public boolean getNextBlock() throws IOException {
if (curRangeIndex < 0 || curRangeIndex >= indexes.size()) return false;
/* seek to the correct offset to the data, and calculate the data size */
IndexHelper.IndexInfo curColPosition = indexes.get(curRangeIndex);
/* see if this read is really necessary. */
if (reversed) {
if ((finishColumn.length > 0
&& comparator.compare(finishColumn, curColPosition.lastName) > 0)
|| (startColumn.length > 0
&& comparator.compare(startColumn, curColPosition.firstName) < 0)) return false;
} else {
if ((startColumn.length > 0 && comparator.compare(startColumn, curColPosition.lastName) > 0)
|| (finishColumn.length > 0
&& comparator.compare(finishColumn, curColPosition.firstName) < 0)) return false;
}
boolean outOfBounds = false;
// seek to current block
// curIndexInfo.offset is the relative offset from the first block
file.seek(firstBlockPos + curColPosition.offset);
// read all columns of current block into memory!
DataInputStream blockIn =
ColumnFamily.serializer()
.getBlockInputStream(file, curColPosition.sizeOnDisk, compressContext);
try {
int size = 0;
while ((size < curColPosition.width) && !outOfBounds) {
IColumn column = emptyColumnFamily.getColumnSerializer().deserialize(blockIn);
size += column.serializedSize();
if (reversed) blockColumns.addFirst(column);
else blockColumns.addLast(column);
/* see if we can stop seeking. */
if (!reversed && finishColumn.length > 0)
outOfBounds = comparator.compare(column.name(), finishColumn) >= 0;
else if (reversed && startColumn.length > 0)
outOfBounds = comparator.compare(column.name(), startColumn) >= 0;
if (outOfBounds) break;
}
} catch (IOException e) {
logger.error(e.toString());
throw e;
} finally {
ColumnFamily.serializer().releaseBlockInputStream(blockIn, compressContext);
}
if (reversed) curRangeIndex--;
else curRangeIndex++;
return true;
}
public BigdataColumnGroupReader(SSTableReader ssTable, DecoratedKey key, FileDataInput input)
throws IOException {
this.file = input;
this.ssTable = ssTable;
assert file.getAbsolutePosition() == realDataStart;
if (ColumnFamily.serializer().isNewRowFormatIndexAtEnd(rowFormat)) {
////// HEADER //////
// skip bloom filter
IndexHelper.skipBloomFilter(file);
// read deletion meta info
emptyColumnFamily =
ColumnFamily.serializer()
.deserializeFromSSTableNoColumns(ssTable.makeColumnFamily(), file);
file.readInt(); // column count
// the position of the first block
firstBlockPos = file.getAbsolutePosition();
////// TRAILER //////
// seek to the trailer
// THE FIRST SEEK!!!
file.seek(dataStart + dataSize - (Integer.SIZE / Byte.SIZE));
// index size (with column index size's int)
int indexSize = file.readInt();
////// INDEX //////
// seek to index position
// THE SECOND SEEK!!!
file.seek(dataStart + dataSize - (Integer.SIZE / Byte.SIZE) - indexSize);
// read index into memory
indexes = IndexHelper.deserializeIndex(file);
} else {
// skip bloom filter
IndexHelper.skipBloomFilter(file);
// read in index
indexes = IndexHelper.deserializeIndex(file);
// read deletion meta info
emptyColumnFamily =
ColumnFamily.serializer()
.deserializeFromSSTableNoColumns(ssTable.makeColumnFamily(), file);
file.readInt(); // column count
// the position of the first block
firstBlockPos = file.getAbsolutePosition();
}
curRangeIndex = IndexHelper.indexFor(startColumn, indexes, comparator, reversed);
if (reversed && curRangeIndex == indexes.size()) curRangeIndex--;
// compression algorithm used when writing
Compression.Algorithm compressAlgo;
try {
compressAlgo =
Compression.getCompressionAlgorithmById(
ColumnFamily.serializer().getNewRowFormatCompressAlgo(rowFormat));
} catch (IllegalArgumentException e) {
logger.error(e.toString());
throw new IOException(e);
}
compressContext = ColumnFamilySerializer.CompressionContext.getInstance(compressAlgo);
}