protected void decodeTags() {
current.tagsLength = ByteBuff.readCompressedInt(currentBuffer);
if (tagCompressionContext != null) {
if (current.uncompressTags) {
// Tag compression is been used. uncompress it into tagsBuffer
current.ensureSpaceForTags();
try {
current.tagsCompressedLength =
tagCompressionContext.uncompressTags(
currentBuffer, current.tagsBuffer, 0, current.tagsLength);
} catch (IOException e) {
throw new RuntimeException("Exception while uncompressing tags", e);
}
} else {
currentBuffer.skip(current.tagsCompressedLength);
current.uncompressTags = true; // Reset this.
}
current.tagsOffset = -1;
} else {
// When tag compress is not used, let us not do copying of tags bytes into tagsBuffer.
// Just mark the tags Offset so as to create the KV buffer later in getKeyValueBuffer()
current.tagsOffset = currentBuffer.position();
currentBuffer.skip(current.tagsLength);
}
}
private void moveToPrevious() {
if (!previous.isValid()) {
throw new IllegalStateException(
"Can move back only once and not in first key in the block.");
}
STATE tmp = previous;
previous = current;
current = tmp;
// move after last key value
currentBuffer.position(current.nextKvOffset);
// Already decoded the tag bytes. We cache this tags into current state and also the total
// compressed length of the tags bytes. For the next time decodeNext() we don't need to decode
// the tags again. This might pollute the Data Dictionary what we use for the compression.
// When current.uncompressTags is false, we will just reuse the current.tagsBuffer and skip
// 'tagsCompressedLength' bytes of source stream.
// See in decodeTags()
current.tagsBuffer = previous.tagsBuffer;
current.tagsCompressedLength = previous.tagsCompressedLength;
current.uncompressTags = false;
// The current key has to be reset with the previous Cell
current.setKey(current.keyBuffer, current.memstoreTS);
previous.invalidate();
}