hgext/infinitepush/indexapi.py

sigpipe-remote: simply delegate pipe forwarding to subprocess we can kill

Instead of using sophisticated logics with thread a non blocking pipes, we
simply spawn two new process in charge of reading the pipe and sending the
result to the client. When it is time to cut the pipe we violently kill them
without any remorse. This close the pipe regardless of any in progress `os.read`
call.

Ironically this is the very same things as what the initial shell setup was
doing, but in Python.

This makes the test pass run properly on Windows. This also reveal that the
Windows behavior is broken as the transaction is not properly rollback. However
this is an adventure for another time. Making the test behave properly was
enough effort.

Differential Revision: https://phab.mercurial-scm.org/D11087

# Infinite push
#
# Copyright 2016 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import


class indexapi(object):
    """Class that manages access to infinitepush index.

    This class is a context manager and all write operations (like
    deletebookmarks, addbookmark etc) should use `with` statement:

      with index:
          index.deletebookmarks(...)
          ...
    """

    def __init__(self):
        """Initializes the metadata store connection."""

    def close(self):
        """Cleans up the metadata store connection."""

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        pass

    def addbundle(self, bundleid, nodesctx):
        """Takes a bundleid and a list of node contexts for each node
        in that bundle and records that."""
        raise NotImplementedError()

    def addbookmark(self, bookmark, node):
        """Takes a bookmark name and hash, and records mapping in the metadata
        store."""
        raise NotImplementedError()

    def addmanybookmarks(self, bookmarks):
        """Takes a dict with mapping from bookmark to hash and records mapping
        in the metadata store."""
        raise NotImplementedError()

    def deletebookmarks(self, patterns):
        """Accepts list of bookmarks and deletes them."""
        raise NotImplementedError()

    def getbundle(self, node):
        """Returns the bundleid for the bundle that contains the given node."""
        raise NotImplementedError()

    def getnode(self, bookmark):
        """Returns the node for the given bookmark. None if it doesn't exist."""
        raise NotImplementedError()

    def getbookmarks(self, query):
        """Returns bookmarks that match the query"""
        raise NotImplementedError()

    def saveoptionaljsonmetadata(self, node, jsonmetadata):
        """Saves optional metadata for a given node"""
        raise NotImplementedError()


class indexexception(Exception):
    pass