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stringHash.h
1 //
2 // Copyright 2018 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
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24 
25 #ifndef TRACE_STRING_HASH_H
26 #define TRACE_STRING_HASH_H
27 
28 #include "pxr/pxr.h"
29 
30 #include <cstdint>
31 
32 PXR_NAMESPACE_OPEN_SCOPE
33 
42  public:
43 
45  template <int N>
46  static constexpr std::uint32_t Hash(const char (&str)[N]) {
47  return djb2HashStr<N-1>(str);
48  }
49 
50  private:
51  // Recursive function computing the xor variant of the djb2 hash
52  // function.
53  template <int N>
54  static constexpr std::uint32_t djb2HashStr(const char* str) {
55  return (djb2HashStr<N-1>(str) * 33) ^ str[N-1];
56  }
57 };
58 
59 // Template recursion base case.
60 template <>
61 constexpr std::uint32_t TraceStringHash::djb2HashStr<0>(const char* str) {
62  return 5381;
63 }
64 
65 PXR_NAMESPACE_CLOSE_SCOPE
66 
67 #endif //TRACE_STRING_HASH_H
This class provides a function to compute compile time hashes for string literals.
Definition: stringHash.h:41
static constexpr std::uint32_t Hash(const char(&str)[N])
Computes a compile time hash of str.
Definition: stringHash.h:46