Mercurial > hg
view mercurial/diffhelper.py @ 45871:a985c4fb23ca
transaction: change list of journal entries into a dictionary
The transaction object used to keep a mapping table of path names to
journal entries and a list of journal entries consisting of path and
file offset to truncate on rollback. The offsets are used in three
cases. repair.strip and rollback process all of them in one go, but they
care about the order. For them, it is perfectly reasonable to read the
journal back from disk as both operations already involve at least one
system call per journal entry. The other consumer is the revlog logic
for moving from inline to external data storage. It doesn't care about
the order of the journal and just needs to original offset stored.
Further optimisations are possible here to move the in-memory journal to
a set(), but without memoisation of the original revlog size this could
turn it into O(n^2) behavior in worst case when many revlogs need to
migrated.
Differential Revision: https://phab.mercurial-scm.org/D9277
author | Joerg Sonnenberger <joerg@bec.de> |
---|---|
date | Sat, 07 Nov 2020 21:34:09 +0100 |
parents | 10f48720ef95 |
children | d4ba4d51f85f |
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# diffhelper.py - helper routines for patch # # Copyright 2009 Matt Mackall <mpm@selenic.com> and others # # 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 from .i18n import _ from . import ( error, pycompat, ) MISSING_NEWLINE_MARKER = b'\\ No newline at end of file\n' def addlines(fp, hunk, lena, lenb, a, b): """Read lines from fp into the hunk The hunk is parsed into two arrays, a and b. a gets the old state of the text, b gets the new state. The control char from the hunk is saved when inserting into a, but not b (for performance while deleting files.) """ while True: todoa = lena - len(a) todob = lenb - len(b) num = max(todoa, todob) if num == 0: break for i in pycompat.xrange(num): s = fp.readline() if not s: raise error.ParseError(_(b'incomplete hunk')) if s == MISSING_NEWLINE_MARKER: fixnewline(hunk, a, b) continue if s == b'\n' or s == b'\r\n': # Some patches may be missing the control char # on empty lines. Supply a leading space. s = b' ' + s hunk.append(s) if s.startswith(b'+'): b.append(s[1:]) elif s.startswith(b'-'): a.append(s) else: b.append(s[1:]) a.append(s) def fixnewline(hunk, a, b): """Fix up the last lines of a and b when the patch has no newline at EOF""" l = hunk[-1] # tolerate CRLF in last line if l.endswith(b'\r\n'): hline = l[:-2] else: hline = l[:-1] if hline.startswith((b' ', b'+')): b[-1] = hline[1:] if hline.startswith((b' ', b'-')): a[-1] = hline hunk[-1] = hline def testhunk(a, b, bstart): """Compare the lines in a with the lines in b a is assumed to have a control char at the start of each line, this char is ignored in the compare. """ alen = len(a) blen = len(b) if alen > blen - bstart or bstart < 0: return False for i in pycompat.xrange(alen): if a[i][1:] != b[i + bstart]: return False return True