/*
* 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 "object.h"
#include "git2/object.h"
#include "repository.h"
#include "commit.h"
#include "hash.h"
#include "tree.h"
#include "blob.h"
#include "oid.h"
#include "tag.h"
bool git_object__strict_input_validation = true;
extern int git_odb_hash(git_oid *out, const void *data, size_t len, git_object_t type);
size_t git_object__size(git_object_t type);
typedef struct {
const char *str; /* type name string */
size_t size; /* size in bytes of the object structure */
int (*parse)(void *self, git_odb_object *obj);
int (*parse_raw)(void *self, const char *data, size_t size);
void (*free)(void *self);
} git_object_def;
static git_object_def git_objects_table[] = {
/* 0 = GIT_OBJECT__EXT1 */
{ "", 0, NULL, NULL, NULL },
/* 1 = GIT_OBJECT_COMMIT */
{ "commit", sizeof(git_commit), git_commit__parse, git_commit__parse_raw, git_commit__free },
/* 2 = GIT_OBJECT_TREE */
{ "tree", sizeof(git_tree), git_tree__parse, git_tree__parse_raw, git_tree__free },
/* 3 = GIT_OBJECT_BLOB */
{ "blob", sizeof(git_blob), git_blob__parse, git_blob__parse_raw, git_blob__free },
/* 4 = GIT_OBJECT_TAG */
{ "tag", sizeof(git_tag), git_tag__parse, git_tag__parse_raw, git_tag__free },
/* 5 = GIT_OBJECT__EXT2 */
{ "", 0, NULL, NULL, NULL },
/* 6 = GIT_OBJECT_OFS_DELTA */
{ "OFS_DELTA", 0, NULL, NULL, NULL },
/* 7 = GIT_OBJECT_REF_DELTA */
{ "REF_DELTA", 0, NULL, NULL, NULL },
};
int git_object__from_raw(
git_object **object_out,
const char *data,
size_t size,
git_object_t type)
{
git_object_def *def;
git_object *object;
size_t object_size;
int error;
GIT_ASSERT_ARG(object_out);
*object_out = NULL;
/* Validate type match */
if (type != GIT_OBJECT_BLOB && type != GIT_OBJECT_TREE && type != GIT_OBJECT_COMMIT && type != GIT_OBJECT_TAG) {
git_error_set(GIT_ERROR_INVALID, "the requested type is invalid");
return GIT_ENOTFOUND;
}
if ((object_size = git_object__size(type)) == 0) {
git_error_set(GIT_ERROR_INVALID, "the requested type is invalid");
return GIT_ENOTFOUND;
}
/* Allocate and initialize base object */
object = git__calloc(1, object_size);
GIT_ERROR_CHECK_ALLOC(object);
object->cached.flags = GIT_CACHE_STORE_PARSED;
object->cached.type = type;
if ((error = git_odb_hash(&object->cached.oid, data, size, type)) < 0)
return error;
/* Parse raw object data */
def = &git_objects_table[type];
GIT_ASSERT(def->free && def->parse_raw);
if ((error = def->parse_raw(object, data, size)) < 0) {
def->free(object);
return error;
}
git_cached_obj_incref(object);
*object_out = object;
return 0;
}
int git_object__from_odb_object(
git_object **object_out,
git_repository *repo,
git_odb_object *odb_obj,
git_object_t type)
{
int error;
size_t object_size;
git_object_def *def;
git_object *object = NULL;
GIT_ASSERT_ARG(object_out);
*object_out = NULL;
/* Validate type match */
if (type != GIT_OBJECT_ANY && type != odb_obj->cached.type) {
git_error_set(GIT_ERROR_INVALID,
"the requested type does not match the type in the ODB");
return GIT_ENOTFOUND;
}
if ((object_size = git_object__size(odb_obj->cached.type)) == 0) {
git_error_set(GIT_ERROR_INVALID, "the requested type is invalid");
return GIT_ENOTFOUND;
}
/* Allocate and initialize base object */
object = git__calloc(1, object_size);
GIT_ERROR_CHECK_ALLOC(object);
git_oid_cpy(&object->cached.oid, &odb_obj->cached.oid);
object->cached.type = odb_obj->cached.type;
object->cached.size = odb_obj->cached.size;
object->repo = repo;
/* Parse raw object data */
def = &git_objects_table[odb_obj->cached.type];
GIT_ASSERT(def->free && def->parse);
if ((error = def->parse(object, odb_obj)) < 0)
def->free(object);
else
*object_out = git_cache_store_parsed(&repo->objects, object);
return error;
}
void git_object__free(void *obj)
{
git_object_t type = ((git_object *)obj)->cached.type;
if (type < 0 || ((size_t)type) >= ARRAY_SIZE(git_objects_table) ||
!git_objects_table[type].free)
git__free(obj);
else
git_objects_table[type].free(obj);
}
int git_object_lookup_prefix(
git_object **object_out,
git_repository *repo,
const git_oid *id,
size_t len,
git_object_t type)
{
git_object *object = NULL;
git_odb *odb = NULL;
git_odb_object *odb_obj = NULL;
int error = 0;
GIT_ASSERT_ARG(repo);
GIT_ASSERT_ARG(object_out);
GIT_ASSERT_ARG(id);
if (len < GIT_OID_MINPREFIXLEN) {
git_error_set(GIT_ERROR_OBJECT, "ambiguous lookup - OID prefix is too short");
return GIT_EAMBIGUOUS;
}
error = git_repository_odb__weakptr(&odb, repo);
if (error < 0)
return error;
if (len > GIT_OID_HEXSZ)
len = GIT_OID_HEXSZ;
if (len == GIT_OID_HEXSZ) {
git_cached_obj *cached = NULL;
/* We want to match the full id : we can first look up in the cache,
* since there is no need to check for non ambiguousity
*/
cached = git_cache_get_any(&repo->objects, id);
if (cached != NULL) {
if (cached->flags == GIT_CACHE_STORE_PARSED) {
object = (git_object *)cached;
if (type != GIT_OBJECT_ANY && type != object->cached.type) {
git_object_free(object);
git_error_set(GIT_ERROR_INVALID,
"the requested type does not match the type in the ODB");
return GIT_ENOTFOUND;
}
*object_out = object;
return 0;
} else if (cached->flags == GIT_CACHE_STORE_RAW) {
odb_obj = (git_odb_object *)cached;
} else {
GIT_ASSERT(!"Wrong caching type in the global object cache");
}
} else {
/* Object was not found in the cache, let's explore the backends.
* We could just use git_odb_read_unique_short_oid,
* it is the same cost for packed and loose object backends,
* but it may be much more costly for sqlite and hiredis.
*/
error = git_odb_read(&odb_obj, odb, id);
}
} else {
git_oid short_oid = {{ 0 }};
git_oid__cpy_prefix(&short_oid, id, len);
/* If len < GIT_OID_HEXSZ (a strict short oid was given), we have
* 2 options :
* - We always search in the cache first. If we find that short oid is
* ambiguous, we can stop. But in all the other cases, we must then
* explore all the backends (to find an object if there was match,
* or to check that oid is not ambiguous if we have found 1 match in
* the cache)
* - We never explore the cache, go right to exploring the backends
* We chose the latter : we explore directly the backends.
*/
error = git_odb_read_prefix(&odb_obj, odb, &short_oid, len);
}
if (error < 0)
return error;
error = git_object__from_odb_object(object_out, repo, odb_obj, type);
git_odb_object_free(odb_obj);
return error;
}
int git_object_lookup(git_object **object_out, git_repository *repo, const git_oid *id, git_object_t type) {
return git_object_lookup_prefix(object_out, repo, id, GIT_OID_HEXSZ, type);
}
void git_object_free(git_object *object)
{
if (object == NULL)
return;
git_cached_obj_decref(object);
}
const git_oid *git_object_id(const git_object *obj)
{
GIT_ASSERT_ARG_WITH_RETVAL(obj, NULL);
return &obj->cached.oid;
}
git_object_t git_object_type(const git_object *obj)
{
GIT_ASSERT_ARG_WITH_RETVAL(obj, GIT_OBJECT_INVALID);
return obj->cached.type;
}
git_repository *git_object_owner(const git_object *obj)
{
GIT_ASSERT_ARG_WITH_RETVAL(obj, NULL);
return obj->repo;
}
const char *git_object_type2string(git_object_t type)
{
if (type < 0 || ((size_t) type) >= ARRAY_SIZE(git_objects_table))
return "";
return git_objects_table[type].str;
}
git_object_t git_object_string2type(const char *str)
{
if (!str)
return GIT_OBJECT_INVALID;
return git_object_stringn2type(str, strlen(str));
}
git_object_t git_object_stringn2type(const char *str, size_t len)
{
size_t i;
if (!str || !len || !*str)
return GIT_OBJECT_INVALID;
for (i = 0; i < ARRAY_SIZE(git_objects_table); i++)
if (*git_objects_table[i].str &&
!git__prefixncmp(str, len, git_objects_table[i].str))
return (git_object_t)i;
return GIT_OBJECT_INVALID;
}
int git_object_typeisloose(git_object_t type)
{
if (type < 0 || ((size_t) type) >= ARRAY_SIZE(git_objects_table))
return 0;
return (git_objects_table[type].size > 0) ? 1 : 0;
}
size_t git_object__size(git_object_t type)
{
if (type < 0 || ((size_t) type) >= ARRAY_SIZE(git_objects_table))
return 0;
return git_objects_table[type].size;
}
static int dereference_object(git_object **dereferenced, git_object *obj)
{
git_object_t type = git_object_type(obj);
switch (type) {
case GIT_OBJECT_COMMIT:
return git_commit_tree((git_tree **)dereferenced, (git_commit*)obj);
case GIT_OBJECT_TAG:
return git_tag_target(dereferenced, (git_tag*)obj);
case GIT_OBJECT_BLOB:
case GIT_OBJECT_TREE:
return GIT_EPEEL;
default:
return GIT_EINVALIDSPEC;
}
}
static int peel_error(int error, const git_oid *oid, git_object_t type)
{
const char *type_name;
char hex_oid[GIT_OID_HEXSZ + 1];
type_name = git_object_type2string(type);
git_oid_fmt(hex_oid, oid);
hex_oid[GIT_OID_HEXSZ] = '\0';
git_error_set(GIT_ERROR_OBJECT, "the git_object of id '%s' can not be "
"successfully peeled into a %s (git_object_t=%i).", hex_oid, type_name, type);
return error;
}
static int check_type_combination(git_object_t type, git_object_t target)
{
if (type == target)
return 0;
switch (type) {
case GIT_OBJECT_BLOB:
case GIT_OBJECT_TREE:
/* a blob or tree can never be peeled to anything but themselves */
return GIT_EINVALIDSPEC;
break;
case GIT_OBJECT_COMMIT:
/* a commit can only be peeled to a tree */
if (target != GIT_OBJECT_TREE && target != GIT_OBJECT_ANY)
return GIT_EINVALIDSPEC;
break;
case GIT_OBJECT_TAG:
/* a tag may point to anything, so we let anything through */
break;
default:
return GIT_EINVALIDSPEC;
}
return 0;
}
int git_object_peel(
git_object **peeled,
const git_object *object,
git_object_t target_type)
{
git_object *source, *deref = NULL;
int error;
GIT_ASSERT_ARG(object);
GIT_ASSERT_ARG(peeled);
GIT_ASSERT_ARG(target_type == GIT_OBJECT_TAG ||
target_type == GIT_OBJECT_COMMIT ||
target_type == GIT_OBJECT_TREE ||
target_type == GIT_OBJECT_BLOB ||
target_type == GIT_OBJECT_ANY);
if ((error = check_type_combination(git_object_type(object), target_type)) < 0)
return peel_error(error, git_object_id(object), target_type);
if (git_object_type(object) == target_type)
return git_object_dup(peeled, (git_object *)object);
source = (git_object *)object;
while (!(error = dereference_object(&deref, source))) {
if (source != object)
git_object_free(source);
if (git_object_type(deref) == target_type) {
*peeled = deref;
return 0;
}
if (target_type == GIT_OBJECT_ANY &&
git_object_type(deref) != git_object_type(object))
{
*peeled = deref;
return 0;
}
source = deref;
deref = NULL;
}
if (source != object)
git_object_free(source);
git_object_free(deref);
if (error)
error = peel_error(error, git_object_id(object), target_type);
return error;
}
int git_object_dup(git_object **dest, git_object *source)
{
git_cached_obj_incref(source);
*dest = source;
return 0;
}
int git_object_lookup_bypath(
git_object **out,
const git_object *treeish,
const char *path,
git_object_t type)
{
int error = -1;
git_tree *tree = NULL;
git_tree_entry *entry = NULL;
GIT_ASSERT_ARG(out);
GIT_ASSERT_ARG(treeish);
GIT_ASSERT_ARG(path);
if ((error = git_object_peel((git_object**)&tree, treeish, GIT_OBJECT_TREE)) < 0 ||
(error = git_tree_entry_bypath(&entry, tree, path)) < 0)
{
goto cleanup;
}
if (type != GIT_OBJECT_ANY && git_tree_entry_type(entry) != type)
{
git_error_set(GIT_ERROR_OBJECT,
"object at path '%s' is not of the asked-for type %d",
path, type);
error = GIT_EINVALIDSPEC;
goto cleanup;
}
error = git_tree_entry_to_object(out, git_object_owner(treeish), entry);
cleanup:
git_tree_entry_free(entry);
git_tree_free(tree);
return error;
}
int git_object_short_id(git_buf *out, const git_object *obj)
{
git_repository *repo;
int len = GIT_ABBREV_DEFAULT, error;
git_oid id = {{0}};
git_odb *odb;
GIT_ASSERT_ARG(out);
GIT_ASSERT_ARG(obj);
if ((error = git_buf_sanitize(out)) < 0)
return error;
repo = git_object_owner(obj);
if ((error = git_repository__configmap_lookup(&len, repo, GIT_CONFIGMAP_ABBREV)) < 0)
return error;
if ((error = git_repository_odb(&odb, repo)) < 0)
return error;
while (len < GIT_OID_HEXSZ) {
/* set up short oid */
memcpy(&id.id, &obj->cached.oid.id, (len + 1) / 2);
if (len & 1)
id.id[len / 2] &= 0xf0;
error = git_odb_exists_prefix(NULL, odb, &id, len);
if (error != GIT_EAMBIGUOUS)
break;
git_error_clear();
len++;
}
if (!error && !(error = git_buf_grow(out, len + 1))) {
git_oid_tostr(out->ptr, len + 1, &id);
out->size = len;
}
git_odb_free(odb);
return error;
}
bool git_object__is_valid(
git_repository *repo, const git_oid *id, git_object_t expected_type)
{
git_odb *odb;
git_object_t actual_type;
size_t len;
int error;
if (!git_object__strict_input_validation)
return true;
if ((error = git_repository_odb__weakptr(&odb, repo)) < 0 ||
(error = git_odb_read_header(&len, &actual_type, odb, id)) < 0)
return false;
if (expected_type != GIT_OBJECT_ANY && expected_type != actual_type) {
git_error_set(GIT_ERROR_INVALID,
"the requested type does not match the type in the ODB");
return false;
}
return true;
}
