geotrellis.raster.render.png.Chunk.scala Maven / Gradle / Ivy

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/*
 * Copyright (c) 2014 Azavea.
 * 
 * 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 geotrellis.raster.render.png

import java.io.ByteArrayOutputStream
import java.io.DataOutputStream
import java.io.File
import java.io.FileOutputStream
import java.io.OutputStream
import java.nio.ByteBuffer
import java.util.zip.CRC32
import java.util.zip.CheckedOutputStream
import java.util.zip.Deflater
import java.util.zip.DeflaterOutputStream

import scala.math.abs

import Util._

final class Chunk(chunkType:Int) {
  val baos = new ByteArrayOutputStream()
  val crc = new CRC32()

  val cos = new CheckedOutputStream(baos, crc)
  writeInt(chunkType)

  def writeInt(i:Int) {
    cos.write(byte(i >> 24))
    cos.write(byte(i >> 16))
    cos.write(byte(i >> 8))
    cos.write(byte(i))
  }

  def writeByte(b:Byte) {
    cos.write(b)
  }

  def writeTo(out:DataOutputStream) {
    cos.flush()
    out.writeInt(baos.size() - 4)
    baos.writeTo(out)
    out.writeInt(crc.getValue().asInstanceOf[Int])
  }
}