Search bar for issues/pulls (#530)

vendor/github.com/blevesearch/bleve/document/field_datetime.go

@@ -0,0 +1,144 @@
+//  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
+}