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c9b8bd8de2
Queue output items and reuse them. Remove the unneeded type system in sql and just use the Go type system. In best case this is more than an order of magnitude speedup: ``` BenchmarkSelectAll_1M-12 1 1841049400 ns/op 274299728 B/op 4198522 allocs/op BenchmarkSelectAll_1M-12 14 84833400 ns/op 169228346 B/op 3146541 allocs/op ```
129 lines
3.5 KiB
Go
129 lines
3.5 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 csv
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import (
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"encoding/csv"
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"github.com/bcicen/jstream"
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"github.com/minio/minio/pkg/s3select/sql"
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)
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// Record - is a CSV record.
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type Record struct {
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columnNames []string
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csvRecord []string
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nameIndexMap map[string]int64
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}
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// Get - gets the value for a column name. CSV fields do not have any
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// defined type (other than the default string). So this function
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// always returns fields using sql.FromBytes so that the type
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// specified/implied by the query can be used, or can be automatically
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// converted based on the query.
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func (r *Record) Get(name string) (*sql.Value, error) {
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index, found := r.nameIndexMap[name]
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if !found {
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return nil, fmt.Errorf("column %v not found", name)
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}
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if index >= int64(len(r.csvRecord)) {
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// No value found for column 'name', hence return null
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// value
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return sql.FromNull(), nil
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}
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return sql.FromBytes([]byte(r.csvRecord[index])), nil
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}
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// Set - sets the value for a column name.
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func (r *Record) Set(name string, value *sql.Value) error {
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r.columnNames = append(r.columnNames, name)
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r.csvRecord = append(r.csvRecord, value.CSVString())
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return nil
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}
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// Reset data in record.
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func (r *Record) Reset() {
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if len(r.columnNames) > 0 {
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r.columnNames = r.columnNames[:0]
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}
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if len(r.csvRecord) > 0 {
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r.csvRecord = r.csvRecord[:0]
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}
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for k := range r.nameIndexMap {
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delete(r.nameIndexMap, k)
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}
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}
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// CopyFrom will copy all records from the incoming and append them to the existing records.
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// The source record must be of a similar type.
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// Note that the lookup index is not copied.
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func (r *Record) CopyFrom(record sql.Record) error {
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other, ok := record.(*Record)
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if !ok {
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return fmt.Errorf("unexpected record type, expected %T, got %T", r, record)
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}
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//before := len(r.csvRecord)
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r.columnNames = append(r.columnNames, other.columnNames...)
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r.csvRecord = append(r.csvRecord, other.csvRecord...)
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return nil
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}
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// WriteCSV - encodes to CSV data.
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func (r *Record) WriteCSV(writer io.Writer, fieldDelimiter rune) error {
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w := csv.NewWriter(writer)
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w.Comma = fieldDelimiter
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if err := w.Write(r.csvRecord); err != nil {
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return err
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}
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w.Flush()
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if err := w.Error(); err != nil {
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return err
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}
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return nil
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}
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// WriteJSON - encodes to JSON data.
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func (r *Record) WriteJSON(writer io.Writer) error {
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var kvs jstream.KVS = make([]jstream.KV, len(r.columnNames))
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for i := 0; i < len(r.columnNames); i++ {
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kvs[i] = jstream.KV{Key: r.columnNames[i], Value: r.csvRecord[i]}
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}
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return json.NewEncoder(writer).Encode(kvs)
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}
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// Raw - returns the underlying data with format info.
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func (r *Record) Raw() (sql.SelectObjectFormat, interface{}) {
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return sql.SelectFmtCSV, r
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}
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// Replace - is not supported for CSV
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func (r *Record) Replace(_ jstream.KVS) error {
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return errors.New("Replace is not supported for CSV")
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}
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// NewRecord - creates new CSV record.
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func NewRecord() *Record {
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return &Record{}
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}
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