view hgext/largefiles/remotestore.py @ 47315:825d5a5907b4

exewrapper: avoid directly linking against python3X.dll

Subsequent code calls `LoadLibrary()` to attempt to load the DLL, but because of
this symbol reference, there is an attempt to load the DLL used during the build
prior to `_main()` running.  This causes the whole process to fail if the DLL
isn't in the standard search path.  That also means it will never load the DLL
for HackableMercurial.  (Maybe we should get rid of that for py3, since you can
install python for a user without admin rights?)

This could also be resolved by calling `GetProcAddress()` on the symbol and
dereferencing it, but using the environment variable is consistent with the
*.bat file since fc8a5c9ecee0.  (The environment variable persists after the
interpreter is initialized.)

Far more concerning is somehow I've gotten my system into a state where setting
the flag causes any output to the pager to be lost (as if it wasn't set at all)
in MSYS, cmd.exe, WSL, and PowerShell using py3.9.0, but the environment
variable works properly.  I'm sure this flag worked on some versions of py3, so
I'm not sure what's going on here.  This is might be related to init config
related changes in 3.8[1], since it works with 3.7.8, but fails with 3.8.1.
Somebody who understands encoding issues better than I do should give some
thought to if we need to make some changes to our encoding strategy on Windows
with py3.

With or without the flag/envvar, there is proper output if the command is
directly paged by piping to `more.com` (in any environment) or `less` (in MSYS
and WSL), or if paging is disabled with `--pager=no`.  Legacy mode is required
though when Mercurial decides to spin up a pager.

[1] https://bugs.python.org/issue41941

Differential Revision: https://phab.mercurial-scm.org/D10756

# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''remote largefile store; the base class for wirestore'''
from __future__ import absolute_import

from mercurial.i18n import _

from mercurial import (
    error,
    pycompat,
    util,
)

from mercurial.utils import (
    stringutil,
    urlutil,
)

from . import (
    basestore,
    lfutil,
    localstore,
)

urlerr = util.urlerr
urlreq = util.urlreq


class remotestore(basestore.basestore):
    '''a largefile store accessed over a network'''

    def __init__(self, ui, repo, url):
        super(remotestore, self).__init__(ui, repo, url)
        self._lstore = None
        if repo is not None:
            self._lstore = localstore.localstore(self.ui, self.repo, self.repo)

    def put(self, source, hash):
        if self.sendfile(source, hash):
            raise error.Abort(
                _(b'remotestore: could not put %s to remote store %s')
                % (source, urlutil.hidepassword(self.url))
            )
        self.ui.debug(
            _(b'remotestore: put %s to remote store %s\n')
            % (source, urlutil.hidepassword(self.url))
        )

    def exists(self, hashes):
        return {
            h: s == 0
            for (h, s) in pycompat.iteritems(
                self._stat(hashes)
            )  # dict-from-generator
        }

    def sendfile(self, filename, hash):
        self.ui.debug(b'remotestore: sendfile(%s, %s)\n' % (filename, hash))
        try:
            with lfutil.httpsendfile(self.ui, filename) as fd:
                return self._put(hash, fd)
        except IOError as e:
            raise error.Abort(
                _(b'remotestore: could not open file %s: %s')
                % (filename, stringutil.forcebytestr(e))
            )

    def _getfile(self, tmpfile, filename, hash):
        try:
            chunks = self._get(hash)
        except urlerr.httperror as e:
            # 401s get converted to error.Aborts; everything else is fine being
            # turned into a StoreError
            raise basestore.StoreError(
                filename, hash, self.url, stringutil.forcebytestr(e)
            )
        except urlerr.urlerror as e:
            # This usually indicates a connection problem, so don't
            # keep trying with the other files... they will probably
            # all fail too.
            raise error.Abort(
                b'%s: %s' % (urlutil.hidepassword(self.url), e.reason)
            )
        except IOError as e:
            raise basestore.StoreError(
                filename, hash, self.url, stringutil.forcebytestr(e)
            )

        return lfutil.copyandhash(chunks, tmpfile)

    def _hashesavailablelocally(self, hashes):
        existslocallymap = self._lstore.exists(hashes)
        localhashes = [hash for hash in hashes if existslocallymap[hash]]
        return localhashes

    def _verifyfiles(self, contents, filestocheck):
        failed = False
        expectedhashes = [
            expectedhash for cset, filename, expectedhash in filestocheck
        ]
        localhashes = self._hashesavailablelocally(expectedhashes)
        stats = self._stat(
            [
                expectedhash
                for expectedhash in expectedhashes
                if expectedhash not in localhashes
            ]
        )

        for cset, filename, expectedhash in filestocheck:
            if expectedhash in localhashes:
                filetocheck = (cset, filename, expectedhash)
                verifyresult = self._lstore._verifyfiles(
                    contents, [filetocheck]
                )
                if verifyresult:
                    failed = True
            else:
                stat = stats[expectedhash]
                if stat:
                    if stat == 1:
                        self.ui.warn(
                            _(b'changeset %s: %s: contents differ\n')
                            % (cset, filename)
                        )
                        failed = True
                    elif stat == 2:
                        self.ui.warn(
                            _(b'changeset %s: %s missing\n') % (cset, filename)
                        )
                        failed = True
                    else:
                        raise RuntimeError(
                            b'verify failed: unexpected response '
                            b'from statlfile (%r)' % stat
                        )
        return failed

    def _put(self, hash, fd):
        '''Put file with the given hash in the remote store.'''
        raise NotImplementedError(b'abstract method')

    def _get(self, hash):
        '''Get a iterator for content with the given hash.'''
        raise NotImplementedError(b'abstract method')

    def _stat(self, hashes):
        """Get information about availability of files specified by
        hashes in the remote store. Return dictionary mapping hashes
        to return code where 0 means that file is available, other
        values if not."""
        raise NotImplementedError(b'abstract method')