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![Linus Torvalds](/assets/img/avatar_default.png)
Instead, just use the tree buffer directly, and use the tree-walk infrastructure to walk the buffers instead of the tree-entry list. The tree-entry list is inefficient, and generates tons of small allocations for no good reason. The tree-walk infrastructure is generally no harder to use than following a linked list, and allows us to do most tree parsing in-place. Some programs still use the old tree-entry lists, and are a bit painful to convert without major surgery. For them we have a helper function that creates a temporary tree-entry list on demand. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
285 lines
6.1 KiB
C
285 lines
6.1 KiB
C
#include "cache.h"
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#include "tree.h"
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#include "blob.h"
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#include "commit.h"
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#include "tag.h"
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#include "tree-walk.h"
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#include <stdlib.h>
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const char *tree_type = "tree";
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static int read_one_entry(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
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{
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int len;
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unsigned int size;
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struct cache_entry *ce;
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if (S_ISDIR(mode))
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return READ_TREE_RECURSIVE;
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len = strlen(pathname);
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size = cache_entry_size(baselen + len);
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ce = xcalloc(1, size);
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ce->ce_mode = create_ce_mode(mode);
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ce->ce_flags = create_ce_flags(baselen + len, stage);
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memcpy(ce->name, base, baselen);
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memcpy(ce->name + baselen, pathname, len+1);
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memcpy(ce->sha1, sha1, 20);
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return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
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}
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static int match_tree_entry(const char *base, int baselen, const char *path, unsigned int mode, const char **paths)
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{
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const char *match;
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int pathlen;
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if (!paths)
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return 1;
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pathlen = strlen(path);
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while ((match = *paths++) != NULL) {
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int matchlen = strlen(match);
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if (baselen >= matchlen) {
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/* If it doesn't match, move along... */
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if (strncmp(base, match, matchlen))
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continue;
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/* The base is a subdirectory of a path which was specified. */
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return 1;
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}
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/* Does the base match? */
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if (strncmp(base, match, baselen))
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continue;
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match += baselen;
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matchlen -= baselen;
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if (pathlen > matchlen)
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continue;
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if (matchlen > pathlen) {
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if (match[pathlen] != '/')
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continue;
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if (!S_ISDIR(mode))
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continue;
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}
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if (strncmp(path, match, pathlen))
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continue;
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return 1;
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}
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return 0;
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}
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int read_tree_recursive(struct tree *tree,
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const char *base, int baselen,
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int stage, const char **match,
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read_tree_fn_t fn)
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{
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struct tree_desc desc;
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if (parse_tree(tree))
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return -1;
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desc.buf = tree->buffer;
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desc.size = tree->size;
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while (desc.size) {
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unsigned mode;
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const char *name;
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const unsigned char *sha1;
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sha1 = tree_entry_extract(&desc, &name, &mode);
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update_tree_entry(&desc);
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if (!match_tree_entry(base, baselen, name, mode, match))
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continue;
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switch (fn(sha1, base, baselen, name, mode, stage)) {
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case 0:
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continue;
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case READ_TREE_RECURSIVE:
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break;;
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default:
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return -1;
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}
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if (S_ISDIR(mode)) {
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int retval;
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int pathlen = strlen(name);
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char *newbase;
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newbase = xmalloc(baselen + 1 + pathlen);
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memcpy(newbase, base, baselen);
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memcpy(newbase + baselen, name, pathlen);
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newbase[baselen + pathlen] = '/';
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retval = read_tree_recursive(lookup_tree(sha1),
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newbase,
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baselen + pathlen + 1,
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stage, match, fn);
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free(newbase);
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if (retval)
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return -1;
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continue;
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}
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}
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return 0;
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}
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int read_tree(struct tree *tree, int stage, const char **match)
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{
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return read_tree_recursive(tree, "", 0, stage, match, read_one_entry);
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}
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struct tree *lookup_tree(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 tree *ret = xcalloc(1, sizeof(struct tree));
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created_object(sha1, &ret->object);
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ret->object.type = tree_type;
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return ret;
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}
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if (!obj->type)
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obj->type = tree_type;
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if (obj->type != tree_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 tree *) obj;
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}
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static int track_tree_refs(struct tree *item)
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{
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int n_refs = 0, i;
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struct object_refs *refs;
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struct tree_desc desc;
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/* Count how many entries there are.. */
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desc.buf = item->buffer;
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desc.size = item->size;
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while (desc.size) {
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n_refs++;
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update_tree_entry(&desc);
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}
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/* Allocate object refs and walk it again.. */
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i = 0;
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refs = alloc_object_refs(n_refs);
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desc.buf = item->buffer;
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desc.size = item->size;
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while (desc.size) {
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unsigned mode;
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const char *name;
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const unsigned char *sha1;
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struct object *obj;
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sha1 = tree_entry_extract(&desc, &name, &mode);
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update_tree_entry(&desc);
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if (S_ISDIR(mode))
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obj = &lookup_tree(sha1)->object;
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else
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obj = &lookup_blob(sha1)->object;
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refs->ref[i++] = obj;
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}
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set_object_refs(&item->object, refs);
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return 0;
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}
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int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
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{
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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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item->buffer = buffer;
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item->size = size;
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if (track_object_refs)
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track_tree_refs(item);
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return 0;
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}
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struct tree_entry_list *create_tree_entry_list(struct tree *tree)
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{
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struct tree_desc desc;
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struct tree_entry_list *ret = NULL;
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struct tree_entry_list **list_p = &ret;
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desc.buf = tree->buffer;
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desc.size = tree->size;
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while (desc.size) {
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unsigned mode;
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const char *path;
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const unsigned char *sha1;
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struct tree_entry_list *entry;
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sha1 = tree_entry_extract(&desc, &path, &mode);
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entry = xmalloc(sizeof(struct tree_entry_list));
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entry->name = path;
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entry->sha1 = sha1;
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entry->mode = mode;
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entry->directory = S_ISDIR(mode) != 0;
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entry->executable = (mode & S_IXUSR) != 0;
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entry->symlink = S_ISLNK(mode) != 0;
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entry->zeropad = *(const char *)(desc.buf) == '0';
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entry->next = NULL;
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update_tree_entry(&desc);
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*list_p = entry;
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list_p = &entry->next;
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}
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return ret;
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}
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void free_tree_entry_list(struct tree_entry_list *list)
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{
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while (list) {
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struct tree_entry_list *next = list->next;
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free(list);
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list = next;
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}
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}
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int parse_tree(struct tree *item)
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{
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char type[20];
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void *buffer;
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unsigned long size;
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if (item->object.parsed)
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return 0;
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buffer = read_sha1_file(item->object.sha1, type, &size);
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if (!buffer)
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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, tree_type)) {
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free(buffer);
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return error("Object %s not a tree",
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sha1_to_hex(item->object.sha1));
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}
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return parse_tree_buffer(item, buffer, size);
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}
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struct tree *parse_tree_indirect(const unsigned char *sha1)
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{
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struct object *obj = parse_object(sha1);
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do {
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if (!obj)
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return NULL;
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if (obj->type == tree_type)
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return (struct tree *) obj;
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else if (obj->type == commit_type)
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obj = &(((struct commit *) obj)->tree->object);
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else if (obj->type == tag_type)
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obj = ((struct tag *) obj)->tagged;
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else
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return NULL;
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if (!obj->parsed)
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parse_object(obj->sha1);
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} while (1);
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}
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