packfile.h - jrn/git - Git at Google

 #ifndef PACKFILE_H
 #define PACKFILE_H

 #include "cache.h"
 #include "oidset.h"

 /* in object-store.h */
 struct packed_git;
 struct object_info;

 /*
  * Generate the filename to be used for a pack file with checksum "sha1" and
  * extension "ext". The result is written into the strbuf "buf", overwriting
  * any existing contents. A pointer to buf->buf is returned as a convenience.
  *
  * Example: odb_pack_name(out, sha1, "idx") => ".git/objects/pack/pack-1234..idx"
  */
 char *odb_pack_name(struct strbuf *buf, const unsigned char *sha1, const char *ext);

 /*
  * Return the name of the (local) packfile with the specified sha1 in
  * its name.  The return value is a pointer to memory that is
  * overwritten each time this function is called.
  */
 char *sha1_pack_name(const unsigned char *sha1);

 /*
  * Return the name of the (local) pack index file with the specified
  * sha1 in its name.  The return value is a pointer to memory that is
  * overwritten each time this function is called.
  */
 char *sha1_pack_index_name(const unsigned char *sha1);

 /*
  * Return the basename of the packfile, omitting any containing directory
  * (e.g., "pack-1234abcd[...].pack").
  */
 const char *pack_basename(struct packed_git *p);

 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);

 typedef void each_file_in_pack_dir_fn(const char *full_path, size_t full_path_len,
 				      const char *file_pach, void *data);
 void for_each_file_in_pack_dir(const char *objdir,
 			       each_file_in_pack_dir_fn fn,
 			       void *data);

 /* A hook to report invalid files in pack directory */
 #define PACKDIR_FILE_PACK 1
 #define PACKDIR_FILE_IDX 2
 #define PACKDIR_FILE_GARBAGE 4
 extern void (*report_garbage)(unsigned seen_bits, const char *path);

 void reprepare_packed_git(struct repository *r);
 void install_packed_git(struct repository *r, struct packed_git *pack);

 struct packed_git *get_packed_git(struct repository *r);
 struct list_head *get_packed_git_mru(struct repository *r);
 struct multi_pack_index *get_multi_pack_index(struct repository *r);
 struct multi_pack_index *get_local_multi_pack_index(struct repository *r);
 struct packed_git *get_all_packs(struct repository *r);

 /*
  * Give a rough count of objects in the repository. This sacrifices accuracy
  * for speed.
  */
 unsigned long repo_approximate_object_count(struct repository *r);
 #define approximate_object_count() repo_approximate_object_count(the_repository)

 struct packed_git *find_sha1_pack(const unsigned char *sha1,
 				  struct packed_git *packs);

 void pack_report(void);

 /*
  * mmap the index file for the specified packfile (if it is not
  * already mmapped).  Return 0 on success.
  */
 int open_pack_index(struct packed_git *);

 /*
  * munmap the index file for the specified packfile (if it is
  * currently mmapped).
  */
 void close_pack_index(struct packed_git *);

 int close_pack_fd(struct packed_git *p);

 uint32_t get_pack_fanout(struct packed_git *p, uint32_t value);

 unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
 void close_pack_windows(struct packed_git *);
 void close_pack(struct packed_git *);
 void close_object_store(struct raw_object_store *o);
 void unuse_pack(struct pack_window **);
 void clear_delta_base_cache(void);
 struct packed_git *add_packed_git(const char *path, size_t path_len, int local);

 /*
  * Unlink the .pack and associated extension files.
  * Does not unlink if 'force_delete' is false and the pack-file is
  * marked as ".keep".
  */
 void unlink_pack_path(const char *pack_name, int force_delete);

 /*
  * Make sure that a pointer access into an mmap'd index file is within bounds,
  * and can provide at least 8 bytes of data.
  *
  * Note that this is only necessary for variable-length segments of the file
  * (like the 64-bit extended offset table), as we compare the size to the
  * fixed-length parts when we open the file.
  */
 void check_pack_index_ptr(const struct packed_git *p, const void *ptr);

 /*
  * Perform binary search on a pack-index for a given oid. Packfile is expected to
  * have a valid pack-index.
  *
  * See 'bsearch_hash' for more information.
  */
 int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result);

 /*
  * Write the oid of the nth object within the specified packfile into the first
  * parameter. Open the index if it is not already open.  Returns 0 on success,
  * negative otherwise.
  */
 int nth_packed_object_id(struct object_id *, struct packed_git *, uint32_t n);

 /*
  * Return the offset of the nth object within the specified packfile.
  * The index must already be opened.
  */
 off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);

 /*
  * If the object named sha1 is present in the specified packfile,
  * return its offset within the packfile; otherwise, return 0.
  */
 off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *);

 int is_pack_valid(struct packed_git *);
 void *unpack_entry(struct repository *r, struct packed_git *, off_t, enum object_type *, unsigned long *);
 unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
 unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
 int unpack_object_header(struct packed_git *, struct pack_window **, off_t *, unsigned long *);
 off_t get_delta_base(struct packed_git *p, struct pack_window **w_curs,
 		     off_t *curpos, enum object_type type,
 		     off_t delta_obj_offset);

 void release_pack_memory(size_t);

 /* global flag to enable extra checks when accessing packed objects */
 extern int do_check_packed_object_crc;

 int packed_object_info(struct repository *r,
 		       struct packed_git *pack,
 		       off_t offset, struct object_info *);

 void mark_bad_packed_object(struct packed_git *, const struct object_id *);
 const struct packed_git *has_packed_and_bad(struct repository *, const struct object_id *);

 #define ON_DISK_KEEP_PACKS 1
 #define IN_CORE_KEEP_PACKS 2

 /*
  * Iff a pack file in the given repository contains the object named by sha1,
  * return true and store its location to e.
  */
 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e);
 int find_kept_pack_entry(struct repository *r, const struct object_id *oid, unsigned flags, struct pack_entry *e);

 int has_object_pack(const struct object_id *oid);
 int has_object_kept_pack(const struct object_id *oid, unsigned flags);

 int has_pack_index(const unsigned char *sha1);

 /*
  * Return 1 if an object in a promisor packfile is or refers to the given
  * object, 0 otherwise.
  */
 int is_promisor_object(const struct object_id *oid);

 /*
  * Expose a function for fuzz testing.
  *
  * load_idx() parses a block of memory as a packfile index and puts the results
  * into a struct packed_git.
  *
  * This function should not be used directly. It is exposed here only so that we
  * have a convenient entry-point for fuzz testing. For real uses, you should
  * probably use open_pack_index() or parse_pack_index() instead.
  */
 int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 	     size_t idx_size, struct packed_git *p);

 #endif
	#ifndef PACKFILE_H
	#define PACKFILE_H

	#include "cache.h"
	#include "oidset.h"

	/* in object-store.h */
	struct packed_git;
	struct object_info;

	/*
	* Generate the filename to be used for a pack file with checksum "sha1" and
	* extension "ext". The result is written into the strbuf "buf", overwriting
	* any existing contents. A pointer to buf->buf is returned as a convenience.
	*
	* Example: odb_pack_name(out, sha1, "idx") => ".git/objects/pack/pack-1234..idx"
	*/
	char odb_pack_name(struct strbuf buf, const unsigned char sha1, const char ext);

	/*
	* Return the name of the (local) packfile with the specified sha1 in
	* its name. The return value is a pointer to memory that is
	* overwritten each time this function is called.
	*/
	char sha1_pack_name(const unsigned char sha1);

	/*
	* Return the name of the (local) pack index file with the specified
	* sha1 in its name. The return value is a pointer to memory that is
	* overwritten each time this function is called.
	*/
	char sha1_pack_index_name(const unsigned char sha1);

	/*
	* Return the basename of the packfile, omitting any containing directory
	* (e.g., "pack-1234abcd[...].pack").
	*/
	const char pack_basename(struct packed_git p);

	struct packed_git parse_pack_index(unsigned char sha1, const char *idx_path);

	typedef void each_file_in_pack_dir_fn(const char *full_path, size_t full_path_len,
	const char file_pach, void data);
	void for_each_file_in_pack_dir(const char *objdir,
	each_file_in_pack_dir_fn fn,
	void *data);

	/* A hook to report invalid files in pack directory */
	#define PACKDIR_FILE_PACK 1
	#define PACKDIR_FILE_IDX 2
	#define PACKDIR_FILE_GARBAGE 4
	extern void (report_garbage)(unsigned seen_bits, const char path);

	void reprepare_packed_git(struct repository *r);
	void install_packed_git(struct repository r, struct packed_git pack);

	struct packed_git get_packed_git(struct repository r);
	struct list_head get_packed_git_mru(struct repository r);
	struct multi_pack_index get_multi_pack_index(struct repository r);
	struct multi_pack_index get_local_multi_pack_index(struct repository r);
	struct packed_git get_all_packs(struct repository r);

	/*
	* Give a rough count of objects in the repository. This sacrifices accuracy
	* for speed.
	*/
	unsigned long repo_approximate_object_count(struct repository *r);
	#define approximate_object_count() repo_approximate_object_count(the_repository)

	struct packed_git find_sha1_pack(const unsigned char sha1,
	struct packed_git *packs);

	void pack_report(void);

	/*
	* mmap the index file for the specified packfile (if it is not
	* already mmapped). Return 0 on success.
	*/
	int open_pack_index(struct packed_git *);

	/*
	* munmap the index file for the specified packfile (if it is
	* currently mmapped).
	*/
	void close_pack_index(struct packed_git *);

	int close_pack_fd(struct packed_git *p);

	uint32_t get_pack_fanout(struct packed_git *p, uint32_t value);

	unsigned char use_pack(struct packed_git , struct pack_window *, off_t, unsigned long );
	void close_pack_windows(struct packed_git *);
	void close_pack(struct packed_git *);
	void close_object_store(struct raw_object_store *o);
	void unuse_pack(struct pack_window **);
	void clear_delta_base_cache(void);
	struct packed_git add_packed_git(const char path, size_t path_len, int local);

	/*
	* Unlink the .pack and associated extension files.
	* Does not unlink if 'force_delete' is false and the pack-file is
	* marked as ".keep".
	*/
	void unlink_pack_path(const char *pack_name, int force_delete);

	/*
	* Make sure that a pointer access into an mmap'd index file is within bounds,
	* and can provide at least 8 bytes of data.
	*
	* Note that this is only necessary for variable-length segments of the file
	* (like the 64-bit extended offset table), as we compare the size to the
	* fixed-length parts when we open the file.
	*/
	void check_pack_index_ptr(const struct packed_git p, const void ptr);

	/*
	* Perform binary search on a pack-index for a given oid. Packfile is expected to
	* have a valid pack-index.
	*
	* See 'bsearch_hash' for more information.
	*/
	int bsearch_pack(const struct object_id oid, const struct packed_git p, uint32_t *result);

	/*
	* Write the oid of the nth object within the specified packfile into the first
	* parameter. Open the index if it is not already open. Returns 0 on success,
	* negative otherwise.
	*/
	int nth_packed_object_id(struct object_id , struct packed_git , uint32_t n);

	/*
	* Return the offset of the nth object within the specified packfile.
	* The index must already be opened.
	*/
	off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);

	/*
	* If the object named sha1 is present in the specified packfile,
	* return its offset within the packfile; otherwise, return 0.
	*/
	off_t find_pack_entry_one(const unsigned char sha1, struct packed_git );

	int is_pack_valid(struct packed_git *);
	void unpack_entry(struct repository r, struct packed_git , off_t, enum object_type , unsigned long *);
	unsigned long unpack_object_header_buffer(const unsigned char buf, unsigned long len, enum object_type type, unsigned long *sizep);
	unsigned long get_size_from_delta(struct packed_git , struct pack_window *, off_t);
	int unpack_object_header(struct packed_git , struct pack_window , off_t , unsigned long *);
	off_t get_delta_base(struct packed_git p, struct pack_window *w_curs,
	off_t *curpos, enum object_type type,
	off_t delta_obj_offset);

	void release_pack_memory(size_t);

	/* global flag to enable extra checks when accessing packed objects */
	extern int do_check_packed_object_crc;

	int packed_object_info(struct repository *r,
	struct packed_git *pack,
	off_t offset, struct object_info *);

	void mark_bad_packed_object(struct packed_git , const struct object_id );
	const struct packed_git has_packed_and_bad(struct repository , const struct object_id *);

	#define ON_DISK_KEEP_PACKS 1
	#define IN_CORE_KEEP_PACKS 2

	/*
	* Iff a pack file in the given repository contains the object named by sha1,
	* return true and store its location to e.
	*/
	int find_pack_entry(struct repository r, const struct object_id oid, struct pack_entry *e);
	int find_kept_pack_entry(struct repository r, const struct object_id oid, unsigned flags, struct pack_entry *e);

	int has_object_pack(const struct object_id *oid);
	int has_object_kept_pack(const struct object_id *oid, unsigned flags);

	int has_pack_index(const unsigned char *sha1);

	/*
	* Return 1 if an object in a promisor packfile is or refers to the given
	* object, 0 otherwise.
	*/
	int is_promisor_object(const struct object_id *oid);

	/*
	* Expose a function for fuzz testing.
	*
	* load_idx() parses a block of memory as a packfile index and puts the results
	* into a struct packed_git.
	*
	* This function should not be used directly. It is exposed here only so that we
	* have a convenient entry-point for fuzz testing. For real uses, you should
	* probably use open_pack_index() or parse_pack_index() instead.
	*/
	int load_idx(const char path, const unsigned int hashsz, void idx_map,
	size_t idx_size, struct packed_git *p);

	#endif