cpp

Coverage Report

Created: 2024-08-07 22:00

/home/uke/oil/mycpp/hash.cc
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Source (jump to first uncovered line)
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#include "mycpp/hash.h"
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#include "mycpp/gc_str.h"
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#include "mycpp/gc_tuple.h"
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unsigned fnv1(const char* data, int len) {
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  // FNV-1 from http://www.isthe.com/chongo/tech/comp/fnv/#FNV-1
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  unsigned h = 2166136261;     // 32-bit FNV-1 offset basis
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  constexpr int p = 16777619;  // 32-bit FNV-1 prime
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  for (int i = 0; i < len; i++) {
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    h *= p;
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    // log("1. h = %d", h);
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    h ^= data[i];
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    // log("2. h = %d", h);
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  }
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  return h;
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}
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unsigned hash_key(BigStr* s) {
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  return s->hash(fnv1);
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}
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unsigned hash_key(int n) {
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  return fnv1(reinterpret_cast<const char*>(&n), sizeof(n));
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}
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unsigned hash_key(mops::BigInt n) {
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  // Bug fix: our dict sizing is a power of 2, and we don't want integers in
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  // the workload to interact badly with it.
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  return fnv1(reinterpret_cast<const char*>(&n), sizeof(n));
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}
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unsigned hash_key(void* p) {
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  // e.g. for Dict<Token*, int>, hash the pointer itself, which means we use
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  // object IDENTITY, not value.
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  return fnv1(reinterpret_cast<const char*>(&p), sizeof(void*));
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}
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unsigned hash_key(Tuple2<int, int>* t1) {
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  return t1->at0() + t1->at1();
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}
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unsigned hash_key(Tuple2<BigStr*, int>* t1) {
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  return t1->at0()->hash(fnv1) + t1->at1();
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}