1 cananian 1.1.2.1 // CachingCodeFactory.java, created Sun Jan 31 16:45:26 1999 by cananian
2 cananian 1.1.2.1 // Copyright (C) 1999 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.2.1 package harpoon.ClassFile;
5 cananian 1.1.2.1
6 cananian 1.1.2.3 import java.util.HashMap;
7 cananian 1.1.2.3 import java.util.Map;
8 cananian 1.1.2.1
9 cananian 1.1.2.1 /**
10 cananian 1.1.2.1 * A <code>CachingCodeFactory</code> caches the conversions performed by
11 cananian 1.1.2.4 * a parent <code>HCodeFactory</code>; the cache can also be directly
12 cananian 1.1.2.4 * modified in order to add or replace method implementations.
13 cananian 1.1.2.1 *
14 cananian 1.1.2.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
15 salcianu 1.4 * @version $Id: CachingCodeFactory.java,v 1.4 2002/04/24 23:48:22 salcianu Exp $
16 cananian 1.1.2.1 */
17 cananian 1.1.2.2 public class CachingCodeFactory implements SerializableCodeFactory {
18 cananian 1.1.2.1 /** Parent code factory. Creates the representations this
19 cananian 1.1.2.2 * <code>CachingCodeFactory</code> caches.
20 cananian 1.1.2.2 * @serial */
21 cananian 1.1.2.1 public final HCodeFactory parent;
22 cananian 1.1.2.1 /** Representation cache. */
23 cananian 1.1.2.5 private final Map h = new HashMap(); // map impl must support null vals
24 cananian 1.1.2.5 /** Flush the representation cache before being saving to disk? */
25 cananian 1.1.2.5 private final boolean flushBeforeSave;
26 cananian 1.1.2.1
27 cananian 1.1.2.1 /** Creates a <code>CachingCodeFactory</code> using the conversions
28 cananian 1.1.2.5 * performed by <code>parent</code>. Cached <code>HCode</code>s
29 cananian 1.1.2.5 * will be flushed before this code factory is serialized. */
30 cananian 1.1.2.1 public CachingCodeFactory(HCodeFactory parent) {
31 cananian 1.1.2.5 this(parent, false);
32 cananian 1.1.2.5 }
33 cananian 1.1.2.5 /** Creates a <code>CachingCodeFactory</code> using the conversions
34 cananian 1.1.2.5 * performed by <code>parent</code>. If <code>saveCode</code> is
35 cananian 1.1.2.5 * <code>true</code>, cached <code>HCode</code>s will *not* be
36 cananian 1.1.2.5 * flushed before serialization. */
37 cananian 1.1.2.5 public CachingCodeFactory(HCodeFactory parent, boolean saveCode) {
38 cananian 1.1.2.1 this.parent = parent;
39 cananian 1.1.2.5 this.flushBeforeSave = !saveCode;
40 cananian 1.1.2.1 }
41 cananian 1.1.2.3 /** Serializable interface. */
42 cananian 1.1.2.5 private void writeObject(java.io.ObjectOutputStream out)
43 cananian 1.1.2.5 throws java.io.IOException {
44 cananian 1.1.2.5 if (flushBeforeSave) h.clear();
45 cananian 1.1.2.5 out.defaultWriteObject();
46 cananian 1.1.2.3 }
47 cananian 1.1.2.1 /** Returns the name of the <code>HCode</code>s generated by this
48 cananian 1.1.2.1 * <code>CachingCodeFactory</code>. Returns the same name as
49 cananian 1.1.2.1 * <code>parent</code> does. */
50 cananian 1.1.2.1 public String getCodeName() { return parent.getCodeName(); }
51 cananian 1.1.2.1 /** Convert a method to an <code>HCode</code>, caching the result.
52 cananian 1.1.2.1 * Cached representations of <code>m</code> in <code>parent</code> are
53 cananian 1.1.2.1 * cleared when this <code>CachingCodeFactory</code> adds the
54 cananian 1.1.2.1 * converted representation of <code>m</code> to its cache. */
55 cananian 1.1.2.1 public HCode convert(HMethod m) {
56 cananian 1.1.2.3 if (h.containsKey(m)) return (HCode) h.get(m); // even if get()==null.
57 cananian 1.1.2.1
58 cananian 1.1.2.1 HCode hc = parent.convert(m);
59 cananian 1.1.2.1 put(m, hc);
60 cananian 1.1.2.1 return hc;
61 cananian 1.1.2.1 }
62 cananian 1.1.2.1 /** Remove the cached representation of <code>m</code> from this
63 cananian 1.1.2.1 * <code>CachingCodeFactory</code> and its <code>parent</code>.
64 cananian 1.1.2.1 */
65 cananian 1.1.2.1 public void clear(HMethod m) {
66 cananian 1.1.2.1 h.remove(m);
67 cananian 1.1.2.1 parent.clear(m);
68 cananian 1.1.2.1 }
69 cananian 1.1.2.1 /** Add or replace a representation for <code>m</code> to this
70 cananian 1.1.2.1 * <code>CachingCodeFactory</code>. This can be used to update
71 cananian 1.1.2.1 * the representation of a method with an optimized or otherwise
72 cananian 1.1.2.1 * modified version. As a side-effect, clears any cached representations
73 cananian 1.1.2.1 * of <code>m</code> from <code>parent</code>. */
74 cananian 1.1.2.1 public void put(HMethod m, HCode hc) {
75 cananian 1.1.2.3 h.put(m, hc); // works even if hc==null
76 salcianu 1.4 // [AS] do we really need this?
77 salcianu 1.4 parent.clear(m);
78 cananian 1.1.2.1 }
79 cananian 1.2 }