mercurial-scm/hg: mercurial/wireprotov2server.py comparison

comparison mercurial/wireprotov2server.py @ 39639:0e03e6a44dee

wireprotov2: define and implement "filedata" command Continuing our trend of implementing *data commands for retrieving information about specific repository data primitives, this commit implements a command for retrieving data about an individual tracked file. The command is very similar to "manifestdata." The only significant difference is that we have a standalone function for obtaining storage for a tracked file. This is to provide a monkeypatch point for extensions to implement path-based access control. With this API available, wire protocol version 2 now exposes all data primitives necessary to implement a full clone. Of course, since "filedata" can only resolve data for a single path at a time, clients would need to issue N commands to perform a full clone. On the Firefox repository, this would be ~461k commands. We'll likely need to implement a file data retrieval command that supports multiple paths. But that can be implemented later. Differential Revision: https://phab.mercurial-scm.org/D4490

author	Gregory Szorc <gregory.szorc@gmail.com>
date	Wed, 05 Sep 2018 09:10:17 -0700
parents	c7a7c7e844e5
children	aa7e312375cf

comparison

equal deleted inserted replaced

-:d292328e0143
+:0e03e6a44dee
 import contextlib
 from .i18n import _
 from .node import (
+hex,
 nullid,
 nullrev,
 )
 from . import (
 changegroup,
 yield {
 b'node': node,
 b'bookmarks': sorted(marks),
 }
+class FileAccessError(Exception):
+"""Represents an error accessing a specific file."""
+def __init__(self, path, msg, args):
+self.path = path
+self.msg = msg
+self.args = args
+def getfilestore(repo, proto, path):
+"""Obtain a file storage object for use with wire protocol.
+Exists as a standalone function so extensions can monkeypatch to add
+access control.
+"""
+# This seems to work even if the file doesn't exist. So catch
+# "empty" files and return an error.
+fl = repo.file(path)
+if not len(fl):
+raise FileAccessError(path, 'unknown file: %s', (path,))
+return fl
+@wireprotocommand('filedata',
+args={
+'nodes': [b'0123456...'],
+'fields': [b'parents', b'revision'],
+'path': b'foo.txt',
+},
+permission='pull')
+def filedata(repo, proto, nodes=None, fields=None, path=None):
+fields = fields or set()
+if nodes is None:
+raise error.WireprotoCommandError('nodes argument must be defined')
+if path is None:
+raise error.WireprotoCommandError('path argument must be defined')
+try:
+# Extensions may wish to access the protocol handler.
+store = getfilestore(repo, proto, path)
+except FileAccessError as e:
+raise error.WireprotoCommandError(e.msg, e.args)
+# Validate requested nodes.
+for node in nodes:
+try:
+store.rev(node)
+except error.LookupError:
+raise error.WireprotoCommandError('unknown file node: %s',
+(hex(node),))
+revs, requests = builddeltarequests(store, nodes)
+yield {
+b'totalitems': len(revs),
+}
+if b'revision' in fields:
+deltas = store.emitrevisiondeltas(requests)
+else:
+deltas = None
+for rev in revs:
+node = store.node(rev)
+if deltas is not None:
+delta = next(deltas)
+else:
+delta = None
+d = {
+b'node': node,
+}
+if b'parents' in fields:
+d[b'parents'] = store.parents(node)
+if b'revision' in fields:
+assert delta is not None
+assert delta.flags == 0
+assert d[b'node'] == delta.node
+if delta.revision is not None:
+revisiondata = delta.revision
+d[b'revisionsize'] = len(revisiondata)
+else:
+d[b'deltabasenode'] = delta.basenode
+revisiondata = delta.delta
+d[b'deltasize'] = len(revisiondata)
+else:
+revisiondata = None
+yield d
+if revisiondata is not None:
+yield revisiondata
+if deltas is not None:
+try:
+next(deltas)
+raise error.ProgrammingError('should not have more deltas')
+except GeneratorExit:
+pass
 @wireprotocommand('heads',
 args={
 'publiconly': False,
 },
 permission='pull')

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comparison mercurial/wireprotov2server.py @ 39639:0e03e6a44dee