summaryrefslogtreecommitdiff
path: root/klm/lm/value.hh
blob: 85e53f14ee0dc2ad0ace5cb4912c66a1c1ef1673 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
#ifndef LM_VALUE__
#define LM_VALUE__

#include "lm/model_type.hh"
#include "lm/value_build.hh"
#include "lm/weights.hh"
#include "util/bit_packing.hh"

#include <inttypes.h>

namespace lm {
namespace ngram {

// Template proxy for probing unigrams and middle.
template <class Weights> class GenericProbingProxy {
  public:
    explicit GenericProbingProxy(const Weights &to) : to_(&to) {}

    GenericProbingProxy() : to_(0) {}

    bool Found() const { return to_ != 0; }

    float Prob() const {
      util::FloatEnc enc;
      enc.f = to_->prob;
      enc.i |= util::kSignBit;
      return enc.f;
    }

    float Backoff() const { return to_->backoff; }

    bool IndependentLeft() const {
      util::FloatEnc enc;
      enc.f = to_->prob;
      return enc.i & util::kSignBit;
    }

  protected:
    const Weights *to_;
};

// Basic proxy for trie unigrams.  
template <class Weights> class GenericTrieUnigramProxy {
  public:
    explicit GenericTrieUnigramProxy(const Weights &to) : to_(&to) {}

    GenericTrieUnigramProxy() : to_(0) {}

    bool Found() const { return to_ != 0; }
    float Prob() const { return to_->prob; }
    float Backoff() const { return to_->backoff; }
    float Rest() const { return Prob(); }

  protected:
    const Weights *to_;
};

struct BackoffValue {
  typedef ProbBackoff Weights;
  static const ModelType kProbingModelType = PROBING;

  class ProbingProxy : public GenericProbingProxy<Weights> {
    public:
      explicit ProbingProxy(const Weights &to) : GenericProbingProxy<Weights>(to) {}
      ProbingProxy() {}
      float Rest() const { return Prob(); }
  };

  class TrieUnigramProxy : public GenericTrieUnigramProxy<Weights> {
    public:
      explicit TrieUnigramProxy(const Weights &to) : GenericTrieUnigramProxy<Weights>(to) {}
      TrieUnigramProxy() {}
      float Rest() const { return Prob(); }
  };

  struct ProbingEntry {
    typedef uint64_t Key;
    typedef Weights Value;
    uint64_t key;
    ProbBackoff value;
    uint64_t GetKey() const { return key; }
  };

  struct TrieUnigramValue {
    Weights weights;
    uint64_t next;
    uint64_t Next() const { return next; }
  };

  const static bool kDifferentRest = false;

  template <class Model, class C> void Callback(const Config &, unsigned int, typename Model::Vocabulary &, C &callback) {
    NoRestBuild build;
    callback(build);
  }
};

struct RestValue {
  typedef RestWeights Weights;
  static const ModelType kProbingModelType = REST_PROBING;

  class ProbingProxy : public GenericProbingProxy<RestWeights> {
    public:
      explicit ProbingProxy(const Weights &to) : GenericProbingProxy<RestWeights>(to) {}
      ProbingProxy() {}
      float Rest() const { return to_->rest; }
  };

  class TrieUnigramProxy : public GenericTrieUnigramProxy<Weights> {
    public:
      explicit TrieUnigramProxy(const Weights &to) : GenericTrieUnigramProxy<Weights>(to) {}
      TrieUnigramProxy() {}
      float Rest() const { return to_->rest; }
  };

// gcc 4.1 doesn't properly back dependent types :-(.  
#pragma pack(push)
#pragma pack(4)
  struct ProbingEntry {
    typedef uint64_t Key;
    typedef Weights Value;
    Key key;
    Value value;
    Key GetKey() const { return key; }
  };

  struct TrieUnigramValue {
    Weights weights;
    uint64_t next;
    uint64_t Next() const { return next; }
  };
#pragma pack(pop)

  const static bool kDifferentRest = true;

  template <class Model, class C> void Callback(const Config &config, unsigned int order, typename Model::Vocabulary &vocab, C &callback) {
    switch (config.rest_function) {
      case Config::REST_MAX:
        {
          MaxRestBuild build;
          callback(build);
        }
        break;
      case Config::REST_LOWER:
        {
          LowerRestBuild<Model> build(config, order, vocab);
          callback(build);
        }
        break;
    }
  }
};

} // namespace ngram
} // namespace lm

#endif // LM_VALUE__