Hi,
I was experimenting with using mmap from clojure but I see vastly
different timings when compared to plain old Java and
MappedByteBuffer.
Here's my code and also represents the largest bit of clojure I have
written:
(import '(java.io File))
(use 'clojure.contrib.mmap)
(def my-file (File. "/home/aim/largelog.bin"))
(defn my-iterate-map [buf]
(let [max (.remaining buf)]
(loop [i (long 1)]
(if (< i max)
(do (.get buf)
(recur (unchecked-inc i))))))
buf)
(time (my-iterate-map (mmap my-file)))
The results I see from clojure are:
;;;; (time (my-iterate-map (mmap my-file))) ...
"Elapsed time: 113191.133057 msecs"
But If I do the same thing in Java I get:
gone in 0.0540 seconds!
Is there something I can do to make the clojure version near or
equivalent to the java code below?
Thanks,
Andy.
--- Java code --
import java.io.File;
import java.io.FileInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
public class Main {
public static void main(String[] args) throws Exception {
File f = new File(args[0]);
FileInputStream fis = new FileInputStream(f);
ByteBuffer buf =
fis.getChannel().map(FileChannel.MapMode.READ_ONLY,
0, f.length());
long then = System.currentTimeMillis();
long sum = 0;
while (buf.hasRemaining()) {
sum += (buf.get() & 0xFF);
}
long now = System.currentTimeMillis();
System.out.printf("gone in %.4f seconds!\n", (((now - then) /
1000.0)));
}
}
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
-~----------~----~----~----~------~----~------~--~---
