On Thu, Nov 10, 2016 at 09:24:56AM +0000, Stanislau Hlebik wrote:
> We can use 32 bytes, but only 20 bytes will be used.
> What’s the point then?
Because some day sha3 or sha256 will be used.
>
> On 11/9/16, 5:22 PM, "Augie Fackler" <r...@durin42.com> wrote:
>
> On Wed, Nov 02, 2016 at 07:06:44AM -0700, Stanislau Hlebik wrote:
> > # HG changeset patch
> > # User Stanislau Hlebik <st...@fb.com>
> > # Date 1478016027 25200
> > # Tue Nov 01 09:00:27 2016 -0700
> > # Branch stable
> > # Node ID f3da841e3d47ccbb0be3892b521607c09fdeab13
> > # Parent a56a624a8a42b93ec980d2c284756a38719dffe6
> > 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>
>
> Enough other formats have 32 bytes of space for nodes (eg revlog) that
> I suspect we should do 32 bytes here too. Thoughts?
>
> > 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
> > @@ -7,8 +7,10 @@
> >
> > from __future__ import absolute_import
> >
> > +import StringIO
> > import errno
> > import os
> > +import struct
> >
> > from .i18n import _
> > from .node import (
> > @@ -23,6 +25,70 @@
> > util,
> > )
> >
> > +_NONEMPTYNODE = struct.pack('?', False)
> > +_EMPTYNODE = struct.pack('?', True)
> > +
> > +def _unpackbookmarksize(stream):
> > + """Returns 0 if stream is empty.
> > + """
> > +
> > + expectedsize = struct.calcsize('>i')
> > + encodedbookmarksize = stream.read(expectedsize)
> > + if len(encodedbookmarksize) == 0:
> > + return 0
> > + if len(encodedbookmarksize) != expectedsize:
> > + raise ValueError(
> > + _('cannot decode bookmark size: '
> > + 'expected size: %d, actual size: %d') %
> > + (expectedsize, len(encodedbookmarksize)))
> > + return struct.unpack('>i', 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, 40 byte hex string or empty
> > + """
> > +
> > + for bookmark, node in bookmarks.iteritems():
> > + yield struct.pack('>i', (len(bookmark)))
> > + yield encoding.fromlocal(bookmark)
> > + if node:
> > + if len(node) != 20 and len(node) != 40:
> > + raise ValueError(_('node must be 20 or bytes long'))
> > + if len(node) == 40:
> > + node = bin(node)
> > + 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 = StringIO.StringIO(buf)
> > + bookmarks = {}
> > + bookmarksize = _unpackbookmarksize(stream)
> > + 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(struct.calcsize('?'))
> > + emptynode = struct.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.
> >
> > _______________________________________________
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> > Mercurial-devel@mercurial-scm.org
> >
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