initial commit

vendor/github.com/blevesearch/bleve/index/firestorm/dictionary.go

@@ -0,0 +1,128 @@
+//  Copyright (c) 2015 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 firestorm
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+const ByteSeparator byte = 0xff
+
+var DictionaryKeyPrefix = []byte{'d'}
+
+type DictionaryRow struct {
+	field uint16
+	term  []byte
+	value DictionaryValue
+}
+
+func NewDictionaryRow(field uint16, term []byte, count uint64) *DictionaryRow {
+	rv := DictionaryRow{
+		field: field,
+		term:  term,
+	}
+	rv.value.Count = proto.Uint64(count)
+	return &rv
+}
+
+func NewDictionaryRowK(key []byte) (*DictionaryRow, error) {
+	rv := DictionaryRow{}
+	buf := bytes.NewBuffer(key)
+	_, err := buf.ReadByte() // type
+	if err != nil {
+		return nil, err
+	}
+
+	err = binary.Read(buf, binary.LittleEndian, &rv.field)
+	if err != nil {
+		return nil, err
+	}
+
+	rv.term, err = buf.ReadBytes(ByteSeparator)
+	// there is no separator expected here, should get EOF
+	if err != io.EOF {
+		return nil, err
+	}
+
+	return &rv, nil
+}
+
+func (dr *DictionaryRow) parseDictionaryV(value []byte) error {
+	err := dr.value.Unmarshal(value)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func NewDictionaryRowKV(key, value []byte) (*DictionaryRow, error) {
+	rv, err := NewDictionaryRowK(key)
+	if err != nil {
+		return nil, err
+	}
+
+	err = rv.parseDictionaryV(value)
+	if err != nil {
+		return nil, err
+	}
+	return rv, nil
+
+}
+
+func (dr *DictionaryRow) Count() uint64 {
+	return dr.value.GetCount()
+}
+
+func (dr *DictionaryRow) SetCount(count uint64) {
+	dr.value.Count = proto.Uint64(count)
+}
+
+func (dr *DictionaryRow) KeySize() int {
+	return 3 + len(dr.term)
+}
+
+func (dr *DictionaryRow) KeyTo(buf []byte) (int, error) {
+	copy(buf[0:], DictionaryKeyPrefix)
+	binary.LittleEndian.PutUint16(buf[1:3], dr.field)
+	copy(buf[3:], dr.term)
+	return 3 + len(dr.term), nil
+}
+
+func (dr *DictionaryRow) Key() []byte {
+	buf := make([]byte, dr.KeySize())
+	n, _ := dr.KeyTo(buf)
+	return buf[:n]
+}
+
+func (dr *DictionaryRow) ValueSize() int {
+	return dr.value.Size()
+}
+
+func (dr *DictionaryRow) ValueTo(buf []byte) (int, error) {
+	return dr.value.MarshalTo(buf)
+}
+
+func (dr *DictionaryRow) Value() []byte {
+	buf := make([]byte, dr.ValueSize())
+	n, _ := dr.ValueTo(buf)
+	return buf[:n]
+}
+
+func DictionaryRowKey(field uint16, term []byte) []byte {
+	buf := make([]byte, 3+len(term))
+	copy(buf[0:], DictionaryKeyPrefix)
+	binary.LittleEndian.PutUint16(buf[1:3], field)
+	copy(buf[3:], term)
+	return buf
+}