aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/apache/avro/api/Reader.hh
blob: 26488145a222991f4e21825ae360da90a7848910 (plain) (blame)
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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/* 
 * Licensed to the Apache Software Foundation (ASF) under one 
 * or more contributor license agreements.  See the NOTICE file 
 * distributed with this work for additional information 
 * regarding copyright ownership.  The ASF licenses this file 
 * to you under the Apache License, Version 2.0 (the 
 * "License"); you may not use this file except in compliance 
 * with the License.  You may obtain a copy of the License at 
 * 
 *     https://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and 
 * limitations under the License. 
 */ 
 
#ifndef avro_Reader_hh__ 
#define avro_Reader_hh__ 
 
#include <stdint.h> 
#include <vector> 
#include <array> 
#include <boost/noncopyable.hpp> 
 
#include "Config.hh" 
#include "Zigzag.hh" 
#include "Types.hh" 
#include "Validator.hh" 
#include "buffer/BufferReader.hh" 
 
namespace avro { 
 
/// 
/// Parses from an avro encoding to the requested type.  Assumes the next item 
/// in the avro binary data is the expected type. 
/// 
 
template<class ValidatorType> 
class ReaderImpl : private boost::noncopyable 
{ 
 
  public: 
 
    explicit ReaderImpl(const InputBuffer &buffer) : 
        reader_(buffer) 
    {} 
 
    ReaderImpl(const ValidSchema &schema, const InputBuffer &buffer) : 
        validator_(schema), 
        reader_(buffer) 
    {} 
 
    void readValue(Null &) { 
        validator_.checkTypeExpected(AVRO_NULL); 
    } 
 
    void readValue(bool &val) { 
        validator_.checkTypeExpected(AVRO_BOOL); 
        uint8_t ival = 0; 
        reader_.read(ival); 
        val = (ival != 0); 
    } 
 
    void readValue(int32_t &val) { 
        validator_.checkTypeExpected(AVRO_INT); 
        uint32_t encoded = static_cast<uint32_t>(readVarInt()); 
        val = decodeZigzag32(encoded); 
    } 
 
    void readValue(int64_t &val) { 
        validator_.checkTypeExpected(AVRO_LONG); 
        uint64_t encoded = readVarInt(); 
        val = decodeZigzag64(encoded); 
    } 
 
    void readValue(float &val) { 
        validator_.checkTypeExpected(AVRO_FLOAT); 
        union { 
            float f; 
            uint32_t i; 
        } v; 
        reader_.read(v.i); 
        val = v.f; 
    } 
 
    void readValue(double &val) { 
        validator_.checkTypeExpected(AVRO_DOUBLE); 
        union { 
            double d; 
            uint64_t i; 
        } v; 
        reader_.read(v.i); 
        val = v.d; 
    } 
 
    void readValue(std::string &val) { 
        validator_.checkTypeExpected(AVRO_STRING); 
        size_t size = static_cast<size_t>(readSize()); 
        reader_.read(val, size); 
    } 
 
    void readBytes(std::vector<uint8_t> &val) { 
        validator_.checkTypeExpected(AVRO_BYTES); 
        size_t size = static_cast<size_t>(readSize()); 
        val.resize(size); 
        reader_.read(reinterpret_cast<char *>(val.data()), size); 
    } 
 
    void readFixed(uint8_t *val, size_t size) { 
        validator_.checkFixedSizeExpected(size); 
        reader_.read(reinterpret_cast<char *>(val), size); 
    } 
 
    template <size_t N> 
    void readFixed(uint8_t (&val)[N]) { 
        this->readFixed(val, N); 
    } 
 
    template <size_t N> 
    void readFixed(std::array<uint8_t, N> &val) { 
        this->readFixed(val.data(), N); 
    } 
 
    void readRecord() { 
        validator_.checkTypeExpected(AVRO_RECORD); 
        validator_.checkTypeExpected(AVRO_LONG); 
        validator_.setCount(1); 
    } 
 
    void readRecordEnd() { 
        validator_.checkTypeExpected(AVRO_RECORD); 
        validator_.checkTypeExpected(AVRO_LONG); 
        validator_.setCount(0); 
    } 
 
    int64_t readArrayBlockSize() { 
        validator_.checkTypeExpected(AVRO_ARRAY); 
        return readCount(); 
    } 
 
    int64_t readUnion() { 
        validator_.checkTypeExpected(AVRO_UNION); 
        return readCount(); 
    } 
 
    int64_t readEnum() { 
        validator_.checkTypeExpected(AVRO_ENUM); 
        return readCount(); 
    } 
 
    int64_t readMapBlockSize() { 
        validator_.checkTypeExpected(AVRO_MAP); 
        return readCount(); 
    } 
 
    Type nextType() const { 
        return validator_.nextTypeExpected(); 
    } 
 
    bool currentRecordName(std::string &name) const { 
        return validator_.getCurrentRecordName(name); 
    } 
 
    bool nextFieldName(std::string &name) const { 
        return validator_.getNextFieldName(name); 
    } 
 
  private: 
 
    uint64_t readVarInt() { 
        uint64_t encoded = 0; 
        uint8_t val = 0; 
        int shift = 0; 
        do { 
            reader_.read(val); 
            uint64_t newbits = static_cast<uint64_t>(val & 0x7f) << shift; 
            encoded |= newbits; 
            shift += 7; 
        } while (val & 0x80); 
 
        return encoded; 
    } 
 
    int64_t readSize() { 
        uint64_t encoded = readVarInt(); 
        int64_t size = decodeZigzag64(encoded); 
        return size; 
    } 
 
    int64_t readCount() { 
        validator_.checkTypeExpected(AVRO_LONG); 
        int64_t count = readSize(); 
        validator_.setCount(count); 
        return count; 
    } 
 
    ValidatorType validator_; 
    BufferReader  reader_; 
 
}; 
 
typedef ReaderImpl<NullValidator> Reader; 
typedef ReaderImpl<Validator> ValidatingReader; 
 
} // namespace avro 
 
#endif