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25 *****************************************************************************/
26 
27 /**************************************************//**
28 @file buf/buf0checksum.h
29 Buffer pool checksum functions, also linked from /extra/innochecksum.cc
30 
31 Created Aug 11, 2011 Vasil Dimov
32 *******************************************************/
33 
34 #ifndef buf0checksum_h
35 #define buf0checksum_h
36 
37 #include "univ.i"
38 
39 #include "buf0types.h"
40 
41 /** Magic value to use instead of checksums when they are disabled */
42 #define BUF_NO_CHECKSUM_MAGIC 0xDEADBEEFUL
43 
44 /********************************************************************//**
45 Calculates a page CRC32 which is stored to the page when it is written
46 to a file. Note that we must be careful to calculate the same value on
47 32-bit and 64-bit architectures.
48 @return	checksum */
49 UNIV_INTERN
50 ib_uint32_t
51 buf_calc_page_crc32(
52 /*================*/
53 	const byte*	page);	/*!< in: buffer page */
54 
55 /********************************************************************//**
56 Calculates a page checksum which is stored to the page when it is written
57 to a file. Note that we must be careful to calculate the same value on
58 32-bit and 64-bit architectures.
59 @return	checksum */
60 UNIV_INTERN
61 ulint
62 buf_calc_page_new_checksum(
63 /*=======================*/
64 	const byte*	page);	/*!< in: buffer page */
65 
66 /********************************************************************//**
67 In versions < 4.0.14 and < 4.1.1 there was a bug that the checksum only
68 looked at the first few bytes of the page. This calculates that old
69 checksum.
70 NOTE: we must first store the new formula checksum to
71 FIL_PAGE_SPACE_OR_CHKSUM before calculating and storing this old checksum
72 because this takes that field as an input!
73 @return	checksum */
74 UNIV_INTERN
75 ulint
76 buf_calc_page_old_checksum(
77 /*=======================*/
78 	const byte*	page);	/*!< in: buffer page */
79 
80 /********************************************************************//**
81 Return a printable string describing the checksum algorithm.
82 @return	algorithm name */
83 UNIV_INTERN
84 const char*
85 buf_checksum_algorithm_name(
86 /*========================*/
87 	srv_checksum_algorithm_t	algo);	/*!< in: algorithm */
88 
89 extern ulong	srv_checksum_algorithm;
90 
91 #endif /* buf0checksum_h */
92