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Java > Open Source Codes > org > xquark > xpath > datamodel > xerces > dom > LCount


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57 package org.xquark.xpath.datamodel.xerces.dom;
58
59
60
61 /** Internal class LCount is used to track the number of
62     listeners registered for a given event name, as an entry
63     in a global hashtable. This should allow us to avoid generating,
64     or discard, events for which no listeners are registered.
65     
66     ***** There should undoubtedly be methods here to manipulate
67     this table. At the moment that code's residing in NodeImpl.
68     Move it when we have a chance to do so. Sorry; we were
69     rushed.
70     
71     ***** Also, I'm currently asking "are there any listeners"
72     by testing captures+bubbles+defaults =? 0. It would probably
73     make sense to have a separate "total" field, calculated at
74     add/remove, to save a few cycles during dispatch. Fix.
75     
76     ???? CONCERN: Hashtables are known to be "overserialized" in
77     current versions of Java. That may impact performance.
78     
79     ???? CONCERN: The hashtable should probably be a per-document object.
80     Finer granularity would be even better, but would cost more cycles to
81     resolve and might not save enough event traffic to be worth the investment.
82 */
83 class LCount
84 {
85     static java.util.Hashtable JavaDoc lCounts=new java.util.Hashtable JavaDoc();
86     public int captures=0,bubbles=0,defaults=0;
87
88     static LCount lookup(String JavaDoc evtName)
89     {
90         LCount lc=(LCount)lCounts.get(evtName);
91         if(lc==null)
92             lCounts.put(evtName,(lc=new LCount()));
93         return lc;
94     }
95 } // class LCount
96
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