Attachment 10866 Details for Bug 27795 – Suggested fix (it optimizes matching for non multiline matching only)

[patch] Suggested fix (it optimizes matching for non multiline matching only)

27795-patch.txt (text/plain), 3.53 KB, created by Oleg Sukhodolsky on 2004-03-19 06:54:36 UTC

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Creator: Oleg Sukhodolsky

Created: 2004-03-19 06:54:36 UTC

Size: 3.53 KB

patch

obsolete

>Index: src/java/org/apache/regexp/RE.java
>===================================================================
>RCS file: /home/cvspublic/jakarta-regexp/src/java/org/apache/regexp/RE.java,v
>retrieving revision 1.21
>diff -c -r1.21 RE.java
>*** src/java/org/apache/regexp/RE.java	27 Feb 2004 02:41:20 -0000	1.21
>--- src/java/org/apache/regexp/RE.java	19 Mar 2004 06:51:26 -0000
>***************
>*** 1443,1448 ****
>--- 1443,1453 ----
>          // Can we optimize the search by looking for a prefix string?
>          if (program.prefix == null)
>          {
>+             if ((program.flags & REProgram.OPT_STARTS_WITH_BOL) != 0
>+                 && (matchFlags & MATCH_MULTILINE) == 0)
>+             {
>+                 return (i == 0) && matchAt(0);
>+             }
>              // Unprefixed matching must try for a match at each character
>              for ( ;! search.isEnd(i - 1); i++)
>              {
>Index: src/java/org/apache/regexp/REProgram.java
>===================================================================
>RCS file: /home/cvspublic/jakarta-regexp/src/java/org/apache/regexp/REProgram.java,v
>retrieving revision 1.4
>diff -c -r1.4 REProgram.java
>*** src/java/org/apache/regexp/REProgram.java	17 Feb 2004 13:37:54 -0000	1.4
>--- src/java/org/apache/regexp/REProgram.java	19 Mar 2004 06:51:26 -0000
>***************
>*** 33,38 ****
>--- 33,39 ----
>  public class REProgram implements Serializable
>  {
>      static final int OPT_HASBACKREFS = 1;
>+     static final int OPT_STARTS_WITH_BOL = 2;
>  
>      char[] instruction;         // The compiled regular expression 'program'
>      int lenInstruction;         // The amount of the instruction buffer in use
>***************
>*** 117,131 ****
>              {
>                  // to the end node
>                  int next = instruction[0 + RE.offsetNext];
>!                 if (instruction[next + RE.offsetOpcode] == RE.OP_END)
>                  {
>!                     // and the branch starts with an atom
>!                     if (lenInstruction >= (RE.nodeSize * 2) && instruction[RE.nodeSize + RE.offsetOpcode] == RE.OP_ATOM)
>                      {
>                          // then get that atom as an prefix because there's no other choice
>                          int lenAtom = instruction[RE.nodeSize + RE.offsetOpdata];
>                          prefix = new char[lenAtom];
>                          System.arraycopy(instruction, RE.nodeSize * 2, prefix, 0, lenAtom);
>                      }
>                  }
>              }
>--- 118,140 ----
>              {
>                  // to the end node
>                  int next = instruction[0 + RE.offsetNext];
>!                 if (instruction[next + RE.offsetOpcode] == RE.OP_END
>!                     && lenInstruction >= (RE.nodeSize * 2))
>                  {
>!                     final char nextOp =
>!                         instruction[RE.nodeSize + RE.offsetOpcode];
>!                     // the branch starts with an atom
>!                     if (nextOp == RE.OP_ATOM)
>                      {
>                          // then get that atom as an prefix because there's no other choice
>                          int lenAtom = instruction[RE.nodeSize + RE.offsetOpdata];
>                          prefix = new char[lenAtom];
>                          System.arraycopy(instruction, RE.nodeSize * 2, prefix, 0, lenAtom);
>+                     }
>+                     // the branch starts with an BOL
>+                     else if (nextOp == RE.OP_BOL)
>+                     {
>+                         flags |= OPT_STARTS_WITH_BOL;
>                      }
>                  }
>              }

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Attachments on bug 27795: 10866