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
|
/**
* 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
*
* http://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 ORC_COLUMN_READER_HH
#define ORC_COLUMN_READER_HH
#include <unordered_map>
#include "orc/Vector.hh"
#include "ByteRLE.hh"
#include "Compression.hh"
#include "Timezone.hh"
#include "wrap/orc-proto-wrapper.hh"
namespace orc {
class StripeStreams {
public:
virtual ~StripeStreams();
/**
* Get the array of booleans for which columns are selected.
* @return the address of an array which contains true at the index of
* each columnId is selected.
*/
virtual const std::vector<bool> getSelectedColumns() const = 0;
/**
* Get the encoding for the given column for this stripe.
*/
virtual proto::ColumnEncoding getEncoding(uint64_t columnId) const = 0;
/**
* Get the stream for the given column/kind in this stripe.
* @param columnId the id of the column
* @param kind the kind of the stream
* @param shouldStream should the reading page the stream in
* @return the new stream
*/
virtual std::unique_ptr<SeekableInputStream>
getStream(uint64_t columnId,
proto::Stream_Kind kind,
bool shouldStream) const = 0;
/**
* Get the memory pool for this reader.
*/
virtual MemoryPool& getMemoryPool() const = 0;
/**
* Get the writer's timezone, so that we can convert their dates correctly.
*/
virtual const Timezone& getWriterTimezone() const = 0;
/**
* Get the error stream.
* @return a pointer to the stream that should get error messages
*/
virtual std::ostream* getErrorStream() const = 0;
/**
* Should the reader throw when the scale overflows when reading Hive 0.11
* decimals.
* @return true if it should throw
*/
virtual bool getThrowOnHive11DecimalOverflow() const = 0;
/**
* What is the scale forced on the Hive 0.11 decimals?
* @return the number of scale digits
*/
virtual int32_t getForcedScaleOnHive11Decimal() const = 0;
};
/**
* The interface for reading ORC data types.
*/
class ColumnReader {
protected:
std::unique_ptr<ByteRleDecoder> notNullDecoder;
uint64_t columnId;
MemoryPool& memoryPool;
public:
ColumnReader(const Type& type, StripeStreams& stipe);
virtual ~ColumnReader();
/**
* Skip number of specified rows.
* @param numValues the number of values to skip
* @return the number of non-null values skipped
*/
virtual uint64_t skip(uint64_t numValues);
/**
* Read the next group of values into this rowBatch.
* @param rowBatch the memory to read into.
* @param numValues the number of values to read
* @param notNull if null, all values are not null. Otherwise, it is
* a mask (with at least numValues bytes) for which values to
* set.
*/
virtual void next(ColumnVectorBatch& rowBatch,
uint64_t numValues,
char* notNull);
/**
* Read the next group of values without decoding
* @param rowBatch the memory to read into.
* @param numValues the number of values to read
* @param notNull if null, all values are not null. Otherwise, it is
* a mask (with at least numValues bytes) for which values to
* set.
*/
virtual void nextEncoded(ColumnVectorBatch& rowBatch,
uint64_t numValues,
char* notNull)
{
rowBatch.isEncoded = false;
next(rowBatch, numValues, notNull);
}
/**
* Seek to beginning of a row group in the current stripe
* @param positions a list of PositionProviders storing the positions
*/
virtual void seekToRowGroup(
std::unordered_map<uint64_t, PositionProvider>& positions);
};
/**
* Create a reader for the given stripe.
*/
std::unique_ptr<ColumnReader> buildReader(const Type& type,
StripeStreams& stripe);
}
#endif
|
