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/*
 * Copyright 2012 Taro L. Saito
 *
 * 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.
 */

//--------------------------------------
//
// IOUtil.scala
// Since: 2012/10/24 3:49 PM
//
//--------------------------------------

package xerial.core.io

import io.Source
import java.net.ServerSocket
import java.io.{File, ByteArrayOutputStream, InputStream}


/**
 * @author leo
 */
object IOUtil {
  def readFile[U](fileName: String)(f: Source => U): U = {
    val source = Source.fromFile(fileName)
    try {
      f(source)
    }
    finally {
      //source.close
    }
  }

  def randomPort: Int = {
    val s = new ServerSocket(0)
    try {
      s.getLocalPort
    }
    finally {
      s.close
    }
  }

  def withResource[U, In <: java.io.Closeable](in: In)(f: In => U): U = {
    try {
      f(in)
    }
    finally {
      if (in != null)
        in.close
    }
  }

  def readFully[U](in: InputStream)(f: Array[Byte] => U): U = {

    val byteArray = withResource(new ByteArrayOutputStream) {
      b =>
        val buf = new Array[Byte](8192)
        withResource(in) {
          src =>
            var readBytes = 0
            while ( {
              readBytes = src.read(buf); readBytes != -1
            }) {
              b.write(buf, 0, readBytes)
            }
        }
        b.toByteArray
    }
    f(byteArray)
  }

  def ensureParentPath(f: File) {
    val parent = f.getParentFile
    if (parent != null && !parent.exists) {
      parent.mkdirs
    }
  }

  def createTempDir(dir: File, prefix: String): File = {
    def newDirName = new File(dir, prefix + System.currentTimeMillis())
    def loop : File = {
      val d = newDirName
      if(!d.exists() && d.mkdirs)
        d
      else
        loop
    }
    loop
  }

}