langtools/src/share/classes/com/sun/tools/javac/util/DiagnosticSource.java
changeset 867 1dff24b5f407
child 1109 853d8c191eac
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/util/DiagnosticSource.java	Tue Jul 15 09:50:36 2008 -0700
@@ -0,0 +1,214 @@
+/*
+ * Copyright 1999-2008 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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 java.util.Map;
+import javax.tools.JavaFileObject;
+
+import com.sun.tools.javac.file.JavacFileManager;
+import com.sun.tools.javac.tree.JCTree;
+
+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 API supported by Sun Microsystems.  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 {
+    public DiagnosticSource(JavaFileObject fo, AbstractLog log) {
+        this.fileObject = fo;
+        this.log = log;
+    }
+
+    /** Return the underlying file object handled by this
+     *  DiagnosticSource object.
+     */
+    public JavaFileObject getFile() {
+        return fileObject;
+    }
+
+    public CharSequence getName()  {
+        return JavacFileManager.getJavacBaseFileName(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) {
+        try {
+            if (findLine(pos)) {
+                int column = 0;
+                for (int bp = lineStart; bp < pos; bp++) {
+                    if (bp >= bufLen) {
+                        return 0;
+                    }
+                    if (buf[bp] == '\t') {
+                        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 Map<JCTree, Integer> getEndPosTable() {
+        return endPosTable;
+    }
+
+    public void setEndPosTable(Map<JCTree, Integer> 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
+     */
+    private 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 Map<JCTree, Integer> 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;
+}