84 lines
2.4 KiB
Go
84 lines
2.4 KiB
Go
/*
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* Minio Cloud Storage, (C) 2019 Minio, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package encoding
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import (
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"fmt"
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"github.com/minio/minio/pkg/s3select/internal/parquet-go/gen-go/parquet"
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)
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func rleEncodeInt32s(i32s []int32, bitWidth int32) (data []byte) {
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j := 0
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for i := 0; i < len(i32s); i = j {
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for j = i + 1; j < len(i32s) && i32s[i] == i32s[j]; j++ {
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}
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headerBytes := varIntEncode(uint64((j - i) << 1))
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data = append(data, headerBytes...)
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valBytes := plainEncodeInt32s([]int32{i32s[i]})
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byteCount := (bitWidth + 7) / 8
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data = append(data, valBytes[:byteCount]...)
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}
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return data
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}
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func rleEncodeInt64s(i64s []int64, bitWidth int32) (data []byte) {
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j := 0
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for i := 0; i < len(i64s); i = j {
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for j = i + 1; j < len(i64s) && i64s[i] == i64s[j]; j++ {
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}
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headerBytes := varIntEncode(uint64((j - i) << 1))
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data = append(data, headerBytes...)
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valBytes := plainEncodeInt64s([]int64{i64s[i]})
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byteCount := (bitWidth + 7) / 8
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data = append(data, valBytes[:byteCount]...)
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}
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return data
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}
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// RLEBitPackedHybridEncode encodes values specified in https://github.com/apache/parquet-format/blob/master/Encodings.md#run-length-encoding--bit-packing-hybrid-rle--3
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//
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// Supported Types: INT32, INT64
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func RLEBitPackedHybridEncode(values interface{}, bitWidth int32, parquetType parquet.Type) []byte {
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var rleBytes []byte
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switch parquetType {
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case parquet.Type_INT32:
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i32s, ok := values.([]int32)
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if !ok {
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panic(fmt.Errorf("expected slice of int32"))
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}
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rleBytes = rleEncodeInt32s(i32s, bitWidth)
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case parquet.Type_INT64:
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i64s, ok := values.([]int64)
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if !ok {
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panic(fmt.Errorf("expected slice of int64"))
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}
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rleBytes = rleEncodeInt64s(i64s, bitWidth)
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default:
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panic(fmt.Errorf("%v parquet type unsupported", parquetType))
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}
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lenBytes := plainEncodeInt32s([]int32{int32(len(rleBytes))})
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return append(lenBytes, rleBytes...)
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}
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