Java tutorial
/*- ******************************************************************************* * Copyright (c) 2011, 2014 Diamond Light Source Ltd. * 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: * Peter Chang - initial API and implementation and/or initial documentation *******************************************************************************/ package org.eclipse.dataset.metadata; import java.io.ByteArrayOutputStream; import java.io.Serializable; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.LinkedHashMap; import java.util.Map; import java.util.Map.Entry; import org.apache.commons.lang.SerializationUtils; /** * Basic implementation of metadata */ public class Metadata implements IMetadata { private static final long serialVersionUID = IMetadata.serialVersionUID; private Map<String, ? extends Serializable> metadata; // NOTE shapes is LinkedHashMap here because the names collection // maintained order. Now that we do not need this collection but if we // do not keep the shapes in a LinkedHashMap, we lose order. private Map<String, int[]> shapes = new LinkedHashMap<String, int[]>(7); private Collection<Serializable> userObjects; private String filePath; public Metadata() { } public Metadata(Map<String, ? extends Serializable> metadata) { this.metadata = metadata; } public Metadata(Collection<String> names) { if (names != null) { for (String n : names) { shapes.put(n, null); } } } /** * Set metadata map * @param metadata */ public void setMetadata(Map<String, ? extends Serializable> metadata) { this.metadata = metadata; } /** * Internal use only * @return metadata map */ protected Map<String, ? extends Serializable> getInternalMetadata() { return metadata; } /** * Set user objects * @param objects */ public void setUserObjects(Collection<Serializable> objects) { userObjects = objects; } /** * Add name and shape of a dataset to metadata * * @param name * @param shape (can be null or zero-length) * * (NOTE method should be public, people can define loaders outside this * package like the DESY FIO loader for instance.) */ public void addDataInfo(String name, int... shape) { shapes.put(name, shape == null || shape.length == 0 ? null : shape); } @Override public Collection<String> getDataNames() { return Collections.unmodifiableCollection(shapes.keySet()); } @Override public Map<String, int[]> getDataShapes() { return Collections.unmodifiableMap(shapes); } @Override public Map<String, Integer> getDataSizes() { Map<String, Integer> sizes = new HashMap<String, Integer>(1); for (Entry<String, int[]> e : shapes.entrySet()) { int[] shape = e.getValue(); if (shape != null && shape.length > 1) sizes.put(e.getKey(), calcSize(shape)); else sizes.put(e.getKey(), null); } if (sizes.size() > 0) { return Collections.unmodifiableMap(sizes); } return null; } @Override public Serializable getMetaValue(String key) throws Exception { return metadata == null ? null : metadata.get(key); } @SuppressWarnings("unchecked") @Override public Collection<String> getMetaNames() throws Exception { return metadata == null ? (Collection<String>) Collections.EMPTY_SET : Collections.unmodifiableCollection(metadata.keySet()); } @Override public Collection<Serializable> getUserObjects() { return userObjects; } @Override public IMetadata clone() { Metadata c = null; try { c = (Metadata) super.clone(); if (metadata != null) { HashMap<String, Serializable> md = new HashMap<String, Serializable>(); c.metadata = md; ByteArrayOutputStream os = new ByteArrayOutputStream(512); for (String k : metadata.keySet()) { Serializable v = metadata.get(k); if (v != null) { // TODO: Note that there is a dependency on org.apache.commons.lang that is only used for // accessing SerializationUtils. In reality, the serialize call really is just: // try (ObjectOutputStream out = new ObjectOutputStream(outputStream)) { // out.writeObject(v); // } finally { // out.close(); // } // and deserialize is similarly simple. SerializationUtils.serialize(v, os); Serializable nv = (Serializable) SerializationUtils.deserialize(os.toByteArray()); os.reset(); md.put(k, nv); } else { md.put(k, null); } } } c.shapes = new HashMap<String, int[]>(1); for (Entry<String, int[]> e : shapes.entrySet()) { int[] s = e.getValue(); c.shapes.put(e.getKey(), s == null ? null : s.clone()); } } catch (CloneNotSupportedException e) { // Allowed for some objects not to be cloned. } catch (Throwable e) { if (e instanceof ClassNotFoundException) { // Fix to http://jira.diamond.ac.uk/browse/SCI-1644 // Happens when cloning meta data with GridPreferences } if (e instanceof RuntimeException) { throw (RuntimeException) e; } } return c; } @Override public String getFilePath() { return filePath; } public void setFilePath(String filePath) { this.filePath = filePath; } /** * Calculate total number of items in given shape * @param shape * @return size */ public static int calcSize(final int[] shape) { long lsize = calcLongSize(shape); // check to see if the size is larger than an integer, i.e. we can't allocate it if (lsize > Integer.MAX_VALUE) { throw new IllegalArgumentException("Size of the dataset is too large to allocate"); } return (int) lsize; } /** * Calculate total number of items in given shape * @param shape * @return size */ public static long calcLongSize(final int[] shape) { double dsize = 1.0; if (shape == null || shape.length == 0) // special case of zero-rank shape return 1; for (int i = 0; i < shape.length; i++) { // make sure the indexes isn't zero or negative if (shape[i] == 0) { return 0; } else if (shape[i] < 0) { throw new IllegalArgumentException(String .format("The %d-th is %d which is an illegal argument as it is negative", i, shape[i])); } dsize *= shape[i]; } // check to see if the size is larger than an integer, i.e. we can't allocate it if (dsize > Long.MAX_VALUE) { throw new IllegalArgumentException("Size of the dataset is too large to allocate"); } return (long) dsize; } }