Scala RandomAccessFile类代码示例

//设置package包名称以及导入依赖的类
package offheap

import java.io.ObjectInputStream
import java.nio.channels.Channels
import java.io.RandomAccessFile
import java.io.ObjectOutputStream

class OnDiskHeap[T <: Node[T]](filename : String) extends Heap[T] {
  val file = new RandomAccessFile(filename, "rw")
  
  def append(node : T, reserve : Int = 1) : Long = {
    file.seek(file.length())
    val pointer = file.getFilePointer
    val oos = new ObjectOutputStream(Channels.newOutputStream(file.getChannel))
    oos.writeObject(node)
    oos.flush()
    var current = file.getFilePointer()
    file.seek(file.length());
    while(current < reserve) {
      file.writeByte(0)
      current += 1
    }
    pointer
  }
  
  def write(pointer : Long, node : T) : Unit = {
    file.seek(pointer)
    val oos = new ObjectOutputStream(Channels.newOutputStream(file.getChannel))
    oos.writeObject(node)
    oos.flush()
  }
  
  def read(pointer : Long) : T = {
    file.seek(pointer)
    val ois = new ObjectInputStream(Channels.newInputStream(file.getChannel))
    val value = ois.readObject
    value.asInstanceOf[T]
  }
  
  def commit() = {
    file.getFD.sync()
  }
} 

//设置package包名称以及导入依赖的类
package org.pgscala.embedded

import java.io.{File, RandomAccessFile}
import java.nio.ByteBuffer

import com.typesafe.scalalogging.StrictLogging

object Lock extends StrictLogging {
  val DefaultBuffer = 32
  def apply(file: File, bufferSize: Int = DefaultBuffer): Builder = new Builder(file, bufferSize)

  class Builder(file: File, bufferSize: Int) {
    def whenFirst[U](whenFirst: => (String, U)): WithFirst[U] = new WithFirst[U](() => whenFirst)
    def whenOther[U](whenOther: String => U): WithOther[U] = new WithOther[U](whenOther)

    class WithFirst[U] private[Builder] (whenFirst: () => (String, U)) {
      def whenOther(whenOther: String => U): WithFirstAndOther[U] = new WithFirstAndOther[U](whenFirst, whenOther)
    }

    class WithOther[U] private[Builder] (whenOther: String => U) {
      def whenFirst(whenFirst: () => (String, U)): WithFirstAndOther[U] = new WithFirstAndOther[U](whenFirst, whenOther)
    }

    class WithFirstAndOther[U] private[Builder] (whenFirst: () => (String, U), whenOther: String => U) {
      def lock(): U = {
        if (!file.isFile) {
          logger.trace(s"Lock file did not exist - creating a new lock: ${file}")
          file.createNewFile()
        }
        val channel = new RandomAccessFile(file, "rw").getChannel
        try {
          val fileLock = channel.lock()
          try {
            val array = new Array[Byte](bufferSize)
            val buffer = ByteBuffer.wrap(array)
            val read = channel.read(buffer)
            if (read <= 0) {
              val (firstPayload, firstResult) = whenFirst()
              buffer.put(firstPayload.getBytes("ISO-8859-1"))
              buffer.flip()
              channel.write(buffer)
              firstResult
            } else {
              val lockBody = new String(array, 0, read, "ISO-8859-1")
              whenOther(lockBody)
            }
          } finally {
            fileLock.release()
          }
        } finally {
          channel.close()
        }
      }
    }
  }
} 

//设置package包名称以及导入依赖的类
package scorex.perma.application

import java.io.{File, RandomAccessFile}

import scorex.crypto.authds.merkle.versioned.MvStoreVersionedMerklizedIndexedSeq
import scorex.crypto.authds.storage.{KVStorage, MvStoreStorageType}
import scorex.crypto.encode.Base58
import scorex.crypto.hash.FastCryptographicHash
import scorex.perma.consensus.PermaAuthData
import scorex.perma.settings.{PermaConstants, PermaSettings}
import scorex.perma.storage.AuthDataStorage
import scorex.settings.Settings
import scorex.utils.ScorexLogging

trait TestAppSupport {
  implicit val settings = TestAppSupport.settings
  val app = TestAppSupport.app
  implicit val consensusModule = app.consensusModule
  implicit val transactionalModule = app.transactionalModule
}

object TestAppSupport extends ScorexLogging {
  implicit val settings = new Settings with PermaSettings {
    lazy val rootHash: Array[Byte] = Base58.decode("13uSUANWHG7PaCac7i9QKDZriUNKXCi84UkS3ijGYTm1").get
    override lazy val filename = "settings-test.json"
  }

  log.info("Generating random data set")
  val treeDir = new File(settings.treeDir)
  treeDir.mkdirs()
  val datasetFile = settings.treeDir + "/data.file"
  new RandomAccessFile(datasetFile, "rw").setLength(PermaConstants.n * PermaConstants.segmentSize)
  log.info("Calculate tree")
  val tree = MvStoreVersionedMerklizedIndexedSeq.fromFile(datasetFile, Some(settings.treeDir), PermaConstants.segmentSize, FastCryptographicHash)

  log.info("Test tree")
  val index = PermaConstants.n - 3
  val leaf = tree.elementAndProof(index).get
  require(leaf.check(tree.rootHash)(FastCryptographicHash))

  log.info("Put ALL data to local storage")
  new File(settings.treeDir).mkdirs()
  implicit lazy val authDataStorage: KVStorage[Long, PermaAuthData, MvStoreStorageType] =
    new AuthDataStorage(Some(settings.authDataStorage))

  def addBlock(i: Long): Unit = {
    val p = tree.elementAndProof(i).get
    authDataStorage.set(i, new PermaAuthData(p.data, p.proof))
    if (i > 0) {
      addBlock(i - 1)
    }
  }

  addBlock(PermaConstants.n - 1)

  val rootHash = tree.rootHash
  val app = new TestApp(rootHash, authDataStorage)

} 

//设置package包名称以及导入依赖的类
package de.sciss.schwaermen
package control

import java.io.RandomAccessFile
import java.nio.ByteBuffer

import de.sciss.file._
import de.sciss.osc

final class UpdateSource(val uid: Int, config: Config, c: OSCClient, val instance: Status, val debFile: File) {
  private[this] val raf         = new RandomAccessFile(debFile, "r")
  val               size: Long  = raf.length()
  private[this] val ch          = raf.getChannel
//  private[this] val promise     = Promise[Unit]
  private[this] val target      = Network.dotToSocketMap(instance.dot)
  private[this] val buf         = ByteBuffer.allocate(6 * 1024)

//  def result: Future[Unit] = promise.future

  private def reply(p: osc.Packet): Unit =
    c.tx.send(p, target)

  def begin(): Unit = {
    reply(Network.oscUpdateInit(uid = uid, size = size))
  }

  def sendNext(offset: Long): Unit = {
    val bytes: ByteBuffer = ch.synchronized {
      if (ch.position != offset) ch.position(offset)
      buf.clear()
      val chunk = math.min(buf.capacity(), size - offset).toInt
      buf.limit(chunk)
      ch.read(buf)
      buf.flip()
      buf
    }
    reply(Network.oscUpdateSet(uid = uid, offset = offset, bytes = bytes))
  }

  def dispose(): Unit = {
    ch.synchronized(ch.close())
  }
} 

//设置package包名称以及导入依赖的类
package com.github.sorhus.webalytics.cruft

import java.io.{DataOutputStream, File, FileOutputStream, RandomAccessFile}
import java.nio.channels.FileChannel.MapMode

import org.roaringbitmap.RoaringBitmap
import org.roaringbitmap.buffer.ImmutableRoaringBitmap

object ImmutableTest extends App {

  val outFile = new File(args(0))
  outFile.createNewFile()
  val fos = new FileOutputStream(outFile)
  val dos = new DataOutputStream(fos)
  val x = RoaringBitmap.bitmapOf(1,3,5)
  x.runOptimize()
  x.serialize(dos)
  dos.close()

  val inFile = new RandomAccessFile(args(0), "r")
  val memoryMapped = inFile.getChannel.map(MapMode.READ_ONLY, 0, inFile.length())
  val bb = memoryMapped.slice()
  val bitset = new ImmutableRoaringBitmap(bb)

  println(ImmutableRoaringBitmap.and(bitset,bitset).getCardinality)
  println(ImmutableRoaringBitmap.andCardinality(bitset,bitset))

  inFile.close()
}