/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "tree-cache.h"
static git_tree_cache *find_child(const git_tree_cache *tree, const char *path)
{
size_t i, dirlen;
const char *end;
end = strchr(path, '/');
if (end == NULL) {
end = strrchr(path, '\0');
}
dirlen = end - path;
for (i = 0; i < tree->children_count; ++i) {
const char *childname = tree->children[i]->name;
if (strlen(childname) == dirlen && !memcmp(path, childname, dirlen))
return tree->children[i];
}
return NULL;
}
void git_tree_cache_invalidate_path(git_tree_cache *tree, const char *path)
{
const char *ptr = path, *end;
if (tree == NULL)
return;
tree->entries = -1;
while (ptr != NULL) {
end = strchr(ptr, '/');
if (end == NULL) /* End of path */
break;
tree = find_child(tree, ptr);
if (tree == NULL) /* We don't have that tree */
return;
tree->entries = -1;
ptr = end + 1;
}
}
const git_tree_cache *git_tree_cache_get(const git_tree_cache *tree, const char *path)
{
const char *ptr = path, *end;
if (tree == NULL) {
return NULL;
}
while (1) {
end = strchr(ptr, '/');
tree = find_child(tree, ptr);
if (tree == NULL) { /* Can't find it */
return NULL;
}
if (end == NULL || *end + 1 == '\0')
return tree;
ptr = end + 1;
}
}
static int read_tree_internal(git_tree_cache **out,
const char **buffer_in, const char *buffer_end, git_tree_cache *parent)
{
git_tree_cache *tree = NULL;
const char *name_start, *buffer;
int count;
size_t name_len;
buffer = name_start = *buffer_in;
if ((buffer = memchr(buffer, '\0', buffer_end - buffer)) == NULL)
goto corrupted;
if (++buffer >= buffer_end)
goto corrupted;
name_len = strlen(name_start);
tree = git__malloc(sizeof(git_tree_cache) + name_len + 1);
GITERR_CHECK_ALLOC(tree);
memset(tree, 0x0, sizeof(git_tree_cache));
tree->parent = parent;
/* NUL-terminated tree name */
memcpy(tree->name, name_start, name_len);
tree->name[name_len] = '\0';
/* Blank-terminated ASCII decimal number of entries in this tree */
if (git__strtol32(&count, buffer, &buffer, 10) < 0)
goto corrupted;
tree->entries = count;
if (*buffer != ' ' || ++buffer >= buffer_end)
goto corrupted;
/* Number of children of the tree, newline-terminated */
if (git__strtol32(&count, buffer, &buffer, 10) < 0 || count < 0)
goto corrupted;
tree->children_count = count;
if (*buffer != '\n' || ++buffer > buffer_end)
goto corrupted;
/* The SHA1 is only there if it's not invalidated */
if (tree->entries >= 0) {
/* 160-bit SHA-1 for this tree and it's children */
if (buffer + GIT_OID_RAWSZ > buffer_end)
goto corrupted;
git_oid_fromraw(&tree->oid, (const unsigned char *)buffer);
buffer += GIT_OID_RAWSZ;
}
/* Parse children: */
if (tree->children_count > 0) {
unsigned int i;
tree->children = git__malloc(tree->children_count * sizeof(git_tree_cache *));
GITERR_CHECK_ALLOC(tree->children);
for (i = 0; i < tree->children_count; ++i) {
if (read_tree_internal(&tree->children[i], &buffer, buffer_end, tree) < 0)
return -1;
}
}
*buffer_in = buffer;
*out = tree;
return 0;
corrupted:
git_tree_cache_free(tree);
giterr_set(GITERR_INDEX, "Corruped TREE extension in index");
return -1;
}
int git_tree_cache_read(git_tree_cache **tree, const char *buffer, size_t buffer_size)
{
const char *buffer_end = buffer + buffer_size;
if (read_tree_internal(tree, &buffer, buffer_end, NULL) < 0)
return -1;
if (buffer < buffer_end) {
giterr_set(GITERR_INDEX, "Corruped TREE extension in index (unexpected trailing data)");
return -1;
}
return 0;
}
void git_tree_cache_free(git_tree_cache *tree)
{
unsigned int i;
if (tree == NULL)
return;
for (i = 0; i < tree->children_count; ++i)
git_tree_cache_free(tree->children[i]);
git__free(tree->children);
git__free(tree);
}
