1
0
mirror of https://github.com/git/git.git synced 2024-11-18 02:53:55 +01:00
git/userdiff.c
Jeff King d9bae1a178 diff: cache textconv output
Running a textconv filter can take a long time. It's
particularly bad for a large file which needs to be spooled
to disk, but even for small files, the fork+exec overhead
can add up for something like "git log -p".

This patch uses the notes-cache mechanism to keep a fast
cache of textconv output. Caches are stored in
refs/notes/textconv/$x, where $x is the userdiff driver
defined in gitattributes.

Caching is enabled only if diff.$x.cachetextconv is true.

In my test repo, on a commit with 45 jpg and avi files
changed and a textconv to show their exif tags:

  [before]
  $ time git show >/dev/null
  real    0m13.724s
  user    0m12.057s
  sys     0m1.624s

  [after, first run]
  $ git config diff.mfo.cachetextconv true
  $ time git show >/dev/null
  real    0m14.252s
  user    0m12.197s
  sys     0m1.800s

  [after, subsequent runs]
  $ time git show >/dev/null
  real    0m0.352s
  user    0m0.148s
  sys     0m0.200s

So for a slight (3.8%) cost on the first run, we achieve an
almost 40x speed up on subsequent runs.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-04-02 00:05:31 -07:00

226 lines
6.2 KiB
C

#include "cache.h"
#include "userdiff.h"
#include "cache.h"
#include "attr.h"
static struct userdiff_driver *drivers;
static int ndrivers;
static int drivers_alloc;
#define PATTERNS(name, pattern, word_regex) \
{ name, NULL, -1, { pattern, REG_EXTENDED }, word_regex }
static struct userdiff_driver builtin_drivers[] = {
PATTERNS("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$",
"[^<>= \t]+|[^[:space:]]|[\x80-\xff]+"),
PATTERNS("java",
"!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
"^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$",
/* -- */
"[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
"|[-+*/<>%&^|=!]="
"|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"
"|[^[:space:]]|[\x80-\xff]+"),
PATTERNS("objc",
/* Negate C statements that can look like functions */
"!^[ \t]*(do|for|if|else|return|switch|while)\n"
/* Objective-C methods */
"^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[ \t]*[A-Za-z_].*)$\n"
/* C functions */
"^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$\n"
/* Objective-C class/protocol definitions */
"^(@(implementation|interface|protocol)[ \t].*)$",
/* -- */
"[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
"|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"
"|[^[:space:]]|[\x80-\xff]+"),
PATTERNS("pascal",
"^((procedure|function|constructor|destructor|interface|"
"implementation|initialization|finalization)[ \t]*.*)$"
"\n"
"^(.*=[ \t]*(class|record).*)$",
/* -- */
"[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
"|<>|<=|>=|:=|\\.\\."
"|[^[:space:]]|[\x80-\xff]+"),
PATTERNS("php", "^[\t ]*((function|class).*)",
/* -- */
"[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
"|[-+*/<>%&^|=!.]=|--|\\+\\+|<<=?|>>=?|===|&&|\\|\\||::|->"
"|[^[:space:]]|[\x80-\xff]+"),
PATTERNS("python", "^[ \t]*((class|def)[ \t].*)$",
/* -- */
"[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+[jJlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
"|[-+*/<>%&^|=!]=|//=?|<<=?|>>=?|\\*\\*=?"
"|[^[:space:]|[\x80-\xff]+"),
/* -- */
PATTERNS("ruby", "^[ \t]*((class|module|def)[ \t].*)$",
/* -- */
"(@|@@|\\$)?[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+|\\?(\\\\C-)?(\\\\M-)?."
"|//=?|[-+*/<>%&^|=!]=|<<=?|>>=?|===|\\.{1,3}|::|[!=]~"
"|[^[:space:]|[\x80-\xff]+"),
PATTERNS("bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
"[={}\"]|[^={}\" \t]+"),
PATTERNS("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
"\\\\[a-zA-Z@]+|\\\\.|[a-zA-Z0-9\x80-\xff]+|[^[:space:]]"),
PATTERNS("cpp",
/* Jump targets or access declarations */
"!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:.*$\n"
/* C/++ functions/methods at top level */
"^([A-Za-z_][A-Za-z_0-9]*([ \t]+[A-Za-z_][A-Za-z_0-9]*([ \t]*::[ \t]*[^[:space:]]+)?){1,}[ \t]*\\([^;]*)$\n"
/* compound type at top level */
"^((struct|class|enum)[^;]*)$",
/* -- */
"[a-zA-Z_][a-zA-Z0-9_]*"
"|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
"|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"
"|[^[:space:]]|[\x80-\xff]+"),
{ "default", NULL, -1, { NULL, 0 } },
};
#undef PATTERNS
static struct userdiff_driver driver_true = {
"diff=true",
NULL,
0,
{ NULL, 0 }
};
static struct userdiff_driver driver_false = {
"!diff",
NULL,
1,
{ NULL, 0 }
};
static struct userdiff_driver *userdiff_find_by_namelen(const char *k, int len)
{
int i;
for (i = 0; i < ndrivers; i++) {
struct userdiff_driver *drv = drivers + i;
if (!strncmp(drv->name, k, len) && !drv->name[len])
return drv;
}
for (i = 0; i < ARRAY_SIZE(builtin_drivers); i++) {
struct userdiff_driver *drv = builtin_drivers + i;
if (!strncmp(drv->name, k, len) && !drv->name[len])
return drv;
}
return NULL;
}
static struct userdiff_driver *parse_driver(const char *var,
const char *value, const char *type)
{
struct userdiff_driver *drv;
const char *dot;
const char *name;
int namelen;
if (prefixcmp(var, "diff."))
return NULL;
dot = strrchr(var, '.');
if (dot == var + 4)
return NULL;
if (strcmp(type, dot+1))
return NULL;
name = var + 5;
namelen = dot - name;
drv = userdiff_find_by_namelen(name, namelen);
if (!drv) {
ALLOC_GROW(drivers, ndrivers+1, drivers_alloc);
drv = &drivers[ndrivers++];
memset(drv, 0, sizeof(*drv));
drv->name = xmemdupz(name, namelen);
drv->binary = -1;
}
return drv;
}
static int parse_funcname(struct userdiff_funcname *f, const char *k,
const char *v, int cflags)
{
if (git_config_string(&f->pattern, k, v) < 0)
return -1;
f->cflags = cflags;
return 1;
}
static int parse_string(const char **d, const char *k, const char *v)
{
if (git_config_string(d, k, v) < 0)
return -1;
return 1;
}
static int parse_tristate(int *b, const char *k, const char *v)
{
if (v && !strcasecmp(v, "auto"))
*b = -1;
else
*b = git_config_bool(k, v);
return 1;
}
static int parse_bool(int *b, const char *k, const char *v)
{
*b = git_config_bool(k, v);
return 1;
}
int userdiff_config(const char *k, const char *v)
{
struct userdiff_driver *drv;
if ((drv = parse_driver(k, v, "funcname")))
return parse_funcname(&drv->funcname, k, v, 0);
if ((drv = parse_driver(k, v, "xfuncname")))
return parse_funcname(&drv->funcname, k, v, REG_EXTENDED);
if ((drv = parse_driver(k, v, "binary")))
return parse_tristate(&drv->binary, k, v);
if ((drv = parse_driver(k, v, "command")))
return parse_string(&drv->external, k, v);
if ((drv = parse_driver(k, v, "textconv")))
return parse_string(&drv->textconv, k, v);
if ((drv = parse_driver(k, v, "cachetextconv")))
return parse_bool(&drv->textconv_want_cache, k, v);
if ((drv = parse_driver(k, v, "wordregex")))
return parse_string(&drv->word_regex, k, v);
return 0;
}
struct userdiff_driver *userdiff_find_by_name(const char *name) {
int len = strlen(name);
return userdiff_find_by_namelen(name, len);
}
struct userdiff_driver *userdiff_find_by_path(const char *path)
{
static struct git_attr *attr;
struct git_attr_check check;
if (!attr)
attr = git_attr("diff");
check.attr = attr;
if (!path)
return NULL;
if (git_checkattr(path, 1, &check))
return NULL;
if (ATTR_TRUE(check.value))
return &driver_true;
if (ATTR_FALSE(check.value))
return &driver_false;
if (ATTR_UNSET(check.value))
return NULL;
return userdiff_find_by_name(check.value);
}