 b212c0ca31
			
		
	
	b212c0ca31
	
	
	
		
			
			We moved away from SHA1_HEADER to a preprocessor if chain, but didn't update the comment discussing the platform defines. Update this comment so it reflects the current state of our codebase. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
			
				
	
	
		
			102 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef HASH_H
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| #define HASH_H
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| 
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| #include "git-compat-util.h"
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| 
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| #if defined(SHA1_PPC)
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| #include "ppc/sha1.h"
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| #elif defined(SHA1_APPLE)
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| #include <CommonCrypto/CommonDigest.h>
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| #elif defined(SHA1_OPENSSL)
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| #include <openssl/sha.h>
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| #elif defined(SHA1_DC)
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| #include "sha1dc_git.h"
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| #else /* SHA1_BLK */
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| #include "block-sha1/sha1.h"
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| #endif
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| 
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| #ifndef platform_SHA_CTX
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| /*
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|  * platform's underlying implementation of SHA-1; could be OpenSSL,
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|  * blk_SHA, Apple CommonCrypto, etc...  Note that the relevant
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|  * SHA-1 header may have already defined platform_SHA_CTX for our
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|  * own implementations like block-sha1 and ppc-sha1, so we list
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|  * the default for OpenSSL compatible SHA-1 implementations here.
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|  */
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| #define platform_SHA_CTX	SHA_CTX
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| #define platform_SHA1_Init	SHA1_Init
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| #define platform_SHA1_Update	SHA1_Update
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| #define platform_SHA1_Final    	SHA1_Final
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| #endif
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| 
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| #define git_SHA_CTX		platform_SHA_CTX
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| #define git_SHA1_Init		platform_SHA1_Init
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| #define git_SHA1_Update		platform_SHA1_Update
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| #define git_SHA1_Final		platform_SHA1_Final
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| 
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| #ifdef SHA1_MAX_BLOCK_SIZE
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| #include "compat/sha1-chunked.h"
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| #undef git_SHA1_Update
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| #define git_SHA1_Update		git_SHA1_Update_Chunked
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| #endif
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| 
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| /*
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|  * Note that these constants are suitable for indexing the hash_algos array and
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|  * comparing against each other, but are otherwise arbitrary, so they should not
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|  * be exposed to the user or serialized to disk.  To know whether a
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|  * git_hash_algo struct points to some usable hash function, test the format_id
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|  * field for being non-zero.  Use the name field for user-visible situations and
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|  * the format_id field for fixed-length fields on disk.
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|  */
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| /* An unknown hash function. */
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| #define GIT_HASH_UNKNOWN 0
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| /* SHA-1 */
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| #define GIT_HASH_SHA1 1
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| /* Number of algorithms supported (including unknown). */
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| #define GIT_HASH_NALGOS (GIT_HASH_SHA1 + 1)
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| 
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| /* A suitably aligned type for stack allocations of hash contexts. */
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| union git_hash_ctx {
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| 	git_SHA_CTX sha1;
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| };
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| typedef union git_hash_ctx git_hash_ctx;
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| 
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| typedef void (*git_hash_init_fn)(git_hash_ctx *ctx);
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| typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len);
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| typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx);
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| 
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| struct git_hash_algo {
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| 	/*
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| 	 * The name of the algorithm, as appears in the config file and in
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| 	 * messages.
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| 	 */
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| 	const char *name;
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| 
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| 	/* A four-byte version identifier, used in pack indices. */
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| 	uint32_t format_id;
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| 
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| 	/* The length of the hash in binary. */
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| 	size_t rawsz;
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| 
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| 	/* The length of the hash in hex characters. */
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| 	size_t hexsz;
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| 
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| 	/* The hash initialization function. */
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| 	git_hash_init_fn init_fn;
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| 
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| 	/* The hash update function. */
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| 	git_hash_update_fn update_fn;
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| 
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| 	/* The hash finalization function. */
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| 	git_hash_final_fn final_fn;
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| 
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| 	/* The OID of the empty tree. */
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| 	const struct object_id *empty_tree;
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| 
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| 	/* The OID of the empty blob. */
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| 	const struct object_id *empty_blob;
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| };
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| extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS];
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| 
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| #endif
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