scouter.server.db.summary.SummaryReader.scala Maven / Gradle / Ivy
/*
* Copyright 2015 the original author or authors.
* @https://github.com/scouter-project/scouter
*
* 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 scouter.server.db.summary;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Hashtable;
import scouter.util.FileUtil;
import scouter.util.IClose;
object SummaryReader {
val table = new Hashtable[String, SummaryReader]();
def open(file: String): SummaryReader = {
table.synchronized {
var reader = table.get(file);
if (reader != null) {
reader.refrence += 1;
} else {
reader = new SummaryReader(file);
table.put(file, reader);
}
return reader;
}
}
}
class SummaryReader(file: String) extends IClose {
var refrence = 0;
val pointFile = new RandomAccessFile(file + ".sum", "rw");
def read(point: Long): Array[Byte] = {
try {
this.synchronized {
pointFile.seek(point);
val len = pointFile.readInt();
val buffer = new Array[Byte](len);
pointFile.read(buffer);
return buffer;
}
} catch {
case e: IOException =>
throw new RuntimeException(e);
}
}
override def close() {
SummaryReader.table.synchronized {
if (this.refrence == 0) {
SummaryReader.table.remove(this.file);
FileUtil.close(pointFile);
} else {
this.refrence -= 1;
}
}
}
}