[LUCENE-568] [PATCH]Multiple threads performance enhancement when querying.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 1.9
• Component/s: core/search

Environment

OS: Red Hat EL 3
Machine: Dual CPUs, 1024M Ram, 100Giga bytes SCSI disks.
Lucene 1.9.1
JVM:JDK1.5.06

• Assignee: Yonik Seeley
• Reporter: Yueyu Lin
• Created: 10/May/06 09:20
• Updated: 28/Aug/22 11:27
• Resolved: 10/May/06 11:33

Description

This improvement will reduce the wait when TermInfosReader calls ensureIndexIsRead().
The small trick like below:
....
private void ensureIndexIsRead() throws IOException {
if (indexTerms != null) // index already read
return; // do nothing
synchronized(this){
System.out.println("Read index@--@");
if(indexTerms != null)

{ System.out.println ("Someone read it.return-_-"); return ; }

readIndex ();
}
}

private synchronized void readIndex() throws IOException{
Term[] m_indexTerms = null;
try {
int indexSize = (int)indexEnum.size; // otherwise read index
m_indexTerms = new Term[indexSize];
indexInfos = new TermInfo[indexSize];
indexPointers = new long[indexSize];

for (int i = 0; indexEnum.next(); i++)

{ m_indexTerms[i] = indexEnum.term(); indexInfos[i] = indexEnum.termInfo(); indexPointers[i] = indexEnum.indexPointer; }

} finally

{ indexEnum.close(); indexEnum = null; indexTerms = m_indexTerms; }

}