gitea/vendor/github.com/blevesearch/bleve/document/field_numeric.go

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2017-01-25 02:43:02 +00:00
// 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"
"github.com/blevesearch/bleve/analysis"
"github.com/blevesearch/bleve/numeric"
)
const DefaultNumericIndexingOptions = StoreField | IndexField
const DefaultPrecisionStep uint = 4
type NumericField struct {
name string
arrayPositions []uint64
options IndexingOptions
value numeric.PrefixCoded
numPlainTextBytes uint64
}
func (n *NumericField) Name() string {
return n.name
}
func (n *NumericField) ArrayPositions() []uint64 {
return n.arrayPositions
}
func (n *NumericField) Options() IndexingOptions {
return n.options
}
func (n *NumericField) 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.Numeric,
})
original, err := n.value.Int64()
if err == nil {
shift := DefaultPrecisionStep
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.Numeric,
}
tokens = append(tokens, &token)
shift += DefaultPrecisionStep
}
}
fieldLength := len(tokens)
tokenFreqs := analysis.TokenFrequency(tokens, n.arrayPositions, n.options.IncludeTermVectors())
return fieldLength, tokenFreqs
}
func (n *NumericField) Value() []byte {
return n.value
}
func (n *NumericField) Number() (float64, error) {
i64, err := n.value.Int64()
if err != nil {
return 0.0, err
}
return numeric.Int64ToFloat64(i64), nil
}
func (n *NumericField) GoString() string {
return fmt.Sprintf("&document.NumericField{Name:%s, Options: %s, Value: %s}", n.name, n.options, n.value)
}
func (n *NumericField) NumPlainTextBytes() uint64 {
return n.numPlainTextBytes
}
func NewNumericFieldFromBytes(name string, arrayPositions []uint64, value []byte) *NumericField {
return &NumericField{
name: name,
arrayPositions: arrayPositions,
value: value,
options: DefaultNumericIndexingOptions,
numPlainTextBytes: uint64(len(value)),
}
}
func NewNumericField(name string, arrayPositions []uint64, number float64) *NumericField {
return NewNumericFieldWithIndexingOptions(name, arrayPositions, number, DefaultNumericIndexingOptions)
}
func NewNumericFieldWithIndexingOptions(name string, arrayPositions []uint64, number float64, options IndexingOptions) *NumericField {
numberInt64 := numeric.Float64ToInt64(number)
prefixCoded := numeric.MustNewPrefixCodedInt64(numberInt64, 0)
return &NumericField{
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),
}
}