mercurial/sshserver.py

Avoid extra filelogs entries.

Right now, there are some situations in which localrepo.filecommit can
create filelog entries even though they're not needed.  For example:

- permissions for a file have changed;

- qrefresh can create a filelog entry identical to its parent (see the
  added test);

- convert-repo creates extra filelog entries in every merge where the
  first parent has added files (for example, changeset ebebe9577a1a of
  the kernel repo added extra filelog entries to files in the
  arch/blackfin directory, even though the merge should only touch the
  drivers/ata directory).  This makes "hg log file" in a converted repo
  less useful than it could be, since it may mention many merges that
  don't actually touch that specific file.

They all come from the same basic problem:  localrepo.commit (through
filecommit) creates new filelog entries for all files passed to it
(except for some cases during a merge).

Patch and test case provided by Benoit.

This should fix issue351.

# sshserver.py - ssh protocol server support for mercurial
#
# Copyright 2005 Matt Mackall <[e-mail]>
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from i18n import _
from node import *
import os, streamclone, sys, tempfile, util

class sshserver(object):
    def __init__(self, ui, repo):
        self.ui = ui
        self.repo = repo
        self.lock = None
        self.fin = sys.stdin
        self.fout = sys.stdout

        sys.stdout = sys.stderr

        # Prevent insertion/deletion of CRs
        util.set_binary(self.fin)
        util.set_binary(self.fout)

    def getarg(self):
        argline = self.fin.readline()[:-1]
        arg, l = argline.split()
        val = self.fin.read(int(l))
        return arg, val

    def respond(self, v):
        self.fout.write("%d\n" % len(v))
        self.fout.write(v)
        self.fout.flush()

    def serve_forever(self):
        while self.serve_one(): pass
        sys.exit(0)

    def serve_one(self):
        cmd = self.fin.readline()[:-1]
        if cmd:
            impl = getattr(self, 'do_' + cmd, None)
            if impl: impl()
            else: self.respond("")
        return cmd != ''

    def do_lookup(self):
        arg, key = self.getarg()
        assert arg == 'key'
        try:
            r = hex(self.repo.lookup(key))
            success = 1
        except Exception,inst:
            r = str(inst)
            success = 0
        self.respond("%s %s\n" % (success, r))

    def do_heads(self):
        h = self.repo.heads()
        self.respond(" ".join(map(hex, h)) + "\n")

    def do_hello(self):
        '''the hello command returns a set of lines describing various
        interesting things about the server, in an RFC822-like format.
        Currently the only one defined is "capabilities", which
        consists of a line in the form:

        capabilities: space separated list of tokens
        '''

        caps = ['unbundle', 'lookup', 'changegroupsubset']
        if self.ui.configbool('server', 'uncompressed'):
            caps.append('stream=%d' % self.repo.changelog.version)
        self.respond("capabilities: %s\n" % (' '.join(caps),))

    def do_lock(self):
        '''DEPRECATED - allowing remote client to lock repo is not safe'''

        self.lock = self.repo.lock()
        self.respond("")

    def do_unlock(self):
        '''DEPRECATED'''

        if self.lock:
            self.lock.release()
        self.lock = None
        self.respond("")

    def do_branches(self):
        arg, nodes = self.getarg()
        nodes = map(bin, nodes.split(" "))
        r = []
        for b in self.repo.branches(nodes):
            r.append(" ".join(map(hex, b)) + "\n")
        self.respond("".join(r))

    def do_between(self):
        arg, pairs = self.getarg()
        pairs = [map(bin, p.split("-")) for p in pairs.split(" ")]
        r = []
        for b in self.repo.between(pairs):
            r.append(" ".join(map(hex, b)) + "\n")
        self.respond("".join(r))

    def do_changegroup(self):
        nodes = []
        arg, roots = self.getarg()
        nodes = map(bin, roots.split(" "))

        cg = self.repo.changegroup(nodes, 'serve')
        while True:
            d = cg.read(4096)
            if not d:
                break
            self.fout.write(d)

        self.fout.flush()

    def do_changegroupsubset(self):
        bases = []
        heads = []
        argmap = dict([self.getarg(), self.getarg()])
        bases = [bin(n) for n in argmap['bases'].split(' ')]
        heads = [bin(n) for n in argmap['heads'].split(' ')]

        cg = self.repo.changegroupsubset(bases, heads, 'serve')
        while True:
            d = cg.read(4096)
            if not d:
                break
            self.fout.write(d)

        self.fout.flush()

    def do_addchangegroup(self):
        '''DEPRECATED'''

        if not self.lock:
            self.respond("not locked")
            return

        self.respond("")
        r = self.repo.addchangegroup(self.fin, 'serve', self.client_url())
        self.respond(str(r))

    def client_url(self):
        client = os.environ.get('SSH_CLIENT', '').split(' ', 1)[0]
        return 'remote:ssh:' + client

    def do_unbundle(self):
        their_heads = self.getarg()[1].split()

        def check_heads():
            heads = map(hex, self.repo.heads())
            return their_heads == [hex('force')] or their_heads == heads

        # fail early if possible
        if not check_heads():
            self.respond(_('unsynced changes'))
            return

        self.respond('')

        # write bundle data to temporary file because it can be big

        try:
            fd, tempname = tempfile.mkstemp(prefix='hg-unbundle-')
            fp = os.fdopen(fd, 'wb+')

            count = int(self.fin.readline())
            while count:
                fp.write(self.fin.read(count))
                count = int(self.fin.readline())

            was_locked = self.lock is not None
            if not was_locked:
                self.lock = self.repo.lock()
            try:
                if not check_heads():
                    # someone else committed/pushed/unbundled while we
                    # were transferring data
                    self.respond(_('unsynced changes'))
                    return
                self.respond('')

                # push can proceed

                fp.seek(0)
                r = self.repo.addchangegroup(fp, 'serve', self.client_url())
                self.respond(str(r))
            finally:
                if not was_locked:
                    self.lock.release()
                    self.lock = None
        finally:
            fp.close()
            os.unlink(tempname)

    def do_stream_out(self):
        streamclone.stream_out(self.repo, self.fout)