зеркало из https://github.com/microsoft/git.git
115 строки
2.9 KiB
C
115 строки
2.9 KiB
C
#include "object.h"
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#include "blob.h"
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#include "tree.h"
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#include "commit.h"
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#include "tag.h"
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#include "delta.h"
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#include "cache.h"
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/* the delta object definition (it can alias any other object) */
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struct delta {
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union {
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struct object object;
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struct blob blob;
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struct tree tree;
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struct commit commit;
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struct tag tag;
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} u;
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};
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struct delta *lookup_delta(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 delta *ret = xmalloc(sizeof(struct delta));
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memset(ret, 0, sizeof(struct delta));
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created_object(sha1, &ret->u.object);
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return ret;
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}
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return (struct delta *) obj;
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}
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int parse_delta_buffer(struct delta *item, void *buffer, unsigned long size)
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{
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struct object *reference;
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struct object_list *p;
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if (item->u.object.delta)
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return 0;
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item->u.object.delta = 1;
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if (size <= 20)
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return -1;
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reference = lookup_object(buffer);
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if (!reference) {
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struct delta *ref = xmalloc(sizeof(struct delta));
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memset(ref, 0, sizeof(struct delta));
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created_object(buffer, &ref->u.object);
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reference = &ref->u.object;
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}
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p = xmalloc(sizeof(*p));
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p->item = &item->u.object;
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p->next = reference->attached_deltas;
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reference->attached_deltas = p;
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return 0;
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}
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int process_deltas(void *src, unsigned long src_size, const char *src_type,
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struct object_list *delta_list)
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{
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int deepest = 0;
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do {
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struct object *obj = delta_list->item;
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static char type[10];
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void *map, *delta, *buf;
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unsigned long map_size, delta_size, buf_size;
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map = map_sha1_file(obj->sha1, &map_size);
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if (!map)
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continue;
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delta = unpack_sha1_file(map, map_size, type, &delta_size);
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munmap(map, map_size);
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if (!delta)
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continue;
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if (strcmp(type, "delta") || delta_size <= 20) {
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free(delta);
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continue;
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}
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buf = patch_delta(src, src_size,
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delta+20, delta_size-20,
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&buf_size);
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free(delta);
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if (!buf)
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continue;
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if (check_sha1_signature(obj->sha1, buf, buf_size, src_type) < 0)
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printf("sha1 mismatch for delta %s\n", sha1_to_hex(obj->sha1));
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if (obj->type && obj->type != src_type) {
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error("got %s when expecting %s for delta %s",
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src_type, obj->type, sha1_to_hex(obj->sha1));
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free(buf);
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continue;
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}
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obj->type = src_type;
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if (src_type == blob_type) {
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parse_blob_buffer((struct blob *)obj, buf, buf_size);
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} else if (src_type == tree_type) {
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parse_tree_buffer((struct tree *)obj, buf, buf_size);
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} else if (src_type == commit_type) {
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parse_commit_buffer((struct commit *)obj, buf, buf_size);
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} else if (src_type == tag_type) {
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parse_tag_buffer((struct tag *)obj, buf, buf_size);
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} else {
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error("unknown object type %s", src_type);
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free(buf);
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continue;
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}
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if (obj->attached_deltas) {
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int depth = process_deltas(buf, buf_size, src_type,
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obj->attached_deltas);
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if (deepest < depth)
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deepest = depth;
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}
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free(buf);
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} while ((delta_list = delta_list->next));
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return deepest + 1;
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}
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