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bd2c39f58f
It turns out that parse_object() is loading and decompressing given object to free it just before calling the specific object parsing function which does mmap and decompress the same object again. This patch introduces the ability to parse specific objects directly from a memory buffer. Without this patch, running git-fsck-cache on the kernel repositorytake: real 0m13.006s user 0m11.421s sys 0m1.218s With this patch applied: real 0m8.060s user 0m7.071s sys 0m0.710s The performance increase is significant, and this is kind of a prerequisite for sane delta object support with fsck. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
89 lines
2.1 KiB
C
89 lines
2.1 KiB
C
#include "tag.h"
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#include "cache.h"
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const char *tag_type = "tag";
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struct tag *lookup_tag(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 = xmalloc(sizeof(struct tag));
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memset(ret, 0, sizeof(struct tag));
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created_object(sha1, &ret->object);
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ret->object.type = tag_type;
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return ret;
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}
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if (obj->type != tag_type) {
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error("Object %s is a %s, not a tree",
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sha1_to_hex(sha1), 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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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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item->tagged = parse_object(object);
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if (item->tagged)
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add_ref(&item->object, item->tagged);
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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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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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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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