Merge "Fix binary reading code performance."

This commit is contained in:
Jean Chalard 2012-04-23 23:39:37 -07:00 committed by Android (Google) Code Review
commit 805fed49e1

View file

@ -1142,6 +1142,12 @@ public class BinaryDictInputOutput {
}
}
// The word cache here is a stopgap bandaid to help the catastrophic performance
// of this method. Since it performs direct, unbuffered random access to the file and
// may be called hundreds of thousands of times, the resulting performance is not
// reasonable without some kind of cache. Thus:
// TODO: perform buffered I/O here and in other places in the code.
private static TreeMap<Integer, String> wordCache = new TreeMap<Integer, String>();
/**
* Finds, as a string, the word at the address passed as an argument.
*
@ -1151,8 +1157,10 @@ public class BinaryDictInputOutput {
* @return the word, as a string.
* @throws IOException if the file can't be read.
*/
private static String getWordAtAddress(RandomAccessFile source, long headerSize,
private static String getWordAtAddress(final RandomAccessFile source, final long headerSize,
int address) throws IOException {
final String cachedString = wordCache.get(address);
if (null != cachedString) return cachedString;
final long originalPointer = source.getFilePointer();
source.seek(headerSize);
final int count = readCharGroupCount(source);
@ -1191,6 +1199,7 @@ public class BinaryDictInputOutput {
}
}
source.seek(originalPointer);
wordCache.put(address, result);
return result;
}