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POIs HashMap.put for String keys generally a bottleneck? How do I speed it up?
 

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  1. POIs HashMap.put for String keys generally a bottleneck? How do I speed it up?
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    <p>I'm writing a <a href="http://en.wikipedia.org/wiki/Random_indexing" rel="nofollow">Random Indexing</a> implementation in Java, which needs to process large corpora and somehow store individual tokens' context and index vectors. A HashMap seemed natural (String -> Token object), but when running Xprof it seems like a disproportionate large portion of the processing goes to adding the token to the HashMap.</p> <p>Am I reading the output correctly? Why is this, and is there some way for me to speed things up?</p> <pre><code>Flat profile of 16.18 secs (606 total ticks): main Interpreted + native Method 6.9% 0 + 42 java.io.FileInputStream.readBytes 5.0% 0 + 30 java.lang.Object.getClass 1.8% 11 + 0 java.lang.String.toLowerCase 1.5% 9 + 0 java.util.HashMap.resize 1.3% 8 + 0 opennlp.tools.tokenize.AbstractTokenizer.tokenize 1.3% 0 + 8 java.util.zip.ZipFile.read 1.2% 0 + 7 java.util.zip.ZipFile.open 0.8% 5 + 0 java.util.Arrays.copyOfRange 0.5% 0 + 3 java.io.FileInputStream.available 0.3% 2 + 0 java.util.HashMap.put 0.3% 0 + 2 sun.misc.Unsafe.compareAndSwapLong 0.3% 2 + 0 java.lang.CharacterDataLatin1.toLowerCase 0.3% 2 + 0 java.util.ArrayList.grow 0.3% 2 + 0 semanticspace.SparseVector.get 0.3% 2 + 0 java.lang.CharacterData.of 0.2% 1 + 0 java.util.HashMap.createEntry 0.2% 1 + 0 java.util.Arrays.copyOf 0.2% 1 + 0 java.lang.Integer.valueOf 0.2% 1 + 0 java.lang.Integer.toString 0.2% 1 + 0 sun.misc.JarIndex.addToList 0.2% 1 + 0 java.util.ArrayList.toArray 0.2% 1 + 0 java.net.URL.toString 0.2% 1 + 0 semanticspace.SparseVector.add 0.2% 1 + 0 sun.reflect.NativeMethodAccessorImpl.invoke0 0.2% 1 + 0 java.io.BufferedInputStream.read1 26.2% 65 + 94 Total interpreted (including elided) Compiled + native Method 36.5% 217 + 4 java.util.HashMap.put 24.3% 133 + 14 semanticspace.SparseVector.add 2.6% 15 + 1 semanticspace.RandomIndexing.getToken 1.3% 8 + 0 java.lang.String.toLowerCase 1.3% 8 + 0 semanticspace.RandomIndexing.read 0.5% 0 + 3 java.util.HashMap.newKeyIterator 0.2% 0 + 1 semanticspace.SparseVector.get 0.2% 1 + 0 java.util.HashMap.containsKey 66.8% 382 + 23 Total compiled Stub + native Method 6.9% 0 + 42 java.lang.System.arraycopy 6.9% 0 + 42 Total stub Flat profile of 0.00 secs (1 total ticks): DestroyJavaVM Thread-local ticks: 100.0% 1 Blocked (of total) Flat profile of 16.17 secs (608 total ticks): Monitor Ctrl-Break Interpreted + native Method 98.2% 0 + 597 java.net.PlainSocketImpl.socketAccept 1.0% 0 + 6 java.net.PlainSocketImpl.initProto 0.7% 0 + 4 java.net.NetworkInterface.getAll 0.2% 0 + 1 java.lang.ClassLoader$NativeLibrary.load 100.0% 0 + 608 Total interpreted Global summary of 16.33 seconds: 100.0% 1326 Received ticks 53.2% 706 Received GC ticks 6.8% 90 Compilation 0.1% 1 Other VM operations </code></pre>
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    1. USJimmy C
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    1. COMaybe your `String` input contains a very large value and the `hashCode` function becomes slower than the others.
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      1. USLuiggi Mendoza
 

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