Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package com.sun.tools.javac.util;

 import java.io.IOException;

 import java.lang.ref.SoftReference;

 import java.nio.CharBuffer;

 import javax.tools.JavaFileObject;

 import com.sun.tools.javac.file.JavacFileManager;

 import com.sun.tools.javac.tree.EndPosTable;

 import static com.sun.tools.javac.util.LayoutCharacters.*;

 /**

  * A simple abstraction of a source file, as needed for use in a diagnostic message.

  * Provides access to the line and position in a line for any given character offset.

  *

  *  <p><b>This is NOT part of any supported API.

  *  If you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public class DiagnosticSource {

     /* constant DiagnosticSource to be used when sourcefile is missing */

     public static final DiagnosticSource NO_SOURCE = new DiagnosticSource() {

         @Override

         protected boolean findLine(int pos) {

             return false;

         }

     };

     public DiagnosticSource(JavaFileObject fo, AbstractLog log) {

         this.fileObject = fo;

         this.log = log;

     }

     private DiagnosticSource() {}

     /** Return the underlying file object handled by this

      *  DiagnosticSource object.

      */

     public JavaFileObject getFile() {

         return fileObject;

     }

     /** Return the one-based line number associated with a given pos

      * for the current source file.  Zero is returned if no line exists

      * for the given position.

      */

     public int getLineNumber(int pos) {

         try {

             if (findLine(pos)) {

                 return line;

             }

             return 0;

         } finally {

             buf = null;

         }

     }

     /** Return the one-based column number associated with a given pos

      * for the current source file.  Zero is returned if no column exists

      * for the given position.

      */

     public int getColumnNumber(int pos, boolean expandTabs) {

         try {

             if (findLine(pos)) {

                 int column = 0;

                 for (int bp = lineStart; bp < pos; bp++) {

                     if (bp >= bufLen) {

                         return 0;

                     }

                     if (buf[bp] == '\t' && expandTabs) {

                         column = (column / TabInc * TabInc) + TabInc;

                     } else {

                         column++;

                     }

                 }

                 return column + 1; // positions are one-based

             }

             return 0;

         } finally {

             buf = null;

         }

     }

     /** Return the content of the line containing a given pos.

      */

     public String getLine(int pos) {

         try {

             if (!findLine(pos))

                 return null;

             int lineEnd = lineStart;

             while (lineEnd < bufLen && buf[lineEnd] != CR && buf[lineEnd] != LF)

                 lineEnd++;

             if (lineEnd - lineStart == 0)

                 return null;

             return new String(buf, lineStart, lineEnd - lineStart);

         } finally {

             buf = null;

         }

     }

     public EndPosTable getEndPosTable() {

         return endPosTable;

     }

     public void setEndPosTable(EndPosTable t) {

         if (endPosTable != null && endPosTable != t)

             throw new IllegalStateException("endPosTable already set");

         endPosTable = t;

     }

     /** Find the line in the buffer that contains the current position

      * @param pos      Character offset into the buffer

      */

     protected boolean findLine(int pos) {

         if (pos == Position.NOPOS)

             return false;

         try {

             // try and recover buffer from soft reference cache

             if (buf == null && refBuf != null)

                 buf = refBuf.get();

             if (buf == null) {

                 buf = initBuf(fileObject);

                 lineStart = 0;

                 line = 1;

             } else if (lineStart > pos) { // messages don't come in order

                 lineStart = 0;

                 line = 1;

             }

             int bp = lineStart;

             while (bp < bufLen && bp < pos) {

                 switch (buf[bp++]) {

                 case CR:

                     if (bp < bufLen && buf[bp] == LF) bp++;

                     line++;

                     lineStart = bp;

                     break;

                 case LF:

                     line++;

                     lineStart = bp;

                     break;

                 }

             }

             return bp <= bufLen;

         } catch (IOException e) {

             log.directError("source.unavailable");

             buf = new char[0];

             return false;

         }

     }

     protected char[] initBuf(JavaFileObject fileObject) throws IOException {

         char[] buf;

         CharSequence cs = fileObject.getCharContent(true);

         if (cs instanceof CharBuffer) {

             CharBuffer cb = (CharBuffer) cs;

             buf = JavacFileManager.toArray(cb);

             bufLen = cb.limit();

         } else {

             buf = cs.toString().toCharArray();

             bufLen = buf.length;

         }

         refBuf = new SoftReference<char[]>(buf);

         return buf;

     }

     /** The underlying file object. */

     protected JavaFileObject fileObject;

     protected EndPosTable endPosTable;

     /** A soft reference to the content of the file object. */

     protected SoftReference<char[]> refBuf;

     /** A temporary hard reference to the content of the file object. */

     protected char[] buf;

     /** The length of the content. */

     protected int bufLen;

     /** The start of a line found by findLine. */

     protected int lineStart;

     /** The line number of a line found by findLine. */

     protected int line;

     /** A log for reporting errors, such as errors accessing the content. */

     protected AbstractLog log;

 }