/
tree_writer.go
75 lines (64 loc) · 2.07 KB
/
tree_writer.go
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// Copyright (c) 2014 Marty Schoch
// 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 gouchstore
import (
"sort"
)
type TreeWriter interface {
AddItem(key, value []byte) error
Sort() error
Write(db *Gouchstore) (*nodePointer, error)
Close() error
}
type InMemoryTreeWriter struct {
keyCompare btreeKeyComparator
reduce reduceFunc
rereduce reduceFunc
reduceContext interface{}
keys [][]byte
vals [][]byte
}
func NewInMemoryTreeWriter(keyCompare btreeKeyComparator, reduce, rereduce reduceFunc, reduceContext interface{}) (*InMemoryTreeWriter, error) {
return &InMemoryTreeWriter{
keyCompare: keyCompare,
reduce: reduce,
rereduce: rereduce,
reduceContext: reduceContext,
keys: make([][]byte, 0),
vals: make([][]byte, 0),
}, nil
}
func (imt *InMemoryTreeWriter) AddItem(key, value []byte) error {
imt.keys = append(imt.keys, key)
imt.vals = append(imt.vals, value)
return nil
}
func (imt *InMemoryTreeWriter) Sort() error {
sortedIds := idAndValueList{
ids: imt.keys,
vals: imt.vals,
}
sort.Sort(sortedIds)
return nil
}
func (imt *InMemoryTreeWriter) Write(db *Gouchstore) (*nodePointer, error) {
targetMr := newBtreeModifyResult(imt.keyCompare, imt.reduce, imt.rereduce, imt.reduceContext, gs_DB_CHUNK_THRESHOLD, gs_DB_CHUNK_THRESHOLD)
for i, key := range imt.keys {
value := imt.vals[i]
db.mrPushItem(key, value, targetMr)
}
newRoot, err := db.completeNewBtree(targetMr)
if err != nil {
return nil, err
}
return newRoot, nil
}
func (imt *InMemoryTreeWriter) Close() error {
return nil
}