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00022 #include <config.h>
00023 #include <drizzled/internal/my_sys.h>
00024
00025 #include <assert.h>
00026
00027 #include <plugin/myisam/myisampack.h>
00028
00029 namespace drizzled
00030 {
00031 namespace internal
00032 {
00033
00034 static int ptr_compare(size_t *compare_length, unsigned char **a, unsigned char **b);
00035 static int ptr_compare_0(size_t *compare_length, unsigned char **a, unsigned char **b);
00036 static int ptr_compare_1(size_t *compare_length, unsigned char **a, unsigned char **b);
00037 static int ptr_compare_2(size_t *compare_length, unsigned char **a, unsigned char **b);
00038 static int ptr_compare_3(size_t *compare_length, unsigned char **a, unsigned char **b);
00039
00040
00041
00042 qsort2_cmp get_ptr_compare (size_t size)
00043 {
00044 if (size < 4)
00045 return (qsort2_cmp) ptr_compare;
00046 switch (size & 3) {
00047 case 0: return (qsort2_cmp) ptr_compare_0;
00048 case 1: return (qsort2_cmp) ptr_compare_1;
00049 case 2: return (qsort2_cmp) ptr_compare_2;
00050 case 3: return (qsort2_cmp) ptr_compare_3;
00051 }
00052 return 0;
00053 }
00054
00055
00056
00057
00058
00059
00060
00061 #define cmp(N) if (first[N] != last[N]) return (int) first[N] - (int) last[N]
00062
00063 static int ptr_compare(size_t *compare_length, unsigned char **a, unsigned char **b)
00064 {
00065 int length= *compare_length;
00066 unsigned char *first,*last;
00067
00068 first= *a; last= *b;
00069 while (--length)
00070 {
00071 if (*first++ != *last++)
00072 return (int) first[-1] - (int) last[-1];
00073 }
00074 return (int) first[0] - (int) last[0];
00075 }
00076
00077
00078 static int ptr_compare_0(size_t *compare_length,unsigned char **a, unsigned char **b)
00079 {
00080 int length= *compare_length;
00081 unsigned char *first,*last;
00082
00083 first= *a; last= *b;
00084 loop:
00085 cmp(0);
00086 cmp(1);
00087 cmp(2);
00088 cmp(3);
00089 if ((length-=4))
00090 {
00091 first+=4;
00092 last+=4;
00093 goto loop;
00094 }
00095 return (0);
00096 }
00097
00098
00099 static int ptr_compare_1(size_t *compare_length,unsigned char **a, unsigned char **b)
00100 {
00101 int length= *compare_length-1;
00102 unsigned char *first,*last;
00103
00104 first= *a+1; last= *b+1;
00105 cmp(-1);
00106 loop:
00107 cmp(0);
00108 cmp(1);
00109 cmp(2);
00110 cmp(3);
00111 if ((length-=4))
00112 {
00113 first+=4;
00114 last+=4;
00115 goto loop;
00116 }
00117 return (0);
00118 }
00119
00120 static int ptr_compare_2(size_t *compare_length,unsigned char **a, unsigned char **b)
00121 {
00122 int length= *compare_length-2;
00123 unsigned char *first,*last;
00124
00125 first= *a +2 ; last= *b +2;
00126 cmp(-2);
00127 cmp(-1);
00128 loop:
00129 cmp(0);
00130 cmp(1);
00131 cmp(2);
00132 cmp(3);
00133 if ((length-=4))
00134 {
00135 first+=4;
00136 last+=4;
00137 goto loop;
00138 }
00139 return (0);
00140 }
00141
00142 static int ptr_compare_3(size_t *compare_length,unsigned char **a, unsigned char **b)
00143 {
00144 int length= *compare_length-3;
00145 unsigned char *first,*last;
00146
00147 first= *a +3 ; last= *b +3;
00148 cmp(-3);
00149 cmp(-2);
00150 cmp(-1);
00151 loop:
00152 cmp(0);
00153 cmp(1);
00154 cmp(2);
00155 cmp(3);
00156 if ((length-=4))
00157 {
00158 first+=4;
00159 last+=4;
00160 goto loop;
00161 }
00162 return (0);
00163 }
00164
00165 void my_store_ptr(unsigned char *buff, size_t pack_length, my_off_t pos)
00166 {
00167 switch (pack_length) {
00168 #if SIZEOF_OFF_T > 4
00169 case 8: mi_int8store(buff,pos); break;
00170 case 7: mi_int7store(buff,pos); break;
00171 case 6: mi_int6store(buff,pos); break;
00172 case 5: mi_int5store(buff,pos); break;
00173 #endif
00174 case 4: mi_int4store(buff,pos); break;
00175 case 3: mi_int3store(buff,pos); break;
00176 case 2: mi_int2store(buff,pos); break;
00177 case 1: buff[0]= (unsigned char) pos; break;
00178 default: assert(0);
00179 }
00180 return;
00181 }
00182
00183 my_off_t my_get_ptr(unsigned char *ptr, size_t pack_length)
00184 {
00185 my_off_t pos;
00186 switch (pack_length) {
00187 #if SIZEOF_OFF_T > 4
00188 case 8: pos= (my_off_t) mi_uint8korr(ptr); break;
00189 case 7: pos= (my_off_t) mi_uint7korr(ptr); break;
00190 case 6: pos= (my_off_t) mi_uint6korr(ptr); break;
00191 case 5: pos= (my_off_t) mi_uint5korr(ptr); break;
00192 #endif
00193 case 4: pos= (my_off_t) mi_uint4korr(ptr); break;
00194 case 3: pos= (my_off_t) mi_uint3korr(ptr); break;
00195 case 2: pos= (my_off_t) mi_uint2korr(ptr); break;
00196 case 1: pos= (my_off_t) *(unsigned char*) ptr; break;
00197 default: assert(0); return 0;
00198 }
00199 return pos;
00200 }
00201
00202 }
00203 }