git/object-store-ll.h

#ifndef OBJECT_STORE_LL_H
#define OBJECT_STORE_LL_H

#include "hashmap.h"
#include "object.h"
#include "list.h"
#include "thread-utils.h"
#include "oidset.h"

struct oidmap;
struct oidtree;
struct strbuf;

struct object_directory { … };

struct input_stream { … };

void prepare_alt_odb(struct repository *r);
int has_alt_odb(struct repository *r);
char *compute_alternate_path(const char *path, struct strbuf *err);
struct object_directory *find_odb(struct repository *r, const char *obj_dir);
alt_odb_fn;
int foreach_alt_odb(alt_odb_fn, void*);
alternate_ref_fn;
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);

/*
 * Replace the current writable object directory with the specified temporary
 * object directory; returns the former primary object directory.
 */
struct object_directory *set_temporary_primary_odb(const char *dir, int will_destroy);

/*
 * Restore a previous ODB replaced by set_temporary_main_odb.
 */
void restore_primary_odb(struct object_directory *restore_odb, const char *old_path);

/*
 * Populate and return the loose object cache array corresponding to the
 * given object ID.
 */
struct oidtree *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);

/* Clear and free the specified object directory */
void free_object_directory(struct object_directory *odb);

struct packed_git { … };

struct multi_pack_index;

static inline int pack_map_entry_cmp(const void *cmp_data UNUSED,
				     const struct hashmap_entry *entry,
				     const struct hashmap_entry *entry2,
				     const void *keydata)
{ … }

struct raw_object_store { … };

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

/*
 * Create a temporary file rooted in the object database directory, or
 * die on failure. The filename is taken from "pattern", which should have the
 * usual "XXXXXX" trailer, and the resulting filename is written into the
 * "template" buffer. Returns the open descriptor.
 */
int odb_mkstemp(struct strbuf *temp_filename, const char *pattern);

/*
 * Create a pack .keep file named "name" (which should generally be the output
 * of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
 * error.
 */
int odb_pack_keep(const char *name);

/*
 * 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 *repo_read_object_file(struct repository *r,
			    const struct object_id *oid,
			    enum object_type *type,
			    unsigned long *size);

/* 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 *);

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

int write_object_file_flags(const void *buf, unsigned long len,
			    enum object_type type, struct object_id *oid,
			    struct object_id *comapt_oid_in, unsigned flags);
static inline int write_object_file(const void *buf, unsigned long len,
				    enum object_type type, struct object_id *oid)
{ … }

int write_object_file_literally(const void *buf, unsigned long len,
				const char *type, struct object_id *oid,
				unsigned flags);
int stream_loose_object(struct input_stream *in_stream, size_t len,
			struct object_id *oid);

/*
 * 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);

struct object_info { … };

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

/* Invoke lookup_replace_object() on the given hash */
#define OBJECT_INFO_LOOKUP_REPLACE …
/* Allow reading from a loose object file of unknown/bogus type */
#define OBJECT_INFO_ALLOW_UNKNOWN_TYPE …
/* Do not retry packed storage after checking packed and loose storage */
#define OBJECT_INFO_QUICK …
/*
 * Do not attempt to fetch the object if missing (even if fetch_is_missing is
 * nonzero).
 */
#define OBJECT_INFO_SKIP_FETCH_OBJECT …
/*
 * 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 …

/* Die if object corruption (not just an object being missing) was detected. */
#define OBJECT_INFO_DIE_IF_CORRUPT …

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

/*
 * Open the loose object at path, check its hash, and return the contents,
 * use the "oi" argument to assert things about the object, or e.g. populate its
 * 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,
		      struct object_id *real_oid,
		      void **contents,
		      struct object_info *oi);

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

/*
 * 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().
 */
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);

/*
 * 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 *);

int has_loose_object(const struct object_id *);

/**
 * format_object_header() is a thin wrapper around s xsnprintf() that
 * writes the initial "<type> <obj-len>" part of the loose object
 * header. It returns the size that snprintf() returns + 1.
 */
int format_object_header(char *str, size_t size, enum object_type type,
			 size_t objsize);

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_with_reference(), 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)
{ … }

static inline void obj_read_unlock(void)
{ … }

/*
 * 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.
 */
each_loose_object_fn;
each_loose_cruft_fn;
each_loose_subdir_fn;
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 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).
 */
each_packed_object_fn;
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_LL_H */