mirror of https://github.com/minio/minio.git
110 lines
2.7 KiB
Go
110 lines
2.7 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 parquet
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import (
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"io"
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"github.com/bcicen/jstream"
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jsonfmt "github.com/minio/minio/pkg/s3select/json"
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"github.com/minio/minio/pkg/s3select/sql"
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parquetgo "github.com/minio/parquet-go"
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parquetgen "github.com/minio/parquet-go/gen-go/parquet"
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)
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// Reader - Parquet record reader for S3Select.
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type Reader struct {
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args *ReaderArgs
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reader *parquetgo.Reader
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}
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// Read - reads single record.
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func (r *Reader) Read(dst sql.Record) (rec sql.Record, rerr error) {
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parquetRecord, err := r.reader.Read()
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if err != nil {
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if err != io.EOF {
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return nil, errParquetParsingError(err)
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}
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return nil, err
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}
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kvs := jstream.KVS{}
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f := func(name string, v parquetgo.Value) bool {
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if v.Value == nil {
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kvs = append(kvs, jstream.KV{Key: name, Value: nil})
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return true
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}
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var value interface{}
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switch v.Type {
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case parquetgen.Type_BOOLEAN:
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value = v.Value.(bool)
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case parquetgen.Type_INT32:
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value = int64(v.Value.(int32))
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case parquetgen.Type_INT64:
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value = int64(v.Value.(int64))
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case parquetgen.Type_FLOAT:
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value = float64(v.Value.(float32))
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case parquetgen.Type_DOUBLE:
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value = v.Value.(float64)
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case parquetgen.Type_INT96, parquetgen.Type_BYTE_ARRAY, parquetgen.Type_FIXED_LEN_BYTE_ARRAY:
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value = string(v.Value.([]byte))
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default:
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rerr = errParquetParsingError(nil)
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return false
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}
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kvs = append(kvs, jstream.KV{Key: name, Value: value})
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return true
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}
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// Apply our range
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parquetRecord.Range(f)
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// Reuse destination if we can.
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dstRec, ok := dst.(*jsonfmt.Record)
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if !ok {
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dstRec = &jsonfmt.Record{}
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}
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dstRec.SelectFormat = sql.SelectFmtParquet
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dstRec.KVS = kvs
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return dstRec, nil
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}
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// Close - closes underlying readers.
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func (r *Reader) Close() error {
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return r.reader.Close()
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}
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// NewReader - creates new Parquet reader using readerFunc callback.
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func NewReader(getReaderFunc func(offset, length int64) (io.ReadCloser, error), args *ReaderArgs) (*Reader, error) {
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reader, err := parquetgo.NewReader(getReaderFunc, nil)
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if err != nil {
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if err != io.EOF {
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return nil, errParquetParsingError(err)
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}
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return nil, err
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}
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return &Reader{
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args: args,
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reader: reader,
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}, nil
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}
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