File size: 6,942 Bytes
9c6594c |
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 |
// 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.
// This module defines an abstract interface for iterating through pages in a
// Parquet column chunk within a row group. It could be extended in the future
// to iterate through all data pages in all chunks in a file.
#pragma once
#include <cstdint>
#include <memory>
#include <optional>
#include <string>
#include "parquet/size_statistics.h"
#include "parquet/statistics.h"
#include "parquet/types.h"
namespace parquet {
// TODO: Parallel processing is not yet safe because of memory-ownership
// semantics (the PageReader may or may not own the memory referenced by a
// page)
//
// TODO(wesm): In the future Parquet implementations may store the crc code
// in format::PageHeader. parquet-mr currently does not, so we also skip it
// here, both on the read and write path
class Page {
public:
Page(const std::shared_ptr<Buffer>& buffer, PageType::type type)
: buffer_(buffer), type_(type) {}
PageType::type type() const { return type_; }
std::shared_ptr<Buffer> buffer() const { return buffer_; }
// @returns: a pointer to the page's data
const uint8_t* data() const { return buffer_->data(); }
// @returns: the total size in bytes of the page's data buffer
int32_t size() const { return static_cast<int32_t>(buffer_->size()); }
private:
std::shared_ptr<Buffer> buffer_;
PageType::type type_;
};
/// \brief Base type for DataPageV1 and DataPageV2 including common attributes
class DataPage : public Page {
public:
int32_t num_values() const { return num_values_; }
Encoding::type encoding() const { return encoding_; }
int64_t uncompressed_size() const { return uncompressed_size_; }
const EncodedStatistics& statistics() const { return statistics_; }
/// Return the row ordinal within the row group to the first row in the data page.
/// Currently it is only present from data pages created by ColumnWriter in order
/// to collect page index.
std::optional<int64_t> first_row_index() const { return first_row_index_; }
const SizeStatistics& size_statistics() const { return size_statistics_; }
virtual ~DataPage() = default;
protected:
DataPage(PageType::type type, const std::shared_ptr<Buffer>& buffer, int32_t num_values,
Encoding::type encoding, int64_t uncompressed_size,
EncodedStatistics statistics, std::optional<int64_t> first_row_index,
SizeStatistics size_statistics)
: Page(buffer, type),
num_values_(num_values),
encoding_(encoding),
uncompressed_size_(uncompressed_size),
statistics_(std::move(statistics)),
first_row_index_(std::move(first_row_index)),
size_statistics_(std::move(size_statistics)) {}
int32_t num_values_;
Encoding::type encoding_;
int64_t uncompressed_size_;
EncodedStatistics statistics_;
/// Row ordinal within the row group to the first row in the data page.
std::optional<int64_t> first_row_index_;
SizeStatistics size_statistics_;
};
class DataPageV1 : public DataPage {
public:
DataPageV1(const std::shared_ptr<Buffer>& buffer, int32_t num_values,
Encoding::type encoding, Encoding::type definition_level_encoding,
Encoding::type repetition_level_encoding, int64_t uncompressed_size,
EncodedStatistics statistics = EncodedStatistics(),
std::optional<int64_t> first_row_index = std::nullopt,
SizeStatistics size_statistics = SizeStatistics())
: DataPage(PageType::DATA_PAGE, buffer, num_values, encoding, uncompressed_size,
std::move(statistics), std::move(first_row_index),
std::move(size_statistics)),
definition_level_encoding_(definition_level_encoding),
repetition_level_encoding_(repetition_level_encoding) {}
Encoding::type repetition_level_encoding() const { return repetition_level_encoding_; }
Encoding::type definition_level_encoding() const { return definition_level_encoding_; }
private:
Encoding::type definition_level_encoding_;
Encoding::type repetition_level_encoding_;
};
class DataPageV2 : public DataPage {
public:
DataPageV2(const std::shared_ptr<Buffer>& buffer, int32_t num_values, int32_t num_nulls,
int32_t num_rows, Encoding::type encoding,
int32_t definition_levels_byte_length, int32_t repetition_levels_byte_length,
int64_t uncompressed_size, bool is_compressed = false,
EncodedStatistics statistics = EncodedStatistics(),
std::optional<int64_t> first_row_index = std::nullopt,
SizeStatistics size_statistics = SizeStatistics())
: DataPage(PageType::DATA_PAGE_V2, buffer, num_values, encoding, uncompressed_size,
std::move(statistics), std::move(first_row_index),
std::move(size_statistics)),
num_nulls_(num_nulls),
num_rows_(num_rows),
definition_levels_byte_length_(definition_levels_byte_length),
repetition_levels_byte_length_(repetition_levels_byte_length),
is_compressed_(is_compressed) {}
int32_t num_nulls() const { return num_nulls_; }
int32_t num_rows() const { return num_rows_; }
int32_t definition_levels_byte_length() const { return definition_levels_byte_length_; }
int32_t repetition_levels_byte_length() const { return repetition_levels_byte_length_; }
bool is_compressed() const { return is_compressed_; }
private:
int32_t num_nulls_;
int32_t num_rows_;
int32_t definition_levels_byte_length_;
int32_t repetition_levels_byte_length_;
bool is_compressed_;
};
class DictionaryPage : public Page {
public:
DictionaryPage(const std::shared_ptr<Buffer>& buffer, int32_t num_values,
Encoding::type encoding, bool is_sorted = false)
: Page(buffer, PageType::DICTIONARY_PAGE),
num_values_(num_values),
encoding_(encoding),
is_sorted_(is_sorted) {}
int32_t num_values() const { return num_values_; }
Encoding::type encoding() const { return encoding_; }
bool is_sorted() const { return is_sorted_; }
private:
int32_t num_values_;
Encoding::type encoding_;
bool is_sorted_;
};
} // namespace parquet
|