Git 2.45.1

[git.git] / object.c

#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);
        }
}

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);
}