/**
* This procedure runs on the unisolated index. The raw data is written directly onto the {@link
* Journal} and the index is added/updated using the given file, version and block and the address
* of the block's data on the {@link Journal}.
*
* @return A {@link Boolean} whose value is <code>true</code> iff the block was overwritten.
*/
@Override
public Object apply(final IIndex ndx) {
// tunnel through to the backing journal.
final AbstractJournal journal = (AbstractJournal) ((AbstractBTree) ndx).getStore();
// obtain the thread-local key builder for that journal.
final IKeyBuilder keyBuilder = ndx.getIndexMetadata().getKeyBuilder();
/*
* Write the block on the journal, obtaining the address at which it
* was written - use 0L as the address for an empty block.
*/
final long addr = len == 0 ? 0L : journal.write(ByteBuffer.wrap(b, off, len));
// form the key for the index entry for this block.
final byte[] key =
keyBuilder
.reset()
.appendText(id, true /* unicode */, false /* successor */)
.append(version)
.append(block)
.getKey();
// record the address of the block in the index.
final boolean overwrite;
{
final DataOutputBuffer out = new DataOutputBuffer(Bytes.SIZEOF_LONG);
// encode the value for the entry.
out.reset().putLong(addr);
final byte[] val = out.toByteArray();
// insert the entry into the index.
overwrite = ndx.insert(key, val) != null;
}
log.info(
"Wrote "
+ len
+ " bytes : id="
+ id
+ ", version="
+ version
+ ", block#="
+ block
+ " @ addr"
+ journal.toString(addr)
+ ", overwrite="
+ overwrite);
return Boolean.valueOf(overwrite);
}
private void doTest(final IUnicodeCompressor c) {
final long begin = System.currentTimeMillis();
final Random r = new Random();
final int ntrials = 100000;
// The source data to be encoded.
final StringBuilder sb = new StringBuilder();
// The buffer onto which we encode that data.
final DataOutputBuffer outEncoded = new DataOutputBuffer();
// The buffer onto which the decoded data are written.
final StringBuilder outDecoded = new StringBuilder();
long nwords = 0L; // #of encoded words.
long nchars = 0L; // #of encoded characters.
long nbytes = 0L; // #of bytes for those encoded characters.
for (int trial = 0; trial < ntrials; trial++) {
final int wordLength = r.nextInt(20) + 1;
// reset
sb.setLength(0);
// build up a string of randomly selected words.
for (int i = 0; i < wordLength; i++) {
if (i > 0) sb.append(" ");
sb.append(words[r.nextInt(words.length)]);
}
final String expected = sb.toString();
/*
* Encode.
*/
final byte[] a;
final int nencoded;
{
// reset the output buffer.
outEncoded.reset();
// encode the data.
nencoded = c.encode(expected, outEncoded);
// the encoded data.
a = outEncoded.toByteArray();
}
nwords += wordLength;
nchars += expected.length();
nbytes += a.length;
/*
* Note: The caller needs to know the exact length to be decoded in
* advance with this api. This implies that we will have to buffer
* the data before it can be copied into an IKeyBuilder. This is not
* a problem as long as it is the only thing in the buffer, but that
* is not true for many use cases, including serialization of a
* BigdataValue.
*/
final String actual;
final int ndecoded;
{
// reset the output buffer.
outDecoded.setLength(0);
// decode.
ndecoded =
c.decode(new ByteArrayInputStream(a, 0 /* off */, a.length /* len */), outDecoded);
// extract the decoded string.
actual = outDecoded.toString();
}
// verify encode/decode.
assertEquals(expected, actual);
// verify #of bytes encoded / #of bytes decoded.
assertEquals(nencoded, ndecoded);
}
final long elapsed = System.currentTimeMillis() - begin;
// The compression ratio.
final double ratio = (double) nbytes / (double) nchars;
if (log.isInfoEnabled())
log.info(
"nwords="
+ nwords
+ ", nchars="
+ nchars
+ ", nbytes="
+ nbytes
+ ", bytes/char="
+ ratio
+ ", elapsed="
+ elapsed);
}
