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bleve/document/field_numeric.go
Marty Schoch 082a5b0b03 major change to fields
now can track array positions for field values
stored fields now include this in the key
and the back index now uses protobufs to simplify serialization
closes #73
2014-08-19 08:58:26 -04:00

116 lines
3.2 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"
"github.com/couchbaselabs/bleve/analysis"
"github.com/couchbaselabs/bleve/numeric_util"
)
const DEFAULT_NUMERIC_INDEXING_OPTIONS = STORE_FIELD | INDEX_FIELD
const DEFAULT_PRECISION_STEP uint = 4
type NumericField struct {
name string
arrayPositions []uint64
options IndexingOptions
value numeric_util.PrefixCoded
}
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 := DEFAULT_PRECISION_STEP
for shift < 64 {
shiftEncoded, err := numeric_util.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 += DEFAULT_PRECISION_STEP
}
}
fieldLength := len(tokens)
tokenFreqs := analysis.TokenFrequency(tokens)
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_util.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 NewNumericFieldFromBytes(name string, arrayPositions []uint64, value []byte) *NumericField {
return &NumericField{
name: name,
arrayPositions: arrayPositions,
value: value,
options: DEFAULT_NUMERIC_INDEXING_OPTIONS,
}
}
func NewNumericField(name string, arrayPositions []uint64, number float64) *NumericField {
return NewNumericFieldWithIndexingOptions(name, arrayPositions, number, DEFAULT_NUMERIC_INDEXING_OPTIONS)
}
func NewNumericFieldWithIndexingOptions(name string, arrayPositions []uint64, number float64, options IndexingOptions) *NumericField {
numberInt64 := numeric_util.Float64ToInt64(number)
prefixCoded := numeric_util.MustNewPrefixCodedInt64(numberInt64, 0)
return &NumericField{
name: name,
arrayPositions: arrayPositions,
value: prefixCoded,
options: options,
}
}