org.cloudata.core.commitlog.CommitLogWritableUtils.java Source code

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Here is the source code for org.cloudata.core.commitlog.CommitLogWritableUtils.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.cloudata.core.commitlog;

import java.nio.ByteBuffer;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class CommitLogWritableUtils {
    static final Log LOG = LogFactory.getLog(CommitLogWritableUtils.class);

    public static String readString(ByteBuffer buf) {
        int stringLength = buf.getInt();
        byte[] stringBuf = new byte[stringLength];
        buf.get(stringBuf);
        return new String(stringBuf);
    }

    public static String[] readStringArray(ByteBuffer buf) {
        int length = buf.getInt();
        if (length > 1000000) {
            LOG.warn("the length in unmarshalling string array is too big : " + length);
        }
        String[] ret = new String[length];
        for (int i = 0; i < length; i++) {
            ret[i] = readString(buf);
        }

        return ret;
    }

    public static void writeString(ByteBuffer buf, String s) {
        byte[] sBytes = s.getBytes();

        buf.putInt(sBytes.length);
        buf.put(sBytes);
    }

    public static void writeStringArray(ByteBuffer buf, String[] array) {
        buf.putInt(array.length);

        for (int i = 0; i < array.length; i++) {
            writeString(buf, array[i]);
        }
    }

    // ////////// for debugging ////////////////
    public static void dump(byte[] array) {
        dumpTo(array, array.length);
    }

    public static void dumpTo(byte[] array, int length) {
        dumpTo(array, 0, length);
    }

    public static synchronized void dumpTo(byte[] array, int start, int length) {
        dumpTo(array, 0, length, null);
    }

    public static synchronized void dumpTo(byte[] array, int start, int length, String info) {
        System.out.println("=== START DUMP ===");

        if (info != null) {
            System.out.println(info);
        }

        System.out.println("byte length : " + length);

        for (int i = start; i < start + length; i++) {
            if (i % 16 == 0) {
                System.out.println("");
            } else if (i % 8 == 0) {
                System.out.print(" ");
            }
            System.out.format("[0x%2x]", array[i]);
        }
        System.out.println("");
        System.out.println("=== END DUMP ===");
    }
}