbered-1, dupes))
                dupes = []
                if omit:
                    skipcount += 1
                else:
                    sys.stdout.write(stash)
                    prevprops = properties
                    numbered += 1
            dupes.append(source.revision)
        # Go back around to copying to the next revision header.
    if mapto:
        mapto.write(("%% %d out of %d original revisions squashed, leaving %d" \
                     % (skipcount, source.revision, numbered-1)) + os.linesep)
        if not compressmap:
            for (numbered, dupes) in outmap:
                if numbered is None:
                    mapto.write("  None <- " + " ".join(map(str, dupes))+os.linesep)
                else:
                    mapto.write(("%6d <- " % numbered) + " ".join(map(str, dupes))+os.linesep)
        else:
            compressed = []
            force_new_range = True
            last_n = -1
            last_oldrevs = []
            # Process the raw outmap into a form that compressees ranges.
            # Squash cliques are left alone.  Ranger between
            # them map to either
            # (1) None followed by a singleton list (single deleted rev)
            # (2) None followed by a two-element list (range of deletions)
            # (3) Single number followed by singleton list = 1-element range)
            # (4) Two-element list followed by two-element list =
            #     multiple elements, old range to new range.
            for (n, oldrevs) in outmap:
                #print >>sys.stderr, "I see:", (n, oldrevs)
                #cliquebase = oldrevs[0]
                if len(oldrevs) > 1:
                    compressed.append((n, oldrevs))
                    force_new_range = True
                else:
                    if (n is None) != (last_n is None):
                        #print >>sys.stderr, "Forcing range break"
                        force_new_range = True
                    if force_new_range:
                        compressed.append((n, oldrevs))
                    else:
                        #print >>sys.stderr, "Adding to range"
                        if len(last_oldrevs) == 1:
                            oldrevs = last_oldrevs + oldrevs
                        else:
                            oldrevs = last_oldrevs[:1] + oldrevs
                        lowerbound = compressed[-1][0]
                        if (last_n is None) and (n is None):
                            compressed[-1] = [None, oldrevs]
                        elif isinstance(lowerbound, int):
                            compressed[-1] = [[lowerbound, n], oldrevs]
                        else:
                            compressed[-1] = [lowerbound[:1] + [n], oldrevs]
                    force_new_range = False
                    last_n = n
                    last_oldrevs = oldrevs
            #print >>sys.stderr, "Compressed:", compressed
            for (a, b) in compressed:
                if a is None:
                    if len(b) == 1:
                        mapto.write("  None         <- %d\n" % b[0])
                        continue
                    else:
                        mapto.write("  None         <- %d..%d\n" % (b[0], b[-1]))
                        continue
                else:
                    if isinstance(a, int) and len(b) == 1:
                        mapto.write("%6d         <- %d\n" % (a, b[0]))
                        continue
                    elif isinstance(a, int) and isinstance(b, list):
                        mapto.write("%6d         <- %d..%d\n" % (a, b[0], b[-1]))
                        continue
                    elif isinstance(a, list) and len(a) == 2 and len(b) == 2:
                        mapto.write("%6d..%-6d <- %d..%d\n" % (a[0], a[1], b[0], b[1]))
                        continue
                sys.stderr.write("repocutter: Internal error on %s\n" % ((a, b),))
                sys.exit(1)

def select(source, selection):
    "Select a portion of the dump file defined by a revision selection."
    emit = 0 in selection
    while True:
        stash = source.read_until_next("Revision-number:")
        if emit:
            sys.stdout.write(stash)
        if not source.has_line_buffered():
            return
        else:
            revision = int(source.linebuffer.split()[1])
            emit = revision in selection
            if emit:
                sys.stdout.write(source.flush())
            elif revision == selection.upperbound()+1:
                return
            else:
                source.flush()

def propdel(source, properties, selection):
    "Delete properties."
    def __revhook(propkeys, propdict):
        for propname in properties:
            if propname in propdict:
                del propdict[propname]
        return (propkeys, propdict)
    def __nodehook(header, properties, content):
        return header + properties + content
    source.report(selection, __nodehook, __revhook)

def propset(source, properties, selection):
    "Set properties."
    def __revhook(propkeys, propdict):
        for prop in properties:
            (propname, propval) = prop.split("=")
            if propname in propdict:
                propdict[propname] = propval
        return (propkeys, propdict)
    def __nodehook(header, properties, content):
        return header + properties + content
    source.report(selection, __nodehook, __revhook)

def proprename(source, properties, selection):
    "Rename properties."
    def __revhook(propkeys, propdict):
        for prop in properties:
            (oldname, newname) = prop.split("->")
            if oldname in propdict:
                propdict[newname] = propdict[oldname]
                del propdict[oldname]
                propkeys[propkeys.index(oldname)] = newname
        return (propkeys, propdict)
    def __nodehook(header, properties, content):
        return header + properties + content
    source.report(selection, __nodehook, __revhook)

def log(source, _selection):
    "Extract log entries."
    while True:
        source.read_until_next("Revision-number:")
        if not source.has_line_buffered():
            return
        else:
            (_stash, props) = source.read_revision_header()
            logentry = props.get("svn:log")
            if logentry:
                print("-" * 72)
                author = props.get("svn:author", "(no author)")
                date = props["svn:date"].split(".")[0]
                date = time.strptime(date, "%Y-%m-%dT%H:%M:%S")
                date = time.strftime("%Y-%m-%d %H:%M:%S +0000 (%a, %d %b %Y)", date)
                print("r%s | %s | %s | %d lines" % (source.revision,
                                                    author,
                                                    date,
                                                    logentry.count(os.linesep)))
                sys.stdout.write("\n" + logentry + "\n")

def setlog(source, logpatch, selection):
    "Mutate log entries."
    logpatch = Logfile(file(logpatch), selection)
    def loghook(propkeys, propdict):
        if "svn:log" in propkeys and source.revision in logpatch:
            (author, _date, logentry) = logpatch[source.revision]
            if author != propdict.get("svn:author", "(no author)"):
                sys.stderr.write("repocutter: author of revision %s doesn't look right, aborting!\n" % source.revision)
                sys.exit(1)
            propdict["svn:log"] = logentry
        return (propkeys, propdict)
    source.apply_property_hook(selection, loghook)

def strip(source, selection, patterns):
    "Strip a portion of the dump file defined by a revision selection."
    def __strip(header, properties, content):
        def get_header(hd, name):
            m = re.search(name + ": (.*)", hd)
            return m and m.group(1)
        def set_length(hd, name, val):
            return re.sub("(?<=%s: )[0-9]+" % name, str(val), hd)

        # first check against the pattern
        ok = True
        offs = header.find("Node-path: ")
        if offs > -1:
            offs += 11
            filepath = header[offs:header[offs:].index("\n")]
            for pattern in patterns:
                if re.search(pattern, filepath):
                    #sys.stderr.write("strip skipping: %s\n" % filepath)
                    ok = False
                    break
        if not ok:
            return header + properties + content
        del ok

        if content:
            tell = "Revision is %s, file path is %s.\n\n\n" % \
                      (source.revision, get_header(header, "Node-path"),)
            # Avoid replacing symlinks, a reposurgeon sanity check barfs.
            if content.startswith("link "):
                content = content + tell
            else:
                content = tell
            header = set_length(header,
                                "Text-content-length", len(content)-2)
            header = set_length(header,
                                "Content-length", len(properties)+len(content)-2)
        header = re.sub("Text-content-md5:.*\n", "", header)
        header = re.sub("Text-content-sha1:.*\n", "", header)
        header = re.sub("Text-copy-source-md5:.*\n", "", header)
        header = re.sub("Text-copy-source-sha1:.*\n", "", header)
        return header + properties + content
    source.report(selection, __strip)

def doreduce(source):
    "Topologically reduce a dump, removing spans of plain file modifications."
    interesting = set([0])
    def __reduce(header, properties, _content):
        def get_header(name):
            m = re.search(name + ": (.*)", header)
            return m and m.group(1)
        if not (get_header("Node-kind") == "file" and get_header("Node-action") == "change") or properties:
            interesting.add(source.revision)
        copysource = get_header("Node-copyfrom-rev")
        if copysource is not None:
            interesting.add(int(copysource))
        return None
    source.report(SubversionRange("0:HEAD"), __reduce, passthrough=False)
    selection = SubversionRange(",".join([str(x) for x in interesting or x+1 in interesting or x-1 in interesting]))
    source.file.seek(0)
    select(source, selection)

def expunge(source, selection, patterns):
    "Strip out ops defined by a revision selection and a path regexp."
    def __expunge(header, properties, content):
        matched = False
        offs = header.find("Node-path: ")
        if offs > -1:
            offs += 11
            filepath = header[offs:offs+header[offs:].index("\n")]
            for pattern in patterns:
                if re.search(pattern, filepath):
                    #sys.stderr.write("expunge skipping: " + filepath +"\n")
                    matched = True
                    break
        if not matched:
            return header + properties + content
    source.report(selection, __expunge)

def pathrename(source, selection, patterns):
    "Hack paths by applying a regexp transformation."
    def __pathrename(header, properties, content):
        offs = header.find("Node-path: ")
        if offs > -1:
            offs += 11
            endoffs = offs + header[offs:].index("\n")
            before = header[:offs]
            pathline = header[offs:endoffs]
            after = header[endoffs:]
            #sys.stderr.write("Patterns: %s %s\n" % (patterns[0], patterns[1]))
            pathline = re.sub(patterns[0].pattern,
                              patterns[1].pattern,
                              pathline)
            header = before + pathline + after
        return header + properties + content
    source.report(selection, __pathrename)

def renumber(source):
    "Renumber all revisions."
    renumbering = {}
    counter = 0
    while True:
        line = source.readline()
        if not line:
            break
        elif line.startswith("Revision-number: "):
            oldrev = line.split(":")[1].strip()
            sys.stdout.write("Revision-number: %d\n" % counter)
            renumbering[oldrev] = counter
            counter += 1
        elif line.startswith("Node-copyfrom-rev:"):
            oldrev = line.split(":")[1].strip()
            sys.stdout.write("Node-copyfrom-rev: %s\n" % renumbering[oldrev])
        else:
            sys.stdout.write(line)

def patterns_compile(patterns):
    return [re.compile(pattern) for pattern in patterns]

if __name__ == '__main__':
    try:
        (options, arguments) = getopt.getopt(sys.argv[1:], "ce:fl:m:p:qr:s",
                                             ["excise", "flagrefs", "revprop=",
                                              "logpatch=", "map=",
                                              "quiet", "range="])
        selection = SubversionRange("0:HEAD")
        timefuzz = 300	# 5 minute fuzz
        compressmap = False
        excise = None
        revprops = []
        progress = True
        flagrefs = False
        logpatch = None
        mapto = None
        for (switch, val) in options:
            if switch in ('-c', '--compressmap'):
                compressmap = True
            elif switch in ('-e', '--excise'):
                excise = SubversionRange(val)
            elif switch in ('-f', '--flagrefs'):
                flagrefs = True
            elif switch in ('-l', '--logentries'):
                logpatch = val
            elif switch in ('-m', '--map'):
                mapto = open(val, "w")
            elif switch in ('-p', '--revprop'):
                revprops.append(val)
            elif switch in ('-q', '--quiet'):
                progress = False
            elif switch in ('-r', '--range'):
                selection = SubversionRange(val)
        if len(arguments) == 0:
            sys.stderr.write("Type 'repocutter help' for usage." + os.linesep)
            sys.exit(1)
        baton = None
        if arguments[0] != 'help':
            if progress:
                baton = Baton(oneliners[arguments[0]], "done")
            else:
                baton = None
        if arguments[0] == "squash":
            squash(DumpfileSource(sys.stdin, baton),
                   timefuzz, mapto, selection, excise, flagrefs, compressmap)
        elif arguments[0] == "propdel":
            propdel(DumpfileSource(sys.stdin, baton), revprops + arguments[1:], selection)
        elif arguments[0] == "propset":
            propset(DumpfileSource(sys.stdin, baton), revprops + arguments[1:], selection)
        elif arguments[0] == "proprename":
            proprename(DumpfileSource(sys.stdin, baton), revprops + arguments[1:], selection)
        elif arguments[0] == "select":
            select(DumpfileSource(sys.stdin, baton), selection)
        elif arguments[0] == "log":
            log(DumpfileSource(sys.stdin, baton), selection)
        elif arguments[0] == "setlog":
            if not logpatch:
                sys.stderr.write("repocutter: setlog requires a log entries file.\n")
            setlog(DumpfileSource(sys.stdin, baton), logpatch, selection)
        elif arguments[0] == "strip":
            strip(DumpfileSource(sys.stdin, baton), selection, patterns_compile(arguments[1:]))
        elif arguments[0] == "pathrename":
            pathrename(DumpfileSource(sys.stdin, baton), selection, patterns_compile(arguments[1:]))
        elif arguments[0] == "expunge":
            expunge(DumpfileSource(sys.stdin, baton), selection, patterns_compile(arguments[1:]))
        elif arguments[0] == "renumber":
            renumber(DumpfileSource(sys.stdin, baton))
        elif arguments[0] == "reduce":
            doreduce(DumpfileSource(open(arguments[1]), baton))
        elif arguments[0] == "help":
            if len(arguments) == 1:
                sys.stdout.write(__doc__)
            else:
                sys.stdout.write(helpdict.get(arguments[1], arguments[1] + ": no such subcommand.\n"))
        else:
            sys.stderr.write(('"%s": unknown subcommand\n' % arguments[0])+os.linesep)
            sys.exit(1)
    except KeyboardInterrupt:
        pass

# script ends here