| @@ -0,0 +1,174 @@ |
| | 1 | #include <u.h> |
| | 2 | #include <libc.h> |
| | 3 | #include "qp.h" |
| | 4 | |
| | 5 | typedef u16int Tbitmap; |
| | 6 | typedef struct Tbranch Tbranch; |
| | 7 | typedef struct Tleaf Tleaf; |
| | 8 | |
| | 9 | struct Tleaf { |
| | 10 | char *k; |
| | 11 | void *v; |
| | 12 | }; |
| | 13 | |
| | 14 | struct Tbranch { |
| | 15 | Trie *twigs; |
| | 16 | u64int x; |
| | 17 | }; |
| | 18 | |
| | 19 | union Trie { |
| | 20 | Tleaf leaf; |
| | 21 | Tbranch branch; |
| | 22 | }; |
| | 23 | |
| | 24 | #define x_flags(x) ((x)>>62) |
| | 25 | #define x_index(x) ((x)>>16 & ((1ULL<<46)-1ULL)) |
| | 26 | #define x_bitmap(x) ((x) & 0xffff) |
| | 27 | |
| | 28 | #define isbranch(t) (x_flags((t)->branch.x) != 0) |
| | 29 | #define hastwig(t, b) (x_bitmap((t)->branch.x) & (b)) |
| | 30 | #define twigoff(t, b) popcount(x_bitmap((t)->branch.x) & ((b)-1)) |
| | 31 | #define twig(t, i) (&(t)->branch.twigs[(i)]) |
| | 32 | #define twigoffmax(off, max, t, b) do{ off = twigoff(t, b); max = popcount(x_bitmap((t)->branch.x)); }while(0) |
| | 33 | #define nibbit(k, f) (1 << (((k) & (((f)-2) ^ 0x0f) & 0xff) >> ((2-(f))<<2))) |
| | 34 | #define twigbit(t, k, len) \ |
| | 35 | (x_index((t)->branch.x) >= (len) ? \ |
| | 36 | 1 : \ |
| | 37 | nibbit((u8int)(k)[x_index((t)->branch.x)], x_flags((t)->branch.x))) |
| | 38 | |
| | 39 | /* |
| | 40 | // need some speed? just say no. |
| | 41 | #define POPCNT BYTE $0xf3; BYTE $0x0f; BYTE $0xb8 |
| | 42 | |
| | 43 | TEXT popcount(SB),$0 |
| | 44 | MOVL b+0(FP), AX |
| | 45 | POPCNT |
| | 46 | RET |
| | 47 | */ |
| | 48 | static u16int |
| | 49 | popcount(u16int b) |
| | 50 | { |
| | 51 | b -= b>>1 & 0x5555; |
| | 52 | b = (b & 0x3333) + ((b>>2) & 0x3333); |
| | 53 | b = (b + (b>>4)) & 0x0f0f; |
| | 54 | b = (b + (b>>8)) & 0x00ff; |
| | 55 | return b; |
| | 56 | } |
| | 57 | |
| | 58 | int |
| | 59 | qpget(Trie *t, char *k, int len, char **pk, char **pv) |
| | 60 | { |
| | 61 | Tbitmap b; |
| | 62 | |
| | 63 | assert(k != nil && pk != nil && pv != nil); |
| | 64 | |
| | 65 | for(; isbranch(t); t = twig(t, twigoff(t, b))){ |
| | 66 | b = twigbit(t, k, len); |
| | 67 | if(!hastwig(t, b)) |
| | 68 | return -1; |
| | 69 | } |
| | 70 | if(strncmp(k, t->leaf.k, len) != 0) |
| | 71 | return -1; |
| | 72 | *pk = t->leaf.k; |
| | 73 | *pv = t->leaf.v; |
| | 74 | |
| | 75 | return 0; |
| | 76 | } |
| | 77 | |
| | 78 | int |
| | 79 | qpnext(Trie *t, char **pk, int *plen, void **pv) |
| | 80 | { |
| | 81 | Tbitmap b; |
| | 82 | uint s, m; |
| | 83 | |
| | 84 | assert(pk != nil && plen != nil && pv != nil); |
| | 85 | |
| | 86 | if(isbranch(t)){ |
| | 87 | b = twigbit(t, *pk, *plen); |
| | 88 | twigoffmax(s, m, t, b); |
| | 89 | for(; s < m; s++){ |
| | 90 | if(qpnext(twig(t, s), pk, plen, pv) == 0) |
| | 91 | return 0; |
| | 92 | } |
| | 93 | return -1; |
| | 94 | } |
| | 95 | |
| | 96 | if(*pk == nil){ |
| | 97 | *pk = t->leaf.k; |
| | 98 | *plen = strlen(*pk); |
| | 99 | *pv = t->leaf.v; |
| | 100 | return 0; |
| | 101 | } |
| | 102 | |
| | 103 | return -1; |
| | 104 | } |
| | 105 | |
| | 106 | Trie * |
| | 107 | qpset(Trie *t, char *k, int len, void *v) |
| | 108 | { |
| | 109 | Trie *t0, t1, t2; |
| | 110 | uint i, s, m; |
| | 111 | u8int f; |
| | 112 | Tbitmap b, b1, b2; |
| | 113 | u8int k2; |
| | 114 | |
| | 115 | assert(k != nil && v != nil); |
| | 116 | if(len < 1) |
| | 117 | len = strlen(k); |
| | 118 | assert(len > 0); |
| | 119 | |
| | 120 | if(t == nil){ |
| | 121 | t = malloc(sizeof(*t)); |
| | 122 | t->leaf.k = k; |
| | 123 | t->leaf.v = v; |
| | 124 | return t; |
| | 125 | } |
| | 126 | |
| | 127 | t0 = t; |
| | 128 | for(; isbranch(t); t = twig(t, i)){ |
| | 129 | b = twigbit(t, k, len); |
| | 130 | i = hastwig(t, b) ? twigoff(t, b) : 0; |
| | 131 | } |
| | 132 | for(i = 0; i <= len && k[i] == t->leaf.k[i]; i++); |
| | 133 | if(i == len+1){ |
| | 134 | t->leaf.v = v; |
| | 135 | return t0; |
| | 136 | } |
| | 137 | |
| | 138 | k2 = (u8int)t->leaf.k[i]; |
| | 139 | f = (((u8int)k[i] ^ k2) & 0xf0) ? 1 : 2; |
| | 140 | b1 = nibbit(k[i], f); |
| | 141 | t1.leaf.k = k; |
| | 142 | t1.leaf.v = v; |
| | 143 | for(t = t0; isbranch(t); t = twig(t, twigoff(t, b))){ |
| | 144 | if(i == x_index(t->branch.x)){ |
| | 145 | if(f == x_flags(t->branch.x)) |
| | 146 | goto growbranch; |
| | 147 | if(f < x_flags(t->branch.x)) |
| | 148 | break; |
| | 149 | }else if(i < x_index(t->branch.x)){ |
| | 150 | break; |
| | 151 | } |
| | 152 | b = twigbit(t, k, len); |
| | 153 | assert(hastwig(t, b)); |
| | 154 | } |
| | 155 | |
| | 156 | t2 = *t; |
| | 157 | b2 = nibbit(k2, f); |
| | 158 | t->branch.twigs = malloc(sizeof(*t)*2); |
| | 159 | t->branch.x = (uvlong)f<<62 | (uvlong)i<<16 | b1 | b2; |
| | 160 | *twig(t, twigoff(t, b1)) = t1; |
| | 161 | *twig(t, twigoff(t, b2)) = t2; |
| | 162 | |
| | 163 | return t0; |
| | 164 | |
| | 165 | growbranch: |
| | 166 | assert(!hastwig(t, b1)); |
| | 167 | twigoffmax(s, m, t, b1); |
| | 168 | t->branch.twigs = realloc(t->branch.twigs, sizeof(*t)*(m+1)); |
| | 169 | memmove(t->branch.twigs+s+1, t->branch.twigs+s, sizeof(*t)*(m-s)); |
| | 170 | memmove(t->branch.twigs+s, &t1, sizeof(t1)); |
| | 171 | t->branch.x |= b1; |
| | 172 | |
| | 173 | return t0; |
| | 174 | } |