# HG changeset patch # User Stanislau Hlebik <st...@fb.com> # Date 1479807211 28800 # Tue Nov 22 01:33:31 2016 -0800 # Node ID d184b91890ae3cbd21f656847b6b2728892b2425 # Parent 9e29d4e4e08b5996adda49cdd0b497d89e2b16ee bookmarks: introduce binary encoding
Bookmarks binary encoding will be used for `bookmarks` bundle2 part. The format is: <4 bytes - bookmark size, big-endian><bookmark> <1 byte - 0 if node is empty 1 otherwise><20 bytes node> BookmarksEncodeError and BookmarksDecodeError maybe thrown if input is incorrect. diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py --- a/mercurial/bookmarks.py +++ b/mercurial/bookmarks.py @@ -8,7 +8,9 @@ from __future__ import absolute_import import errno +import io import os +import struct from .i18n import _ from .node import ( @@ -23,6 +25,72 @@ util, ) +_NONEMPTYNODE = struct.pack('?', False) +_EMPTYNODE = struct.pack('?', True) + +def _unpackbookmarksize(stream): + """Returns 0 if stream is empty. + """ + + intstruct = struct.Struct('>i') + expectedsize = intstruct.size + encodedbookmarksize = stream.read(expectedsize) + if not encodedbookmarksize: + return 0 + if len(encodedbookmarksize) != expectedsize: + raise ValueError( + _('cannot decode bookmark size: ' + 'expected size: %d, actual size: %d') % + (expectedsize, len(encodedbookmarksize))) + return intstruct.unpack(encodedbookmarksize)[0] + +def encodebookmarks(bookmarks): + """Encodes bookmark to node mapping to the byte string. + + Format: <4 bytes - bookmark size><bookmark> + <1 byte - 0 if node is empty 1 otherwise><20 bytes node> + Node may be 20 byte binary string or empty + """ + + intstruct = struct.Struct('>i') + for bookmark, node in sorted(bookmarks.iteritems()): + encodedbookmark = encoding.fromlocal(bookmark) + yield intstruct.pack(len(encodedbookmark)) + yield encodedbookmark + if node: + if len(node) != 20: + raise ValueError(_('node must be 20 or bytes long')) + yield _NONEMPTYNODE + yield node + else: + yield _EMPTYNODE + +def decodebookmarks(buf): + """Decodes buffer into bookmark to node mapping. + + Node is either 20 bytes or empty. + """ + + stream = io.BytesIO(buf) + bookmarks = {} + bookmarksize = _unpackbookmarksize(stream) + boolstruct = struct.Struct('?') + while bookmarksize: + bookmark = stream.read(bookmarksize) + if len(bookmark) != bookmarksize: + raise ValueError( + _('cannot decode bookmark: expected size: %d, ' + 'actual size: %d') % (bookmarksize, len(bookmark))) + bookmark = encoding.tolocal(bookmark) + packedemptynodeflag = stream.read(boolstruct.size) + emptynode = boolstruct.unpack(packedemptynodeflag)[0] + node = '' + if not emptynode: + node = stream.read(20) + bookmarks[bookmark] = node + bookmarksize = _unpackbookmarksize(stream) + return bookmarks + def _getbkfile(repo): """Hook so that extensions that mess with the store can hook bm storage. _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel