/*
* 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"
#include "pool.h"
#include "tree.h"
static git_tree_cache *find_child(
const git_tree_cache *tree, const char *path, const char *end)
{
size_t i, dirlen = end ? (size_t)(end - path) : strlen(path);
for (i = 0; i < tree->children_count; ++i) {
git_tree_cache *child = tree->children[i];
if (child->namelen == dirlen && !memcmp(path, child->name, dirlen))
return child;
}
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->entry_count = -1;
while (ptr != NULL) {
end = strchr(ptr, '/');
if (end == NULL) /* End of path */
break;
tree = find_child(tree, ptr, end);
if (tree == NULL) /* We don't have that tree */
return;
tree->entry_count = -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, end);
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_pool *pool)
{
git_tree_cache *tree = NULL;
const char *name_start, *buffer;
int count;
buffer = name_start = *buffer_in;
if ((buffer = memchr(buffer, '\0', buffer_end - buffer)) == NULL)
goto corrupted;
if (++buffer >= buffer_end)
goto corrupted;
if (git_tree_cache_new(&tree, name_start, pool) < 0)
return -1;
/* Blank-terminated ASCII decimal number of entries in this tree */
if (git__strntol32(&count, buffer, buffer_end - buffer, &buffer, 10) < 0)
goto corrupted;
tree->entry_count = count;
if (*buffer != ' ' || ++buffer >= buffer_end)
goto corrupted;
/* Number of children of the tree, newline-terminated */
if (git__strntol32(&count, buffer, buffer_end - 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->entry_count >= 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_pool_malloc(pool, tree->children_count * sizeof(git_tree_cache *));
GITERR_CHECK_ALLOC(tree->children);
memset(tree->children, 0x0, tree->children_count * sizeof(git_tree_cache *));
for (i = 0; i < tree->children_count; ++i) {
if (read_tree_internal(&tree->children[i], &buffer, buffer_end, pool) < 0)
goto corrupted;
}
}
*buffer_in = buffer;
*out = tree;
return 0;
corrupted:
giterr_set(GITERR_INDEX, "corrupted TREE extension in index");
return -1;
}
int git_tree_cache_read(git_tree_cache **tree, const char *buffer, size_t buffer_size, git_pool *pool)
{
const char *buffer_end = buffer + buffer_size;
if (read_tree_internal(tree, &buffer, buffer_end, pool) < 0)
return -1;
if (buffer < buffer_end) {
giterr_set(GITERR_INDEX, "corrupted TREE extension in index (unexpected trailing data)");
return -1;
}
return 0;
}
static int read_tree_recursive(git_tree_cache *cache, const git_tree *tree, git_pool *pool)
{
git_repository *repo;
size_t i, j, nentries, ntrees;
int error;
repo = git_tree_owner(tree);
git_oid_cpy(&cache->oid, git_tree_id(tree));
nentries = git_tree_entrycount(tree);
/*
* We make sure we know how many trees we need to allocate for
* so we don't have to realloc and change the pointers for the
* parents.
*/
ntrees = 0;
for (i = 0; i < nentries; i++) {
const git_tree_entry *entry;
entry = git_tree_entry_byindex(tree, i);
if (git_tree_entry_filemode(entry) == GIT_FILEMODE_TREE)
ntrees++;
}
cache->children_count = ntrees;
cache->children = git_pool_mallocz(pool, ntrees * sizeof(git_tree_cache *));
GITERR_CHECK_ALLOC(cache->children);
j = 0;
for (i = 0; i < nentries; i++) {
const git_tree_entry *entry;
git_tree *subtree;
entry = git_tree_entry_byindex(tree, i);
if (git_tree_entry_filemode(entry) != GIT_FILEMODE_TREE) {
cache->entry_count++;
continue;
}
if ((error = git_tree_cache_new(&cache->children[j], git_tree_entry_name(entry), pool)) < 0)
return error;
if ((error = git_tree_lookup(&subtree, repo, git_tree_entry_id(entry))) < 0)
return error;
error = read_tree_recursive(cache->children[j], subtree, pool);
git_tree_free(subtree);
cache->entry_count += cache->children[j]->entry_count;
j++;
if (error < 0)
return error;
}
return 0;
}
int git_tree_cache_read_tree(git_tree_cache **out, const git_tree *tree, git_pool *pool)
{
int error;
git_tree_cache *cache;
if ((error = git_tree_cache_new(&cache, "", pool)) < 0)
return error;
if ((error = read_tree_recursive(cache, tree, pool)) < 0)
return error;
*out = cache;
return 0;
}
int git_tree_cache_new(git_tree_cache **out, const char *name, git_pool *pool)
{
size_t name_len;
git_tree_cache *tree;
name_len = strlen(name);
tree = git_pool_malloc(pool, sizeof(git_tree_cache) + name_len + 1);
GITERR_CHECK_ALLOC(tree);
memset(tree, 0x0, sizeof(git_tree_cache));
/* NUL-terminated tree name */
tree->namelen = name_len;
memcpy(tree->name, name, name_len);
tree->name[name_len] = '\0';
*out = tree;
return 0;
}
static void write_tree(git_buf *out, git_tree_cache *tree)
{
size_t i;
git_buf_printf(out, "%s%c%"PRIdZ" %"PRIuZ"\n", tree->name, 0, tree->entry_count, tree->children_count);
if (tree->entry_count != -1)
git_buf_put(out, (const char *) &tree->oid, GIT_OID_RAWSZ);
for (i = 0; i < tree->children_count; i++)
write_tree(out, tree->children[i]);
}
int git_tree_cache_write(git_buf *out, git_tree_cache *tree)
{
write_tree(out, tree);
return git_buf_oom(out) ? -1 : 0;
}