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@massie
Created September 12, 2014 23:00
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Scala SHA-1 Example
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))
}
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massie commented Sep 12, 2014

Output:

1a50d065799c4d32637dbe11eb66e5f1e8b35b89
9570 ms

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

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