Refactor DefaultSplitCharacter#checkDatePattern to increase perfomance

DEVSIX-4680

Author: ar3em

itext/src/main/java/com/itextpdf/text/pdf/DefaultSplitCharacter.java

@@ -60,6 +60,8 @@
  */
 public class DefaultSplitCharacter implements SplitCharacter {
 
+    private static final Pattern DATE_PATTERN = Pattern.compile("(\\d{2,4}-\\d{2}-\\d{2,4})");
+
     /**
      * An instance of the default SplitCharacter.
      */
@@ -154,11 +156,12 @@ protected char getCurrentCharacter(int current, char[] cc, PdfChunk[] ck) {
     }
 
     private char[] checkDatePattern(String data) {
-        String regex = "(\\d{2,4}-\\d{2}-\\d{2,4})";
-        Matcher m = Pattern.compile(regex).matcher(data);
-        if (m.find()) {
-            String tmpData = m.group(1).replace('-', '\u2011');
-            data = data.replaceAll(m.group(1), tmpData);
+        if (data.contains("-")) {
+            Matcher m = DATE_PATTERN.matcher(data);
+            if (m.find()) {
+                String tmpData = m.group(1).replace('-', '\u2011');
+                data = data.replaceAll(m.group(1), tmpData);
+            }
         }
         return data.toCharArray();
     }

itext/src/test/java/com/itextpdf/text/pdf/DefaultSplitCharacterProfilingTest.java

@@ -0,0 +1,54 @@
+package com.itextpdf.text.pdf;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.text.MessageFormat;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class DefaultSplitCharacterProfilingTest {
+
+    private static final String INPUT_DIR = "./src/test/resources/com/itextpdf/text/pdf/DefaultSplitCharacterProfilingTest/";
+
+    private static final String CHECK_DATE_PATTERN_FAIL_MESSAGE =
+            "The test verifies the optimization of the checkDatePattern method. This failure indicates that the optimization was broken.";
+
+    private static final String READ_FILE_FAIL_MESSAGE = "Failed to read test file {0}. The test could not be completed.";
+
+    private static final int TIME_LIMIT = 20000;
+
+    @Test(timeout = 30000)
+    public void checkDatePatternProfilingTest() {
+        String testFile = INPUT_DIR + "profilingText.txt";
+        String str = readFile(testFile);
+        if (str == null) {
+            Assert.fail(MessageFormat.format(READ_FILE_FAIL_MESSAGE, testFile));
+        }
+        long startTime = System.currentTimeMillis();
+        for (int i = 0; i < 70000; i++) {
+            isSplitCharacter(str);
+        }
+        long time = System.currentTimeMillis() - startTime;
+        System.out.println("Test run time: " + time);
+        Assert.assertTrue(CHECK_DATE_PATTERN_FAIL_MESSAGE, time < TIME_LIMIT);
+    }
+
+    private static void isSplitCharacter(String text) {
+        new DefaultSplitCharacter().isSplitCharacter(0, 0, text.length() + 1, text.toCharArray(), null);
+    }
+
+    private static String readFile(String fileName) {
+        StringBuilder stringBuilder = new StringBuilder();
+        try {
+            BufferedReader reader = new BufferedReader(new FileReader(fileName));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                stringBuilder.append(line);
+            }
+            reader.close();
+            return stringBuilder.toString();
+        } catch (Exception e) {
+            return null;
+        }
+    }
+}