@Override
public void startBlockEncoding(HFileBlockEncodingContext blkEncodingCtx, DataOutputStream out)
throws IOException {
if (blkEncodingCtx.getClass() != HFileBlockDefaultEncodingContext.class) {
throw new IOException(
this.getClass().getName()
+ " only accepts "
+ HFileBlockDefaultEncodingContext.class.getName()
+ " as the "
+ "encoding context.");
}
HFileBlockDefaultEncodingContext encodingCtx =
(HFileBlockDefaultEncodingContext) blkEncodingCtx;
encodingCtx.prepareEncoding(out);
if (encodingCtx.getHFileContext().isIncludesTags()
&& encodingCtx.getHFileContext().isCompressTags()) {
if (encodingCtx.getTagCompressionContext() != null) {
// It will be overhead to create the TagCompressionContext again and again for every block
// encoding.
encodingCtx.getTagCompressionContext().clear();
} else {
try {
TagCompressionContext tagCompressionContext =
new TagCompressionContext(LRUDictionary.class, Byte.MAX_VALUE);
encodingCtx.setTagCompressionContext(tagCompressionContext);
} catch (Exception e) {
throw new IOException("Failed to initialize TagCompressionContext", e);
}
}
}
StreamUtils.writeInt(out, 0); // DUMMY length. This will be updated in endBlockEncoding()
blkEncodingCtx.setEncodingState(new BufferedDataBlockEncodingState());
}
/**
* @param cell
* @param out
* @param encodingCtx
* @return unencoded size added
* @throws IOException
*/
protected final int afterEncodingKeyValue(
Cell cell, DataOutputStream out, HFileBlockDefaultEncodingContext encodingCtx)
throws IOException {
int size = 0;
if (encodingCtx.getHFileContext().isIncludesTags()) {
int tagsLength = cell.getTagsLength();
ByteBufferUtils.putCompressedInt(out, tagsLength);
// There are some tags to be written
if (tagsLength > 0) {
TagCompressionContext tagCompressionContext = encodingCtx.getTagCompressionContext();
// When tag compression is enabled, tagCompressionContext will have a not null value. Write
// the tags using Dictionary compression in such a case
if (tagCompressionContext != null) {
tagCompressionContext.compressTags(
out, cell.getTagsArray(), cell.getTagsOffset(), tagsLength);
} else {
out.write(cell.getTagsArray(), cell.getTagsOffset(), tagsLength);
}
}
size += tagsLength + KeyValue.TAGS_LENGTH_SIZE;
}
if (encodingCtx.getHFileContext().isIncludesMvcc()) {
// Copy memstore timestamp from the byte buffer to the output stream.
long memstoreTS = cell.getSequenceId();
WritableUtils.writeVLong(out, memstoreTS);
// TODO use a writeVLong which returns the #bytes written so that 2 time parsing can be
// avoided.
size += WritableUtils.getVIntSize(memstoreTS);
}
return size;
}