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26 
27 /******************************************************************//**
28 @file include/ut0sort.h
29 Sort utility
30 
31 Created 11/9/1995 Heikki Tuuri
32 ***********************************************************************/
33 
34 #ifndef ut0sort_h
35 #define ut0sort_h
36 
37 #include "univ.i"
38 
39 /* This module gives a macro definition of the body of
40 a standard sort function for an array of elements of any
41 type. The comparison function is given as a parameter to
42 the macro. The sort algorithm is mergesort which has logarithmic
43 worst case.
44 */
45 
46 /*******************************************************************//**
47 This macro expands to the body of a standard sort function.
48 The sort function uses mergesort and must be defined separately
49 for each type of array.
50 Also the comparison function has to be defined individually
51 for each array cell type. SORT_FUN is the sort function name.
52 The function takes the array to be sorted (ARR),
53 the array of auxiliary space (AUX_ARR) of same size,
54 and the low (LOW), inclusive, and high (HIGH), noninclusive,
55 limits for the sort interval as arguments.
56 CMP_FUN is the comparison function name. It takes as arguments
57 two elements from the array and returns 1, if the first is bigger,
58 0 if equal, and -1 if the second bigger. */
59 
60 #define UT_SORT_FUNCTION_BODY(SORT_FUN, ARR, AUX_ARR, LOW, HIGH, CMP_FUN)\
61 {\
62 	ulint		ut_sort_mid77;\
63 	ulint		ut_sort_i77;\
64 	ulint		ut_sort_low77;\
65 	ulint		ut_sort_high77;\
66 \
67 	ut_ad((LOW) < (HIGH));\
68 	ut_ad(ARR);\
69 	ut_ad(AUX_ARR);\
70 \
71 	if ((LOW) == (HIGH) - 1) {\
72 		return;\
73 	} else if ((LOW) == (HIGH) - 2) {\
74 		if (CMP_FUN((ARR)[LOW], (ARR)[(HIGH) - 1]) > 0) {\
75 			(AUX_ARR)[LOW] = (ARR)[LOW];\
76 			(ARR)[LOW] = (ARR)[(HIGH) - 1];\
77 			(ARR)[(HIGH) - 1] = (AUX_ARR)[LOW];\
78 		}\
79 		return;\
80 	}\
81 \
82 	ut_sort_mid77 = ((LOW) + (HIGH)) / 2;\
83 \
84 	SORT_FUN((ARR), (AUX_ARR), (LOW), ut_sort_mid77);\
85 	SORT_FUN((ARR), (AUX_ARR), ut_sort_mid77, (HIGH));\
86 \
87 	ut_sort_low77 = (LOW);\
88 	ut_sort_high77 = ut_sort_mid77;\
89 \
90 	for (ut_sort_i77 = (LOW); ut_sort_i77 < (HIGH); ut_sort_i77++) {\
91 \
92 		if (ut_sort_low77 >= ut_sort_mid77) {\
93 			(AUX_ARR)[ut_sort_i77] = (ARR)[ut_sort_high77];\
94 			ut_sort_high77++;\
95 		} else if (ut_sort_high77 >= (HIGH)) {\
96 			(AUX_ARR)[ut_sort_i77] = (ARR)[ut_sort_low77];\
97 			ut_sort_low77++;\
98 		} else if (CMP_FUN((ARR)[ut_sort_low77],\
99 				   (ARR)[ut_sort_high77]) > 0) {\
100 			(AUX_ARR)[ut_sort_i77] = (ARR)[ut_sort_high77];\
101 			ut_sort_high77++;\
102 		} else {\
103 			(AUX_ARR)[ut_sort_i77] = (ARR)[ut_sort_low77];\
104 			ut_sort_low77++;\
105 		}\
106 	}\
107 \
108 	memcpy((void*) ((ARR) + (LOW)), (AUX_ARR) + (LOW),\
109 	       ((HIGH) - (LOW)) * sizeof *(ARR));\
110 }\
111 
112 
113 #endif
114 
115