view hgext/largefiles/basestore.py @ 27558:b5b54825de6b

pull: make a single call to obsstore.add (issue5006)

Prior to this, a pull of 90k markers (already known locally!) was
making about 2000 calls to obsstore.add, which was repeatedly building
a full set of known markers (in addition to other transaction
overhead). This quadratic behavior accounted for about 50 seconds of a
70 second no-op pull. After this change, we're down to 20 seconds.

While it would seem simplest to just cache the known set for
obsstore.add, this would also introduce issues of correct cache invalidation.
The extra pointless transaction overhead would also remain.

# Copyright 2009-2010 Gregory P. Ward
# Copyright 2009-2010 Intelerad Medical Systems Incorporated
# 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.

'''base class for store implementations and store-related utility code'''

import re

from mercurial import util, node, hg, error
from mercurial.i18n import _

import lfutil

class StoreError(Exception):
    '''Raised when there is a problem getting files from or putting
    files to a central store.'''
    def __init__(self, filename, hash, url, detail):
        self.filename = filename
        self.hash = hash
        self.url = url
        self.detail = detail

    def longmessage(self):
        return (_("error getting id %s from url %s for file %s: %s\n") %
                 (self.hash, util.hidepassword(self.url), self.filename,
                  self.detail))

    def __str__(self):
        return "%s: %s" % (util.hidepassword(self.url), self.detail)

class basestore(object):
    def __init__(self, ui, repo, url):
        self.ui = ui
        self.repo = repo
        self.url = url

    def put(self, source, hash):
        '''Put source file into the store so it can be retrieved by hash.'''
        raise NotImplementedError('abstract method')

    def exists(self, hashes):
        '''Check to see if the store contains the given hashes. Given an
        iterable of hashes it returns a mapping from hash to bool.'''
        raise NotImplementedError('abstract method')

    def get(self, files):
        '''Get the specified largefiles from the store and write to local
        files under repo.root.  files is a list of (filename, hash)
        tuples.  Return (success, missing), lists of files successfully
        downloaded and those not found in the store.  success is a list
        of (filename, hash) tuples; missing is a list of filenames that
        we could not get.  (The detailed error message will already have
        been presented to the user, so missing is just supplied as a
        summary.)'''
        success = []
        missing = []
        ui = self.ui

        at = 0
        available = self.exists(set(hash for (_filename, hash) in files))
        for filename, hash in files:
            ui.progress(_('getting largefiles'), at, unit='lfile',
                total=len(files))
            at += 1
            ui.note(_('getting %s:%s\n') % (filename, hash))

            if not available.get(hash):
                ui.warn(_('%s: largefile %s not available from %s\n')
                        % (filename, hash, util.hidepassword(self.url)))
                missing.append(filename)
                continue

            if self._gethash(filename, hash):
                success.append((filename, hash))
            else:
                missing.append(filename)

        ui.progress(_('getting largefiles'), None)
        return (success, missing)

    def _gethash(self, filename, hash):
        """Get file with the provided hash and store it in the local repo's
        store and in the usercache.
        filename is for informational messages only.
        """
        util.makedirs(lfutil.storepath(self.repo, ''))
        storefilename = lfutil.storepath(self.repo, hash)

        tmpname = storefilename + '.tmp'
        tmpfile = util.atomictempfile(tmpname,
                                      createmode=self.repo.store.createmode)

        try:
            gothash = self._getfile(tmpfile, filename, hash)
        except StoreError as err:
            self.ui.warn(err.longmessage())
            gothash = ""
        tmpfile.close()

        if gothash != hash:
            if gothash != "":
                self.ui.warn(_('%s: data corruption (expected %s, got %s)\n')
                             % (filename, hash, gothash))
            util.unlink(tmpname)
            return False

        util.rename(tmpname, storefilename)
        lfutil.linktousercache(self.repo, hash)
        return True

    def verify(self, revs, contents=False):
        '''Verify the existence (and, optionally, contents) of every big
        file revision referenced by every changeset in revs.
        Return 0 if all is well, non-zero on any errors.'''
        failed = False

        self.ui.status(_('searching %d changesets for largefiles\n') %
                       len(revs))
        verified = set()                # set of (filename, filenode) tuples

        for rev in revs:
            cctx = self.repo[rev]
            cset = "%d:%s" % (cctx.rev(), node.short(cctx.node()))

            for standin in cctx:
                if self._verifyfile(cctx, cset, contents, standin, verified):
                    failed = True

        numrevs = len(verified)
        numlfiles = len(set([fname for (fname, fnode) in verified]))
        if contents:
            self.ui.status(
                _('verified contents of %d revisions of %d largefiles\n')
                % (numrevs, numlfiles))
        else:
            self.ui.status(
                _('verified existence of %d revisions of %d largefiles\n')
                % (numrevs, numlfiles))
        return int(failed)

    def _getfile(self, tmpfile, filename, hash):
        '''Fetch one revision of one file from the store and write it
        to tmpfile.  Compute the hash of the file on-the-fly as it
        downloads and return the hash.  Close tmpfile.  Raise
        StoreError if unable to download the file (e.g. it does not
        exist in the store).'''
        raise NotImplementedError('abstract method')

    def _verifyfile(self, cctx, cset, contents, standin, verified):
        '''Perform the actual verification of a file in the store.
        'cset' is only used in warnings.
        'contents' controls verification of content hash.
        'standin' is the standin path of the largefile to verify.
        'verified' is maintained as a set of already verified files.
        Returns _true_ if it is a standin and any problems are found!
        '''
        raise NotImplementedError('abstract method')

import localstore, wirestore

_storeprovider = {
    'file':  [localstore.localstore],
    'http':  [wirestore.wirestore],
    'https': [wirestore.wirestore],
    'ssh': [wirestore.wirestore],
    }

_scheme_re = re.compile(r'^([a-zA-Z0-9+-.]+)://')

# During clone this function is passed the src's ui object
# but it needs the dest's ui object so it can read out of
# the config file. Use repo.ui instead.
def _openstore(repo, remote=None, put=False):
    ui = repo.ui

    if not remote:
        lfpullsource = getattr(repo, 'lfpullsource', None)
        if lfpullsource:
            path = ui.expandpath(lfpullsource)
        elif put:
            path = ui.expandpath('default-push', 'default')
        else:
            path = ui.expandpath('default')

        # ui.expandpath() leaves 'default-push' and 'default' alone if
        # they cannot be expanded: fallback to the empty string,
        # meaning the current directory.
        if path == 'default-push' or path == 'default':
            path = ''
            remote = repo
        else:
            path, _branches = hg.parseurl(path)
            remote = hg.peer(repo, {}, path)

    # The path could be a scheme so use Mercurial's normal functionality
    # to resolve the scheme to a repository and use its path
    path = util.safehasattr(remote, 'url') and remote.url() or remote.path

    match = _scheme_re.match(path)
    if not match:                       # regular filesystem path
        scheme = 'file'
    else:
        scheme = match.group(1)

    try:
        storeproviders = _storeprovider[scheme]
    except KeyError:
        raise error.Abort(_('unsupported URL scheme %r') % scheme)

    for classobj in storeproviders:
        try:
            return classobj(ui, repo, remote)
        except lfutil.storeprotonotcapable:
            pass

    raise error.Abort(_('%s does not appear to be a largefile store') %
                     util.hidepassword(path))