terraform/vendor/google.golang.org/appengine/search/field.go

145 lines
3.8 KiB
Go

// Copyright 2014 Google Inc. All rights reserved.
// Use of this source code is governed by the Apache 2.0
// license that can be found in the LICENSE file.
package search
import (
"fmt"
"reflect"
)
// Field is a name/value pair. A search index's document can be loaded and
// saved as a sequence of Fields.
type Field struct {
// Name is the field name.
Name string
// Value is the field value. The valid types are:
// - string,
// - search.Atom,
// - search.HTML,
// - time.Time (stored with millisecond precision),
// - float64,
// - GeoPoint.
Value interface{}
// Language is a two-letter ISO 693-1 code for the field's language,
// defaulting to "en" if nothing is specified. It may only be specified for
// fields of type string and search.HTML.
Language string
// Derived marks fields that were calculated as a result of a
// FieldExpression provided to Search. This field is ignored when saving a
// document.
Derived bool
}
// DocumentMetadata is a struct containing information describing a given document.
type DocumentMetadata struct {
// Rank is an integer specifying the order the document will be returned in
// search results. If zero, the rank will be set to the number of seconds since
// 2011-01-01 00:00:00 UTC when being Put into an index.
Rank int
}
// FieldLoadSaver can be converted from and to a slice of Fields
// with additional document metadata.
type FieldLoadSaver interface {
Load([]Field, *DocumentMetadata) error
Save() ([]Field, *DocumentMetadata, error)
}
// FieldList converts a []Field to implement FieldLoadSaver.
type FieldList []Field
// Load loads all of the provided fields into l.
// It does not first reset *l to an empty slice.
func (l *FieldList) Load(f []Field, _ *DocumentMetadata) error {
*l = append(*l, f...)
return nil
}
// Save returns all of l's fields as a slice of Fields.
func (l *FieldList) Save() ([]Field, *DocumentMetadata, error) {
return *l, nil, nil
}
var _ FieldLoadSaver = (*FieldList)(nil)
// structFLS adapts a struct to be a FieldLoadSaver.
type structFLS struct {
reflect.Value
}
func (s structFLS) Load(fields []Field, _ *DocumentMetadata) (err error) {
for _, field := range fields {
f := s.FieldByName(field.Name)
if !f.IsValid() {
err = &ErrFieldMismatch{
FieldName: field.Name,
Reason: "no such struct field",
}
continue
}
if !f.CanSet() {
err = &ErrFieldMismatch{
FieldName: field.Name,
Reason: "cannot set struct field",
}
continue
}
v := reflect.ValueOf(field.Value)
if ft, vt := f.Type(), v.Type(); ft != vt {
err = &ErrFieldMismatch{
FieldName: field.Name,
Reason: fmt.Sprintf("type mismatch: %v for %v data", ft, vt),
}
continue
}
f.Set(v)
}
return err
}
func (s structFLS) Save() ([]Field, *DocumentMetadata, error) {
fields := make([]Field, 0, s.NumField())
for i := 0; i < s.NumField(); i++ {
f := s.Field(i)
if !f.CanSet() {
continue
}
fields = append(fields, Field{
Name: s.Type().Field(i).Name,
Value: f.Interface(),
})
}
return fields, nil, nil
}
// newStructFLS returns a FieldLoadSaver for the struct pointer p.
func newStructFLS(p interface{}) (FieldLoadSaver, error) {
v := reflect.ValueOf(p)
if v.Kind() != reflect.Ptr || v.IsNil() || v.Elem().Kind() != reflect.Struct {
return nil, ErrInvalidDocumentType
}
return structFLS{v.Elem()}, nil
}
// LoadStruct loads the fields from f to dst. dst must be a struct pointer.
func LoadStruct(dst interface{}, f []Field) error {
x, err := newStructFLS(dst)
if err != nil {
return err
}
return x.Load(f, nil)
}
// SaveStruct returns the fields from src as a slice of Field.
// src must be a struct pointer.
func SaveStruct(src interface{}) ([]Field, error) {
x, err := newStructFLS(src)
if err != nil {
return nil, err
}
fs, _, err := x.Save()
return fs, err
}