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	#ifndef OBJECT_STORE_H
	#define OBJECT_STORE_H

	#include "cache.h"
	#include "oidmap.h"
	#include "list.h"
	#include "oid-array.h"
	#include "strbuf.h"
	#include "thread-utils.h"

	struct object_directory {
	struct object_directory *next;

	/*
	* Used to store the results of readdir(3) calls when we are OK
	* sacrificing accuracy due to races for speed. That includes
	* object existence with OBJECT_INFO_QUICK, as well as
	* our search for unique abbreviated hashes. Don't use it for tasks
	* requiring greater accuracy!
	*
	* Be sure to call odb_load_loose_cache() before using.
	*/
	char loose_objects_subdir_seen[256];
	struct oid_array loose_objects_cache[256];

	/*
	* Path to the alternative object store. If this is a relative path,
	* it is relative to the current working directory.
	*/
	char *path;
	};

	void prepare_alt_odb(struct repository *r);
	char compute_alternate_path(const char path, struct strbuf *err);
	typedef int alt_odb_fn(struct object_directory , void );
	int foreach_alt_odb(alt_odb_fn, void*);
	typedef void alternate_ref_fn(const struct object_id oid, void );
	void for_each_alternate_ref(alternate_ref_fn, void *);

	/*
	* Add the directory to the on-disk alternates file; the new entry will also
	* take effect in the current process.
	*/
	void add_to_alternates_file(const char *dir);

	/*
	* Add the directory to the in-memory list of alternates (along with any
	* recursive alternates it points to), but do not modify the on-disk alternates
	* file.
	*/
	void add_to_alternates_memory(const char *dir);

	/*
	* Populate and return the loose object cache array corresponding to the
	* given object ID.
	*/
	struct oid_array odb_loose_cache(struct object_directory odb,
	const struct object_id *oid);

	/* Empty the loose object cache for the specified object directory. */
	void odb_clear_loose_cache(struct object_directory *odb);

	struct packed_git {
	struct hashmap_entry packmap_ent;
	struct packed_git *next;
	struct list_head mru;
	struct pack_window *windows;
	off_t pack_size;
	const void *index_data;
	size_t index_size;
	uint32_t num_objects;
	uint32_t num_bad_objects;
	uint32_t crc_offset;
	unsigned char *bad_object_sha1;
	int index_version;
	time_t mtime;
	int pack_fd;
	int index; /* for builtin/pack-objects.c */
	unsigned pack_local:1,
	pack_keep:1,
	pack_keep_in_core:1,
	freshened:1,
	do_not_close:1,
	pack_promisor:1,
	multi_pack_index:1;
	unsigned char hash[GIT_MAX_RAWSZ];
	struct revindex_entry *revindex;
	const uint32_t *revindex_data;
	const uint32_t *revindex_map;
	size_t revindex_size;
	/* something like ".git/objects/pack/xxxxx.pack" */
	char pack_name[FLEX_ARRAY]; /* more */
	};

	struct multi_pack_index;

	static inline int pack_map_entry_cmp(const void *unused_cmp_data,
	const struct hashmap_entry *entry,
	const struct hashmap_entry *entry2,
	const void *keydata)
	{
	const char *key = keydata;
	const struct packed_git pg1, pg2;

	pg1 = container_of(entry, const struct packed_git, packmap_ent);
	pg2 = container_of(entry2, const struct packed_git, packmap_ent);

	return strcmp(pg1->pack_name, key ? key : pg2->pack_name);
	}

	struct raw_object_store {
	/*
	* Set of all object directories; the main directory is first (and
	* cannot be NULL after initialization). Subsequent directories are
	* alternates.
	*/
	struct object_directory *odb;
	struct object_directory **odb_tail;
	int loaded_alternates;

	/*
	* A list of alternate object directories loaded from the environment;
	* this should not generally need to be accessed directly, but will
	* populate the "odb" list when prepare_alt_odb() is run.
	*/
	char *alternate_db;

	/*
	* Objects that should be substituted by other objects
	* (see git-replace(1)).
	*/
	struct oidmap *replace_map;
	unsigned replace_map_initialized : 1;
	pthread_mutex_t replace_mutex; /* protect object replace functions */

	struct commit_graph *commit_graph;
	unsigned commit_graph_attempted : 1; /* if loading has been attempted */

	/*
	* private data
	*
	* should only be accessed directly by packfile.c and midx.c
	*/
	struct multi_pack_index *multi_pack_index;

	/*
	* private data
	*
	* should only be accessed directly by packfile.c
	*/

	struct packed_git *packed_git;
	/* A most-recently-used ordered version of the packed_git list. */
	struct list_head packed_git_mru;

	struct {
	struct packed_git **packs;
	unsigned flags;
	} kept_pack_cache;

	/*
	* A map of packfiles to packed_git structs for tracking which
	* packs have been loaded already.
	*/
	struct hashmap pack_map;

	/*
	* A fast, rough count of the number of objects in the repository.
	* These two fields are not meant for direct access. Use
	* approximate_object_count() instead.
	*/
	unsigned long approximate_object_count;
	unsigned approximate_object_count_valid : 1;

	/*
	* Whether packed_git has already been populated with this repository's
	* packs.
	*/
	unsigned packed_git_initialized : 1;
	};

	struct raw_object_store *raw_object_store_new(void);
	void raw_object_store_clear(struct raw_object_store *o);

	/*
	* Put in `buf` the name of the file in the local object database that
	* would be used to store a loose object with the specified oid.
	*/
	const char loose_object_path(struct repository r, struct strbuf *buf,
	const struct object_id *oid);

	void map_loose_object(struct repository r, const struct object_id *oid,
	unsigned long *size);

	void read_object_file_extended(struct repository r,
	const struct object_id *oid,
	enum object_type *type,
	unsigned long *size, int lookup_replace);
	static inline void repo_read_object_file(struct repository r,
	const struct object_id *oid,
	enum object_type *type,
	unsigned long *size)
	{
	return read_object_file_extended(r, oid, type, size, 1);
	}
	#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
	#define read_object_file(oid, type, size) repo_read_object_file(the_repository, oid, type, size)
	#endif

	/* Read and unpack an object file into memory, write memory to an object file */
	int oid_object_info(struct repository r, const struct object_id , unsigned long *);

	int hash_object_file(const struct git_hash_algo algo, const void buf,
	unsigned long len, const char *type,
	struct object_id *oid);

	int write_object_file(const void *buf, unsigned long len,
	const char type, struct object_id oid);

	int hash_object_file_literally(const void *buf, unsigned long len,
	const char type, struct object_id oid,
	unsigned flags);

	/*
	* Add an object file to the in-memory object store, without writing it
	* to disk.
	*
	* Callers are responsible for calling write_object_file to record the
	* object in persistent storage before writing any other new objects
	* that reference it.
	*/
	int pretend_object_file(void *, unsigned long, enum object_type,
	struct object_id *oid);

	int force_object_loose(const struct object_id *oid, time_t mtime);

	/*
	* Open the loose object at path, check its hash, and return the contents,
	* type, and size. If the object is a blob, then "contents" may return NULL,
	* to allow streaming of large blobs.
	*
	* Returns 0 on success, negative on error (details may be written to stderr).
	*/
	int read_loose_object(const char *path,
	const struct object_id *expected_oid,
	enum object_type *type,
	unsigned long *size,
	void **contents);

	/* Retry packed storage after checking packed and loose storage */
	#define HAS_OBJECT_RECHECK_PACKED 1

	/*
	* Returns 1 if the object exists. This function will not lazily fetch objects
	* in a partial clone.
	*/
	int has_object(struct repository r, const struct object_id oid,
	unsigned flags);

	/*
	* These macros and functions are deprecated. If checking existence for an
	* object that is likely to be missing and/or whose absence is relatively
	* inconsequential (or is consequential but the caller is prepared to handle
	* it), use has_object(), which has better defaults (no lazy fetch in a partial
	* clone and no rechecking of packed storage). In the unlikely event that a
	* caller needs to assert existence of an object that it fully expects to
	* exist, and wants to trigger a lazy fetch in a partial clone, use
	* oid_object_info_extended() with a NULL struct object_info.
	*
	* These functions can be removed once all callers have migrated to
	* has_object() and/or oid_object_info_extended().
	*/
	#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
	#define has_sha1_file_with_flags(sha1, flags) repo_has_sha1_file_with_flags(the_repository, sha1, flags)
	#define has_sha1_file(sha1) repo_has_sha1_file(the_repository, sha1)
	#endif
	int repo_has_object_file(struct repository r, const struct object_id oid);
	int repo_has_object_file_with_flags(struct repository *r,
	const struct object_id *oid, int flags);
	#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
	#define has_object_file(oid) repo_has_object_file(the_repository, oid)
	#define has_object_file_with_flags(oid, flags) repo_has_object_file_with_flags(the_repository, oid, flags)
	#endif

	/*
	* Return true iff an alternate object database has a loose object
	* with the specified name. This function does not respect replace
	* references.
	*/
	int has_loose_object_nonlocal(const struct object_id *);

	void assert_oid_type(const struct object_id *oid, enum object_type expect);

	/*
	* Enabling the object read lock allows multiple threads to safely call the
	* following functions in parallel: repo_read_object_file(), read_object_file(),
	* read_object_file_extended(), read_object_with_reference(), read_object(),
	* oid_object_info() and oid_object_info_extended().
	*
	* obj_read_lock() and obj_read_unlock() may also be used to protect other
	* section which cannot execute in parallel with object reading. Since the used
	* lock is a recursive mutex, these sections can even contain calls to object
	* reading functions. However, beware that in these cases zlib inflation won't
	* be performed in parallel, losing performance.
	*
	* TODO: oid_object_info_extended()'s call stack has a recursive behavior. If
	* any of its callees end up calling it, this recursive call won't benefit from
	* parallel inflation.
	*/
	void enable_obj_read_lock(void);
	void disable_obj_read_lock(void);

	extern int obj_read_use_lock;
	extern pthread_mutex_t obj_read_mutex;

	static inline void obj_read_lock(void)
	{
	if(obj_read_use_lock)
	pthread_mutex_lock(&obj_read_mutex);
	}

	static inline void obj_read_unlock(void)
	{
	if(obj_read_use_lock)
	pthread_mutex_unlock(&obj_read_mutex);
	}

	struct object_info {
	/* Request */
	enum object_type *typep;
	unsigned long *sizep;
	off_t *disk_sizep;
	struct object_id *delta_base_oid;
	struct strbuf *type_name;
	void **contentp;

	/* Response */
	enum {
	OI_CACHED,
	OI_LOOSE,
	OI_PACKED,
	OI_DBCACHED
	} whence;
	union {
	/*
	* struct {
	* ... Nothing to expose in this case
	* } cached;
	* struct {
	* ... Nothing to expose in this case
	* } loose;
	*/
	struct {
	struct packed_git *pack;
	off_t offset;
	unsigned int is_delta;
	} packed;
	} u;
	};

	/*
	* Initializer for a "struct object_info" that wants no items. You may
	* also memset() the memory to all-zeroes.
	*/
	#define OBJECT_INFO_INIT {NULL}

	/* Invoke lookup_replace_object() on the given hash */
	#define OBJECT_INFO_LOOKUP_REPLACE 1
	/* Allow reading from a loose object file of unknown/bogus type */
	#define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
	/* Do not retry packed storage after checking packed and loose storage */
	#define OBJECT_INFO_QUICK 8
	/* Do not check loose object */
	#define OBJECT_INFO_IGNORE_LOOSE 16
	/*
	* Do not attempt to fetch the object if missing (even if fetch_is_missing is
	* nonzero).
	*/
	#define OBJECT_INFO_SKIP_FETCH_OBJECT 32
	/*
	* This is meant for bulk prefetching of missing blobs in a partial
	* clone. Implies OBJECT_INFO_SKIP_FETCH_OBJECT and OBJECT_INFO_QUICK
	*/
	#define OBJECT_INFO_FOR_PREFETCH (OBJECT_INFO_SKIP_FETCH_OBJECT \| OBJECT_INFO_QUICK)

	int oid_object_info_extended(struct repository *r,
	const struct object_id *,
	struct object_info *, unsigned flags);

	/*
	* Iterate over the files in the loose-object parts of the object
	* directory "path", triggering the following callbacks:
	*
	* - loose_object is called for each loose object we find.
	*
	* - loose_cruft is called for any files that do not appear to be
	* loose objects. Note that we only look in the loose object
	* directories "objects/[0-9a-f]{2}/", so we will not report
	* "objects/foobar" as cruft.
	*
	* - loose_subdir is called for each top-level hashed subdirectory
	* of the object directory (e.g., "$OBJDIR/f0"). It is called
	* after the objects in the directory are processed.
	*
	* Any callback that is NULL will be ignored. Callbacks returning non-zero
	* will end the iteration.
	*
	* In the "buf" variant, "path" is a strbuf which will also be used as a
	* scratch buffer, but restored to its original contents before
	* the function returns.
	*/
	typedef int each_loose_object_fn(const struct object_id *oid,
	const char *path,
	void *data);
	typedef int each_loose_cruft_fn(const char *basename,
	const char *path,
	void *data);
	typedef int each_loose_subdir_fn(unsigned int nr,
	const char *path,
	void *data);
	int for_each_file_in_obj_subdir(unsigned int subdir_nr,
	struct strbuf *path,
	each_loose_object_fn obj_cb,
	each_loose_cruft_fn cruft_cb,
	each_loose_subdir_fn subdir_cb,
	void *data);
	int for_each_loose_file_in_objdir(const char *path,
	each_loose_object_fn obj_cb,
	each_loose_cruft_fn cruft_cb,
	each_loose_subdir_fn subdir_cb,
	void *data);
	int for_each_loose_file_in_objdir_buf(struct strbuf *path,
	each_loose_object_fn obj_cb,
	each_loose_cruft_fn cruft_cb,
	each_loose_subdir_fn subdir_cb,
	void *data);

	/* Flags for for_each__object() below. /
	enum for_each_object_flags {
	/* Iterate only over local objects, not alternates. */
	FOR_EACH_OBJECT_LOCAL_ONLY = (1<<0),

	/* Only iterate over packs obtained from the promisor remote. */
	FOR_EACH_OBJECT_PROMISOR_ONLY = (1<<1),

	/*
	* Visit objects within a pack in packfile order rather than .idx order
	*/
	FOR_EACH_OBJECT_PACK_ORDER = (1<<2),
	};

	/*
	* Iterate over all accessible loose objects without respect to
	* reachability. By default, this includes both local and alternate objects.
	* The order in which objects are visited is unspecified.
	*
	* Any flags specific to packs are ignored.
	*/
	int for_each_loose_object(each_loose_object_fn, void *,
	enum for_each_object_flags flags);

	/*
	* Iterate over all accessible packed objects without respect to reachability.
	* By default, this includes both local and alternate packs.
	*
	* Note that some objects may appear twice if they are found in multiple packs.
	* Each pack is visited in an unspecified order. By default, objects within a
	* pack are visited in pack-idx order (i.e., sorted by oid).
	*/
	typedef int each_packed_object_fn(const struct object_id *oid,
	struct packed_git *pack,
	uint32_t pos,
	void *data);
	int for_each_object_in_pack(struct packed_git *p,
	each_packed_object_fn, void *data,
	enum for_each_object_flags flags);
	int for_each_packed_object(each_packed_object_fn, void *,
	enum for_each_object_flags flags);

	#endif /* OBJECT_STORE_H */

Jun	JUL	Aug
	18
2020	2021	2022

git / git

git/object-store.h