Revision f3badaed5106a16499d0fae31a382f9047b272d7 authored by Jeff King on 11 February 2016, 22:26:18 UTC, committed by Junio C Hamano on 16 March 2016, 17:41:03 UTC
The "struct name_path" data is examined in only two places:
we generate it in process_tree(), and we convert it to a
single string in path_name(). Everyone else just passes it
through to those functions.

We can further note that process_tree() already keeps a
single strbuf with the leading tree path, for use with
tree_entry_interesting().

Instead of building a separate name_path linked list, let's
just use the one we already build in "base". This reduces
the amount of code (especially tricky code in path_name()
which did not check for integer overflows caused by deep
or large pathnames).

It is also more efficient in some instances.  Any time we
were using tree_entry_interesting, we were building up the
strbuf anyway, so this is an immediate and obvious win
there. In cases where we were not, we trade off storing
"pathname/" in a strbuf on the heap for each level of the
path, instead of two pointers and an int on the stack (with
one pointer into the tree object). On a 64-bit system, the
latter is 20 bytes; so if path components are less than that
on average, this has lower peak memory usage.  In practice
it probably doesn't matter either way; we are already
holding in memory all of the tree objects leading up to each
pathname, and for normal-depth pathnames, we are only
talking about hundreds of bytes.

This patch leaves "struct name_path" as a thin wrapper
around the strbuf, to avoid disrupting callbacks. We should
fix them, but leaving it out makes this diff easier to view.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 8eee9f9
Raw File
kwset.h
/* This file has been copied from commit e7ac713d^ in the GNU grep git
 * repository. A few small changes have been made to adapt the code to
 * Git.
 */

/* kwset.h - header declaring the keyword set library.
   Copyright (C) 1989, 1998, 2005 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */

/* Written August 1989 by Mike Haertel.
   The author may be reached (Email) at the address mike@ai.mit.edu,
   or (US mail) as Mike Haertel c/o Free Software Foundation. */

struct kwsmatch
{
  int index;			/* Index number of matching keyword. */
  size_t offset[1];		/* Offset of each submatch. */
  size_t size[1];		/* Length of each submatch. */
};

struct kwset_t;
typedef struct kwset_t* kwset_t;

/* Return an opaque pointer to a newly allocated keyword set, or NULL
   if enough memory cannot be obtained.  The argument if non-NULL
   specifies a table of character translations to be applied to all
   pattern and search text. */
extern kwset_t kwsalloc(unsigned char const *);

/* Incrementally extend the keyword set to include the given string.
   Return NULL for success, or an error message.  Remember an index
   number for each keyword included in the set. */
extern const char *kwsincr(kwset_t, char const *, size_t);

/* When the keyword set has been completely built, prepare it for
   use.  Return NULL for success, or an error message. */
extern const char *kwsprep(kwset_t);

/* Search through the given buffer for a member of the keyword set.
   Return a pointer to the leftmost longest match found, or NULL if
   no match is found.  If foundlen is non-NULL, store the length of
   the matching substring in the integer it points to.  Similarly,
   if foundindex is non-NULL, store the index of the particular
   keyword found therein. */
extern size_t kwsexec(kwset_t, char const *, size_t, struct kwsmatch *);

/* Deallocate the given keyword set and all its associated storage. */
extern void kwsfree(kwset_t);

back to top