/
util.go
75 lines (68 loc) · 2.48 KB
/
util.go
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// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package databaseio provides transformations and utilities to interact with
// generic database database/sql API. See also: https://golang.org/pkg/database/sql/
package databaseio
import (
"reflect"
"strings"
"github.com/apache/beam/sdks/go/pkg/beam/internal/errors"
)
//mapFields maps column into field index in record type
func mapFields(columns []string, recordType reflect.Type) ([]int, error) {
var indexedFields = map[string]int{}
for i := 0; i < recordType.NumField(); i++ {
if isExported := recordType.Field(i).PkgPath == ""; !isExported {
continue
}
fieldName := recordType.Field(i).Name
indexedFields[fieldName] = i
indexedFields[strings.ToLower(fieldName)] = i //to account for various matching strategies
aTag := recordType.Field(i).Tag
if column := aTag.Get("column"); column != "" {
indexedFields[column] = i
}
}
var mappedFieldIndex = make([]int, len(columns))
for i, column := range columns {
fieldIndex, ok := indexedFields[column]
if !ok {
fieldIndex, ok = indexedFields[strings.ToLower(column)]
}
if !ok {
fieldIndex, ok = indexedFields[strings.Replace(strings.ToLower(column), "_", "", strings.Count(column, "_"))]
}
if !ok {
return nil, errors.Errorf("failed to matched a %v field for SQL column: %v", recordType, column)
}
mappedFieldIndex[i] = fieldIndex
}
return mappedFieldIndex, nil
}
func asDereferenceSlice(aSlice []interface{}) {
for i, value := range aSlice {
if value == nil {
continue
}
aSlice[i] = reflect.ValueOf(value).Elem().Interface()
}
}
func asMap(keys []string, values []interface{}) map[string]interface{} {
var result = make(map[string]interface{})
for i, key := range keys {
result[key] = values[i]
}
return result
}