Especially with the new index format to come, it is more appropriate to encapsulate more into check_packed_git_idx() and assume less of the index format in struct packed_git. To that effect, the index_base is renamed to index_data with void * type so it is not used directly but other pointers initialized with it. This allows for a couple pointer cast removal, as well as providing a better generic name to grep for when adding support for new index versions or formats. And index_data is declared const too while at it. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
		
			
				
	
	
		
			53 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			53 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef PACK_H
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#define PACK_H
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#include "object.h"
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/*
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 * Packed object header
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 */
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#define PACK_SIGNATURE 0x5041434b	/* "PACK" */
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#define PACK_VERSION 2
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#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
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struct pack_header {
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	uint32_t hdr_signature;
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	uint32_t hdr_version;
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	uint32_t hdr_entries;
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};
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/*
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 * The first four bytes of index formats later than version 1 should
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 * start with this signature, as all older git binaries would find this
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 * value illegal and abort reading the file.
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 *
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 * This is the case because the number of objects in a packfile
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 * cannot exceed 1,431,660,000 as every object would need at least
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 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
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 * version 1 of the index file due to the offsets limited to 32 bits.
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 * Clearly the signature exceeds this maximum.
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 *
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 * Very old git binaries will also compare the first 4 bytes to the
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 * next 4 bytes in the index and abort with a "non-monotonic index"
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 * error if the second 4 byte word is smaller than the first 4
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 * byte word.  This would be true in the proposed future index
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 * format as idx_signature would be greater than idx_version.
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 */
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#define PACK_IDX_SIGNATURE 0xff744f63	/* "\377tOc" */
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/*
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 * Packed object index header
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 */
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struct pack_idx_header {
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	uint32_t idx_signature;
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	uint32_t idx_version;
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};
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extern int verify_pack(struct packed_git *, int);
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#define PH_ERROR_EOF		(-1)
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#define PH_ERROR_PACK_SIGNATURE	(-2)
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#define PH_ERROR_PROTOCOL	(-3)
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extern int read_pack_header(int fd, struct pack_header *);
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#endif
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