Merge branch 'ds/multi-pack-index'

[thirdparty/git.git] / hash.h

diff --git a/hash.h b/hash.h
index adde708cf26d90ffd7ae10e6cdb8bfd7c08b1db5..e0f3f16b06b7930e448912bdc699a47125a19b0c 100644 (file)
--- a/hash.h
+++ b/hash.h
@@ -16,6 +16,7 @@
 #endif
 
 #if defined(SHA256_GCRYPT)
+#define SHA256_NEEDS_CLONE_HELPER
 #include "sha256/gcrypt.h"
 #elif defined(SHA256_OPENSSL)
 #include <openssl/sha.h>
@@ -54,12 +55,28 @@
 #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
@@ -85,6 +102,7 @@ union git_hash_ctx {
 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);
 
@@ -110,6 +128,9 @@ struct git_hash_algo {
        /* 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;
 
@@ -131,10 +152,36 @@ extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS];
 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;
 }
 
+/* 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];
+};
+
+#define the_hash_algo the_repository->hash_algo
+
 #endif