fm.common.rich.RichInputStream.scala Maven / Gradle / Ivy

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/*
 * Copyright 2014 Frugal Mechanic (http://frugalmechanic.com)
 *
 * 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 fm.common.rich

import fm.common.{IOUtils, Snappy, ZStandard}
import java.io.{BufferedInputStream, File, InputStream}
import java.util.zip.GZIPInputStream
import org.apache.commons.compress.archivers.{ArchiveEntry, ArchiveInputStream, ArchiveStreamFactory}
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream
import org.apache.commons.compress.compressors.xz.XZCompressorInputStream

/**
 * Rich wrapper for an InputStream
 * 
 * Note:  This class has an optional dependency on Snappy Java (https://github.com/xerial/snappy-java)
 */
final class RichInputStream(val is: InputStream) extends AnyVal {
  
  def toByteArray(): Array[Byte] = IOUtils.toByteArray(is)
  
  def toBufferedInputStream: BufferedInputStream = is match {
    case buffered: BufferedInputStream => buffered
    case _ => new BufferedInputStream(is)
  }
  
  def gunzip:   InputStream = new GZIPInputStream(is)
  def unsnappy: InputStream = Snappy.newInputStream(is)
  def bunzip2:  InputStream = new BZip2CompressorInputStream(is)
  def unxz:     InputStream = new XZCompressorInputStream(is)
  def unzstd:   InputStream = ZStandard.newInputStream(is)
  
  // This appears to be as fast as using ZipInputStream directly
  def unzip: InputStream = unarchive(toBufferedInputStream, ArchiveStreamFactory.ZIP)
  def unjar: InputStream = unarchive(toBufferedInputStream, ArchiveStreamFactory.JAR)
  def untar: InputStream = unarchive(toBufferedInputStream, ArchiveStreamFactory.TAR)

  // Does not work: org.apache.commons.compress.archivers.StreamingNotSupportedException: The 7z doesn't support streaming.
//  def un7zip: InputStream = unarchive(toBufferedInputStream, ArchiveStreamFactory.SEVEN_Z)
  
//  def unzip: InputStream = {
//    import java.util.zip._
//    val zis = new ZipInputStream(is)
//    
//    var entry: ZipEntry = null
//    
//    // We want to skip over any directory entries and also any OS X added ._{OriginalFileName} files
//    // Also ignore the META-INF stuff in JAR files
//    do {
//      entry = zis.getNextEntry()
//      require(entry != null, s"ZIP Input Stream doesn't appear to have a file in it?")
//    } while (entry.isDirectory || new File(entry.getName).getName.startsWith("._") || entry.getName.startsWith("META-INF/"))
//    
//    require(entry != null, s"ZIP Input Stream doesn't appear to have a file in it?")
//      
//    zis
//  }
  
  /** For debugging archive files */
  def showArchiveEntries(): Unit = {    
    val ais: ArchiveInputStream = new ArchiveStreamFactory().createArchiveInputStream(is)
    var e: ArchiveEntry = ais.getNextEntry()
    while(e != null) {
      println(s"""name: "${e.getName}", isDirectory: ${e.isDirectory}, size: ${e.getSize}""")
      e = ais.getNextEntry()
    }
  }
  
  private def unarchive(is: BufferedInputStream, archiverName: String): InputStream = {
    // From http://commons.apache.org/proper/commons-compress/examples.html
    // The stream classes all wrap around streams provided by the calling code and they work on them directly without any additional buffering. 
    // On the other hand most of them will benefit from buffering so it is highly recommended that users wrap their stream in Buffered(In|Out)putStreams before using the Commons Compress API.
    val ais: ArchiveInputStream = new ArchiveStreamFactory().createArchiveInputStream(archiverName, is)
    
    var entry: ArchiveEntry = null
    
    // We want to skip over any directory entries and also any OS X added ._{OriginalFileName} files
    // Also ignore the META-INF stuff in JAR files
    while({
      entry = ais.getNextEntry()
      require(entry != null, s"${archiverName.toUpperCase} Input Stream doesn't appear to have a file in it?")
      entry.isDirectory || new File(entry.getName).getName.startsWith("._") || entry.getName.startsWith("META-INF/")
    })
    
    require(entry != null, s"${archiverName.toUpperCase} Input Stream doesn't appear to have a file in it?")
      
    ais
  }

}