src/java.base/share/classes/java/util/regex/Grapheme.java

rev 55125 : 8225061: Performance regression in Regex
Reviewed-by: TBD

*** 28,37 ****
--- 28,50 ----
  import java.util.Objects;
  
  final class Grapheme {
  
      /**
+      * Determines if there is an extended  grapheme cluster boundary between two
+      * continuing characters {@code cp1} and {@code cp2}.
+      * <p>
+      * See Unicode Standard Annex #29 Unicode Text Segmentation for the specification
+      * for the extended grapheme cluster boundary rules
+      * <p>
+      * Note: this method does not take care of stateful breaking.
+      */
+     static boolean isBoundary(int cp1, int cp2) {
+         return rules[getType(cp1)][getType(cp2)];
+     }
+ 
+     /**
       * Look for the next extended grapheme cluster boundary in a CharSequence. It assumes
       * the start of the char sequence is a boundary.
       * <p>
       * See Unicode Standard Annex #29 Unicode Text Segmentation for the specification
       * for the extended grapheme cluster boundary rules. The following implementation
*** 48,79 ****
  
          int ch0 = Character.codePointAt(src, 0);
          int ret = Character.charCount(ch0);
          int ch1;
          // indicates whether gb11 or gb12 is underway
!         boolean gb11 = EmojiData.isExtendedPictographic(ch0);
!         int riCount = getType(ch0) == RI ? 1 : 0;
          while (ret < limit) {
              ch1 = Character.codePointAt(src, ret);
!             int t0 = getType(ch0);
!             int t1 = getType(ch1);
  
              if (gb11 && t0 == ZWJ && t1 == EXTENDED_PICTOGRAPHIC) {
                  gb11 = false;
              } else if (riCount % 2 == 1 && t0 == RI && t1 == RI) {
                  // continue for gb12
              } else if (rules[t0][t1]) {
                  if (ret > off) {
                      break;
                  } else {
!                     gb11 = EmojiData.isExtendedPictographic(ch1);
                      riCount = 0;
                  }
              }
  
!             riCount += getType(ch1) == RI ? 1 : 0;
!             ch0 = ch1;
              ret += Character.charCount(ch1);
          }
          return ret;
      }
  
--- 61,93 ----
  
          int ch0 = Character.codePointAt(src, 0);
          int ret = Character.charCount(ch0);
          int ch1;
          // indicates whether gb11 or gb12 is underway
!         int t0 = getGraphemeType(ch0);
!         int riCount = t0 == RI ? 1 : 0;
!         boolean gb11 = t0 == EXTENDED_PICTOGRAPHIC;
          while (ret < limit) {
              ch1 = Character.codePointAt(src, ret);
!             int t1 = getGraphemeType(ch1);
  
              if (gb11 && t0 == ZWJ && t1 == EXTENDED_PICTOGRAPHIC) {
                  gb11 = false;
              } else if (riCount % 2 == 1 && t0 == RI && t1 == RI) {
                  // continue for gb12
              } else if (rules[t0][t1]) {
                  if (ret > off) {
                      break;
                  } else {
!                     gb11 = t1 == EXTENDED_PICTOGRAPHIC;
                      riCount = 0;
                  }
              }
  
!             riCount += (t1 == RI) ? 1 : 0;
!             t0 = t1;
! 
              ret += Character.charCount(ch1);
          }
          return ret;
      }
  
*** 161,191 ****
                 cp >= 0x109A && cp <= 0x109C ||
                 cp == 0x1A61 || cp == 0x1A63 || cp == 0x1A64 ||
                 cp == 0xAA7B || cp == 0xAA7D;
      }
  
      @SuppressWarnings("fallthrough")
      private static int getType(int cp) {
          if (EmojiData.isExtendedPictographic(cp)) {
              return EXTENDED_PICTOGRAPHIC;
          }
  
          int type = Character.getType(cp);
          switch(type) {
-         case Character.CONTROL:
-             if (cp == 0x000D)
-                 return CR;
-             if (cp == 0x000A)
-                 return LF;
-             return CONTROL;
          case Character.UNASSIGNED:
              // NOTE: #tr29 lists "Unassigned and Default_Ignorable_Code_Point" as Control
              // but GraphemeBreakTest.txt lists u+0378/reserved-0378 as "Other"
              // so type it as "Other" to make the test happy
              if (cp == 0x0378)
                  return OTHER;
  
          case Character.LINE_SEPARATOR:
          case Character.PARAGRAPH_SEPARATOR:
          case Character.SURROGATE:
              return CONTROL;
          case Character.FORMAT:
--- 175,214 ----
                 cp >= 0x109A && cp <= 0x109C ||
                 cp == 0x1A61 || cp == 0x1A63 || cp == 0x1A64 ||
                 cp == 0xAA7B || cp == 0xAA7D;
      }
  
+     private static int getGraphemeType(int cp) {
+         if (cp < 0x007F) { // ASCII
+             if (cp < 32) { // Control characters
+                 if (cp == 0x000D)
+                     return CR;
+                 if (cp == 0x000A)
+                     return LF;
+                 return CONTROL;
+             }
+             return OTHER;
+         }
+         return getType(cp);
+     }
+ 
      @SuppressWarnings("fallthrough")
      private static int getType(int cp) {
          if (EmojiData.isExtendedPictographic(cp)) {
              return EXTENDED_PICTOGRAPHIC;
          }
  
          int type = Character.getType(cp);
          switch(type) {
          case Character.UNASSIGNED:
              // NOTE: #tr29 lists "Unassigned and Default_Ignorable_Code_Point" as Control
              // but GraphemeBreakTest.txt lists u+0378/reserved-0378 as "Other"
              // so type it as "Other" to make the test happy
              if (cp == 0x0378)
                  return OTHER;
  
+         case Character.CONTROL:
          case Character.LINE_SEPARATOR:
          case Character.PARAGRAPH_SEPARATOR:
          case Character.SURROGATE:
              return CONTROL;
          case Character.FORMAT: