org.eclipse.mat.snapshot.model.PrettyPrinter Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of haha Show documentation

Java library to automate the analysis of Android heap dumps.

There is a newer version: 2.1

/**
 * ****************************************************************************
 * Copyright (c) 2008 SAP AG.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * SAP AG - initial API and implementation
 * *****************************************************************************
 */
package org.eclipse.mat.snapshot.model;

import org.eclipse.mat.SnapshotException;

/**
 * Utility class to extract String representations of heap dump objects.
 */
public final class PrettyPrinter {
  /**
   * Convert a java.lang.String object into a String.
   */
  public static String objectAsString(IObject stringObject, int limit) throws SnapshotException {
    Integer count = (Integer) stringObject.resolveValue("count"); //$NON-NLS-1$
    if (count == null) return null;
    if (count.intValue() == 0) return ""; //$NON-NLS-1$

    IPrimitiveArray charArray = (IPrimitiveArray) stringObject.resolveValue("value"); //$NON-NLS-1$
    if (charArray == null) return null;

    Integer offset = (Integer) stringObject.resolveValue("offset"); //$NON-NLS-1$
    if (offset == null) return null;

    return arrayAsString(charArray, offset, count, limit);
  }

  /**
   * Convert a char[] object into a String.
   */
  public static String arrayAsString(IPrimitiveArray charArray, int offset, int count, int limit) {
    if (charArray.getType() != IObject.Type.CHAR) return null;

    int length = charArray.getLength();

    int contentToRead = count <= limit ? count : limit;
    if (contentToRead > length - offset) contentToRead = length - offset;

    char[] value;
    if (offset == 0 && length == contentToRead) {
      value = (char[]) charArray.getValueArray();
    } else {
      value = (char[]) charArray.getValueArray(offset, contentToRead);
    }

    if (value == null) return null;

    StringBuilder result = new StringBuilder(value.length);
    for (int ii = 0; ii < value.length; ii++) {
      char val = value[ii];
      if (val >= 32 && val < 127) {
        result.append(val);
      } else {
        result.append("\\u").append(String.format("%04x", 0xFFFF & val)); //$NON-NLS-1$//$NON-NLS-2$
      }
    }
    if (limit < count) result.append("..."); //$NON-NLS-1$
    return result.toString();
  }

  private PrettyPrinter() {
  }
}