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1
4 package gnu.mapping;
5
6 public class InheritingEnvironment extends SimpleEnvironment
7 {
8 int numInherited;
9 Environment[] inherited;
10 Namespace[] namespaceMap;
11 Object  [] propertyMap;
12 int baseTimestamp;
13
14 public InheritingEnvironment (String name, Environment parent)
15 {
16 super(name);
17 addParent(parent);
18 if (parent instanceof SimpleEnvironment)
19 {
20 int timestamp = ++((SimpleEnvironment) parent).currentTimestamp;
21 baseTimestamp = timestamp;
22 currentTimestamp = timestamp;
23 }
24 }
25
26 public final int getNumParents () { return numInherited; }
27 public final Environment getParent (int index) { return inherited[index]; }
28
29 public void addParent (Environment env)
30 {
31 if (numInherited == 0)
32 inherited = new Environment[4];
33 else if (numInherited <= inherited.length)
34 {
35 Environment[] newInherited
36 = new Environment[2 * numInherited];
37 System.arraycopy(inherited, 0, newInherited, 0, numInherited);
38 inherited = newInherited;
39 }
40 inherited[numInherited] = env;
41 numInherited++;
42 }
43
44 public NamedLocation lookupInherited (Symbol name, Object property, int hash)
45 {
46 for (int i = 0; i < numInherited; i++)
47 {
48 Symbol sym = name;
49 Object prop = property;
50 if (namespaceMap != null && namespaceMap.length > 2*i)
51 {
52 Object srcNamespace = namespaceMap[2*i];
53 Object dstNamespace = namespaceMap[2*i+1];
54 if (srcNamespace != null || dstNamespace != null)
55 {
56 if (name.getNamespace() != dstNamespace)
57 continue;
58 sym = Symbol.make(srcNamespace, name.getName());
59 }
60 }
61 if (propertyMap != null && propertyMap.length > 2*i)
62 {
63 Object srcProperty = propertyMap[2*i];
64 Object dstProperty = propertyMap[2*i+1];
65 if (srcProperty != null || dstProperty != null)
66 {
67 if (property != dstProperty)
68 continue;
69 prop = srcProperty;
70 }
71 }
72 NamedLocation loc = inherited[i].lookup(sym, prop, hash);
73 if (loc != null && loc.isBound())
74 {
75 if (! (loc instanceof SharedLocation)
76 || ((SharedLocation) loc).timestamp < baseTimestamp)
77 return loc;
78 }
79 }
80 return null;
81 }
82
83 public NamedLocation lookup (Symbol name, Object property, int hash)
84 {
85 NamedLocation loc = super.lookup(name, property, hash);
86 if (loc != null && loc.isBound())
87 return loc;
88 return lookupInherited(name, property, hash);
89 }
90
91 public synchronized NamedLocation
92 getLocation (Symbol name, Object property, int hash, boolean create)
93 {
94 NamedLocation loc = lookupDirect(name, property, hash);
95 if (loc != null && (create || loc.isBound()))
96 return loc;
97 if ((flags & INDIRECT_DEFINES) != 0 && create)
98 loc = inherited[0].getLocation(name, property, hash, true);
99 else
100 loc = lookupInherited(name, property, hash);
101
102 if (loc != null)
103 {
104 if (create )
105 {
106 NamedLocation xloc = addUnboundLocation(name, property, hash);
107 if ((flags & CAN_DEFINE) == 0 && loc.isBound())
108 redefineError(name, property, xloc);
109 xloc.base = loc;
110 if (loc.value == IndirectableLocation.INDIRECT_FLUIDS)
111 xloc.value = loc.value;
112 else if ((flags & DIRECT_INHERITED_ON_SET) != 0)
113 xloc.value = IndirectableLocation.DIRECT_ON_SET;
114 else
115 xloc.value = null;
116 if (xloc instanceof SharedLocation)
117 ((SharedLocation) xloc).timestamp = baseTimestamp;
118 return xloc;
119 }
120 else
121 return loc;
122 }
123 return create ? addUnboundLocation(name, property, hash) : null;
124 }
125
126 public LocationEnumeration enumerateAllLocations()
127 {
128 LocationEnumeration it = new LocationEnumeration(table, 1 << log2Size);
129 it.env = this;
130 if (inherited != null && inherited.length > 0)
131 {
132 it.inherited = inherited[0].enumerateAllLocations();
133 it.index = 0;
134 }
135 return it;
136 }
137
138 protected boolean hasMoreElements (LocationEnumeration it)
139 {
140 if (it.inherited != null)
141 {
142 for (;;)
143 {
144 NamedLocation loc = it.curLoc;
145 for (;;)
146 {
147 it.inherited.curLoc = loc;
148 if (! it.inherited.hasMoreElements())
149 {
150 it.curLoc = it.inherited.curLoc;
151 break;
152 }
153 loc = it.inherited.curLoc;
154 if (lookup(loc.name, loc.property) == loc)
155 {
156 it.curLoc = loc;
157 return true;
158 }
159 loc = loc.next;
160 }
161 if (++it.index == numInherited)
162 break;
163 it.inherited = inherited[it.index].enumerateAllLocations();
164 }
165 it.inherited = null;
166 it.bindings = table;
167 it.index = 1 << log2Size;
168 }
169 return super.hasMoreElements(it);
170 }
171
172 protected void toStringBase (StringBuffer sbuf)
173 {
174 sbuf.append(" baseTs:");
175 sbuf.append(baseTimestamp);
176 for (int i = 0; i < numInherited; i++)
177 {
178 sbuf.append(" base:");
179 sbuf.append(inherited[i].toStringVerbose());
180 }
181 }
182 }
183 |
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