/**
* Note: For efficiency, we directly use SequenceFile.Reader instead of SequenceFileInputFormat-
* InputSplits-RecordReader (SequenceFileRecordReader). First, this has no drawbacks since the
* SequenceFileRecordReader internally uses SequenceFile.Reader as well. Second, it is
* advantageous if the actual sequence files are larger than the file splits created by
* informat.getSplits (which is usually aligned to the HDFS block size) because then there is
* overhead for finding the actual split between our 1k-1k blocks. This case happens if the read
* matrix was create by CP or when jobs directly write to large output files (e.g., parfor matrix
* partitioning).
*
* @param path
* @param job
* @param fs
* @param dest
* @param rlen
* @param clen
* @param brlen
* @param bclen
* @throws IOException
* @throws IllegalAccessException
* @throws InstantiationException
* @throws DMLRuntimeException
*/
@SuppressWarnings("deprecation")
private static void readBinaryBlockMatrixFromHDFS(
Path path,
JobConf job,
FileSystem fs,
MatrixBlock dest,
long rlen,
long clen,
int brlen,
int bclen)
throws IOException, DMLRuntimeException {
boolean sparse = dest.isInSparseFormat();
MatrixIndexes key = new MatrixIndexes();
MatrixBlock value = new MatrixBlock();
// set up preferred custom serialization framework for binary block format
if (MRJobConfiguration.USE_BINARYBLOCK_SERIALIZATION)
MRJobConfiguration.addBinaryBlockSerializationFramework(job);
for (Path lpath : getSequenceFilePaths(fs, path)) // 1..N files
{
// directly read from sequence files (individual partfiles)
SequenceFile.Reader reader = new SequenceFile.Reader(fs, lpath, job);
try {
// note: next(key, value) does not yet exploit the given serialization classes, record
// reader does but is generally slower.
while (reader.next(key, value)) {
// empty block filter (skip entire block)
if (value.isEmptyBlock(false)) continue;
int row_offset = (int) (key.getRowIndex() - 1) * brlen;
int col_offset = (int) (key.getColumnIndex() - 1) * bclen;
int rows = value.getNumRows();
int cols = value.getNumColumns();
// bound check per block
if (row_offset + rows < 0
|| row_offset + rows > rlen
|| col_offset + cols < 0
|| col_offset + cols > clen) {
throw new IOException(
"Matrix block ["
+ (row_offset + 1)
+ ":"
+ (row_offset + rows)
+ ","
+ (col_offset + 1)
+ ":"
+ (col_offset + cols)
+ "] "
+ "out of overall matrix range [1:"
+ rlen
+ ",1:"
+ clen
+ "].");
}
// copy block to result
if (sparse) {
dest.appendToSparse(value, row_offset, col_offset);
// note: append requires final sort
} else {
dest.copy(
row_offset, row_offset + rows - 1, col_offset, col_offset + cols - 1, value, false);
}
}
} finally {
IOUtilFunctions.closeSilently(reader);
}
}
if (sparse && clen > bclen) {
// no need to sort if 1 column block since always sorted
dest.sortSparseRows();
}
}
/**
* @param path
* @param job
* @param src
* @param rlen
* @param clen
* @param brlen
* @param bclen
* @throws IOException
*/
protected void writeTextCellMatrixToHDFS(
Path path, JobConf job, MatrixBlock src, long rlen, long clen) throws IOException {
boolean sparse = src.isInSparseFormat();
boolean entriesWritten = false;
FileSystem fs = FileSystem.get(job);
BufferedWriter br = new BufferedWriter(new OutputStreamWriter(fs.create(path, true)));
int rows = src.getNumRows();
int cols = src.getNumColumns();
// bound check per block
if (rows > rlen || cols > clen) {
throw new IOException(
"Matrix block [1:"
+ rows
+ ",1:"
+ cols
+ "] "
+ "out of overall matrix range [1:"
+ rlen
+ ",1:"
+ clen
+ "].");
}
try {
// for obj reuse and preventing repeated buffer re-allocations
StringBuilder sb = new StringBuilder();
if (sparse) // SPARSE
{
SparseRowsIterator iter = src.getSparseRowsIterator();
while (iter.hasNext()) {
IJV cell = iter.next();
sb.append(cell.i + 1);
sb.append(' ');
sb.append(cell.j + 1);
sb.append(' ');
sb.append(cell.v);
sb.append('\n');
br.write(sb.toString()); // same as append
sb.setLength(0);
entriesWritten = true;
}
} else // DENSE
{
for (int i = 0; i < rows; i++) {
String rowIndex = Integer.toString(i + 1);
for (int j = 0; j < cols; j++) {
double lvalue = src.getValueDenseUnsafe(i, j);
if (lvalue != 0) // for nnz
{
sb.append(rowIndex);
sb.append(' ');
sb.append(j + 1);
sb.append(' ');
sb.append(lvalue);
sb.append('\n');
br.write(sb.toString()); // same as append
sb.setLength(0);
entriesWritten = true;
}
}
}
}
// handle empty result
if (!entriesWritten) {
br.write("1 1 0\n");
}
} finally {
IOUtilFunctions.closeSilently(br);
}
}
