/
Index.scala
91 lines (71 loc) · 2.28 KB
/
Index.scala
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/*
* Copyright 2011 P.Budzik
*
* 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.
*
* User: przemek
* Date: 12/27/11
* Time: 6:05 PM
*/
package bytecask
import collection.mutable.Map
import java.io.File
import bytecask.Utils._
/*
Index (aka Keydir)- keeps position and length of entry in file
*/
final class Index(io: IO) extends Logging with Locking with Tracking {
private val index = Map[Bytes, IndexEntry]()
def init() {
debug("Initializing index...")
if (ls(io.dir).toList.filter(_.length() > 0).map(indexFile(_)).filter(!_).size > 0) incErrors
}
private def indexFile(file: File) = {
IO.readDataEntries(file, addEntry)
}
private def addEntry(file: File, entry: DataEntry) = writeLock {
index.put(entry.key, IndexEntry(file.getName, entry.pos, entry.size, entry.timestamp))
}
def update(key: Bytes, pos: Int, length: Int, timestamp: Int) = writeLock {
index.put(key, IndexEntry(IO.ACTIVE_FILE_NAME, pos, length, timestamp))
}
def get(key: Bytes) = readLock {
index.get(key)
}
def delete(key: Bytes) = writeLock {
index.remove(key)
}
def postSplit(file: String) {
writeLock {
for ((key, entry) <- index) {
if (entry.isActive) {
index.put(key, IndexEntry(file, entry.pos, entry.length, entry.timestamp))
}
}
}
}
def hasEntry(entry: DataEntry) = {
val e = index.get(entry.key)
//debug("hasEntry: " + e + " -> " + entry)
!e.isEmpty && e.get.timestamp == entry.timestamp
}
def contains(key: Bytes) = index.contains(key)
def size = index.size
def keys = index.keys
def getIndex = index
}
case class IndexEntry(file: String, pos: Int, length: Int, timestamp: Int) {
//FIXME: reduce size as it is kept in memory
def isInactive = file != IO.ACTIVE_FILE_NAME
def isActive = !isInactive
}