brooklyn-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From henev...@apache.org
Subject [5/7] incubator-brooklyn git commit: Strings.removeAllFromStart/End only call substring() once.
Date Thu, 14 May 2015 19:53:51 GMT
Strings.removeAllFromStart/End only call substring() once.

Java 7 update 6 changed the cost of String.substring from O(1) to O(n).
This commit changes the two removeAll methods to make one substring calls
rather than one per match.


Project: http://git-wip-us.apache.org/repos/asf/incubator-brooklyn/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-brooklyn/commit/28f7c594
Tree: http://git-wip-us.apache.org/repos/asf/incubator-brooklyn/tree/28f7c594
Diff: http://git-wip-us.apache.org/repos/asf/incubator-brooklyn/diff/28f7c594

Branch: refs/heads/master
Commit: 28f7c5942fb15e890da1e585d085af81336b0e5c
Parents: 4e78e67
Author: Sam Corbett <sam.corbett@cloudsoftcorp.com>
Authored: Tue May 12 20:26:57 2015 +0100
Committer: Sam Corbett <sam.corbett@cloudsoftcorp.com>
Committed: Thu May 14 11:05:31 2015 +0100

----------------------------------------------------------------------
 .../main/java/brooklyn/util/text/Strings.java   | 30 +++++++++++++-------
 .../java/brooklyn/util/text/StringsTest.java    |  6 ++++
 2 files changed, 25 insertions(+), 11 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-brooklyn/blob/28f7c594/utils/common/src/main/java/brooklyn/util/text/Strings.java
----------------------------------------------------------------------
diff --git a/utils/common/src/main/java/brooklyn/util/text/Strings.java b/utils/common/src/main/java/brooklyn/util/text/Strings.java
index 5736441..05957c4 100644
--- a/utils/common/src/main/java/brooklyn/util/text/Strings.java
+++ b/utils/common/src/main/java/brooklyn/util/text/Strings.java
@@ -151,20 +151,24 @@ public class Strings {
         return string;
     }
 
-    /** as removeFromEnd, but repeats until all such suffixes are gone */
-    public static String removeAllFromEnd(String string, String ...suffixes) {
+    /**
+     * As removeFromEnd, but repeats until all such suffixes are gone
+     */
+    public static String removeAllFromEnd(String string, String... suffixes) {
+        if (isEmpty(string)) return string;
+        int index = string.length();
         boolean anotherLoopNeeded = true;
         while (anotherLoopNeeded) {
             if (isEmpty(string)) return string;
             anotherLoopNeeded = false;
             for (String suffix : suffixes)
-                if (string.endsWith(suffix)) {
-                    string = string.substring(0, string.length() - suffix.length());
+                if (!isEmpty(suffix) && string.startsWith(suffix, index - suffix.length()))
{
+                    index -= suffix.length();
                     anotherLoopNeeded = true;
                     break;
                 }
         }
-        return string;
+        return string.substring(0, index);
     }
 
     /**
@@ -193,20 +197,24 @@ public class Strings {
         return string;
     }
 
-    /** as removeFromStart, but repeats until all such suffixes are gone */
-    public static String removeAllFromStart(String string, String ...prefixes) {
+    /**
+     * As {@link #removeFromStart(String, String)}, repeating until all such prefixes are
gone.
+     */
+    public static String removeAllFromStart(String string, String... prefixes) {
+        int index = 0;
         boolean anotherLoopNeeded = true;
         while (anotherLoopNeeded) {
             if (isEmpty(string)) return string;
             anotherLoopNeeded = false;
-            for (String prefix : prefixes)
-                if (string.startsWith(prefix)) {
-                    string = string.substring(prefix.length());
+            for (String prefix : prefixes) {
+                if (!isEmpty(prefix) && string.startsWith(prefix, index)) {
+                    index += prefix.length();
                     anotherLoopNeeded = true;
                     break;
                 }
+            }
         }
-        return string;
+        return string.substring(index);
     }
 
     /** convenience for {@link com.google.common.base.Joiner} */

http://git-wip-us.apache.org/repos/asf/incubator-brooklyn/blob/28f7c594/utils/common/src/test/java/brooklyn/util/text/StringsTest.java
----------------------------------------------------------------------
diff --git a/utils/common/src/test/java/brooklyn/util/text/StringsTest.java b/utils/common/src/test/java/brooklyn/util/text/StringsTest.java
index a9780c1..5759c6f 100644
--- a/utils/common/src/test/java/brooklyn/util/text/StringsTest.java
+++ b/utils/common/src/test/java/brooklyn/util/text/StringsTest.java
@@ -108,12 +108,15 @@ public class StringsTest extends FixedLocaleTest {
     public void testRemoveAllFromEnd() {
         assertEquals(Strings.removeAllFromEnd("", "bar"), "");
         assertEquals(Strings.removeAllFromEnd(null, "bar"), null);
+        assertEquals(Strings.removeAllFromEnd("foo", ""), "foo");
 
         assertEquals(Strings.removeAllFromEnd("foobar", "foo", "bar"), "");
         assertEquals(Strings.removeAllFromEnd("foobar", "ar", "car", "b", "o"), "f");
         // test they are applied in order
         assertEquals(Strings.removeAllFromEnd("foobar", "ar", "car", "b", "ob"), "foo");
         assertEquals(Strings.removeAllFromEnd("foobar", "zz", "x"), "foobar");
+        assertEquals(Strings.removeAllFromEnd("foobarbaz", "bar", "baz"), "foo");
+        assertEquals(Strings.removeAllFromEnd("foobarbaz", "baz", "", "foo", "bar", "baz"),
"");
     }
 
     public void testRemoveFromStart() {
@@ -129,6 +132,7 @@ public class StringsTest extends FixedLocaleTest {
     public void testRemoveAllFromStart() {
         assertEquals(Strings.removeAllFromStart("", "foo"), "");
         assertEquals(Strings.removeAllFromStart(null, "foo"), null);
+        assertEquals(Strings.removeAllFromStart("foo", ""), "foo");
 
         assertEquals(Strings.removeAllFromStart("foobar", "foo"), "bar");
         assertEquals(Strings.removeAllFromStart("foo", "bar"), "foo");
@@ -138,6 +142,8 @@ public class StringsTest extends FixedLocaleTest {
         assertEquals(Strings.removeAllFromStart("foobar", "ob", "fo", "o"), "ar");
         // test they are applied in order, "ob" doesn't match because "o" eats the o
         assertEquals(Strings.removeAllFromStart("foobar", "o", "fo", "ob"), "bar");
+        assertEquals(Strings.removeAllFromStart("foobarbaz", "bar", "foo"), "baz");
+        assertEquals(Strings.removeAllFromStart("foobarbaz", "baz", "bar", "foo"), "");
     }
 
     public void testRemoveFromStart2() {


Mime
View raw message