1 // Copyright 2000-2005 the Contributors, as shown in the revision logs.
2 // Licensed under the Apache Public Source License 2.0 ("the License").
3 // You may not use this file except in compliance with the License.
7 import org.ibex.util.*;
11 /** The minimum set of functionality required for objects which are manipulated by JavaScript */
12 public interface JS extends Pausable {
14 /** Returns an enumeration of the keys in this object. */
15 public JS.Enumeration keys() throws JSExn;
17 /** Return the value associated with the given key. */
18 public JS get(JS key) throws JSExn;
20 /** Store a specific value against the given key. */
21 public void put(JS key, JS value) throws JSExn;
23 /** Executes or unpauses the task, running it in a
24 * <i>pausable</i> context. */
25 public Object run(Object o) throws Exception, AlreadyRunningException;
27 /** Pauses the running task at its convienience. */
28 public void pause() throws NotPausableException;
30 /** Calls a specific method with given arguments on this object.
31 * An exception is thrown if there is no such method or the
32 * arguments are invalid. */
33 public JS call(JS method, JS[] args) throws JSExn;
35 /** Calls this object with the given arguments, running it in an
36 * <i>unpausable</i> context. An exception is thrown if this
37 * object is not callable or the arguments are invalid. */
38 public JS call(JS[] args) throws JSExn;
40 /** Returns the names of the formal arguments, if any.
41 * This function must never return a null object. */
42 public String[] getFormalArgs();
44 /** Put a value to the given key, calling any write traps that have
45 * been placed on the key.
47 * This function may block for an indeterminate amount of time.
49 * Write traps may change the final value before it is put, thus
50 * be careful to read the latest value from this function's return
51 * before doing any more work with it.
53 public JS putAndTriggerTraps(JS key, JS value) throws JSExn;
55 /** Gets the value for a given key, calling any read traps that have
56 * been placed on the key.
58 * This function may block for an indeterminate amount of time.
60 public JS getAndTriggerTraps(JS key) throws JSExn;
62 /** Calls the write traps placed on a given key with the given value
63 * and returns the result without saving it to this object's key store. */
64 public JS justTriggerTraps(JS key, JS value) throws JSExn;
66 public void addTrap(JS key, JS function) throws JSExn;
67 public void delTrap(JS key, JS function) throws JSExn;
68 public Trap getTrap(JS key) throws JSExn;
70 // FIXME: consider renaming/removing these
71 public InputStream getInputStream() throws IOException, JSExn;
73 public String coerceToString();
76 // Implementations ////////////////////////////////////////////////////////
78 /** Provides the lightest possible implementation of JS, throwing
79 * exceptions on every mutable operation. */
80 public static class Immutable implements JS {
81 private static final String[] emptystr = new String[0];
83 public JS unclone() { return this; }
84 public JS.Enumeration keys() throws JSExn { throw new JSExn(
85 "object has no key set, class ["+ getClass().getName() +"]"); }
86 public JS get(JS key) throws JSExn { return null; }
87 public void put(JS key, JS val) throws JSExn { throw new JSExn(
88 "'" + key + "' is read only on class ["+ getClass().getName() +"]"); }
89 public InputStream getInputStream() throws IOException, JSExn { throw new JSExn(
90 "object has not associated stream, class ["+ getClass().getName() +"]"); }
92 public Object run(Object o) throws Exception { throw new JSExn(
93 "object cannot be called, class ["+ getClass().getName() +"]"); }
94 public void pause() { throw new NotPausableException(); }
96 public JS call(JS[] args) throws JSExn { throw new JSExn( "object cannot be called, class ["+ getClass().getName() +"]"); }
97 public JS call(JS method, JS[] args) throws JSExn {
98 if (method == null) return call(args);
99 throw new JSExn("method not found: " + JSU.str(method) + " class="+this.getClass().getName());
101 public String[] getFormalArgs() { return emptystr; }
103 public void declare(JS key) throws JSExn { throw new JSExn(
104 "object cannot declare key: "+ JSU.str(key)); }
105 public void undeclare(JS key) throws JSExn { } // FIXME throw error?
107 public JS putAndTriggerTraps(JS key, JS val) throws JSExn { throw new JSExn(
108 "'" + key + "' is trap read only on class ["+ getClass().getName() +"]"); }
109 public JS getAndTriggerTraps(JS key) throws JSExn { return null; } // FIXME throw errors?
110 public JS justTriggerTraps(JS key, JS value) throws JSExn { return null; }
112 public void addTrap(JS key, JS function) throws JSExn {
113 Log.warn(this, "'" + JSU.str(key) + "' is not trappable on class ["+ getClass().getName() +"]"); }
114 public void delTrap(JS key, JS function) throws JSExn {
115 Log.warn(this, "'" + JSU.str(key) + "' trap is read only on class ["+ getClass().getName() +"]"); }
116 public Trap getTrap(JS key) throws JSExn {
117 //Log.warn(this, "'" + JSU.str(key) + "' is not trappable on class ["+ getClass().getName() +"]");
121 public String coerceToString() { return "object"; }
124 public interface Cloneable {}
126 public static class Clone implements JS {
127 protected final JS clonee;
128 public Clone(JS clonee) throws JSExn {
129 if (!(clonee instanceof Cloneable)) throw new JSExn(
130 clonee.getClass().getName() + " is not implement cloneable");
131 this.clonee = clonee;
134 public JS unclone() { return clonee.unclone(); }
135 public boolean equals(Object o) { return clonee.equals(o); }
137 public Enumeration keys() throws JSExn { return clonee.keys(); }
138 public JS get(JS k) throws JSExn { return clonee.get(k); }
139 public void put(JS k, JS v) throws JSExn { clonee.put(k, v); }
140 public InputStream getInputStream() throws IOException, JSExn {
141 return clonee.getInputStream(); }
143 public Object run(Object o) throws Exception { return clonee.run(o); }
144 public void pause() { clonee.pause(); }
146 public JS call(JS m, JS[] a) throws JSExn { return clonee.call(m, a); }
147 public JS call(JS[] a) throws JSExn { return clonee.call(a); }
148 public String[] getFormalArgs() { return clonee.getFormalArgs(); }
150 public JS putAndTriggerTraps(JS k, JS v) throws JSExn {
151 return clonee.putAndTriggerTraps(k, v); }
152 public JS getAndTriggerTraps(JS k) throws JSExn {
153 return clonee.getAndTriggerTraps(k); }
154 public JS justTriggerTraps(JS k, JS v) throws JSExn {
155 return clonee.justTriggerTraps(k, v); }
157 public void addTrap(JS k, JS f) throws JSExn { clonee.addTrap(k, f); }
158 public void delTrap(JS k, JS f) throws JSExn { clonee.delTrap(k, f); }
159 public Trap getTrap(JS k) throws JSExn { return clonee.getTrap(k); }
161 public String coerceToString() { return clonee.coerceToString(); }
164 public static class Obj extends Basket.Hash implements JS {
165 private static final String[] emptystr = new String[0];
166 private static final Placeholder holder = new Placeholder();
168 // HACK: this is hideously, disgustingly ugly.... we need N-ary Hash classes
169 /** entries[index + 0] // key
170 * entries[index + 1] // value
171 * entries[index + 2] // trap
174 protected void entryAdded(int p) {}
175 protected void entryUpdated(int p) {}
176 protected void entryRemoved(int p) {}
178 public Obj() { super(3, 4, 0.75F); }
180 public JS unclone() { return this; }
181 public InputStream getInputStream() throws IOException, JSExn { throw new JSExn(
182 "object has not associated stream, class ["+ getClass().getName() +"]"); }
184 public Object run(Object o) throws Exception { throw new JSExn(
185 "object cannot be called, class ["+ getClass().getName() +"]"); }
186 public void pause() { throw new NotPausableException(); }
188 public JS call(JS[] args) throws JSExn { throw new JSExn(
189 "object cannot be called, class ["+ getClass().getName() +"]"); }
190 public JS call(JS method, JS[] args) throws JSExn { throw new JSExn(
191 "method not found: " + JSU.str(method)); }
192 public String[] getFormalArgs() { return emptystr; }
194 public Enumeration keys() throws JSExn {
195 return new Enumeration(null) {
196 private int dest = -1, next = -1;
197 public boolean _hasNext() {
198 for (int i = Math.max(0, dest); i < usedslots; i++)
199 if (i > 0 ? entries[i * indexmultiple] != null : true &&
200 entries[i * indexmultiple] != this) { next = i; return true; }
203 public JS _next() throws JSExn {
204 if (next < 0 && !hasNext()) throw new NoSuchElementException();
205 int index = next; dest = next; next = -1;
206 return (JS)entries[index * indexmultiple];
210 public JS get(JS key) throws JSExn { int i = indexOf(key);
211 return i < 0 ? null : entries[i + 1] instanceof Placeholder ? null : (JS)entries[i + 1]; }
212 public void put(JS key, JS val) throws JSExn {
213 // NOTE: only way value can be stored as null is using declare()
214 int dest = put(indexOf(key), key);
215 if (val == null) entries[dest + 1] = holder;
216 else entries[dest + 1] = val; }
218 /*public boolean hasValue(JS key, JS value) {
219 int i = indexOf(key); return i >= 0 && entries[i + 1] != null; }
220 public boolean hasTrap(JS key, JS trap) {
221 int i = indexOf(key); return i >= 0 && entries[i + 2] != null; }*/
223 public void declare(JS key) throws JSExn { entries[put(indexOf(key), key) + 1] = null; }
224 public void undeclare(JS key) throws JSExn { remove(indexOf(key)); }
226 public JS putAndTriggerTraps(JS key, JS val) throws JSExn {
227 Trap t = null; int i = indexOf(key);
228 if (i >= 0) t = (Trap)entries[i + 2];
229 if (t != null && (t = t.write()) != null) {
230 val = (JS)new Interpreter(t, val, false).run(null);
232 put(key, val); // HACK: necessary for subclasses overriding put()
233 /*if (i < 0) i = put(i, key);
234 if (val == null) entries[i + 1] = holder;
235 else entries[i + 1] = val;*/
238 public JS getAndTriggerTraps(JS key) throws JSExn {
239 Trap t = null; int i = indexOf(key);
240 if (i < 0) return get(key); // HACK: necessary for subclasses overriding get()
241 t = (Trap)entries[i + 2];
242 return t == null ? (JS)entries[i + 1] : (JS)new Interpreter(t, null, false).run(null);
244 public JS justTriggerTraps(JS key, JS val) throws JSExn {
245 Trap t = null; int i = indexOf(key);
246 if (i >= 0) t = (Trap)entries[i + 2];
247 if (t == null || (t = t.write()) == null) return val;
248 return (JS)new Interpreter(t, val, true).run(null);
251 public void addTrap(JS key, JS f) throws JSExn {
252 if (f.getFormalArgs() == null || f.getFormalArgs().length > 1) throw new JSExn(
253 "traps must take either one argument (write) or no arguments (read)");
254 int i = indexOf(key); if (i < 0) i = put(i, key);
255 for (Trap t = (Trap)entries[i + 2]; t != null; t = t.next())
256 if (t.function().equals(f)) return;
257 entries[i + 2] = new TrapHolder(this, key, f, (Trap)entries[i + 2]);
260 public void delTrap(JS key, JS f) throws JSExn {
261 int i = indexOf(key); if (i < 0) return;
262 Trap t = (Trap)entries[i + 2];
263 if (t.function().equals(f)) { entries[i + 2] = t.next(); return; }
264 for (; t.next() != null; t = t.next())
265 if (t.next().function().equals(f)) { ((TrapHolder)t).next = t.next().next(); return; }
268 public Trap getTrap(JS key) throws JSExn {
269 int i = indexOf(key); return i < 0 ? null : (Trap)entries[i + 2];
272 public String coerceToString() { return "object"; }
274 private static final class Placeholder implements Serializable {}
276 private static final class TrapHolder implements Trap {
277 private final JS target, key, function;
279 TrapHolder(JS t, JS k, JS f, Trap n) { target = t; key = k; function = f; next = n; }
281 public JS key() { return key; }
282 public JS target() { return target; }
283 public JS function() { return function; }
285 public boolean isReadTrap() {
286 return function.getFormalArgs() == null || function.getFormalArgs().length == 0; }
287 public boolean isWriteTrap() {
288 return function.getFormalArgs() != null && function.getFormalArgs().length != 0; }
290 public Trap next() { return next; }
291 public Trap nextRead() {
292 Trap t = next; while (t != null && t.isWriteTrap()) t = t.next(); return t; }
293 public Trap nextWrite() {
294 Trap t = next; while (t != null && t.isReadTrap()) t = t.next(); return t; }
295 public Trap read() { return isReadTrap() ? this : nextRead(); }
296 public Trap write() { return isWriteTrap() ? this : nextWrite(); }
300 public interface Trap {
303 public JS function();
304 public boolean isReadTrap();
305 public boolean isWriteTrap();
307 public Trap nextRead();
308 public Trap nextWrite();
310 public Trap read(); // FIXME reconsider these function names
314 /** An empty class used for instanceof matching the result of JS.get()
315 * to decide if the key is a method (to be called with JS.callMethod(). */
316 public static final class Method extends Immutable {}
319 public static abstract class Enumeration extends Immutable {
320 public static final Enumeration EMPTY = new Empty(null);
322 private final Enumeration parent;
324 public Enumeration(Enumeration parent) { this.parent = parent; }
326 protected abstract boolean _hasNext();
327 protected abstract JS _next() throws JSExn;
329 public final boolean hasNext() {
330 return _hasNext() || parent != null ? parent.hasNext() : false; }
331 public final JS next() throws JSExn {
332 if (_hasNext()) return _next();
333 if (parent == null) throw new NoSuchElementException("reached end of set");
334 return parent.next();
337 public JS get(JS key) throws JSExn {
338 //#switch(JSU.str(key))
339 case "hasNext": return JSU.B(hasNext());
340 case "next": return next();
342 return super.get(key);
345 public static final class Empty extends Enumeration {
346 public Empty(Enumeration parent) { super(parent); }
347 protected boolean _hasNext() { return false; }
348 protected JS _next() { throw new NoSuchElementException(); }
351 public static final class JavaIterator extends Enumeration {
352 private final Iterator i;
353 public JavaIterator(Enumeration parent, Iterator i) { super(parent); this.i = i; }
354 protected boolean _hasNext() { return i.hasNext(); }
355 protected JS _next() { return (JS)i.next(); }
358 public static final class RandomAccessList extends Enumeration {
359 private final List l;
360 private int pos = 0, size;
361 public RandomAccessList(Enumeration parent, List list) {
362 super(parent); l = list; size = l.size(); }
363 protected boolean _hasNext() { return pos < size; }
364 protected JS _next() { return (JS)l.get(pos++); }