initial commit

vendor/github.com/blevesearch/bleve/index/upside_down/index_reader.go

@@ -0,0 +1,166 @@
+//  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 upside_down
+
+import (
+	"github.com/blevesearch/bleve/document"
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/index/store"
+)
+
+type IndexReader struct {
+	index    *UpsideDownCouch
+	kvreader store.KVReader
+	docCount uint64
+}
+
+func (i *IndexReader) TermFieldReader(term []byte, fieldName string) (index.TermFieldReader, error) {
+	fieldIndex, fieldExists := i.index.fieldCache.FieldNamed(fieldName, false)
+	if fieldExists {
+		return newUpsideDownCouchTermFieldReader(i, term, uint16(fieldIndex))
+	}
+	return newUpsideDownCouchTermFieldReader(i, []byte{ByteSeparator}, ^uint16(0))
+}
+
+func (i *IndexReader) FieldDict(fieldName string) (index.FieldDict, error) {
+	return i.FieldDictRange(fieldName, nil, nil)
+}
+
+func (i *IndexReader) FieldDictRange(fieldName string, startTerm []byte, endTerm []byte) (index.FieldDict, error) {
+	fieldIndex, fieldExists := i.index.fieldCache.FieldNamed(fieldName, false)
+	if fieldExists {
+		return newUpsideDownCouchFieldDict(i, uint16(fieldIndex), startTerm, endTerm)
+	}
+	return newUpsideDownCouchFieldDict(i, ^uint16(0), []byte{ByteSeparator}, []byte{})
+}
+
+func (i *IndexReader) FieldDictPrefix(fieldName string, termPrefix []byte) (index.FieldDict, error) {
+	return i.FieldDictRange(fieldName, termPrefix, termPrefix)
+}
+
+func (i *IndexReader) DocIDReader(start, end string) (index.DocIDReader, error) {
+	return newUpsideDownCouchDocIDReader(i, start, end)
+}
+
+func (i *IndexReader) Document(id string) (doc *document.Document, err error) {
+	// first hit the back index to confirm doc exists
+	var backIndexRow *BackIndexRow
+	backIndexRow, err = i.index.backIndexRowForDoc(i.kvreader, id)
+	if err != nil {
+		return
+	}
+	if backIndexRow == nil {
+		return
+	}
+	doc = document.NewDocument(id)
+	storedRow := NewStoredRow([]byte(id), 0, []uint64{}, 'x', nil)
+	storedRowScanPrefix := storedRow.ScanPrefixForDoc()
+	it := i.kvreader.PrefixIterator(storedRowScanPrefix)
+	defer func() {
+		if cerr := it.Close(); err == nil && cerr != nil {
+			err = cerr
+		}
+	}()
+	key, val, valid := it.Current()
+	for valid {
+		safeVal := make([]byte, len(val))
+		copy(safeVal, val)
+		var row *StoredRow
+		row, err = NewStoredRowKV(key, safeVal)
+		if err != nil {
+			doc = nil
+			return
+		}
+		if row != nil {
+			fieldName := i.index.fieldCache.FieldIndexed(row.field)
+			field := decodeFieldType(row.typ, fieldName, row.arrayPositions, row.value)
+			if field != nil {
+				doc.AddField(field)
+			}
+		}
+
+		it.Next()
+		key, val, valid = it.Current()
+	}
+	return
+}
+
+func (i *IndexReader) DocumentFieldTerms(id string) (index.FieldTerms, error) {
+	back, err := i.index.backIndexRowForDoc(i.kvreader, id)
+	if err != nil {
+		return nil, err
+	}
+	rv := make(index.FieldTerms, len(back.termEntries))
+	for _, entry := range back.termEntries {
+		fieldName := i.index.fieldCache.FieldIndexed(uint16(*entry.Field))
+		terms, ok := rv[fieldName]
+		if !ok {
+			terms = make([]string, 0)
+		}
+		terms = append(terms, *entry.Term)
+		rv[fieldName] = terms
+	}
+	return rv, nil
+}
+
+func (i *IndexReader) Fields() (fields []string, err error) {
+	fields = make([]string, 0)
+	it := i.kvreader.PrefixIterator([]byte{'f'})
+	defer func() {
+		if cerr := it.Close(); err == nil && cerr != nil {
+			err = cerr
+		}
+	}()
+	key, val, valid := it.Current()
+	for valid {
+		var row UpsideDownCouchRow
+		row, err = ParseFromKeyValue(key, val)
+		if err != nil {
+			fields = nil
+			return
+		}
+		if row != nil {
+			fieldRow, ok := row.(*FieldRow)
+			if ok {
+				fields = append(fields, fieldRow.name)
+			}
+		}
+
+		it.Next()
+		key, val, valid = it.Current()
+	}
+	return
+}
+
+func (i *IndexReader) GetInternal(key []byte) ([]byte, error) {
+	internalRow := NewInternalRow(key, nil)
+	return i.kvreader.Get(internalRow.Key())
+}
+
+func (i *IndexReader) DocCount() uint64 {
+	return i.docCount
+}
+
+func (i *IndexReader) Close() error {
+	return i.kvreader.Close()
+}
+
+func incrementBytes(in []byte) []byte {
+	rv := make([]byte, len(in))
+	copy(rv, in)
+	for i := len(rv) - 1; i >= 0; i-- {
+		rv[i] = rv[i] + 1
+		if rv[i] != 0 {
+			// didn't overflow, so stop
+			break
+		}
+	}
+	return rv
+}