langtools/src/share/classes/com/sun/tools/javac/util/BaseFileManager.java
changeset 4548 bc0d5b3c3b2d
child 5520 86e4b9a9da40
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/util/BaseFileManager.java	Fri Dec 11 14:26:27 2009 -0800
@@ -0,0 +1,355 @@
+/*
+ * Copyright 2009 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 com.sun.tools.javac.code.Source;
+import com.sun.tools.javac.main.JavacOption;
+import com.sun.tools.javac.main.OptionName;
+import com.sun.tools.javac.main.RecognizedOptions;
+import com.sun.tools.javac.util.JCDiagnostic.SimpleDiagnosticPosition;
+import java.io.ByteArrayOutputStream;
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStreamWriter;
+import java.lang.ref.SoftReference;
+import java.lang.reflect.Constructor;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CoderResult;
+import java.nio.charset.CodingErrorAction;
+import java.nio.charset.IllegalCharsetNameException;
+import java.nio.charset.UnsupportedCharsetException;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import javax.tools.JavaFileObject;
+import javax.tools.JavaFileObject.Kind;
+
+/**
+ * Utility methods for building a filemanager.
+ * There are no references here to file-system specific objects such as
+ * java.io.File or java.nio.file.Path.
+ */
+public class BaseFileManager {
+    protected BaseFileManager(Charset charset) {
+        this.charset = charset;
+        byteBufferCache = new ByteBufferCache();
+    }
+
+    /**
+     * Set the context for JavacPathFileManager.
+     */
+    protected void setContext(Context context) {
+        log = Log.instance(context);
+        options = Options.instance(context);
+        classLoaderClass = options.get("procloader");
+    }
+
+    /**
+     * The log to be used for error reporting.
+     */
+    public Log log;
+
+    /**
+     * User provided charset (through javax.tools).
+     */
+    protected Charset charset;
+
+    protected Options options;
+
+    protected String classLoaderClass;
+
+    protected Source getSource() {
+        String sourceName = options.get(OptionName.SOURCE);
+        Source source = null;
+        if (sourceName != null)
+            source = Source.lookup(sourceName);
+        return (source != null ? source : Source.DEFAULT);
+    }
+
+    protected ClassLoader getClassLoader(URL[] urls) {
+        ClassLoader thisClassLoader = getClass().getClassLoader();
+
+        // Bug: 6558476
+        // Ideally, ClassLoader should be Closeable, but before JDK7 it is not.
+        // On older versions, try the following, to get a closeable classloader.
+
+        // 1: Allow client to specify the class to use via hidden option
+        if (classLoaderClass != null) {
+            try {
+                Class<? extends ClassLoader> loader =
+                        Class.forName(classLoaderClass).asSubclass(ClassLoader.class);
+                Class<?>[] constrArgTypes = { URL[].class, ClassLoader.class };
+                Constructor<? extends ClassLoader> constr = loader.getConstructor(constrArgTypes);
+                return constr.newInstance(new Object[] { urls, thisClassLoader });
+            } catch (Throwable t) {
+                // ignore errors loading user-provided class loader, fall through
+            }
+        }
+
+        // 2: If URLClassLoader implements Closeable, use that.
+        if (Closeable.class.isAssignableFrom(URLClassLoader.class))
+            return new URLClassLoader(urls, thisClassLoader);
+
+        // 3: Try using private reflection-based CloseableURLClassLoader
+        try {
+            return new CloseableURLClassLoader(urls, thisClassLoader);
+        } catch (Throwable t) {
+            // ignore errors loading workaround class loader, fall through
+        }
+
+        // 4: If all else fails, use plain old standard URLClassLoader
+        return new URLClassLoader(urls, thisClassLoader);
+    }
+
+    // <editor-fold defaultstate="collapsed" desc="Option handling">
+    public boolean handleOption(String current, Iterator<String> remaining) {
+        for (JavacOption o: javacFileManagerOptions) {
+            if (o.matches(current))  {
+                if (o.hasArg()) {
+                    if (remaining.hasNext()) {
+                        if (!o.process(options, current, remaining.next()))
+                            return true;
+                    }
+                } else {
+                    if (!o.process(options, current))
+                        return true;
+                }
+                // operand missing, or process returned false
+                throw new IllegalArgumentException(current);
+            }
+        }
+
+        return false;
+    }
+    // where
+        private static JavacOption[] javacFileManagerOptions =
+            RecognizedOptions.getJavacFileManagerOptions(
+            new RecognizedOptions.GrumpyHelper());
+
+    public int isSupportedOption(String option) {
+        for (JavacOption o : javacFileManagerOptions) {
+            if (o.matches(option))
+                return o.hasArg() ? 1 : 0;
+        }
+        return -1;
+    }
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Encoding">
+    private String defaultEncodingName;
+    private String getDefaultEncodingName() {
+        if (defaultEncodingName == null) {
+            defaultEncodingName =
+                new OutputStreamWriter(new ByteArrayOutputStream()).getEncoding();
+        }
+        return defaultEncodingName;
+    }
+
+    public String getEncodingName() {
+        String encName = options.get(OptionName.ENCODING);
+        if (encName == null)
+            return getDefaultEncodingName();
+        else
+            return encName;
+    }
+
+    public CharBuffer decode(ByteBuffer inbuf, boolean ignoreEncodingErrors) {
+        String encodingName = getEncodingName();
+        CharsetDecoder decoder;
+        try {
+            decoder = getDecoder(encodingName, ignoreEncodingErrors);
+        } catch (IllegalCharsetNameException e) {
+            log.error("unsupported.encoding", encodingName);
+            return (CharBuffer)CharBuffer.allocate(1).flip();
+        } catch (UnsupportedCharsetException e) {
+            log.error("unsupported.encoding", encodingName);
+            return (CharBuffer)CharBuffer.allocate(1).flip();
+        }
+
+        // slightly overestimate the buffer size to avoid reallocation.
+        float factor =
+            decoder.averageCharsPerByte() * 0.8f +
+            decoder.maxCharsPerByte() * 0.2f;
+        CharBuffer dest = CharBuffer.
+            allocate(10 + (int)(inbuf.remaining()*factor));
+
+        while (true) {
+            CoderResult result = decoder.decode(inbuf, dest, true);
+            dest.flip();
+
+            if (result.isUnderflow()) { // done reading
+                // make sure there is at least one extra character
+                if (dest.limit() == dest.capacity()) {
+                    dest = CharBuffer.allocate(dest.capacity()+1).put(dest);
+                    dest.flip();
+                }
+                return dest;
+            } else if (result.isOverflow()) { // buffer too small; expand
+                int newCapacity =
+                    10 + dest.capacity() +
+                    (int)(inbuf.remaining()*decoder.maxCharsPerByte());
+                dest = CharBuffer.allocate(newCapacity).put(dest);
+            } else if (result.isMalformed() || result.isUnmappable()) {
+                // bad character in input
+
+                // report coding error (warn only pre 1.5)
+                if (!getSource().allowEncodingErrors()) {
+                    log.error(new SimpleDiagnosticPosition(dest.limit()),
+                              "illegal.char.for.encoding",
+                              charset == null ? encodingName : charset.name());
+                } else {
+                    log.warning(new SimpleDiagnosticPosition(dest.limit()),
+                                "illegal.char.for.encoding",
+                                charset == null ? encodingName : charset.name());
+                }
+
+                // skip past the coding error
+                inbuf.position(inbuf.position() + result.length());
+
+                // undo the flip() to prepare the output buffer
+                // for more translation
+                dest.position(dest.limit());
+                dest.limit(dest.capacity());
+                dest.put((char)0xfffd); // backward compatible
+            } else {
+                throw new AssertionError(result);
+            }
+        }
+        // unreached
+    }
+
+    public CharsetDecoder getDecoder(String encodingName, boolean ignoreEncodingErrors) {
+        Charset cs = (this.charset == null)
+            ? Charset.forName(encodingName)
+            : this.charset;
+        CharsetDecoder decoder = cs.newDecoder();
+
+        CodingErrorAction action;
+        if (ignoreEncodingErrors)
+            action = CodingErrorAction.REPLACE;
+        else
+            action = CodingErrorAction.REPORT;
+
+        return decoder
+            .onMalformedInput(action)
+            .onUnmappableCharacter(action);
+    }
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="ByteBuffers">
+    /**
+     * Make a byte buffer from an input stream.
+     */
+    public ByteBuffer makeByteBuffer(InputStream in)
+        throws IOException {
+        int limit = in.available();
+        if (limit < 1024) limit = 1024;
+        ByteBuffer result = byteBufferCache.get(limit);
+        int position = 0;
+        while (in.available() != 0) {
+            if (position >= limit)
+                // expand buffer
+                result = ByteBuffer.
+                    allocate(limit <<= 1).
+                    put((ByteBuffer)result.flip());
+            int count = in.read(result.array(),
+                position,
+                limit - position);
+            if (count < 0) break;
+            result.position(position += count);
+        }
+        return (ByteBuffer)result.flip();
+    }
+
+    public void recycleByteBuffer(ByteBuffer bb) {
+        byteBufferCache.put(bb);
+    }
+
+    /**
+     * A single-element cache of direct byte buffers.
+     */
+    private static class ByteBufferCache {
+        private ByteBuffer cached;
+        ByteBuffer get(int capacity) {
+            if (capacity < 20480) capacity = 20480;
+            ByteBuffer result =
+                (cached != null && cached.capacity() >= capacity)
+                ? (ByteBuffer)cached.clear()
+                : ByteBuffer.allocate(capacity + capacity>>1);
+            cached = null;
+            return result;
+        }
+        void put(ByteBuffer x) {
+            cached = x;
+        }
+    }
+
+    private final ByteBufferCache byteBufferCache;
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Content cache">
+    public CharBuffer getCachedContent(JavaFileObject file) {
+        SoftReference<CharBuffer> r = contentCache.get(file);
+        return (r == null ? null : r.get());
+    }
+
+    public void cache(JavaFileObject file, CharBuffer cb) {
+        contentCache.put(file, new SoftReference<CharBuffer>(cb));
+    }
+
+    protected final Map<JavaFileObject, SoftReference<CharBuffer>> contentCache
+            = new HashMap<JavaFileObject, SoftReference<CharBuffer>>();
+    // </editor-fold>
+
+    public static Kind getKind(String name) {
+        if (name.endsWith(Kind.CLASS.extension))
+            return Kind.CLASS;
+        else if (name.endsWith(Kind.SOURCE.extension))
+            return Kind.SOURCE;
+        else if (name.endsWith(Kind.HTML.extension))
+            return Kind.HTML;
+        else
+            return Kind.OTHER;
+    }
+
+    protected static <T> T nullCheck(T o) {
+        o.getClass(); // null check
+        return o;
+    }
+
+    protected static <T> Collection<T> nullCheck(Collection<T> it) {
+        for (T t : it)
+            t.getClass(); // null check
+        return it;
+    }
+}