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git/object.c
Patrick Steinhardt e7da938570 global: introduce USE_THE_REPOSITORY_VARIABLE macro
Use of the `the_repository` variable is deprecated nowadays, and we
slowly but steadily convert the codebase to not use it anymore. Instead,
callers should be passing down the repository to work on via parameters.

It is hard though to prove that a given code unit does not use this
variable anymore. The most trivial case, merely demonstrating that there
is no direct use of `the_repository`, is already a bit of a pain during
code reviews as the reviewer needs to manually verify claims made by the
patch author. The bigger problem though is that we have many interfaces
that implicitly rely on `the_repository`.

Introduce a new `USE_THE_REPOSITORY_VARIABLE` macro that allows code
units to opt into usage of `the_repository`. The intent of this macro is
to demonstrate that a certain code unit does not use this variable
anymore, and to keep it from new dependencies on it in future changes,
be it explicit or implicit

For now, the macro only guards `the_repository` itself as well as
`the_hash_algo`. There are many more known interfaces where we have an
implicit dependency on `the_repository`, but those are not guarded at
the current point in time. Over time though, we should start to add
guards as required (or even better, just remove them).

Define the macro as required in our code units. As expected, most of our
code still relies on the global variable. Nearly all of our builtins
rely on the variable as there is no way yet to pass `the_repository` to
their entry point. For now, declare the macro in "biultin.h" to keep the
required changes at least a little bit more contained.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 10:26:33 -07:00

666 lines
16 KiB
C

#define USE_THE_REPOSITORY_VARIABLE
#include "git-compat-util.h"
#include "gettext.h"
#include "hex.h"
#include "object.h"
#include "replace-object.h"
#include "object-file.h"
#include "object-store.h"
#include "blob.h"
#include "statinfo.h"
#include "tree.h"
#include "commit.h"
#include "tag.h"
#include "alloc.h"
#include "packfile.h"
#include "commit-graph.h"
#include "loose.h"
unsigned int get_max_object_index(void)
{
return the_repository->parsed_objects->obj_hash_size;
}
struct object *get_indexed_object(unsigned int idx)
{
return the_repository->parsed_objects->obj_hash[idx];
}
static const char *object_type_strings[] = {
NULL, /* OBJ_NONE = 0 */
"commit", /* OBJ_COMMIT = 1 */
"tree", /* OBJ_TREE = 2 */
"blob", /* OBJ_BLOB = 3 */
"tag", /* OBJ_TAG = 4 */
};
const char *type_name(unsigned int type)
{
if (type >= ARRAY_SIZE(object_type_strings))
return NULL;
return object_type_strings[type];
}
int type_from_string_gently(const char *str, ssize_t len, int gentle)
{
int i;
if (len < 0)
len = strlen(str);
for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
if (!xstrncmpz(object_type_strings[i], str, len))
return i;
if (gentle)
return -1;
die(_("invalid object type \"%s\""), str);
}
/*
* Return a numerical hash value between 0 and n-1 for the object with
* the specified sha1. n must be a power of 2. Please note that the
* return value is *not* consistent across computer architectures.
*/
static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
{
return oidhash(oid) & (n - 1);
}
/*
* Insert obj into the hash table hash, which has length size (which
* must be a power of 2). On collisions, simply overflow to the next
* empty bucket.
*/
static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
{
unsigned int j = hash_obj(&obj->oid, size);
while (hash[j]) {
j++;
if (j >= size)
j = 0;
}
hash[j] = obj;
}
/*
* Look up the record for the given sha1 in the hash map stored in
* obj_hash. Return NULL if it was not found.
*/
struct object *lookup_object(struct repository *r, const struct object_id *oid)
{
unsigned int i, first;
struct object *obj;
if (!r->parsed_objects->obj_hash)
return NULL;
first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
if (oideq(oid, &obj->oid))
break;
i++;
if (i == r->parsed_objects->obj_hash_size)
i = 0;
}
if (obj && i != first) {
/*
* Move object to where we started to look for it so
* that we do not need to walk the hash table the next
* time we look for it.
*/
SWAP(r->parsed_objects->obj_hash[i],
r->parsed_objects->obj_hash[first]);
}
return obj;
}
/*
* Increase the size of the hash map stored in obj_hash to the next
* power of 2 (but at least 32). Copy the existing values to the new
* hash map.
*/
static void grow_object_hash(struct repository *r)
{
int i;
/*
* Note that this size must always be power-of-2 to match hash_obj
* above.
*/
int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
struct object **new_hash;
CALLOC_ARRAY(new_hash, new_hash_size);
for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
struct object *obj = r->parsed_objects->obj_hash[i];
if (!obj)
continue;
insert_obj_hash(obj, new_hash, new_hash_size);
}
free(r->parsed_objects->obj_hash);
r->parsed_objects->obj_hash = new_hash;
r->parsed_objects->obj_hash_size = new_hash_size;
}
void *create_object(struct repository *r, const struct object_id *oid, void *o)
{
struct object *obj = o;
obj->parsed = 0;
obj->flags = 0;
oidcpy(&obj->oid, oid);
if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
grow_object_hash(r);
insert_obj_hash(obj, r->parsed_objects->obj_hash,
r->parsed_objects->obj_hash_size);
r->parsed_objects->nr_objs++;
return obj;
}
void *object_as_type(struct object *obj, enum object_type type, int quiet)
{
if (obj->type == type)
return obj;
else if (obj->type == OBJ_NONE) {
if (type == OBJ_COMMIT)
init_commit_node((struct commit *) obj);
else
obj->type = type;
return obj;
}
else {
if (!quiet)
error(_("object %s is a %s, not a %s"),
oid_to_hex(&obj->oid),
type_name(obj->type), type_name(type));
return NULL;
}
}
struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid)
{
struct object *obj = lookup_object(r, oid);
if (!obj)
obj = create_object(r, oid, alloc_object_node(r));
return obj;
}
struct object *lookup_object_by_type(struct repository *r,
const struct object_id *oid,
enum object_type type)
{
switch (type) {
case OBJ_COMMIT:
return (struct object *)lookup_commit(r, oid);
case OBJ_TREE:
return (struct object *)lookup_tree(r, oid);
case OBJ_TAG:
return (struct object *)lookup_tag(r, oid);
case OBJ_BLOB:
return (struct object *)lookup_blob(r, oid);
default:
BUG("unknown object type %d", type);
}
}
enum peel_status peel_object(struct repository *r,
const struct object_id *name,
struct object_id *oid)
{
struct object *o = lookup_unknown_object(r, name);
if (o->type == OBJ_NONE) {
int type = oid_object_info(r, name, NULL);
if (type < 0 || !object_as_type(o, type, 0))
return PEEL_INVALID;
}
if (o->type != OBJ_TAG)
return PEEL_NON_TAG;
o = deref_tag_noverify(r, o);
if (!o)
return PEEL_INVALID;
oidcpy(oid, &o->oid);
return PEEL_PEELED;
}
struct object *parse_object_buffer(struct repository *r, const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
{
struct object *obj;
*eaten_p = 0;
obj = NULL;
if (type == OBJ_BLOB) {
struct blob *blob = lookup_blob(r, oid);
if (blob) {
parse_blob_buffer(blob);
obj = &blob->object;
}
} else if (type == OBJ_TREE) {
struct tree *tree = lookup_tree(r, oid);
if (tree) {
obj = &tree->object;
if (!tree->buffer)
tree->object.parsed = 0;
if (!tree->object.parsed) {
if (parse_tree_buffer(tree, buffer, size))
return NULL;
*eaten_p = 1;
}
}
} else if (type == OBJ_COMMIT) {
struct commit *commit = lookup_commit(r, oid);
if (commit) {
if (parse_commit_buffer(r, commit, buffer, size, 1))
return NULL;
if (save_commit_buffer &&
!get_cached_commit_buffer(r, commit, NULL)) {
set_commit_buffer(r, commit, buffer, size);
*eaten_p = 1;
}
obj = &commit->object;
}
} else if (type == OBJ_TAG) {
struct tag *tag = lookup_tag(r, oid);
if (tag) {
if (parse_tag_buffer(r, tag, buffer, size))
return NULL;
obj = &tag->object;
}
} else {
warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
obj = NULL;
}
return obj;
}
struct object *parse_object_or_die(const struct object_id *oid,
const char *name)
{
struct object *o = parse_object(the_repository, oid);
if (o)
return o;
die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
}
struct object *parse_object_with_flags(struct repository *r,
const struct object_id *oid,
enum parse_object_flags flags)
{
int skip_hash = !!(flags & PARSE_OBJECT_SKIP_HASH_CHECK);
int discard_tree = !!(flags & PARSE_OBJECT_DISCARD_TREE);
unsigned long size;
enum object_type type;
int eaten;
const struct object_id *repl = lookup_replace_object(r, oid);
void *buffer;
struct object *obj;
obj = lookup_object(r, oid);
if (obj && obj->parsed)
return obj;
if (skip_hash) {
struct commit *commit = lookup_commit_in_graph(r, repl);
if (commit)
return &commit->object;
}
if ((!obj || obj->type == OBJ_BLOB) &&
oid_object_info(r, oid, NULL) == OBJ_BLOB) {
if (!skip_hash && stream_object_signature(r, repl) < 0) {
error(_("hash mismatch %s"), oid_to_hex(oid));
return NULL;
}
parse_blob_buffer(lookup_blob(r, oid));
return lookup_object(r, oid);
}
/*
* If the caller does not care about the tree buffer and does not
* care about checking the hash, we can simply verify that we
* have the on-disk object with the correct type.
*/
if (skip_hash && discard_tree &&
(!obj || obj->type == OBJ_TREE) &&
oid_object_info(r, oid, NULL) == OBJ_TREE) {
return &lookup_tree(r, oid)->object;
}
buffer = repo_read_object_file(r, oid, &type, &size);
if (buffer) {
if (!skip_hash &&
check_object_signature(r, repl, buffer, size, type) < 0) {
free(buffer);
error(_("hash mismatch %s"), oid_to_hex(repl));
return NULL;
}
obj = parse_object_buffer(r, oid, type, size,
buffer, &eaten);
if (!eaten)
free(buffer);
if (discard_tree && type == OBJ_TREE)
free_tree_buffer((struct tree *)obj);
return obj;
}
return NULL;
}
struct object *parse_object(struct repository *r, const struct object_id *oid)
{
return parse_object_with_flags(r, oid, 0);
}
struct object_list *object_list_insert(struct object *item,
struct object_list **list_p)
{
struct object_list *new_list = xmalloc(sizeof(struct object_list));
new_list->item = item;
new_list->next = *list_p;
*list_p = new_list;
return new_list;
}
int object_list_contains(struct object_list *list, struct object *obj)
{
while (list) {
if (list->item == obj)
return 1;
list = list->next;
}
return 0;
}
void object_list_free(struct object_list **list)
{
while (*list) {
struct object_list *p = *list;
*list = p->next;
free(p);
}
}
/*
* A zero-length string to which object_array_entry::name can be
* initialized without requiring a malloc/free.
*/
static char object_array_slopbuf[1];
void object_array_init(struct object_array *array)
{
struct object_array blank = OBJECT_ARRAY_INIT;
memcpy(array, &blank, sizeof(*array));
}
void add_object_array_with_path(struct object *obj, const char *name,
struct object_array *array,
unsigned mode, const char *path)
{
unsigned nr = array->nr;
unsigned alloc = array->alloc;
struct object_array_entry *objects = array->objects;
struct object_array_entry *entry;
if (nr >= alloc) {
alloc = (alloc + 32) * 2;
REALLOC_ARRAY(objects, alloc);
array->alloc = alloc;
array->objects = objects;
}
entry = &objects[nr];
entry->item = obj;
if (!name)
entry->name = NULL;
else if (!*name)
/* Use our own empty string instead of allocating one: */
entry->name = object_array_slopbuf;
else
entry->name = xstrdup(name);
entry->mode = mode;
if (path)
entry->path = xstrdup(path);
else
entry->path = NULL;
array->nr = ++nr;
}
void add_object_array(struct object *obj, const char *name, struct object_array *array)
{
add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
}
/*
* Free all memory associated with an entry; the result is
* in an unspecified state and should not be examined.
*/
static void object_array_release_entry(struct object_array_entry *ent)
{
if (ent->name != object_array_slopbuf)
free(ent->name);
free(ent->path);
}
struct object *object_array_pop(struct object_array *array)
{
struct object *ret;
if (!array->nr)
return NULL;
ret = array->objects[array->nr - 1].item;
object_array_release_entry(&array->objects[array->nr - 1]);
array->nr--;
return ret;
}
void object_array_filter(struct object_array *array,
object_array_each_func_t want, void *cb_data)
{
unsigned nr = array->nr, src, dst;
struct object_array_entry *objects = array->objects;
for (src = dst = 0; src < nr; src++) {
if (want(&objects[src], cb_data)) {
if (src != dst)
objects[dst] = objects[src];
dst++;
} else {
object_array_release_entry(&objects[src]);
}
}
array->nr = dst;
}
void object_array_clear(struct object_array *array)
{
int i;
for (i = 0; i < array->nr; i++)
object_array_release_entry(&array->objects[i]);
FREE_AND_NULL(array->objects);
array->nr = array->alloc = 0;
}
/*
* Return true if array already contains an entry.
*/
static int contains_object(struct object_array *array,
const struct object *item, const char *name)
{
unsigned nr = array->nr, i;
struct object_array_entry *object = array->objects;
for (i = 0; i < nr; i++, object++)
if (item == object->item && !strcmp(object->name, name))
return 1;
return 0;
}
void object_array_remove_duplicates(struct object_array *array)
{
unsigned nr = array->nr, src;
struct object_array_entry *objects = array->objects;
array->nr = 0;
for (src = 0; src < nr; src++) {
if (!contains_object(array, objects[src].item,
objects[src].name)) {
if (src != array->nr)
objects[array->nr] = objects[src];
array->nr++;
} else {
object_array_release_entry(&objects[src]);
}
}
}
void clear_object_flags(unsigned flags)
{
int i;
for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
struct object *obj = the_repository->parsed_objects->obj_hash[i];
if (obj)
obj->flags &= ~flags;
}
}
void repo_clear_commit_marks(struct repository *r, unsigned int flags)
{
int i;
for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
struct object *obj = r->parsed_objects->obj_hash[i];
if (obj && obj->type == OBJ_COMMIT)
obj->flags &= ~flags;
}
}
struct parsed_object_pool *parsed_object_pool_new(void)
{
struct parsed_object_pool *o = xmalloc(sizeof(*o));
memset(o, 0, sizeof(*o));
o->blob_state = allocate_alloc_state();
o->tree_state = allocate_alloc_state();
o->commit_state = allocate_alloc_state();
o->tag_state = allocate_alloc_state();
o->object_state = allocate_alloc_state();
o->is_shallow = -1;
CALLOC_ARRAY(o->shallow_stat, 1);
o->buffer_slab = allocate_commit_buffer_slab();
return o;
}
struct raw_object_store *raw_object_store_new(void)
{
struct raw_object_store *o = xmalloc(sizeof(*o));
memset(o, 0, sizeof(*o));
INIT_LIST_HEAD(&o->packed_git_mru);
hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
pthread_mutex_init(&o->replace_mutex, NULL);
return o;
}
void free_object_directory(struct object_directory *odb)
{
free(odb->path);
odb_clear_loose_cache(odb);
loose_object_map_clear(&odb->loose_map);
free(odb);
}
static void free_object_directories(struct raw_object_store *o)
{
while (o->odb) {
struct object_directory *next;
next = o->odb->next;
free_object_directory(o->odb);
o->odb = next;
}
kh_destroy_odb_path_map(o->odb_by_path);
o->odb_by_path = NULL;
}
void raw_object_store_clear(struct raw_object_store *o)
{
FREE_AND_NULL(o->alternate_db);
oidmap_free(o->replace_map, 1);
FREE_AND_NULL(o->replace_map);
pthread_mutex_destroy(&o->replace_mutex);
free_commit_graph(o->commit_graph);
o->commit_graph = NULL;
o->commit_graph_attempted = 0;
free_object_directories(o);
o->odb_tail = NULL;
o->loaded_alternates = 0;
INIT_LIST_HEAD(&o->packed_git_mru);
close_object_store(o);
o->packed_git = NULL;
hashmap_clear(&o->pack_map);
}
void parsed_object_pool_clear(struct parsed_object_pool *o)
{
/*
* As objects are allocated in slabs (see alloc.c), we do
* not need to free each object, but each slab instead.
*
* Before doing so, we need to free any additional memory
* the objects may hold.
*/
unsigned i;
for (i = 0; i < o->obj_hash_size; i++) {
struct object *obj = o->obj_hash[i];
if (!obj)
continue;
if (obj->type == OBJ_TREE)
free_tree_buffer((struct tree*)obj);
else if (obj->type == OBJ_COMMIT)
release_commit_memory(o, (struct commit*)obj);
else if (obj->type == OBJ_TAG)
release_tag_memory((struct tag*)obj);
}
FREE_AND_NULL(o->obj_hash);
o->obj_hash_size = 0;
free_commit_buffer_slab(o->buffer_slab);
o->buffer_slab = NULL;
clear_alloc_state(o->blob_state);
clear_alloc_state(o->tree_state);
clear_alloc_state(o->commit_state);
clear_alloc_state(o->tag_state);
clear_alloc_state(o->object_state);
stat_validity_clear(o->shallow_stat);
FREE_AND_NULL(o->blob_state);
FREE_AND_NULL(o->tree_state);
FREE_AND_NULL(o->commit_state);
FREE_AND_NULL(o->tag_state);
FREE_AND_NULL(o->object_state);
FREE_AND_NULL(o->shallow_stat);
}