view hgext/infinitepush/store.py @ 46527:018d622e814d

test-copies: reinstall initial identical (empty) files for chained copied This effectively back out changeset deeb215be337. Changeset deeb215be33 does not really include a justification for its change and make mes uncomfortable. I have been thinking about it and they are two options: - either having empty/full files does not make a difference, and deeb215be337 is a gratuitous changes. - either having empty/full files do make a difference and deeb215be33 silently change the test coverage. In such situation if we want the "not empty" case to be tested, we should add new cases to cover them In practice, we know that the "file content did not change, but merge still need to create a new filenode" case exists (for example if merging result in similar content but both parent of the file need to be recorded), and that such case are easy to miss/mess-up in the tests. Having all the file using the same (empty) content was done on purpose to increase the coverage of such corner case. As a result I am reinstalling the previous test situation. To increase the coverage of some case involving content-merge in test-copies-chain-merge.t, we will add a new, dedicated, cases later in this series, once various cleanup and test improvement have been set in place. This changeset starts with reinstalling the previous situation as (1) it is more fragile, so I am more confided getting it back in the initial situation, (2) I have specific test further down the line that are base on these one. The next changeset will slightly alter the test to use non-empty files for these tests (with identical content). It should help to make the initial intent "merge file with identical content" clearer. I am still using a two steps (backout, then change content) approach to facilitate careful validation of the output change. Doing so has a large impact on the output of the "copy info in changeset extra" variant added in 5e72827dae1e (2 changesets after deeb215be33). It seems to highlight various breakage when merge without content change are involved, this is a good example of why we want to explicitly test theses cases. Because the different -do- matters a lot. Fixing the "copy info in changeset extra" is not a priority here. Because (1) this changeset does not break anything, it only highlight that they were always broken. (2) the only people using "copy info in changeset extra" do not have merge. Differential Revision: https://phab.mercurial-scm.org/D9587
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Thu, 10 Dec 2020 14:25:36 +0100
parents 59fa3890d40a
children 6000f5b25c9b
line wrap: on
line source

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

# based on bundleheads extension by Gregory Szorc <gps@mozilla.com>

from __future__ import absolute_import

import abc
import os
import subprocess

from mercurial.node import hex
from mercurial.pycompat import open
from mercurial import pycompat
from mercurial.utils import (
    hashutil,
    procutil,
)


class BundleWriteException(Exception):
    pass


class BundleReadException(Exception):
    pass


class abstractbundlestore(object):  # pytype: disable=ignored-metaclass
    """Defines the interface for bundle stores.

    A bundle store is an entity that stores raw bundle data. It is a simple
    key-value store. However, the keys are chosen by the store. The keys can
    be any Python object understood by the corresponding bundle index (see
    ``abstractbundleindex`` below).
    """

    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def write(self, data):
        """Write bundle data to the store.

        This function receives the raw data to be written as a str.
        Throws BundleWriteException
        The key of the written data MUST be returned.
        """

    @abc.abstractmethod
    def read(self, key):
        """Obtain bundle data for a key.

        Returns None if the bundle isn't known.
        Throws BundleReadException
        The returned object should be a file object supporting read()
        and close().
        """


class filebundlestore(object):
    """bundle store in filesystem

    meant for storing bundles somewhere on disk and on network filesystems
    """

    def __init__(self, ui, repo):
        self.ui = ui
        self.repo = repo
        self.storepath = ui.configpath(b'scratchbranch', b'storepath')
        if not self.storepath:
            self.storepath = self.repo.vfs.join(
                b"scratchbranches", b"filebundlestore"
            )
        if not os.path.exists(self.storepath):
            os.makedirs(self.storepath)

    def _dirpath(self, hashvalue):
        """First two bytes of the hash are the name of the upper
        level directory, next two bytes are the name of the
        next level directory"""
        return os.path.join(self.storepath, hashvalue[0:2], hashvalue[2:4])

    def _filepath(self, filename):
        return os.path.join(self._dirpath(filename), filename)

    def write(self, data):
        filename = hex(hashutil.sha1(data).digest())
        dirpath = self._dirpath(filename)

        if not os.path.exists(dirpath):
            os.makedirs(dirpath)

        with open(self._filepath(filename), b'wb') as f:
            f.write(data)

        return filename

    def read(self, key):
        try:
            with open(self._filepath(key), b'rb') as f:
                return f.read()
        except IOError:
            return None


def format_placeholders_args(args, filename=None, handle=None):
    """Formats `args` with Infinitepush replacements.

    Hack to get `str.format()`-ed strings working in a BC way with
    bytes.
    """
    formatted_args = []
    for arg in args:
        if filename and arg == b'{filename}':
            formatted_args.append(filename)
        elif handle and arg == b'{handle}':
            formatted_args.append(handle)
        else:
            formatted_args.append(arg)
    return formatted_args


class externalbundlestore(abstractbundlestore):
    def __init__(self, put_binary, put_args, get_binary, get_args):
        """
        `put_binary` - path to binary file which uploads bundle to external
            storage and prints key to stdout
        `put_args` - format string with additional args to `put_binary`
                     {filename} replacement field can be used.
        `get_binary` - path to binary file which accepts filename and key
            (in that order), downloads bundle from store and saves it to file
        `get_args` - format string with additional args to `get_binary`.
                     {filename} and {handle} replacement field can be used.
        """

        self.put_args = put_args
        self.get_args = get_args
        self.put_binary = put_binary
        self.get_binary = get_binary

    def _call_binary(self, args):
        p = subprocess.Popen(
            pycompat.rapply(procutil.tonativestr, args),
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            close_fds=True,
        )
        stdout, stderr = p.communicate()
        returncode = p.returncode
        return returncode, stdout, stderr

    def write(self, data):
        # Won't work on windows because you can't open file second time without
        # closing it
        # TODO: rewrite without str.format() and replace NamedTemporaryFile()
        # with pycompat.namedtempfile()
        with pycompat.namedtempfile() as temp:
            temp.write(data)
            temp.flush()
            temp.seek(0)
            formatted_args = format_placeholders_args(
                self.put_args, filename=temp.name
            )
            returncode, stdout, stderr = self._call_binary(
                [self.put_binary] + formatted_args
            )

            if returncode != 0:
                raise BundleWriteException(
                    b'Failed to upload to external store: %s' % stderr
                )
            stdout_lines = stdout.splitlines()
            if len(stdout_lines) == 1:
                return stdout_lines[0]
            else:
                raise BundleWriteException(
                    b'Bad output from %s: %s' % (self.put_binary, stdout)
                )

    def read(self, handle):
        # Won't work on windows because you can't open file second time without
        # closing it
        with pycompat.namedtempfile() as temp:
            formatted_args = format_placeholders_args(
                self.get_args, filename=temp.name, handle=handle
            )
            returncode, stdout, stderr = self._call_binary(
                [self.get_binary] + formatted_args
            )

            if returncode != 0:
                raise BundleReadException(
                    b'Failed to download from external store: %s' % stderr
                )
            return temp.read()