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 fnv1(reinterpret_cast<const char*>(&n), sizeof(n));
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25 | }
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26 |
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27 | unsigned hash_key(mops::BigInt n) {
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28 | // Bug fix: our dict sizing is a power of 2, and we don't want integers in
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29 | // the workload to interact badly with it.
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30 | return fnv1(reinterpret_cast<const char*>(&n), sizeof(n));
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31 | }
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32 |
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33 | unsigned hash_key(void* p) {
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34 | // e.g. for Dict<Token*, int>, hash the pointer itself, which means we use
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35 | // object IDENTITY, not value.
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36 | return fnv1(reinterpret_cast<const char*>(&p), sizeof(void*));
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37 | }
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38 |
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39 | unsigned hash_key(Tuple2<int, int>* t1) {
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40 | return t1->at0() + t1->at1();
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41 | }
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42 |
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43 | unsigned hash_key(Tuple2<BigStr*, int>* t1) {
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44 | return t1->at0()->hash(fnv1) + t1->at1();
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45 | }
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