minio/pkg/s3select/parquet/reader.go

139 lines
3.9 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package parquet
import (
"fmt"
"io"
"time"
"github.com/bcicen/jstream"
parquetgo "github.com/minio/minio/pkg/s3select/internal/parquet-go"
parquetgen "github.com/minio/minio/pkg/s3select/internal/parquet-go/gen-go/parquet"
jsonfmt "github.com/minio/minio/pkg/s3select/json"
"github.com/minio/minio/pkg/s3select/sql"
)
// Reader - Parquet record reader for S3Select.
type Reader struct {
args *ReaderArgs
reader *parquetgo.Reader
}
// Read - reads single record.
func (r *Reader) Read(dst sql.Record) (rec sql.Record, rerr error) {
defer func() {
if rec := recover(); rec != nil {
rerr = fmt.Errorf("panic reading parquet record: %v", rec)
}
}()
parquetRecord, err := r.reader.Read()
if err != nil {
if err != io.EOF {
return nil, errParquetParsingError(err)
}
return nil, err
}
kvs := jstream.KVS{}
f := func(name string, v parquetgo.Value) bool {
if v.Value == nil {
kvs = append(kvs, jstream.KV{Key: name, Value: nil})
return true
}
var value interface{}
switch v.Type {
case parquetgen.Type_BOOLEAN:
value = v.Value.(bool)
case parquetgen.Type_INT32:
value = int64(v.Value.(int32))
if v.Schema != nil && v.Schema.ConvertedType != nil {
switch *v.Schema.ConvertedType {
case parquetgen.ConvertedType_DATE:
value = sql.FormatSQLTimestamp(time.Unix(60*60*24*int64(v.Value.(int32)), 0).UTC())
}
}
case parquetgen.Type_INT64:
value = v.Value.(int64)
if v.Schema != nil && v.Schema.ConvertedType != nil {
switch *v.Schema.ConvertedType {
// Only UTC supported, add one NS to never be exactly midnight.
case parquetgen.ConvertedType_TIMESTAMP_MILLIS:
value = sql.FormatSQLTimestamp(time.Unix(0, 0).Add(time.Duration(v.Value.(int64)) * time.Millisecond).UTC())
case parquetgen.ConvertedType_TIMESTAMP_MICROS:
value = sql.FormatSQLTimestamp(time.Unix(0, 0).Add(time.Duration(v.Value.(int64)) * time.Microsecond).UTC())
}
}
case parquetgen.Type_FLOAT:
value = float64(v.Value.(float32))
case parquetgen.Type_DOUBLE:
value = v.Value.(float64)
case parquetgen.Type_INT96, parquetgen.Type_BYTE_ARRAY, parquetgen.Type_FIXED_LEN_BYTE_ARRAY:
value = string(v.Value.([]byte))
default:
rerr = errParquetParsingError(nil)
return false
}
kvs = append(kvs, jstream.KV{Key: name, Value: value})
return true
}
// Apply our range
parquetRecord.Range(f)
// Reuse destination if we can.
dstRec, ok := dst.(*jsonfmt.Record)
if !ok {
dstRec = &jsonfmt.Record{}
}
dstRec.SelectFormat = sql.SelectFmtParquet
dstRec.KVS = kvs
return dstRec, nil
}
// Close - closes underlying readers.
func (r *Reader) Close() error {
return r.reader.Close()
}
// NewReader - creates new Parquet reader using readerFunc callback.
func NewReader(getReaderFunc func(offset, length int64) (io.ReadCloser, error), args *ReaderArgs) (r *Reader, err error) {
defer func() {
if rec := recover(); rec != nil {
err = fmt.Errorf("panic reading parquet header: %v", rec)
}
}()
reader, err := parquetgo.NewReader(getReaderFunc, nil)
if err != nil {
if err != io.EOF {
return nil, errParquetParsingError(err)
}
return nil, err
}
return &Reader{
args: args,
reader: reader,
}, nil
}