git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
c8f03d8aeea3839c5aaf2d6e2cd5486cecf2498b blob 8068 bytes (raw)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
 
#ifndef HASH_H
#define HASH_H

#include "git-compat-util.h"
#include "repository.h"

#if defined(SHA1_PPC)
#include "ppc/sha1.h"
#elif 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_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 and ppc-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)

/* 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

/* 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;
};

/* 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;
};
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

extern const struct object_id null_oid;

static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
{
	/*
	 * 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 (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
		return memcmp(sha1, sha2, GIT_MAX_RAWSZ);
	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
}

static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
{
	return hashcmp(oid1->hash, oid2->hash);
}

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

static inline int oideq(const struct object_id *oid1, const struct object_id *oid2)
{
	return hasheq(oid1->hash, oid2->hash);
}

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);
}

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);
}

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

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);
}

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

#endif
debug log:

solving c8f03d8aee ...
found c8f03d8aee in git.git.git

Code repositories for project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).