githaven-fork/vendor/github.com/blevesearch/bleve/document/field_datetime.go
2017-01-25 10:43:02 +08:00

145 lines
3.9 KiB
Go

// Copyright (c) 2014 Couchbase, Inc.
//
// Licensed 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 document
import (
"fmt"
"math"
"time"
"github.com/blevesearch/bleve/analysis"
"github.com/blevesearch/bleve/numeric"
)
const DefaultDateTimeIndexingOptions = StoreField | IndexField
const DefaultDateTimePrecisionStep uint = 4
var MinTimeRepresentable = time.Unix(0, math.MinInt64)
var MaxTimeRepresentable = time.Unix(0, math.MaxInt64)
type DateTimeField struct {
name string
arrayPositions []uint64
options IndexingOptions
value numeric.PrefixCoded
numPlainTextBytes uint64
}
func (n *DateTimeField) Name() string {
return n.name
}
func (n *DateTimeField) ArrayPositions() []uint64 {
return n.arrayPositions
}
func (n *DateTimeField) Options() IndexingOptions {
return n.options
}
func (n *DateTimeField) Analyze() (int, analysis.TokenFrequencies) {
tokens := make(analysis.TokenStream, 0)
tokens = append(tokens, &analysis.Token{
Start: 0,
End: len(n.value),
Term: n.value,
Position: 1,
Type: analysis.DateTime,
})
original, err := n.value.Int64()
if err == nil {
shift := DefaultDateTimePrecisionStep
for shift < 64 {
shiftEncoded, err := numeric.NewPrefixCodedInt64(original, shift)
if err != nil {
break
}
token := analysis.Token{
Start: 0,
End: len(shiftEncoded),
Term: shiftEncoded,
Position: 1,
Type: analysis.DateTime,
}
tokens = append(tokens, &token)
shift += DefaultDateTimePrecisionStep
}
}
fieldLength := len(tokens)
tokenFreqs := analysis.TokenFrequency(tokens, n.arrayPositions, n.options.IncludeTermVectors())
return fieldLength, tokenFreqs
}
func (n *DateTimeField) Value() []byte {
return n.value
}
func (n *DateTimeField) DateTime() (time.Time, error) {
i64, err := n.value.Int64()
if err != nil {
return time.Time{}, err
}
return time.Unix(0, i64).UTC(), nil
}
func (n *DateTimeField) GoString() string {
return fmt.Sprintf("&document.DateField{Name:%s, Options: %s, Value: %s}", n.name, n.options, n.value)
}
func (n *DateTimeField) NumPlainTextBytes() uint64 {
return n.numPlainTextBytes
}
func NewDateTimeFieldFromBytes(name string, arrayPositions []uint64, value []byte) *DateTimeField {
return &DateTimeField{
name: name,
arrayPositions: arrayPositions,
value: value,
options: DefaultDateTimeIndexingOptions,
numPlainTextBytes: uint64(len(value)),
}
}
func NewDateTimeField(name string, arrayPositions []uint64, dt time.Time) (*DateTimeField, error) {
return NewDateTimeFieldWithIndexingOptions(name, arrayPositions, dt, DefaultDateTimeIndexingOptions)
}
func NewDateTimeFieldWithIndexingOptions(name string, arrayPositions []uint64, dt time.Time, options IndexingOptions) (*DateTimeField, error) {
if canRepresent(dt) {
dtInt64 := dt.UnixNano()
prefixCoded := numeric.MustNewPrefixCodedInt64(dtInt64, 0)
return &DateTimeField{
name: name,
arrayPositions: arrayPositions,
value: prefixCoded,
options: options,
// not correct, just a place holder until we revisit how fields are
// represented and can fix this better
numPlainTextBytes: uint64(8),
}, nil
}
return nil, fmt.Errorf("cannot represent %s in this type", dt)
}
func canRepresent(dt time.Time) bool {
if dt.Before(MinTimeRepresentable) || dt.After(MaxTimeRepresentable) {
return false
}
return true
}