@Override
protected void setupLocal() {
// Precompute the first input chunk index and start row inside that chunk for this partition
Vec anyInVec = _srcVecs[0];
long[] partSizes = Utils.partitione(anyInVec.length(), _ratios);
long pnrows = 0;
for (int p = 0; p < _partIdx; p++) pnrows += partSizes[p];
long[] espc = anyInVec._espc;
while (_pcidx < espc.length - 1 && (pnrows -= (espc[_pcidx + 1] - espc[_pcidx])) > 0)
_pcidx++;
assert pnrows <= 0;
_psrow = (int) (pnrows + espc[_pcidx + 1] - espc[_pcidx]);
}
// The task computes ESPC per split
static long[ /*nsplits*/][ /*nchunks*/] computeEspcPerSplit(
long[] espc, long len, float[] ratios) {
assert espc.length > 0 && espc[0] == 0;
assert espc[espc.length - 1] == len;
long[] partSizes = Utils.partitione(len, ratios); // Split of whole vector
int nparts = ratios.length + 1;
long[][] r = new long[nparts][espc.length]; // espc for each partition
long nrows = 0;
long start = 0;
for (int p = 0, c = 0; p < nparts; p++) {
int nc = 0; // number of chunks for this partition
for (; c < espc.length - 1 && (espc[c + 1] - start) <= partSizes[p]; c++)
r[p][++nc] = espc[c + 1] - start;
if (r[p][nc] < partSizes[p])
r[p][++nc] = partSizes[p]; // last item in espc contains number of rows
r[p] = Arrays.copyOf(r[p], nc + 1);
// Transfer rest of lines to the next part
nrows = nrows - partSizes[p];
start += partSizes[p];
}
return r;
}