132 lines
3.6 KiB
Go
132 lines
3.6 KiB
Go
// Copyright (c) 2015-2021 MinIO, Inc.
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//
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// This file is part of MinIO Object Storage stack
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package csv
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import (
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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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csv "github.com/minio/csvparser"
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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) (sql.Record, 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 r, 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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// Clone the record.
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func (r *Record) Clone(dst sql.Record) sql.Record {
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other, ok := dst.(*Record)
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if !ok {
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other = &Record{}
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}
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if len(other.columnNames) > 0 {
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other.columnNames = other.columnNames[:0]
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}
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if len(other.csvRecord) > 0 {
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other.csvRecord = other.csvRecord[:0]
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}
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other.columnNames = append(other.columnNames, r.columnNames...)
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other.csvRecord = append(other.csvRecord, r.csvRecord...)
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return other
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}
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// WriteCSV - encodes to CSV data.
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func (r *Record) WriteCSV(writer io.Writer, opts sql.WriteCSVOpts) error {
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w := csv.NewWriter(writer)
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w.Comma = opts.FieldDelimiter
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w.AlwaysQuote = opts.AlwaysQuote
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w.Quote = opts.Quote
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w.QuoteEscape = opts.QuoteEscape
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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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return w.Error()
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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(_ interface{}) 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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