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885a86abe2
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>
108 lines
2.6 KiB
C
108 lines
2.6 KiB
C
#include "cache.h"
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#include "tag.h"
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const char *tag_type = "tag";
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struct object *deref_tag(struct object *o, const char *warn, int warnlen)
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{
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while (o && o->type == TYPE_TAG)
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o = parse_object(((struct tag *)o)->tagged->sha1);
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if (!o && warn) {
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if (!warnlen)
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warnlen = strlen(warn);
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error("missing object referenced by '%.*s'", warnlen, warn);
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}
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return o;
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}
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struct tag *lookup_tag(const unsigned char *sha1)
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{
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struct object *obj = lookup_object(sha1);
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if (!obj) {
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struct tag *ret = xcalloc(1, sizeof(struct tag));
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created_object(sha1, &ret->object);
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ret->object.type = TYPE_TAG;
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return ret;
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}
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if (!obj->type)
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obj->type = TYPE_TAG;
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if (obj->type != TYPE_TAG) {
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error("Object %s is a %s, not a tree",
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sha1_to_hex(sha1), typename(obj->type));
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return NULL;
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}
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return (struct tag *) obj;
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}
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int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
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{
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int typelen, taglen;
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unsigned char object[20];
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const char *type_line, *tag_line, *sig_line;
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char type[20];
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if (item->object.parsed)
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return 0;
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item->object.parsed = 1;
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if (size < 64)
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return -1;
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if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
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return -1;
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type_line = data + 48;
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if (memcmp("\ntype ", type_line-1, 6))
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return -1;
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tag_line = strchr(type_line, '\n');
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if (!tag_line || memcmp("tag ", ++tag_line, 4))
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return -1;
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sig_line = strchr(tag_line, '\n');
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if (!sig_line)
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return -1;
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sig_line++;
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typelen = tag_line - type_line - strlen("type \n");
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if (typelen >= 20)
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return -1;
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memcpy(type, type_line + 5, typelen);
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type[typelen] = '\0';
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taglen = sig_line - tag_line - strlen("tag \n");
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item->tag = xmalloc(taglen + 1);
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memcpy(item->tag, tag_line + 4, taglen);
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item->tag[taglen] = '\0';
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item->tagged = lookup_object_type(object, type);
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if (item->tagged && track_object_refs) {
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struct object_refs *refs = alloc_object_refs(1);
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refs->ref[0] = item->tagged;
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set_object_refs(&item->object, refs);
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}
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return 0;
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}
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int parse_tag(struct tag *item)
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{
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char type[20];
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void *data;
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unsigned long size;
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int ret;
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if (item->object.parsed)
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return 0;
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data = read_sha1_file(item->object.sha1, type, &size);
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if (!data)
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return error("Could not read %s",
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sha1_to_hex(item->object.sha1));
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if (strcmp(type, tag_type)) {
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free(data);
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return error("Object %s not a tag",
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sha1_to_hex(item->object.sha1));
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}
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ret = parse_tag_buffer(item, data, size);
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free(data);
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return ret;
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}
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