Revision 24ff4d56cf400126aa93ac9a5b9d8a21afadf3f6 authored by Björn Gustavsson on 06 March 2010, 14:30:29 UTC, committed by Junio C Hamano on 07 March 2010, 07:53:00 UTC
In the next commit, we will make it possible for blank context lines to match beyond the end of the file. That means that a hunk with a preimage that has more lines than present in the file may be possible to successfully apply. Therefore, we must remove the quick rejection test in find_pos(). find_pos() will already work correctly without the quick rejection test, but that might not be obvious. Therefore, comment the test for handling out-of-range line numbers in find_pos() and cast the "line" variable to the same (unsigned) type as img->nr. What are performance implications of removing the quick rejection test? It can only help "git apply" to reject a patch faster. For example, if I have a file with one million lines and a patch that removes slightly more than 50 percent of the lines and try to apply that patch twice, the second attempt will fail slightly faster with the test than without (based on actual measurements). However, there is the pathological case of a patch with many more context lines than the default three, and applying that patch using "git apply -C1". Without the rejection test, the running time will be roughly proportional to the number of context lines times the size of the file. That could be handled by writing a more complicated rejection test (it would have to count the number of blanks at the end of the preimage), but I don't find that worth doing until there is a real-world use case that would benfit from it. It would be possible to keep the quick rejection test if --whitespace=fix is not given, but I don't like that from a testing point of view. Signed-off-by: Björn Gustavsson <bgustavsson@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 9b25949
trace.c
/*
* GIT - The information manager from hell
*
* Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
* Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
* Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
* Copyright (C) 2006 Mike McCormack
* Copyright (C) 2006 Christian Couder
*
* 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "cache.h"
#include "quote.h"
/* Get a trace file descriptor from GIT_TRACE env variable. */
static int get_trace_fd(int *need_close)
{
char *trace = getenv("GIT_TRACE");
if (!trace || !strcmp(trace, "") ||
!strcmp(trace, "0") || !strcasecmp(trace, "false"))
return 0;
if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
return STDERR_FILENO;
if (strlen(trace) == 1 && isdigit(*trace))
return atoi(trace);
if (is_absolute_path(trace)) {
int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
if (fd == -1) {
fprintf(stderr,
"Could not open '%s' for tracing: %s\n"
"Defaulting to tracing on stderr...\n",
trace, strerror(errno));
return STDERR_FILENO;
}
*need_close = 1;
return fd;
}
fprintf(stderr, "What does '%s' for GIT_TRACE mean?\n", trace);
fprintf(stderr, "If you want to trace into a file, "
"then please set GIT_TRACE to an absolute pathname "
"(starting with /).\n");
fprintf(stderr, "Defaulting to tracing on stderr...\n");
return STDERR_FILENO;
}
static const char err_msg[] = "Could not trace into fd given by "
"GIT_TRACE environment variable";
void trace_printf(const char *fmt, ...)
{
struct strbuf buf;
va_list ap;
int fd, len, need_close = 0;
fd = get_trace_fd(&need_close);
if (!fd)
return;
strbuf_init(&buf, 64);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf)) {
strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf))
die("broken vsnprintf");
}
strbuf_setlen(&buf, len);
write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
strbuf_release(&buf);
if (need_close)
close(fd);
}
void trace_argv_printf(const char **argv, const char *fmt, ...)
{
struct strbuf buf;
va_list ap;
int fd, len, need_close = 0;
fd = get_trace_fd(&need_close);
if (!fd)
return;
strbuf_init(&buf, 64);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf)) {
strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf))
die("broken vsnprintf");
}
strbuf_setlen(&buf, len);
sq_quote_argv(&buf, argv, 0);
strbuf_addch(&buf, '\n');
write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
strbuf_release(&buf);
if (need_close)
close(fd);
}
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