MemCacheSupport.java

/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is Forte for Java, Community Edition. The Initial
 * Developer of the Original Code is Sun Microsystems, Inc. Portions
 * Copyright 1997-2000 Sun Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.editor;

/**
* Manages in-memory character cache to store contents of the document.
*
* @author Miloslav Metelka
* @version 1.00
*/

class MemCacheSupport extends DocCacheSupport {

    /** Increment for extending the cache */
    private static final int CACHE_INCREMENT = 2048;

    /** Memory cache array */
    char buffer[] = Analyzer.EMPTY_CHAR_ARRAY;


    /** Construct new memory cacheSupport with zero size */
    public MemCacheSupport() {
    }

    /** Construct new memory cacheSupport. Initialize the memory array.
    * @param ensureCapacity how much space preallocate
    */
    public MemCacheSupport(int ensureCapacity) {
        buffer = new char[ensureCapacity];
    }

    /** check if there's enough space in the cache
    * @param reqLen how many chars has to be available
    */
    private void checkSpace(int reqLen) {
        if(buffer.length < reqLen) {
            char tempCache[] = new char[reqLen + CACHE_INCREMENT + reqLen / 8];
            System.arraycopy(buffer, 0, tempCache, 0, getDocLength());
            buffer = tempCache;
        }
    }

    public void ensureCapacity(int capacity) {
        checkSpace(capacity);
    }

    public void read(int pos, char cache[], int offset, int len) {
        if (len == 0) {
            return; // immediate return for void operations
        }
        System.arraycopy(buffer, pos, cache, offset, len); // copy part of the cache
    }

    public void write(int pos, char cache[], int offset, int len) {
        if (len == 0) {
            return; // immediate return for void operations
        }
        checkSpace(pos + len);
        System.arraycopy(cache, offset, buffer, pos, len);
        docLen = Math.max(docLen, pos + len);
    }

    public void insert(int pos, char cache[], int offset, int len) {
        if (len == 0) {
            return; // immediate return for void operations
        }
        checkSpace(getDocLength() + len);
        System.arraycopy(buffer, pos, buffer, pos + len, getDocLength() - pos);
        System.arraycopy(cache, offset, buffer, pos, len);
        docLen += len;
    }

    public void insertString(int pos, String text, int offset, int len) {
        if (len == 0) {
            return; // immediate return for void operations
        }
        checkSpace(getDocLength() + len);
        System.arraycopy(buffer, pos, buffer, pos + len, getDocLength() - pos);
        text.getChars(offset, offset + len, buffer, pos);
        docLen += len;
    }

    public void remove(int pos, int len) {
        if (len == 0) {
            return; // immediate return for void operations
        }
        System.arraycopy(buffer, pos + len, buffer, pos, getDocLength() - (pos + len));
        docLen -= len;
    }

    public boolean supportsDirectMode() {
        return true;
    }

    public char[] getDirectModeBuffer() {
        return buffer;
    }

}

/*
 * Log
 *  10   Gandalf-post-FCS1.8.1.0     4/3/00   Miloslav Metelka undo update
 *  9    Gandalf   1.8         11/14/99 Miloslav Metelka 
 *  8    Gandalf   1.7         10/23/99 Ian Formanek    NO SEMANTIC CHANGE - Sun
 *       Microsystems Copyright in File Comment
 *  7    Gandalf   1.6         9/16/99  Miloslav Metelka 
 *  6    Gandalf   1.5         9/10/99  Miloslav Metelka 
 *  5    Gandalf   1.4         7/20/99  Miloslav Metelka 
 *  4    Gandalf   1.3         6/1/99   Miloslav Metelka 
 *  3    Gandalf   1.2         4/23/99  Miloslav Metelka Undo added and internal 
 *       improvements
 *  2    Gandalf   1.1         3/27/99  Miloslav Metelka 
 *  1    Gandalf   1.0         2/3/99   Miloslav Metelka 
 * $
 */