content: /**
   * 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.
   */
  
  /**
   * This file originally comes from the Apache Hadoop project. Changes have been made to the file.
   *
   */
  
  package backtype.storm.utils;
  
  import java.io.*;
  
  
  import java.util.zip.GZIPInputStream;
  import java.util.zip.GZIPOutputStream;
  
  public final class WritableUtils  {
  
    public static byte[] readCompressedByteArray(DataInput in) throws IOException {
      int length = in.readInt();
      if (length == -1) return null;
      byte[] buffer = new byte[length];
      in.readFully(buffer);      // could/should use readFully(buffer,0,length)?
      GZIPInputStream gzi = new GZIPInputStream(new ByteArrayInputStream(buffer, 0, buffer.length));
      byte[] outbuf = new byte[length];
      ByteArrayOutputStream bos =  new ByteArrayOutputStream();
      int len;
      while((len=gzi.read(outbuf, 0, outbuf.length)) != -1){
        bos.write(outbuf, 0, len);
      }
      byte[] decompressed =  bos.toByteArray();
      bos.close();
      gzi.close();
      return decompressed;
    }
  
    public static void skipCompressedByteArray(DataInput in) throws IOException {
      int length = in.readInt();
      if (length != -1) {
        skipFully(in, length);
      }
    }
  
    public static int  writeCompressedByteArray(DataOutput out, byte[] bytes) throws IOException {
      if (bytes != null) {
        ByteArrayOutputStream bos =  new ByteArrayOutputStream();
        GZIPOutputStream gzout = new GZIPOutputStream(bos);
        gzout.write(bytes, 0, bytes.length);
        gzout.close();
        byte[] buffer = bos.toByteArray();
        int len = buffer.length;
        out.writeInt(len);
        out.write(buffer, 0, len);
        /* debug only! Once we have confidence, can lose this. */
        return ((bytes.length != 0) ? (100*buffer.length)/bytes.length : 0);
      } else {
        out.writeInt(-1);
        return -1;
      }
    }
  
  
    /* Ugly utility, maybe someone else can do this better  */
    public static String readCompressedString(DataInput in) throws IOException {
      byte[] bytes = readCompressedByteArray(in);
      if (bytes == null) return null;
      return new String(bytes, "UTF-8");
    }
  
  
    public static int  writeCompressedString(DataOutput out, String s) throws IOException {
      return writeCompressedByteArray(out, (s != null) ? s.getBytes("UTF-8") : null);
    }
  
    /*
     *
     * Write a String as a Network Int n, followed by n Bytes
     * Alternative to 16 bit read/writeUTF.
     * Encoding standard is... ?
     *
     */
    public static void writeString(DataOutput out, String s) throws IOException {
      if (s != null) {
        byte[] buffer = s.getBytes("UTF-8");
        int len = buffer.length;
        out.writeInt(len);
        out.write(buffer, 0, len);
      } else {
        out.writeInt(-1);
      }
    }
  
    /*
     * Read a String as a Network Int n, followed by n Bytes
     * Alternative to 16 bit read/writeUTF.
     * Encoding standard is... ?
     *
     */
    public static String readString(DataInput in) throws IOException{
      int length = in.readInt();
      if (length == -1) return null;
      byte[] buffer = new byte[length];
      in.readFully(buffer);      // could/should use readFully(buffer,0,length)?
      return new String(buffer,"UTF-8");
    }
  
  
    /*
     * Write a String array as a Nework Int N, followed by Int N Byte Array Strings.
     * Could be generalised using introspection.
     *
     */
    public static void writeStringArray(DataOutput out, String[] s) throws IOException{
      out.writeInt(s.length);
      for(int i = 0; i < s.length; i++) {
        writeString(out, s[i]);
      }
    }
  
    /*
     * Write a String array as a Nework Int N, followed by Int N Byte Array of
     * compressed Strings. Handles also null arrays and null values.
     * Could be generalised using introspection.
     *
     */
    public static void writeCompressedStringArray(DataOutput out, String[] s) throws IOException{
      if (s == null) {
        out.writeInt(-1);
        return;
      }
      out.writeInt(s.length);
      for(int i = 0; i < s.length; i++) {
        writeCompressedString(out, s[i]);
      }
    }
  
    /*
     * Write a String array as a Nework Int N, followed by Int N Byte Array Strings.
     * Could be generalised using introspection. Actually this bit couldn't...
     *
     */
    public static String[] readStringArray(DataInput in) throws IOException {
      int len = in.readInt();
      if (len == -1) return null;
      String[] s = new String[len];
      for(int i = 0; i < len; i++) {
        s[i] = readString(in);
      }
      return s;
    }
  
  
    /*
     * Write a String array as a Nework Int N, followed by Int N Byte Array Strings.
     * Could be generalised using introspection. Handles null arrays and null values.
     *
     */
    public static  String[] readCompressedStringArray(DataInput in) throws IOException {
      int len = in.readInt();
      if (len == -1) return null;
      String[] s = new String[len];
      for(int i = 0; i < len; i++) {
        s[i] = readCompressedString(in);
      }
      return s;
    }
  
  
    /*
     *
     * Test Utility Method Display Byte Array.
     *
     */
    public static void displayByteArray(byte[] record){
      int i;
      for(i=0;i < record.length -1; i++){
        if (i % 16 == 0) { System.out.println(); }
        System.out.print(Integer.toHexString(record[i]  >> 4 & 0x0F));
        System.out.print(Integer.toHexString(record[i] & 0x0F));
        System.out.print(",");
      }
      System.out.print(Integer.toHexString(record[i]  >> 4 & 0x0F));
      System.out.print(Integer.toHexString(record[i] & 0x0F));
      System.out.println();
    }
  
  
    /**
     * Serializes an integer to a binary stream with zero-compressed encoding.
     * For -120 <= i <= 127, only one byte is used with the actual value.
     * For other values of i, the first byte value indicates whether the
     * integer is positive or negative, and the number of bytes that follow.
     * If the first byte value v is between -121 and -124, the following integer
     * is positive, with number of bytes that follow are -(v+120).
     * If the first byte value v is between -125 and -128, the following integer
     * is negative, with number of bytes that follow are -(v+124). Bytes are
     * stored in the high-non-zero-byte-first order.
     *
     * @param stream Binary output stream
     * @param i Integer to be serialized
     * @throws java.io.IOException
     */
    public static void writeVInt(DataOutput stream, int i) throws IOException {
      writeVLong(stream, i);
    }
  
    /**
     * Serializes a long to a binary stream with zero-compressed encoding.
     * For -112 <= i <= 127, only one byte is used with the actual value.
     * For other values of i, the first byte value indicates whether the
     * long is positive or negative, and the number of bytes that follow.
     * If the first byte value v is between -113 and -120, the following long
     * is positive, with number of bytes that follow are -(v+112).
     * If the first byte value v is between -121 and -128, the following long
     * is negative, with number of bytes that follow are -(v+120). Bytes are
     * stored in the high-non-zero-byte-first order.
     *
     * @param stream Binary output stream
     * @param i Long to be serialized
     * @throws java.io.IOException
     */
    public static void writeVLong(DataOutput stream, long i) throws IOException {
      if (i >= -112 && i <= 127) {
        stream.writeByte((byte)i);
        return;
      }
  
      int len = -112;
      if (i < 0) {
        i ^= -1L; // take one's complement'
        len = -120;
      }
  
      long tmp = i;
      while (tmp != 0) {
        tmp = tmp >> 8;
        len--;
      }
  
      stream.writeByte((byte)len);
  
      len = (len < -120) ? -(len + 120) : -(len + 112);
  
      for (int idx = len; idx != 0; idx--) {
        int shiftbits = (idx - 1) * 8;
        long mask = 0xFFL << shiftbits;
        stream.writeByte((byte)((i & mask) >> shiftbits));
      }
    }
  
  
    /**
     * Reads a zero-compressed encoded long from input stream and returns it.
     * @param stream Binary input stream
     * @throws java.io.IOException
     * @return deserialized long from stream.
     */
    public static long readVLong(DataInput stream) throws IOException {
      byte firstByte = stream.readByte();
      int len = decodeVIntSize(firstByte);
      if (len == 1) {
        return firstByte;
      }
      long i = 0;
      for (int idx = 0; idx < len-1; idx++) {
        byte b = stream.readByte();
        i = i << 8;
        i = i | (b & 0xFF);
      }
      return (isNegativeVInt(firstByte) ? (i ^ -1L) : i);
    }
  
    /**
     * Reads a zero-compressed encoded integer from input stream and returns it.
     * @param stream Binary input stream
     * @throws java.io.IOException
     * @return deserialized integer from stream.
     */
    public static int readVInt(DataInput stream) throws IOException {
      return (int) readVLong(stream);
    }
  
    /**
     * Given the first byte of a vint/vlong, determine the sign
     * @param value the first byte
     * @return is the value negative
     */
    public static boolean isNegativeVInt(byte value) {
      return value < -120 || (value >= -112 && value < 0);
    }
  
    /**
     * Parse the first byte of a vint/vlong to determine the number of bytes
     * @param value the first byte of the vint/vlong
     * @return the total number of bytes (1 to 9)
     */
    public static int decodeVIntSize(byte value) {
      if (value >= -112) {
        return 1;
      } else if (value < -120) {
        return -119 - value;
      }
      return -111 - value;
    }
  
    /**
     * Get the encoded length if an integer is stored in a variable-length format
     * @return the encoded length
     */
    public static int getVIntSize(long i) {
      if (i >= -112 && i <= 127) {
        return 1;
      }
  
      if (i < 0) {
        i ^= -1L; // take one's complement'
      }
      // find the number of bytes with non-leading zeros
      int dataBits = Long.SIZE - Long.numberOfLeadingZeros(i);
      // find the number of data bytes + length byte
      return (dataBits + 7) / 8 + 1;
    }
  
    /**
     * Skip <i>len</i> number of bytes in input stream<i>in</i>
     * @param in input stream
     * @param len number of bytes to skip
     * @throws IOException when skipped less number of bytes
     */
    public static void skipFully(DataInput in, int len) throws IOException {
      int total = 0;
      int cur = 0;
  
      while ((total<len) && ((cur = in.skipBytes(len-total)) > 0)) {
          total += cur;
      }
  
      if (total<len) {
        throw new IOException("Not able to skip " + len + " bytes, possibly " +
                              "due to end of input.");
      }
    }
  }
  