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PO
 

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  1. PO
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    <p>Why not just use a sorted collection as your table model instead of a list. TreeMap seems logical since your entries are all ordered. If you also need fast access by row or any other column, you can simply add a secondary map. Basically you are doing what database indexes do.</p> <p>I thought for some reason that you could use the map.headSet(key) and find the kth entry -- this won't work. You need to be able to get from table row -> EventID (or close to it).</p> <p>if you use a model like this</p> <pre><code>Map&lt;EventID, Event&gt; model = new TreeSet&lt;EventID, Event&gt;(); </code></pre> <p>Conceptually your getValueAt() looks like this:</p> <pre><code>getValueAt(int row, column) { eventID = getSortPosition(row); Event e = model.headSet(eventID).next(); return getColumn(e, column); } </code></pre> <p>The key is being able to efficiently maintain a map from sort index -> key (an inverse map). This is non-trival since inserting a new event at the very top affects the absolute order of all those below it. It seems like there should be a CS answer here, but it escapes me.</p> <p>Here is the most basic implementation: - on every insert, you update your map, then materialize your sorted map.</p> <pre><code>ArrayList&lt;Event&gt; orderedEvents = new ArrayList&lt;Event&gt;(); public void insert(Event event) { model.put(event.getID(), event); // update the model.headSet().addAll(orderedEvents); } </code></pre> <p>Your getValueAt() would be pretty simple.</p> <pre><code>getValueAt(int row, column) {w); Event e = orderedEvents.get(row); return getColumn(e, column); } </code></pre> <ul> <li>this makes insertions O(n) instead of O(n log n) (still not great)</li> </ul> <p><strong>I think you should reconsider your UI design</strong> If you are having users browse a 100K row table, adding a search filter will solve your performance problem:</p> <ul> <li>No user will EVER read 100k rows</li> <li>If it is meaningfull for your users to search by eventID then this works great, when the users selects the eventID, you do: sortedMap.headSet( searchFilterID ) // take first 200 put them into your table</li> <li>If it is meaningfull for users to search by time, then make a map from and do the same. </li> </ul>
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    1. POEfficient look-up in a List
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    1. USJustin
    1. USJustin
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    1. COHow would this work? Specifically, How would TableModel's getValueAt(int, int) method work?
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      1. USAdamski
    2. COshould have thought it through more carefully. Its still possible as i describe in my edit.
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      1. USJustin
    3. COUI redesign: only if it is really shown as a table. A better visualization (2D or 3D) can easily handle that many rows. That is more than 20 pixels/element on a 1920*1200 screen, without scrolling :)
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      1. USStephan Eggermont
 

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