Re: FastCat 'performance'

From:
Daniel Pitts <newsgroup.nospam@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Wed, 27 Feb 2013 13:32:20 -0800
Message-ID:
<EXuXs.78383$KR.72352@newsfe27.iad>
On 2/27/13 12:58 PM, Joerg Meier wrote:

On Wed, 27 Feb 2013 12:38:11 -0800, Daniel Pitts wrote:

I've made the Strings you append longer, and I've fixed the estimates
for the FastCat and the StringBu*ers constructors to be spot-on:

Fresh SB/FCs:
Cat> Init: 00.000ms, Loop: 00.175ms, End: 00.000ms, Total: 00.175ms.
Buf> Init: 00.000ms, Loop: 00.227ms, End: 00.000ms, Total: 00.227ms.
Bui> Init: 00.000ms, Loop: 00.236ms, End: 00.000ms, Total: 00.236ms.
Reused SB/FCs:
Cat> Init: 00.000ms, Loop: 00.023ms, End: 00.375ms, Total: 00.398ms.
Buf> Init: 00.101ms, Loop: 00.048ms, End: 00.130ms, Total: 00.279ms.
Bui> Init: 00.092ms, Loop: 00.052ms, End: 00.130ms, Total: 00.274ms.


I'm curious, would you mind sharing the updated code on a pastebin
somewhere ? Writing benchmarks is always tricky, so I'd be happy to learn
from your changes.

Liebe Gruesse,
        Joerg

Here it is in all its glory:

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import com.mindprod.fastcat.FastCat;

class CatTester {
     public static final String LONG_STRING =
"abcdefgabcdefgabcdefgabcdefgabc" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "defgabcdefgabcdefgabcdefgabcdefgabcde" +
             "fg"
             ;
     public static final String ANOTHER_STRING = "xvck" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "blahblahblahblahxjcvh" +
             "";

     private interface Tester {
        public void init();
        public int test(final long junk);
         String conclude();
     }

    private static class TestFastCat implements Tester {
        protected FastCat sb;

        public TestFastCat() {
        }

         public void init() {
         }

         public String conclude() {
             if (sb != null) {
                 return sb.toString();
             }
             return null;
         }

        public int test(final long junk) {
            final FastCat sbLocal = sb == null ? new FastCat(6) : sb;
            final int start = sbLocal.length();
             sbLocal.append(LONG_STRING);
             sbLocal.append(1234);
             sbLocal.append(ANOTHER_STRING);
             sbLocal.append(junk);
             sbLocal.append(ANOTHER_STRING);
             sbLocal.append(junk + 1);
             if (sbLocal != sb) {
                 sbLocal.toString();
             }
            return sbLocal.length() - start;
        }
    }

    private static class TestStringBuffer implements Tester {
        protected StringBuffer sb;

        public TestStringBuffer() {
        }

         public void init() {
         }

         public int test(final long junk) {
            final StringBuffer sbLocal = sb == null ? new StringBuffer() : sb;
            final int start = sbLocal.length();
            sbLocal.append(LONG_STRING);
            sbLocal.append(1234);
            sbLocal.append(ANOTHER_STRING);
            sbLocal.append(junk);
            sbLocal.append(ANOTHER_STRING);
            sbLocal.append(junk + 1);
             if (sbLocal != sb) {
                 sbLocal.toString();
             }
            return sbLocal.length() - start;
        }

         public String conclude() {
             if (sb != null) {
                 return sb.toString();
             }
             return null;
         }

    }

    private static class TestStringBuilder implements Tester {
         protected StringBuilder sb;

        public TestStringBuilder() {
        }

         public void init() {
         }

         public int test(final long junk) {
            final StringBuilder sbLocal = sb == null ? new StringBuilder() : sb;
            final int start = sbLocal.length();
            sbLocal.append(LONG_STRING);
            sbLocal.append(1234);
            sbLocal.append(ANOTHER_STRING);
            sbLocal.append(junk);
            sbLocal.append(ANOTHER_STRING);
            sbLocal.append(junk + 1);
             if (sbLocal != sb) {
                 sbLocal.toString();
             }
            return sbLocal.length() - start;
        }

         public String conclude() {
             if (sb != null) {
                 return sb.toString();
             }
             return null;
         }

    }

    public static void main(final String[] args) {
        new CatTester().test();
    }

    private final DateFormat DF = new SimpleDateFormat("ss'.'SSS'ms'");

    private long loopTest(final String name, final Tester tester, final int
loops) {
         final long start = System.currentTimeMillis();
         tester.init();
         final long initTime = System.currentTimeMillis();
         long junk = 0;
         for (int i = 1; i < loops; i++) {
             junk += tester.test(junk);
         }
         final long appendTime = System.currentTimeMillis();
         tester.conclude();
         if (name != null) {
             System.out.println(String.format("%s> Init: %s, Loop: %s,
End: %s, Total: %s.",
                     name,
                     timestamp(start, initTime),
                     timestamp(initTime, appendTime),
                     timestamp(appendTime),
                     timestamp(start))
                     );
        }
         return junk;
    }

    private void test() {
        final int loops = 100000;

        // To warm up the VM, HotSpot etc
         loopTest(null, new TestFastCat(), loops);
         final long length = loopTest(null, new TestStringBuilder(),
loops) / 10;
         loopTest(null, new TestStringBuffer(), loops);
         loopTest(null, new TestFastCatReuse(loops), loops);
         loopTest(null, new TestStringBufferReuse(length), loops);
         loopTest(null, new TestStringBuilderReuse(length), loops);
         for (int i = 0; i < 3; ++i) {
             System.out.println("Fresh SB/FCs:");
             loopTest("Cat", new TestFastCat(), loops);
             loopTest("Buf", new TestStringBuffer(), loops);
             loopTest("Bui", new TestStringBuilder(), loops);

             System.out.println("Reused SB/FCs:");
             loopTest("Cat", new TestFastCatReuse(loops), loops);
             loopTest("Buf", new TestStringBufferReuse(length), loops);
             loopTest("Bui", new TestStringBuilderReuse(length), loops);
         }
    }

     private String timestamp(final long start) {
         return timestamp(start, System.currentTimeMillis());
     }

     private String timestamp(final long start, long endTime) {
        return DF.format(new Date(endTime - start));
    }

     private static class TestFastCatReuse extends TestFastCat {
         private final int loops;

         public TestFastCatReuse(int loops) {
             this.loops = loops;
         }

         public void init() { sb = new FastCat(loops * 6); }
     }

     private static class TestStringBufferReuse extends TestStringBuffer {
         private final long length;

         public TestStringBufferReuse(long length) {
             this.length = length;
         }

         public void init() { sb = new StringBuffer((int) length);}
     }

     private static class TestStringBuilderReuse extends TestStringBuilder {
         private final long length;

         public TestStringBuilderReuse(long length) {
             this.length = length;
         }

         public void init() { sb = new StringBuilder((int) length); }
     }
}

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