Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/exports/StepCSVWriter.java @ 5779:ebec12def170
Datacage: Add a pool of builders to make it multi threadable.
XML DOM is not thread safe. Therefore the old implementation only allowed one thread
to use the builder at a time. As the complexity of the configuration
has increased over time this has become a bottleneck of the whole application
because it took quiet some time to build a result. Furthermore the builder code path
is visited very frequent. So many concurrent requests were piled up
resulting in long waits for the users.
To mitigate this problem a round robin pool of builders is used now.
Each of the pooled builders has an independent copy of the XML template
and can be run in parallel.
The number of builders is determined by the system property
'flys.datacage.pool.size'. It defaults to 4.
author | Sascha L. Teichmann <teichmann@intevation.de> |
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date | Sun, 21 Apr 2013 12:48:09 +0200 |
parents | 475dd07c2cb1 |
children |
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package de.intevation.flys.exports; import au.com.bytecode.opencsv.CSVWriter; import java.util.ArrayList; import java.util.Arrays; /** * Class to overcome shortcoming of CSVWriter to accept String-Arrays only. * The StepCSVWriter buffers incoming values, such that rows in a csv can be * created more dynamically. Do not forget to call flush(). */ public class StepCSVWriter { /** Writer to use when calling flush. */ CSVWriter writer = null; /** Buffer of strings (values). */ ArrayList<String> buffer; /** Trivial constructor. */ public StepCSVWriter() { buffer = new ArrayList<String>(); } /** Set writer. */ public void setCSVWriter(CSVWriter writer) { this.writer = writer; } /** Add a value to next flush. */ public void addNext(String value) { buffer.add(value); } /** Add many values to next flush. */ public void addNexts(String ... values) { buffer.addAll(Arrays.asList(values)); } /** Write the row with csvwriter. */ public void flush() { writer.writeNext(buffer.toArray(new String[buffer.size()])); buffer.clear(); } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :