| OLD | NEW | 
|---|
| 1 #include <string.h> | 1 #include <string.h> | 
| 2 #include <stdint.h> | 2 #include <stdint.h> | 
| 3 | 3 | 
| 4 static char *twobyte_strstr(const unsigned char *h, const unsigned char *n) | 4 static char* twobyte_strstr(const unsigned char* h, const unsigned char* n) { | 
| 5 { | 5   uint16_t nw = n[0] << 8 | n[1], hw = h[0] << 8 | h[1]; | 
| 6 »       uint16_t nw = n[0]<<8 | n[1], hw = h[0]<<8 | h[1]; | 6   for (h++; *h && hw != nw; hw = hw << 8 | *++h) | 
| 7 »       for (h++; *h && hw != nw; hw = hw<<8 | *++h); | 7     ; | 
| 8 »       return *h ? (char *)h-1 : 0; | 8   return *h ? (char*)h - 1 : 0; | 
| 9 } | 9 } | 
| 10 | 10 | 
| 11 static char *threebyte_strstr(const unsigned char *h, const unsigned char *n) | 11 static char* threebyte_strstr(const unsigned char* h, const unsigned char* n) { | 
| 12 { | 12   uint32_t nw = n[0] << 24 | n[1] << 16 | n[2] << 8; | 
| 13 »       uint32_t nw = n[0]<<24 | n[1]<<16 | n[2]<<8; | 13   uint32_t hw = h[0] << 24 | h[1] << 16 | h[2] << 8; | 
| 14 »       uint32_t hw = h[0]<<24 | h[1]<<16 | h[2]<<8; | 14   for (h += 2; *h && hw != nw; hw = (hw | *++h) << 8) | 
| 15 »       for (h+=2; *h && hw != nw; hw = (hw|*++h)<<8); | 15     ; | 
| 16 »       return *h ? (char *)h-2 : 0; | 16   return *h ? (char*)h - 2 : 0; | 
| 17 } | 17 } | 
| 18 | 18 | 
| 19 static char *fourbyte_strstr(const unsigned char *h, const unsigned char *n) | 19 static char* fourbyte_strstr(const unsigned char* h, const unsigned char* n) { | 
| 20 { | 20   uint32_t nw = n[0] << 24 | n[1] << 16 | n[2] << 8 | n[3]; | 
| 21 »       uint32_t nw = n[0]<<24 | n[1]<<16 | n[2]<<8 | n[3]; | 21   uint32_t hw = h[0] << 24 | h[1] << 16 | h[2] << 8 | h[3]; | 
| 22 »       uint32_t hw = h[0]<<24 | h[1]<<16 | h[2]<<8 | h[3]; | 22   for (h += 3; *h && hw != nw; hw = hw << 8 | *++h) | 
| 23 »       for (h+=3; *h && hw != nw; hw = hw<<8 | *++h); | 23     ; | 
| 24 »       return *h ? (char *)h-3 : 0; | 24   return *h ? (char*)h - 3 : 0; | 
| 25 } | 25 } | 
| 26 | 26 | 
| 27 #define MAX(a,b) ((a)>(b)?(a):(b)) | 27 #define MAX(a, b) ((a) > (b) ? (a) : (b)) | 
| 28 #define MIN(a,b) ((a)<(b)?(a):(b)) | 28 #define MIN(a, b) ((a) < (b) ? (a) : (b)) | 
| 29 | 29 | 
| 30 #define BITOP(a,b,op) \ | 30 #define BITOP(a, b, op)                              \ | 
| 31  ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a)))) | 31   ((a)[(size_t)(b) / (8 * sizeof *(a))] op(size_t) 1 \ | 
|  | 32    << ((size_t)(b) % (8 * sizeof *(a)))) | 
| 32 | 33 | 
| 33 static char *twoway_strstr(const unsigned char *h, const unsigned char *n) | 34 static char* twoway_strstr(const unsigned char* h, const unsigned char* n) { | 
| 34 { | 35   const unsigned char* z; | 
| 35 »       const unsigned char *z; | 36   size_t l, ip, jp, k, p, ms, p0, mem, mem0; | 
| 36 »       size_t l, ip, jp, k, p, ms, p0, mem, mem0; | 37   size_t byteset[32 / sizeof(size_t)] = {0}; | 
| 37 »       size_t byteset[32 / sizeof(size_t)] = { 0 }; | 38   size_t shift[256]; | 
| 38 »       size_t shift[256]; |  | 
| 39 | 39 | 
| 40 »       /* Computing length of needle and fill shift table */ | 40   /* Computing length of needle and fill shift table */ | 
| 41 »       for (l=0; n[l] && h[l]; l++) | 41   for (l = 0; n[l] && h[l]; l++) | 
| 42 »       »       BITOP(byteset, n[l], |=), shift[n[l]] = l+1; | 42     BITOP(byteset, n[l], |=), shift[n[l]] = l + 1; | 
| 43 »       if (n[l]) return 0; /* hit the end of h */ | 43   if (n[l]) | 
|  | 44     return 0; /* hit the end of h */ | 
| 44 | 45 | 
| 45 »       /* Compute maximal suffix */ | 46   /* Compute maximal suffix */ | 
| 46 »       ip = -1; jp = 0; k = p = 1; | 47   ip = -1; | 
| 47 »       while (jp+k<l) { | 48   jp = 0; | 
| 48 »       »       if (n[ip+k] == n[jp+k]) { | 49   k = p = 1; | 
| 49 »       »       »       if (k == p) { | 50   while (jp + k < l) { | 
| 50 »       »       »       »       jp += p; | 51     if (n[ip + k] == n[jp + k]) { | 
| 51 »       »       »       »       k = 1; | 52       if (k == p) { | 
| 52 »       »       »       } else k++; | 53         jp += p; | 
| 53 »       »       } else if (n[ip+k] > n[jp+k]) { | 54         k = 1; | 
| 54 »       »       »       jp += k; | 55       } else | 
| 55 »       »       »       k = 1; | 56         k++; | 
| 56 »       »       »       p = jp - ip; | 57     } else if (n[ip + k] > n[jp + k]) { | 
| 57 »       »       } else { | 58       jp += k; | 
| 58 »       »       »       ip = jp++; | 59       k = 1; | 
| 59 »       »       »       k = p = 1; | 60       p = jp - ip; | 
| 60 »       »       } | 61     } else { | 
| 61 »       } | 62       ip = jp++; | 
| 62 »       ms = ip; | 63       k = p = 1; | 
| 63 »       p0 = p; | 64     } | 
|  | 65   } | 
|  | 66   ms = ip; | 
|  | 67   p0 = p; | 
| 64 | 68 | 
| 65 »       /* And with the opposite comparison */ | 69   /* And with the opposite comparison */ | 
| 66 »       ip = -1; jp = 0; k = p = 1; | 70   ip = -1; | 
| 67 »       while (jp+k<l) { | 71   jp = 0; | 
| 68 »       »       if (n[ip+k] == n[jp+k]) { | 72   k = p = 1; | 
| 69 »       »       »       if (k == p) { | 73   while (jp + k < l) { | 
| 70 »       »       »       »       jp += p; | 74     if (n[ip + k] == n[jp + k]) { | 
| 71 »       »       »       »       k = 1; | 75       if (k == p) { | 
| 72 »       »       »       } else k++; | 76         jp += p; | 
| 73 »       »       } else if (n[ip+k] < n[jp+k]) { | 77         k = 1; | 
| 74 »       »       »       jp += k; | 78       } else | 
| 75 »       »       »       k = 1; | 79         k++; | 
| 76 »       »       »       p = jp - ip; | 80     } else if (n[ip + k] < n[jp + k]) { | 
| 77 »       »       } else { | 81       jp += k; | 
| 78 »       »       »       ip = jp++; | 82       k = 1; | 
| 79 »       »       »       k = p = 1; | 83       p = jp - ip; | 
| 80 »       »       } | 84     } else { | 
| 81 »       } | 85       ip = jp++; | 
| 82 »       if (ip+1 > ms+1) ms = ip; | 86       k = p = 1; | 
| 83 »       else p = p0; | 87     } | 
|  | 88   } | 
|  | 89   if (ip + 1 > ms + 1) | 
|  | 90     ms = ip; | 
|  | 91   else | 
|  | 92     p = p0; | 
| 84 | 93 | 
| 85 »       /* Periodic needle? */ | 94   /* Periodic needle? */ | 
| 86 »       if (memcmp(n, n+p, ms+1)) { | 95   if (memcmp(n, n + p, ms + 1)) { | 
| 87 »       »       mem0 = 0; | 96     mem0 = 0; | 
| 88 »       »       p = MAX(ms, l-ms-1) + 1; | 97     p = MAX(ms, l - ms - 1) + 1; | 
| 89 »       } else mem0 = l-p; | 98   } else | 
| 90 »       mem = 0; | 99     mem0 = l - p; | 
|  | 100   mem = 0; | 
| 91 | 101 | 
| 92 »       /* Initialize incremental end-of-haystack pointer */ | 102   /* Initialize incremental end-of-haystack pointer */ | 
| 93 »       z = h; | 103   z = h; | 
| 94 | 104 | 
| 95 »       /* Search loop */ | 105   /* Search loop */ | 
| 96 »       for (;;) { | 106   for (;;) { | 
| 97 »       »       /* Update incremental end-of-haystack pointer */ | 107     /* Update incremental end-of-haystack pointer */ | 
| 98 »       »       if (z-h < l) { | 108     if (z - h < l) { | 
| 99 »       »       »       /* Fast estimate for MIN(l,63) */ | 109       /* Fast estimate for MIN(l,63) */ | 
| 100 »       »       »       size_t grow = l | 63; | 110       size_t grow = l | 63; | 
| 101 »       »       »       const unsigned char *z2 = memchr(z, 0, grow); | 111       const unsigned char* z2 = memchr(z, 0, grow); | 
| 102 »       »       »       if (z2) { | 112       if (z2) { | 
| 103 »       »       »       »       z = z2; | 113         z = z2; | 
| 104 »       »       »       »       if (z-h < l) return 0; | 114         if (z - h < l) | 
| 105 »       »       »       } else z += grow; | 115           return 0; | 
| 106 »       »       } | 116       } else | 
|  | 117         z += grow; | 
|  | 118     } | 
| 107 | 119 | 
| 108 »       »       /* Check last byte first; advance by shift on mismatch */ | 120     /* Check last byte first; advance by shift on mismatch */ | 
| 109 »       »       if (BITOP(byteset, h[l-1], &)) { | 121     if (BITOP(byteset, h[l - 1], &)) { | 
| 110 »       »       »       k = l-shift[h[l-1]]; | 122       k = l - shift[h[l - 1]]; | 
| 111 »       »       »       //printf("adv by %zu (on %c) at [%s] (%zu;l=%zu)\n", k, 
     h[l-1], h, shift[h[l-1]], l); | 123       // printf("adv by %zu (on %c) at [%s] (%zu;l=%zu)\n", k, h[l-1], h, | 
| 112 »       »       »       if (k) { | 124       // shift[h[l-1]], l); | 
| 113 »       »       »       »       if (mem0 && mem && k < p) k = l-p; | 125       if (k) { | 
| 114 »       »       »       »       h += k; | 126         if (mem0 && mem && k < p) | 
| 115 »       »       »       »       mem = 0; | 127           k = l - p; | 
| 116 »       »       »       »       continue; | 128         h += k; | 
| 117 »       »       »       } | 129         mem = 0; | 
| 118 »       »       } else { | 130         continue; | 
| 119 »       »       »       h += l; | 131       } | 
| 120 »       »       »       mem = 0; | 132     } else { | 
| 121 »       »       »       continue; | 133       h += l; | 
| 122 »       »       } | 134       mem = 0; | 
|  | 135       continue; | 
|  | 136     } | 
| 123 | 137 | 
| 124 »       »       /* Compare right half */ | 138     /* Compare right half */ | 
| 125 »       »       for (k=MAX(ms+1,mem); n[k] && n[k] == h[k]; k++); | 139     for (k = MAX(ms + 1, mem); n[k] && n[k] == h[k]; k++) | 
| 126 »       »       if (n[k]) { | 140       ; | 
| 127 »       »       »       h += k-ms; | 141     if (n[k]) { | 
| 128 »       »       »       mem = 0; | 142       h += k - ms; | 
| 129 »       »       »       continue; | 143       mem = 0; | 
| 130 »       »       } | 144       continue; | 
| 131 »       »       /* Compare left half */ | 145     } | 
| 132 »       »       for (k=ms+1; k>mem && n[k-1] == h[k-1]; k--); | 146     /* Compare left half */ | 
| 133 »       »       if (k <= mem) return (char *)h; | 147     for (k = ms + 1; k > mem && n[k - 1] == h[k - 1]; k--) | 
| 134 »       »       h += p; | 148       ; | 
| 135 »       »       mem = mem0; | 149     if (k <= mem) | 
| 136 »       } | 150       return (char*)h; | 
|  | 151     h += p; | 
|  | 152     mem = mem0; | 
|  | 153   } | 
| 137 } | 154 } | 
| 138 | 155 | 
| 139 char *strstr(const char *h, const char *n) | 156 char* strstr(const char* h, const char* n) { | 
| 140 { | 157   /* Return immediately on empty needle */ | 
| 141 »       /* Return immediately on empty needle */ | 158   if (!n[0]) | 
| 142 »       if (!n[0]) return (char *)h; | 159     return (char*)h; | 
| 143 | 160 | 
| 144 »       /* Use faster algorithms for short needles */ | 161   /* Use faster algorithms for short needles */ | 
| 145 »       h = strchr(h, *n); | 162   h = strchr(h, *n); | 
| 146 »       if (!h || !n[1]) return (char *)h; | 163   if (!h || !n[1]) | 
| 147 »       if (!h[1]) return 0; | 164     return (char*)h; | 
| 148 »       if (!n[2]) return twobyte_strstr((void *)h, (void *)n); | 165   if (!h[1]) | 
| 149 »       if (!h[2]) return 0; | 166     return 0; | 
| 150 »       if (!n[3]) return threebyte_strstr((void *)h, (void *)n); | 167   if (!n[2]) | 
| 151 »       if (!h[3]) return 0; | 168     return twobyte_strstr((void*)h, (void*)n); | 
| 152 »       if (!n[4]) return fourbyte_strstr((void *)h, (void *)n); | 169   if (!h[2]) | 
|  | 170     return 0; | 
|  | 171   if (!n[3]) | 
|  | 172     return threebyte_strstr((void*)h, (void*)n); | 
|  | 173   if (!h[3]) | 
|  | 174     return 0; | 
|  | 175   if (!n[4]) | 
|  | 176     return fourbyte_strstr((void*)h, (void*)n); | 
| 153 | 177 | 
| 154 »       return twoway_strstr((void *)h, (void *)n); | 178   return twoway_strstr((void*)h, (void*)n); | 
| 155 } | 179 } | 
| OLD | NEW | 
|---|