[thirdparty/git.git] / hash.h

#ifndef HASH_H
#define HASH_H

#include "repository.h"

#if defined(SHA1_APPLE)
#include <CommonCrypto/CommonDigest.h>
#elif defined(SHA1_OPENSSL)
#include <openssl/sha.h>
#elif defined(SHA1_DC)
#include "sha1dc_git.h"
#else /* SHA1_BLK */
#include "block-sha1/sha1.h"
#endif

#if defined(SHA256_NETTLE)
#include "sha256/nettle.h"
#elif defined(SHA256_GCRYPT)
#define SHA256_NEEDS_CLONE_HELPER
#include "sha256/gcrypt.h"
#elif defined(SHA256_OPENSSL)
#include <openssl/sha.h>
#else
#include "sha256/block/sha256.h"
#endif

#ifndef platform_SHA_CTX
/*
 * platform's underlying implementation of SHA-1; could be OpenSSL,
 * blk_SHA, Apple CommonCrypto, etc...  Note that the relevant
 * SHA-1 header may have already defined platform_SHA_CTX for our
 * own implementations like block-sha1, so we list
 * the default for OpenSSL compatible SHA-1 implementations here.
 */
#define platform_SHA_CTX	SHA_CTX
#define platform_SHA1_Init	SHA1_Init
#define platform_SHA1_Update	SHA1_Update
#define platform_SHA1_Final    	SHA1_Final
#endif

#define git_SHA_CTX		platform_SHA_CTX
#define git_SHA1_Init		platform_SHA1_Init
#define git_SHA1_Update		platform_SHA1_Update
#define git_SHA1_Final		platform_SHA1_Final

#ifndef platform_SHA256_CTX
#define platform_SHA256_CTX	SHA256_CTX
#define platform_SHA256_Init	SHA256_Init
#define platform_SHA256_Update	SHA256_Update
#define platform_SHA256_Final	SHA256_Final
#endif

#define git_SHA256_CTX		platform_SHA256_CTX
#define git_SHA256_Init		platform_SHA256_Init
#define git_SHA256_Update	platform_SHA256_Update
#define git_SHA256_Final	platform_SHA256_Final

#ifdef platform_SHA256_Clone
#define git_SHA256_Clone	platform_SHA256_Clone
#endif

#ifdef SHA1_MAX_BLOCK_SIZE
#include "compat/sha1-chunked.h"
#undef git_SHA1_Update
#define git_SHA1_Update		git_SHA1_Update_Chunked
#endif

static inline void git_SHA1_Clone(git_SHA_CTX *dst, const git_SHA_CTX *src)
{
	memcpy(dst, src, sizeof(*dst));
}

#ifndef SHA256_NEEDS_CLONE_HELPER
static inline void git_SHA256_Clone(git_SHA256_CTX *dst, const git_SHA256_CTX *src)
{
	memcpy(dst, src, sizeof(*dst));
}
#endif

/*
 * Note that these constants are suitable for indexing the hash_algos array and
 * comparing against each other, but are otherwise arbitrary, so they should not
 * be exposed to the user or serialized to disk.  To know whether a
 * git_hash_algo struct points to some usable hash function, test the format_id
 * field for being non-zero.  Use the name field for user-visible situations and
 * the format_id field for fixed-length fields on disk.
 */
/* An unknown hash function. */
#define GIT_HASH_UNKNOWN 0
/* SHA-1 */
#define GIT_HASH_SHA1 1
/* SHA-256  */
#define GIT_HASH_SHA256 2
/* Number of algorithms supported (including unknown). */
#define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1)

/* "sha1", big-endian */
#define GIT_SHA1_FORMAT_ID 0x73686131

/* The length in bytes and in hex digits of an object name (SHA-1 value). */
#define GIT_SHA1_RAWSZ 20
#define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
/* The block size of SHA-1. */
#define GIT_SHA1_BLKSZ 64

/* "s256", big-endian */
#define GIT_SHA256_FORMAT_ID 0x73323536

/* The length in bytes and in hex digits of an object name (SHA-256 value). */
#define GIT_SHA256_RAWSZ 32
#define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ)
/* The block size of SHA-256. */
#define GIT_SHA256_BLKSZ 64

/* The length in byte and in hex digits of the largest possible hash value. */
#define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ
#define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ
/* The largest possible block size for any supported hash. */
#define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ

struct object_id {
	unsigned char hash[GIT_MAX_RAWSZ];
	int algo;	/* XXX requires 4-byte alignment */
};

#define GET_OID_QUIETLY           01
#define GET_OID_COMMIT            02
#define GET_OID_COMMITTISH        04
#define GET_OID_TREE             010
#define GET_OID_TREEISH          020
#define GET_OID_BLOB             040
#define GET_OID_FOLLOW_SYMLINKS 0100
#define GET_OID_RECORD_PATH     0200
#define GET_OID_ONLY_TO_DIE    04000
#define GET_OID_REQUIRE_PATH  010000

#define GET_OID_DISAMBIGUATORS \
	(GET_OID_COMMIT | GET_OID_COMMITTISH | \
	GET_OID_TREE | GET_OID_TREEISH | \
	GET_OID_BLOB)

enum get_oid_result {
	FOUND = 0,
	MISSING_OBJECT = -1, /* The requested object is missing */
	SHORT_NAME_AMBIGUOUS = -2,
	/* The following only apply when symlinks are followed */
	DANGLING_SYMLINK = -4, /*
				* The initial symlink is there, but
				* (transitively) points to a missing
				* in-tree file
				*/
	SYMLINK_LOOP = -5,
	NOT_DIR = -6, /*
		       * Somewhere along the symlink chain, a path is
		       * requested which contains a file as a
		       * non-final element.
		       */
};

/* A suitably aligned type for stack allocations of hash contexts. */
union git_hash_ctx {
	git_SHA_CTX sha1;
	git_SHA256_CTX sha256;
};
typedef union git_hash_ctx git_hash_ctx;

typedef void (*git_hash_init_fn)(git_hash_ctx *ctx);
typedef void (*git_hash_clone_fn)(git_hash_ctx *dst, const git_hash_ctx *src);
typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len);
typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx);
typedef void (*git_hash_final_oid_fn)(struct object_id *oid, git_hash_ctx *ctx);

struct git_hash_algo {
	/*
	 * The name of the algorithm, as appears in the config file and in
	 * messages.
	 */
	const char *name;

	/* A four-byte version identifier, used in pack indices. */
	uint32_t format_id;

	/* The length of the hash in binary. */
	size_t rawsz;

	/* The length of the hash in hex characters. */
	size_t hexsz;

	/* The block size of the hash. */
	size_t blksz;

	/* The hash initialization function. */
	git_hash_init_fn init_fn;

	/* The hash context cloning function. */
	git_hash_clone_fn clone_fn;

	/* The hash update function. */
	git_hash_update_fn update_fn;

	/* The hash finalization function. */
	git_hash_final_fn final_fn;

	/* The hash finalization function for object IDs. */
	git_hash_final_oid_fn final_oid_fn;

	/* The OID of the empty tree. */
	const struct object_id *empty_tree;

	/* The OID of the empty blob. */
	const struct object_id *empty_blob;

	/* The all-zeros OID. */
	const struct object_id *null_oid;
};
extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS];

/*
 * Return a GIT_HASH_* constant based on the name.  Returns GIT_HASH_UNKNOWN if
 * the name doesn't match a known algorithm.
 */
int hash_algo_by_name(const char *name);
/* Identical, except based on the format ID. */
int hash_algo_by_id(uint32_t format_id);
/* Identical, except based on the length. */
int hash_algo_by_length(int len);
/* Identical, except for a pointer to struct git_hash_algo. */
static inline int hash_algo_by_ptr(const struct git_hash_algo *p)
{
	return p - hash_algos;
}

#define the_hash_algo the_repository->hash_algo

const struct object_id *null_oid(void);

static inline int hashcmp_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop)
{
	/*
	 * Teach the compiler that there are only two possibilities of hash size
	 * here, so that it can optimize for this case as much as possible.
	 */
	if (algop->rawsz == GIT_MAX_RAWSZ)
		return memcmp(sha1, sha2, GIT_MAX_RAWSZ);
	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
}

static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
{
	return hashcmp_algop(sha1, sha2, the_hash_algo);
}

static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
{
	const struct git_hash_algo *algop;
	if (!oid1->algo)
		algop = the_hash_algo;
	else
		algop = &hash_algos[oid1->algo];
	return hashcmp_algop(oid1->hash, oid2->hash, algop);
}

static inline int hasheq_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop)
{
	/*
	 * We write this here instead of deferring to hashcmp so that the
	 * compiler can properly inline it and avoid calling memcmp.
	 */
	if (algop->rawsz == GIT_MAX_RAWSZ)
		return !memcmp(sha1, sha2, GIT_MAX_RAWSZ);
	return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
}

static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2)
{
	return hasheq_algop(sha1, sha2, the_hash_algo);
}

static inline int oideq(const struct object_id *oid1, const struct object_id *oid2)
{
	const struct git_hash_algo *algop;
	if (!oid1->algo)
		algop = the_hash_algo;
	else
		algop = &hash_algos[oid1->algo];
	return hasheq_algop(oid1->hash, oid2->hash, algop);
}

static inline int is_null_oid(const struct object_id *oid)
{
	return oideq(oid, null_oid());
}

static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
{
	memcpy(sha_dst, sha_src, the_hash_algo->rawsz);
}

static inline void oidcpy(struct object_id *dst, const struct object_id *src)
{
	memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
	dst->algo = src->algo;
}

/* Like oidcpy() but zero-pads the unused bytes in dst's hash array. */
static inline void oidcpy_with_padding(struct object_id *dst,
				       const struct object_id *src)
{
	size_t hashsz;

	if (!src->algo)
		hashsz = the_hash_algo->rawsz;
	else
		hashsz = hash_algos[src->algo].rawsz;

	memcpy(dst->hash, src->hash, hashsz);
	memset(dst->hash + hashsz, 0, GIT_MAX_RAWSZ - hashsz);
	dst->algo = src->algo;
}

static inline struct object_id *oiddup(const struct object_id *src)
{
	struct object_id *dst = xmalloc(sizeof(struct object_id));
	oidcpy(dst, src);
	return dst;
}

static inline void hashclr(unsigned char *hash)
{
	memset(hash, 0, the_hash_algo->rawsz);
}

static inline void oidclr(struct object_id *oid)
{
	memset(oid->hash, 0, GIT_MAX_RAWSZ);
	oid->algo = hash_algo_by_ptr(the_hash_algo);
}

static inline void oidread(struct object_id *oid, const unsigned char *hash)
{
	memcpy(oid->hash, hash, the_hash_algo->rawsz);
	oid->algo = hash_algo_by_ptr(the_hash_algo);
}

static inline int is_empty_blob_sha1(const unsigned char *sha1)
{
	return hasheq(sha1, the_hash_algo->empty_blob->hash);
}

static inline int is_empty_blob_oid(const struct object_id *oid)
{
	return oideq(oid, the_hash_algo->empty_blob);
}

static inline int is_empty_tree_sha1(const unsigned char *sha1)
{
	return hasheq(sha1, the_hash_algo->empty_tree->hash);
}

static inline int is_empty_tree_oid(const struct object_id *oid)
{
	return oideq(oid, the_hash_algo->empty_tree);
}

static inline void oid_set_algo(struct object_id *oid, const struct git_hash_algo *algop)
{
	oid->algo = hash_algo_by_ptr(algop);
}

const char *empty_tree_oid_hex(void);
const char *empty_blob_oid_hex(void);

#endif
Commit	Line	Data
f18f816c	1	#ifndef HASH_H
	2	#define HASH_H
	3
3fa6f2aa	4	#include "repository.h"
f50e766b	5
9dc523aa	6	#if defined(SHA1_APPLE)
f18f816c	7	#include <CommonCrypto/CommonDigest.h>
	8	#elif defined(SHA1_OPENSSL)
	9	#include <openssl/sha.h>
8325e43b	10	#elif defined(SHA1_DC)
36f048c5	11	#include "sha1dc_git.h"
f18f816c	12	#else /* SHA1_BLK */
	13	#include "block-sha1/sha1.h"
	14	#endif
	15
e5557358	16	#if defined(SHA256_NETTLE)
	17	#include "sha256/nettle.h"
	18	#elif defined(SHA256_GCRYPT)
768e30ea	19	#define SHA256_NEEDS_CLONE_HELPER
27dc04c5	20	#include "sha256/gcrypt.h"
4b4e2918	21	#elif defined(SHA256_OPENSSL)
4b4e2918	22	#include <openssl/sha.h>
27dc04c5	23	#else
13eeedb5	24	#include "sha256/block/sha256.h"
27dc04c5	25	#endif
13eeedb5	26
164e7163	27	#ifndef platform_SHA_CTX
	28	/*
	29	* platform's underlying implementation of SHA-1; could be OpenSSL,
b212c0ca	30	* blk_SHA, Apple CommonCrypto, etc... Note that the relevant
b212c0ca	31	* SHA-1 header may have already defined platform_SHA_CTX for our
9dc523aa	32	* own implementations like block-sha1, so we list
164e7163	33	* the default for OpenSSL compatible SHA-1 implementations here.
	34	*/
	35	#define platform_SHA_CTX SHA_CTX
	36	#define platform_SHA1_Init SHA1_Init
	37	#define platform_SHA1_Update SHA1_Update
	38	#define platform_SHA1_Final SHA1_Final
	39	#endif
	40
	41	#define git_SHA_CTX platform_SHA_CTX
	42	#define git_SHA1_Init platform_SHA1_Init
	43	#define git_SHA1_Update platform_SHA1_Update
	44	#define git_SHA1_Final platform_SHA1_Final
	45
13eeedb5	46	#ifndef platform_SHA256_CTX
	47	#define platform_SHA256_CTX SHA256_CTX
	48	#define platform_SHA256_Init SHA256_Init
	49	#define platform_SHA256_Update SHA256_Update
	50	#define platform_SHA256_Final SHA256_Final
	51	#endif
	52
	53	#define git_SHA256_CTX platform_SHA256_CTX
	54	#define git_SHA256_Init platform_SHA256_Init
	55	#define git_SHA256_Update platform_SHA256_Update
	56	#define git_SHA256_Final platform_SHA256_Final
	57
768e30ea	58	#ifdef platform_SHA256_Clone
	59	#define git_SHA256_Clone platform_SHA256_Clone
	60	#endif
	61
164e7163	62	#ifdef SHA1_MAX_BLOCK_SIZE
	63	#include "compat/sha1-chunked.h"
	64	#undef git_SHA1_Update
	65	#define git_SHA1_Update git_SHA1_Update_Chunked
	66	#endif
	67
768e30ea	68	static inline void git_SHA1_Clone(git_SHA_CTX dst, const git_SHA_CTX src)
	69	{
	70	memcpy(dst, src, sizeof(*dst));
	71	}
	72
	73	#ifndef SHA256_NEEDS_CLONE_HELPER
	74	static inline void git_SHA256_Clone(git_SHA256_CTX dst, const git_SHA256_CTX src)
	75	{
	76	memcpy(dst, src, sizeof(*dst));
	77	}
	78	#endif
	79
f50e766b	80	/*
	81	* Note that these constants are suitable for indexing the hash_algos array and
	82	* comparing against each other, but are otherwise arbitrary, so they should not
	83	* be exposed to the user or serialized to disk. To know whether a
	84	* git_hash_algo struct points to some usable hash function, test the format_id
	85	* field for being non-zero. Use the name field for user-visible situations and
	86	* the format_id field for fixed-length fields on disk.
	87	*/
	88	/* An unknown hash function. */
	89	#define GIT_HASH_UNKNOWN 0
	90	/* SHA-1 */
	91	#define GIT_HASH_SHA1 1
13eeedb5	92	/* SHA-256 */
13eeedb5	93	#define GIT_HASH_SHA256 2
f50e766b	94	/* Number of algorithms supported (including unknown). */
13eeedb5	95	#define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1)
f50e766b	96
27f3796a HWN	97	/* "sha1", big-endian */
	98	#define GIT_SHA1_FORMAT_ID 0x73686131
	99
ab795f0d	100	/* The length in bytes and in hex digits of an object name (SHA-1 value). */
	101	#define GIT_SHA1_RAWSZ 20
	102	#define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
	103	/* The block size of SHA-1. */
	104	#define GIT_SHA1_BLKSZ 64
	105
27f3796a HWN	106	/* "s256", big-endian */
	107	#define GIT_SHA256_FORMAT_ID 0x73323536
	108
ab795f0d	109	/* The length in bytes and in hex digits of an object name (SHA-256 value). */
	110	#define GIT_SHA256_RAWSZ 32
	111	#define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ)
	112	/* The block size of SHA-256. */
	113	#define GIT_SHA256_BLKSZ 64
	114
	115	/* The length in byte and in hex digits of the largest possible hash value. */
	116	#define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ
	117	#define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ
	118	/* The largest possible block size for any supported hash. */
	119	#define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ
	120
	121	struct object_id {
	122	unsigned char hash[GIT_MAX_RAWSZ];
8bcda98d	123	int algo; /* XXX requires 4-byte alignment */
ab795f0d	124	};
ab795f0d	125
41227cb1 EN	126	#define GET_OID_QUIETLY 01
	127	#define GET_OID_COMMIT 02
	128	#define GET_OID_COMMITTISH 04
	129	#define GET_OID_TREE 010
	130	#define GET_OID_TREEISH 020
	131	#define GET_OID_BLOB 040
	132	#define GET_OID_FOLLOW_SYMLINKS 0100
	133	#define GET_OID_RECORD_PATH 0200
	134	#define GET_OID_ONLY_TO_DIE 04000
	135	#define GET_OID_REQUIRE_PATH 010000
	136
	137	#define GET_OID_DISAMBIGUATORS \
	138	(GET_OID_COMMIT \| GET_OID_COMMITTISH \| \
	139	GET_OID_TREE \| GET_OID_TREEISH \| \
	140	GET_OID_BLOB)
	141
	142	enum get_oid_result {
	143	FOUND = 0,
	144	MISSING_OBJECT = -1, /* The requested object is missing */
	145	SHORT_NAME_AMBIGUOUS = -2,
	146	/* The following only apply when symlinks are followed */
	147	DANGLING_SYMLINK = -4, /*
	148	* The initial symlink is there, but
	149	* (transitively) points to a missing
	150	* in-tree file
	151	*/
	152	SYMLINK_LOOP = -5,
	153	NOT_DIR = -6, /*
	154	* Somewhere along the symlink chain, a path is
	155	* requested which contains a file as a
	156	* non-final element.
	157	*/
	158	};
	159
ac73cedf	160	/* A suitably aligned type for stack allocations of hash contexts. */
	161	union git_hash_ctx {
	162	git_SHA_CTX sha1;
13eeedb5	163	git_SHA256_CTX sha256;
ac73cedf	164	};
	165	typedef union git_hash_ctx git_hash_ctx;
	166
	167	typedef void (git_hash_init_fn)(git_hash_ctx ctx);
768e30ea	168	typedef void (git_hash_clone_fn)(git_hash_ctx dst, const git_hash_ctx *src);
ac73cedf	169	typedef void (git_hash_update_fn)(git_hash_ctx ctx, const void *in, size_t len);
ac73cedf	170	typedef void (git_hash_final_fn)(unsigned char hash, git_hash_ctx *ctx);
ab795f0d	171	typedef void (git_hash_final_oid_fn)(struct object_id oid, git_hash_ctx *ctx);
f50e766b	172
	173	struct git_hash_algo {
	174	/*
	175	* The name of the algorithm, as appears in the config file and in
	176	* messages.
	177	*/
	178	const char *name;
	179
	180	/* A four-byte version identifier, used in pack indices. */
	181	uint32_t format_id;
	182
f50e766b	183	/* The length of the hash in binary. */
	184	size_t rawsz;
	185
	186	/* The length of the hash in hex characters. */
	187	size_t hexsz;
	188
a2ce0a75	189	/* The block size of the hash. */
	190	size_t blksz;
	191
f50e766b	192	/* The hash initialization function. */
	193	git_hash_init_fn init_fn;
	194
768e30ea	195	/* The hash context cloning function. */
	196	git_hash_clone_fn clone_fn;
	197
f50e766b	198	/* The hash update function. */
	199	git_hash_update_fn update_fn;
	200
	201	/* The hash finalization function. */
	202	git_hash_final_fn final_fn;
	203
ab795f0d	204	/* The hash finalization function for object IDs. */
	205	git_hash_final_oid_fn final_oid_fn;
	206
f50e766b	207	/* The OID of the empty tree. */
	208	const struct object_id *empty_tree;
	209
	210	/* The OID of the empty blob. */
	211	const struct object_id *empty_blob;
14228447	212
	213	/* The all-zeros OID. */
	214	const struct object_id *null_oid;
f50e766b	215	};
	216	extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS];
	217
2f90b9d9	218	/*
	219	* Return a GIT_HASH_* constant based on the name. Returns GIT_HASH_UNKNOWN if
	220	* the name doesn't match a known algorithm.
	221	*/
	222	int hash_algo_by_name(const char *name);
	223	/* Identical, except based on the format ID. */
	224	int hash_algo_by_id(uint32_t format_id);
95399788	225	/* Identical, except based on the length. */
95399788	226	int hash_algo_by_length(int len);
2f90b9d9	227	/* Identical, except for a pointer to struct git_hash_algo. */
	228	static inline int hash_algo_by_ptr(const struct git_hash_algo *p)
	229	{
	230	return p - hash_algos;
	231	}
	232
c0566d78 JK	233	#define the_hash_algo the_repository->hash_algo
c0566d78 JK	234
14228447	235	const struct object_id *null_oid(void);
3fa6f2aa	236
5a6dce70	237	static inline int hashcmp_algop(const unsigned char sha1, const unsigned char sha2, const struct git_hash_algo *algop)
3fa6f2aa JK	238	{
	239	/*
	240	* Teach the compiler that there are only two possibilities of hash size
	241	* here, so that it can optimize for this case as much as possible.
	242	*/
5a6dce70	243	if (algop->rawsz == GIT_MAX_RAWSZ)
3fa6f2aa JK	244	return memcmp(sha1, sha2, GIT_MAX_RAWSZ);
	245	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
	246	}
	247
5a6dce70	248	static inline int hashcmp(const unsigned char sha1, const unsigned char sha2)
	249	{
	250	return hashcmp_algop(sha1, sha2, the_hash_algo);
	251	}
	252
3fa6f2aa JK	253	static inline int oidcmp(const struct object_id oid1, const struct object_id oid2)
3fa6f2aa JK	254	{
5a6dce70	255	const struct git_hash_algo *algop;
	256	if (!oid1->algo)
	257	algop = the_hash_algo;
	258	else
	259	algop = &hash_algos[oid1->algo];
	260	return hashcmp_algop(oid1->hash, oid2->hash, algop);
3fa6f2aa JK	261	}
3fa6f2aa JK	262
5a6dce70	263	static inline int hasheq_algop(const unsigned char sha1, const unsigned char sha2, const struct git_hash_algo *algop)
3fa6f2aa JK	264	{
	265	/*
	266	* We write this here instead of deferring to hashcmp so that the
	267	* compiler can properly inline it and avoid calling memcmp.
	268	*/
5a6dce70	269	if (algop->rawsz == GIT_MAX_RAWSZ)
3fa6f2aa JK	270	return !memcmp(sha1, sha2, GIT_MAX_RAWSZ);
	271	return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
	272	}
	273
5a6dce70	274	static inline int hasheq(const unsigned char sha1, const unsigned char sha2)
	275	{
	276	return hasheq_algop(sha1, sha2, the_hash_algo);
	277	}
	278
3fa6f2aa JK	279	static inline int oideq(const struct object_id oid1, const struct object_id oid2)
3fa6f2aa JK	280	{
5a6dce70	281	const struct git_hash_algo *algop;
	282	if (!oid1->algo)
	283	algop = the_hash_algo;
	284	else
	285	algop = &hash_algos[oid1->algo];
	286	return hasheq_algop(oid1->hash, oid2->hash, algop);
3fa6f2aa JK	287	}
	288
	289	static inline int is_null_oid(const struct object_id *oid)
	290	{
14228447	291	return oideq(oid, null_oid());
3fa6f2aa JK	292	}
	293
	294	static inline void hashcpy(unsigned char sha_dst, const unsigned char sha_src)
	295	{
	296	memcpy(sha_dst, sha_src, the_hash_algo->rawsz);
	297	}
	298
	299	static inline void oidcpy(struct object_id dst, const struct object_id src)
	300	{
	301	memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
5a6dce70	302	dst->algo = src->algo;
3fa6f2aa JK	303	}
3fa6f2aa JK	304
3d20ed27 MT	305	/* Like oidcpy() but zero-pads the unused bytes in dst's hash array. */
3d20ed27 MT	306	static inline void oidcpy_with_padding(struct object_id *dst,
90e07f0a	307	const struct object_id *src)
3d20ed27 MT	308	{
	309	size_t hashsz;
	310
	311	if (!src->algo)
	312	hashsz = the_hash_algo->rawsz;
	313	else
	314	hashsz = hash_algos[src->algo].rawsz;
	315
	316	memcpy(dst->hash, src->hash, hashsz);
	317	memset(dst->hash + hashsz, 0, GIT_MAX_RAWSZ - hashsz);
	318	dst->algo = src->algo;
	319	}
	320
3fa6f2aa JK	321	static inline struct object_id oiddup(const struct object_id src)
	322	{
	323	struct object_id *dst = xmalloc(sizeof(struct object_id));
	324	oidcpy(dst, src);
	325	return dst;
	326	}
	327
	328	static inline void hashclr(unsigned char *hash)
	329	{
	330	memset(hash, 0, the_hash_algo->rawsz);
	331	}
	332
	333	static inline void oidclr(struct object_id *oid)
	334	{
	335	memset(oid->hash, 0, GIT_MAX_RAWSZ);
5a6dce70	336	oid->algo = hash_algo_by_ptr(the_hash_algo);
3fa6f2aa JK	337	}
	338
	339	static inline void oidread(struct object_id oid, const unsigned char hash)
	340	{
	341	memcpy(oid->hash, hash, the_hash_algo->rawsz);
5a6dce70	342	oid->algo = hash_algo_by_ptr(the_hash_algo);
3fa6f2aa JK	343	}
	344
	345	static inline int is_empty_blob_sha1(const unsigned char *sha1)
	346	{
	347	return hasheq(sha1, the_hash_algo->empty_blob->hash);
	348	}
	349
	350	static inline int is_empty_blob_oid(const struct object_id *oid)
	351	{
	352	return oideq(oid, the_hash_algo->empty_blob);
	353	}
	354
	355	static inline int is_empty_tree_sha1(const unsigned char *sha1)
	356	{
	357	return hasheq(sha1, the_hash_algo->empty_tree->hash);
	358	}
	359
	360	static inline int is_empty_tree_oid(const struct object_id *oid)
	361	{
	362	return oideq(oid, the_hash_algo->empty_tree);
	363	}
	364
5a6dce70	365	static inline void oid_set_algo(struct object_id oid, const struct git_hash_algo algop)
	366	{
	367	oid->algo = hash_algo_by_ptr(algop);
	368	}
	369
3fa6f2aa JK	370	const char *empty_tree_oid_hex(void);
	371	const char *empty_blob_oid_hex(void);
	372
f18f816c	373	#endif