Scala SHA-1 Example

gistfile1.scala

package  example
import java.io.FileInputStream
import java.security.MessageDigest

object Sha1Example {

  def main(args: Array[String]): Unit = {
    val start = System.currentTimeMillis()
    val sha1 = MessageDigest.getInstance("SHA1")
    val bytes = new Array[Byte](1024 * 1024)
    val fis = new FileInputStream("/workspace/data/ALL.chr22.phase1_release_v3.20101123.snps_indels_svs.genotypes.vcf.gz")
    Stream.continually(fis.read(bytes)).takeWhile(-1 !=).foreach(sha1.update(bytes, 0, _))
    val hashBytes = sha1.digest() // finalize the hash
    val sb = new StringBuffer()
    hashBytes.foreach { a => sb.append(Integer.toString((a & 0xff) + 0x100, 16).substring(1))}
    val end = System.currentTimeMillis()
    println(sb.toString)
    println("%d ms".format(end - start))
  }

Output:

1a50d065799c4d32637dbe11eb66e5f1e8b35b89
9570 ms

which means my MacBook Pro, Mid 2012 2.3 GHz Intel Core i7 w/ flash storage handle ~180MB/s