git-commit-vandalism/tree.c
Linus Torvalds 885a86abe2 Shrink "struct object" a bit
This shrinks "struct object" by a small amount, by getting rid of the
"struct type *" pointer and replacing it with a 3-bit bitfield instead.

In addition, we merge the bitfields and the "flags" field, which
incidentally should also remove a useless 4-byte padding from the object
when in 64-bit mode.

Now, our "struct object" is still too damn large, but it's now less
obviously bloated, and of the remaining fields, only the "util" (which is
not used by most things) is clearly something that should be eventually
discarded.

This shrinks the "git-rev-list --all" memory use by about 2.5% on the
kernel archive (and, perhaps more importantly, on the larger mozilla
archive). That may not sound like much, but I suspect it's more on a
64-bit platform.

There are other remaining inefficiencies (the parent lists, for example,
probably have horrible malloc overhead), but this was pretty obvious.

Most of the patch is just changing the comparison of the "type" pointer
from one of the constant string pointers to the appropriate new TYPE_xxx
small integer constant.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-17 18:49:18 -07:00

231 lines
5.0 KiB
C

#include "cache.h"
#include "tree.h"
#include "blob.h"
#include "commit.h"
#include "tag.h"
#include "tree-walk.h"
#include <stdlib.h>
const char *tree_type = "tree";
static int read_one_entry(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
{
int len;
unsigned int size;
struct cache_entry *ce;
if (S_ISDIR(mode))
return READ_TREE_RECURSIVE;
len = strlen(pathname);
size = cache_entry_size(baselen + len);
ce = xcalloc(1, size);
ce->ce_mode = create_ce_mode(mode);
ce->ce_flags = create_ce_flags(baselen + len, stage);
memcpy(ce->name, base, baselen);
memcpy(ce->name + baselen, pathname, len+1);
memcpy(ce->sha1, sha1, 20);
return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
}
static int match_tree_entry(const char *base, int baselen, const char *path, unsigned int mode, const char **paths)
{
const char *match;
int pathlen;
if (!paths)
return 1;
pathlen = strlen(path);
while ((match = *paths++) != NULL) {
int matchlen = strlen(match);
if (baselen >= matchlen) {
/* If it doesn't match, move along... */
if (strncmp(base, match, matchlen))
continue;
/* The base is a subdirectory of a path which was specified. */
return 1;
}
/* Does the base match? */
if (strncmp(base, match, baselen))
continue;
match += baselen;
matchlen -= baselen;
if (pathlen > matchlen)
continue;
if (matchlen > pathlen) {
if (match[pathlen] != '/')
continue;
if (!S_ISDIR(mode))
continue;
}
if (strncmp(path, match, pathlen))
continue;
return 1;
}
return 0;
}
int read_tree_recursive(struct tree *tree,
const char *base, int baselen,
int stage, const char **match,
read_tree_fn_t fn)
{
struct tree_desc desc;
struct name_entry entry;
if (parse_tree(tree))
return -1;
desc.buf = tree->buffer;
desc.size = tree->size;
while (tree_entry(&desc, &entry)) {
if (!match_tree_entry(base, baselen, entry.path, entry.mode, match))
continue;
switch (fn(entry.sha1, base, baselen, entry.path, entry.mode, stage)) {
case 0:
continue;
case READ_TREE_RECURSIVE:
break;;
default:
return -1;
}
if (S_ISDIR(entry.mode)) {
int retval;
char *newbase;
newbase = xmalloc(baselen + 1 + entry.pathlen);
memcpy(newbase, base, baselen);
memcpy(newbase + baselen, entry.path, entry.pathlen);
newbase[baselen + entry.pathlen] = '/';
retval = read_tree_recursive(lookup_tree(entry.sha1),
newbase,
baselen + entry.pathlen + 1,
stage, match, fn);
free(newbase);
if (retval)
return -1;
continue;
}
}
return 0;
}
int read_tree(struct tree *tree, int stage, const char **match)
{
return read_tree_recursive(tree, "", 0, stage, match, read_one_entry);
}
struct tree *lookup_tree(const unsigned char *sha1)
{
struct object *obj = lookup_object(sha1);
if (!obj) {
struct tree *ret = xcalloc(1, sizeof(struct tree));
created_object(sha1, &ret->object);
ret->object.type = TYPE_TREE;
return ret;
}
if (!obj->type)
obj->type = TYPE_TREE;
if (obj->type != TYPE_TREE) {
error("Object %s is a %s, not a tree",
sha1_to_hex(sha1), typename(obj->type));
return NULL;
}
return (struct tree *) obj;
}
static int track_tree_refs(struct tree *item)
{
int n_refs = 0, i;
struct object_refs *refs;
struct tree_desc desc;
struct name_entry entry;
/* Count how many entries there are.. */
desc.buf = item->buffer;
desc.size = item->size;
while (desc.size) {
n_refs++;
update_tree_entry(&desc);
}
/* Allocate object refs and walk it again.. */
i = 0;
refs = alloc_object_refs(n_refs);
desc.buf = item->buffer;
desc.size = item->size;
while (tree_entry(&desc, &entry)) {
struct object *obj;
if (S_ISDIR(entry.mode))
obj = &lookup_tree(entry.sha1)->object;
else
obj = &lookup_blob(entry.sha1)->object;
refs->ref[i++] = obj;
}
set_object_refs(&item->object, refs);
return 0;
}
int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
{
if (item->object.parsed)
return 0;
item->object.parsed = 1;
item->buffer = buffer;
item->size = size;
if (track_object_refs)
track_tree_refs(item);
return 0;
}
int parse_tree(struct tree *item)
{
char type[20];
void *buffer;
unsigned long size;
if (item->object.parsed)
return 0;
buffer = read_sha1_file(item->object.sha1, type, &size);
if (!buffer)
return error("Could not read %s",
sha1_to_hex(item->object.sha1));
if (strcmp(type, tree_type)) {
free(buffer);
return error("Object %s not a tree",
sha1_to_hex(item->object.sha1));
}
return parse_tree_buffer(item, buffer, size);
}
struct tree *parse_tree_indirect(const unsigned char *sha1)
{
struct object *obj = parse_object(sha1);
do {
if (!obj)
return NULL;
if (obj->type == TYPE_TREE)
return (struct tree *) obj;
else if (obj->type == TYPE_COMMIT)
obj = &(((struct commit *) obj)->tree->object);
else if (obj->type == TYPE_TAG)
obj = ((struct tag *) obj)->tagged;
else
return NULL;
if (!obj->parsed)
parse_object(obj->sha1);
} while (1);
}