| 1 | #include "mycpp/hash.h"
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| 2 |
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| 3 | #include "mycpp/gc_str.h"
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| 4 | #include "mycpp/gc_tuple.h"
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| 5 |
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| 6 | unsigned fnv1(const char* data, int len) {
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| 7 | // FNV-1 from http://www.isthe.com/chongo/tech/comp/fnv/#FNV-1
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| 8 | unsigned h = 2166136261; // 32-bit FNV-1 offset basis
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| 9 | constexpr int p = 16777619; // 32-bit FNV-1 prime
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| 10 | for (int i = 0; i < len; i++) {
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| 11 | h *= p;
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| 12 | // log("1. h = %d", h);
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| 13 | h ^= data[i];
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| 14 | // log("2. h = %d", h);
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| 15 | }
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| 16 | return h;
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| 17 | }
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| 18 |
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| 19 | unsigned hash_key(BigStr* s) {
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| 20 | return s->hash(fnv1);
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| 21 | }
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| 22 |
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| 23 | unsigned hash_key(int n) {
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| 24 | return n;
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| 25 | }
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| 26 |
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| 27 | unsigned hash_key(Tuple2<int, int>* t1) {
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| 28 | return t1->at0() + t1->at1();
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| 29 | }
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| 30 |
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| 31 | unsigned hash_key(Tuple2<BigStr*, int>* t1) {
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| 32 | return t1->at0()->hash(fnv1) + t1->at1();
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| 33 | }
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| 34 |
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| 35 | // e.g. for Dict<Token*, int>, hash the pointer itself, which means we use
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| 36 | // object IDENTITY, not value.
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| 37 | unsigned hash_key(void* p) {
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| 38 | return fnv1(reinterpret_cast<const char*>(&p), sizeof(void*));
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| 39 | }
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