Java lowercasing speed has caught up and bypassed our own homegrown optimalization.

2 files changed, 28 insertions, 97 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/text/Lowercase.java b/vespajlib/src/main/java/com/yahoo/text/Lowercase.java
index a04ba1cfe13..6304f7f0a39 100644
--- a/vespajlib/src/main/java/com/yahoo/text/Lowercase.java
+++ b/vespajlib/src/main/java/com/yahoo/text/Lowercase.java
@@ -12,64 +12,6 @@ import java.util.Locale;
  */
 public final class Lowercase {
 
-    private static final char[] lowercase = new char[123];
-
-    static {
-        lowercase[0x41] = 'a';
-        lowercase[0x42] = 'b';
-        lowercase[0x43] = 'c';
-        lowercase[0x44] = 'd';
-        lowercase[0x45] = 'e';
-        lowercase[0x46] = 'f';
-        lowercase[0x47] = 'g';
-        lowercase[0x48] = 'h';
-        lowercase[0x49] = 'i';
-        lowercase[0x4A] = 'j';
-        lowercase[0x4B] = 'k';
-        lowercase[0x4C] = 'l';
-        lowercase[0x4D] = 'm';
-        lowercase[0x4E] = 'n';
-        lowercase[0x4F] = 'o';
-        lowercase[0x50] = 'p';
-        lowercase[0x51] = 'q';
-        lowercase[0x52] = 'r';
-        lowercase[0x53] = 's';
-        lowercase[0x54] = 't';
-        lowercase[0x55] = 'u';
-        lowercase[0x56] = 'v';
-        lowercase[0x57] = 'w';
-        lowercase[0x58] = 'x';
-        lowercase[0x59] = 'y';
-        lowercase[0x5A] = 'z';
-
-        lowercase[0x61] = 'a';
-        lowercase[0x62] = 'b';
-        lowercase[0x63] = 'c';
-        lowercase[0x64] = 'd';
-        lowercase[0x65] = 'e';
-        lowercase[0x66] = 'f';
-        lowercase[0x67] = 'g';
-        lowercase[0x68] = 'h';
-        lowercase[0x69] = 'i';
-        lowercase[0x6A] = 'j';
-        lowercase[0x6B] = 'k';
-        lowercase[0x6C] = 'l';
-        lowercase[0x6D] = 'm';
-        lowercase[0x6E] = 'n';
-        lowercase[0x6F] = 'o';
-        lowercase[0x70] = 'p';
-        lowercase[0x71] = 'q';
-        lowercase[0x72] = 'r';
-        lowercase[0x73] = 's';
-        lowercase[0x74] = 't';
-        lowercase[0x75] = 'u';
-        lowercase[0x76] = 'v';
-        lowercase[0x77] = 'w';
-        lowercase[0x78] = 'x';
-        lowercase[0x79] = 'y';
-        lowercase[0x7A] = 'z';
-    }
-
     /**
      * Return a lowercased version of the given string. Since this is language
      * independent, this is more of a case normalization operation than
@@ -80,40 +22,11 @@ public final class Lowercase {
      * @return a string containing only lowercase character
      */
     public static String toLowerCase(String in) {
-        // def is picked from http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#toLowerCase%28%29
-        String lower = toLowerCasePrintableAsciiOnly(in);
-        return (lower == null) ? in.toLowerCase(Locale.ENGLISH) : lower;
+        return in.toLowerCase(Locale.ENGLISH);
+
     }
     public static String toUpperCase(String in) {
-        // def is picked from http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#toLowerCase%28%29
         return in.toUpperCase(Locale.ENGLISH);
     }
 
-    private static String toLowerCasePrintableAsciiOnly(String in) {
-        boolean anyUpper = false;
-        for (int i = 0; i < in.length(); i++) {
-            char c = in.charAt(i);
-            if (c < 0x41) {  //lower than A-Z
-                return null;
-            }
-            if (c > 0x5A && c < 0x61) {  //between A-Z and a-z
-                return null;
-            }
-            if (c > 0x7A) {  //higher than a-z
-                return null;
-            }
-            if (c != lowercase[c]) {
-                anyUpper = true;
-            }
-        }
-        if (!anyUpper) {
-            return in;
-        }
-        StringBuilder builder = new StringBuilder(in.length());
-        for (int i = 0; i < in.length(); i++) {
-            builder.append((char) (in.charAt(i) | ((char) 0x20)));
-        }
-        return builder.toString();
-    }
-
 }
diff --git a/vespajlib/src/test/java/com/yahoo/text/LowercaseTestCase.java b/vespajlib/src/test/java/com/yahoo/text/LowercaseTestCase.java
index 8a3e6ed134d..a1379594ba0 100644
--- a/vespajlib/src/test/java/com/yahoo/text/LowercaseTestCase.java
+++ b/vespajlib/src/test/java/com/yahoo/text/LowercaseTestCase.java
@@ -7,6 +7,7 @@ import org.junit.Test;
 import java.util.Locale;
 
 import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 
 /**
@@ -49,12 +50,28 @@ public class LowercaseTestCase {
     }
 
     @Test
+    public void test7bitAscii() {
+        for(char c = 0; c < 128; c++) {
+            char [] carray = {c};
+            String s = new String(carray);
+            assertEquals(Lowercase.toLowerCase(s), s.toLowerCase(Locale.ENGLISH));
+            assertEquals(Lowercase.toUpperCase(s), s.toUpperCase(Locale.ENGLISH));
+        }
+    }
+
+    @Test
     @Ignore
     public void performance() {
+        for (int i=0; i < 2; i++) {
+            benchmark(i);
+        }
+    }
+
+    private void benchmark(int i) {
         Lowercase.toLowerCase("warmup");
-        String lowercaseInput = "abcdefghijklmnopqrstuvwxyz";
-        String uppercaseInput = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
-        String mixedcaseInput = "AbCDEfGHIJklmnoPQRStuvwXyz";
+        String lowercaseInput = "abcdefghijklmnopqrstuvwxyz" + i;
+        String uppercaseInput = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + i;
+        String mixedcaseInput = "AbCDEfGHIJklmnoPQRStuvwXyz" + i;
 
         System.err.println("Lowercase input: ");
         testPerformance(lowercaseInput);
@@ -67,12 +84,14 @@ public class LowercaseTestCase {
     }
 
     private void testPerformance(String input) {
-        final int NUM = 10000000;
+        final int NUM = 100000000;
         long elapsedTimeOwnImpl;
+        long ownCount = 0;
+        long javaCount = 0;
         {
             long startTimeOwnImpl = System.currentTimeMillis();
             for (int i = 0; i < NUM; i++) {
-                Lowercase.toLowerCase(input);
+                ownCount += Lowercase.toLowerCase(input).length();
             }
             elapsedTimeOwnImpl = System.currentTimeMillis() - startTimeOwnImpl;
             System.err.println("Own implementation: " + elapsedTimeOwnImpl);
@@ -82,7 +101,7 @@ public class LowercaseTestCase {
         {
             long startTimeJava = System.currentTimeMillis();
             for (int i = 0; i < NUM; i++) {
-                input.toLowerCase(Locale.ENGLISH);
+                javaCount += input.toLowerCase(Locale.ENGLISH).length();
             }
             elapsedTimeJava = System.currentTimeMillis() - startTimeJava;
             System.err.println("Java's implementation: " + elapsedTimeJava);
@@ -90,7 +109,6 @@ public class LowercaseTestCase {
 
         long diff = elapsedTimeJava - elapsedTimeOwnImpl;
         double diffPercentage = (((double) diff) / ((double) elapsedTimeJava)) * 100.0;
-        System.err.println("Own implementation is " + diffPercentage + " % faster.");
-
+        System.err.println("Own implementation is " + diffPercentage + " % faster. owncount=" + ownCount + " javaCount=" + javaCount);
     }
 }