@Override
public void nextBatch() throws IOException {
for (int i = 0; i < bags.length; i++) {
bags[i].clear();
}
key = currKey;
for (int i = 0; i < batchSize; i++) {
if (iter.hasNext()) {
NullableTuple ntup = iter.next();
int index = ntup.getIndex();
Tuple copy = getValueTuple(ntup, index);
if (numInputs == 1) {
// this is for multi-query merge where
// the numInputs is always 1, but the index
// (the position of the inner plan in the
// enclosed operator) may not be 1.
bags[0].add(copy);
} else {
bags[index].add(copy);
}
}
}
}
/**
* Calls getNext to get next ForEach result. The input for POJoinPackage is a (key, NullableTuple)
* pair. We will materialize n-1 inputs into bags, feed input#n one tuple a time to the delegated
* ForEach operator, the input for ForEach is
*
* <p>(input#1, input#2, input#3....input#n[i]), i=(1..k), suppose input#n consists
*
* <p>of k tuples. For every ForEach input, pull all the results from ForEach. getNext will be
* called multiple times for a particular input, it returns one output tuple from ForEach every
* time we call getNext, so we need to maintain internal status to keep tracking of where we are.
*/
@Override
public Result getNext(Tuple t) throws ExecException {
if (firstTime) {
firstTime = false;
if (PigMapReduce.sJobConf != null) {
String bagType = PigMapReduce.sJobConf.get("pig.cachedbag.type");
if (bagType != null && bagType.equalsIgnoreCase("default")) {
useDefaultBag = true;
}
}
}
// if a previous call to foreach.getNext()
// has still not returned all output, process it
if (forEach.processingPlan) {
forEachResult = forEach.getNext(t1);
switch (forEachResult.returnStatus) {
case POStatus.STATUS_OK:
case POStatus.STATUS_NULL:
case POStatus.STATUS_ERR:
return forEachResult;
case POStatus.STATUS_EOP:
break;
}
}
NullableTuple it = null;
// If we see a new NullableTupleIterator, materialize n-1 inputs, construct ForEach input
// tuple res = (key, input#1, input#2....input#n), the only missing value is input#n,
// we will get input#n one tuple a time, fill in res, feed to ForEach.
// After this block, we have the first tuple of input#n in hand (kept in variable it)
if (newKey) {
lastInputTuple = false;
// Put n-1 inputs into bags
dbs = new DataBag[numInputs];
for (int i = 0; i < numInputs - 1; i++) {
dbs[i] =
useDefaultBag
? BagFactory.getInstance().newDefaultBag()
// In a very rare case if there is a POStream after this
// POJoinPackage in the pipeline and is also blocking the pipeline;
// constructor argument should be 2 * numInputs. But for one obscure
// case we don't want to pay the penalty all the time.
: new InternalCachedBag(numInputs - 1);
}
// For last bag, we always use NonSpillableBag.
dbs[lastBagIndex] = new NonSpillableDataBag((int) chunkSize);
// For each Nullable tuple in the input, put it
// into the corresponding bag based on the index,
// except for the last input, which we will stream
// The tuples will arrive in the order of the index,
// starting from index 0 and such that all tuples for
// a given index arrive before a tuple for the next
// index does.
while (tupIter.hasNext()) {
it = tupIter.next();
int itIndex = it.getIndex();
if (itIndex != numInputs - 1) {
dbs[itIndex].add(getValueTuple(it, itIndex));
} else {
lastInputTuple = true;
break;
}
if (reporter != null) reporter.progress();
}
// If we don't have any tuple for input#n
// we do not need any further process, return EOP
if (!lastInputTuple) {
// we will return at this point because we ought
// to be having a flatten on this last input
// and we have an empty bag which should result
// in this key being taken out of the output
newKey = true;
return eopResult;
}
res = mTupleFactory.newTuple(numInputs + 1);
for (int i = 0; i < dbs.length; i++) res.set(i + 1, dbs[i]);
res.set(0, key);
// if we have an inner anywhere and the corresponding
// bag is empty, we can just return
for (int i = 0; i < dbs.length - 1; i++) {
if (inner[i] && dbs[i].size() == 0) {
detachInput();
return eopResult;
}
}
newKey = false;
// set up the bag with last input to contain
// a chunk of CHUNKSIZE values OR the entire bag if
// it has less than CHUNKSIZE values - the idea is in most
// cases the values are > CHUNKSIZE in number and in
// those cases we will be sending the last bag
// as a set of smaller chunked bags thus holding lesser
// in memory
// the first tuple can be directly retrieved from "it"
dbs[lastBagIndex].add(getValueTuple(it, it.getIndex()));
for (int i = 0; i < chunkSize - 1 && tupIter.hasNext(); i++) {
it = tupIter.next();
dbs[lastBagIndex].add(getValueTuple(it, it.getIndex()));
}
// Attach the input to forEach
forEach.attachInput(res);
// pull output tuple from ForEach
Result forEachResult = forEach.getNext(t1);
{
switch (forEachResult.returnStatus) {
case POStatus.STATUS_OK:
case POStatus.STATUS_NULL:
case POStatus.STATUS_ERR:
return forEachResult;
case POStatus.STATUS_EOP:
break;
}
}
}
// Keep attaching input tuple to ForEach, until:
// 1. We can initialize ForEach.getNext();
// 2. There is no more input#n
while (true) {
if (tupIter.hasNext()) {
// try setting up a bag of CHUNKSIZE OR
// the remainder of the bag of last input
// (if < CHUNKSIZE) to foreach
dbs[lastBagIndex].clear(); // clear last chunk
for (int i = 0; i < chunkSize && tupIter.hasNext(); i++) {
it = tupIter.next();
dbs[lastBagIndex].add(getValueTuple(it, it.getIndex()));
}
} else
// if we do not have any more tuples for input#n, return EOP
{
detachInput();
newKey = true;
return eopResult;
}
// Attach the input to forEach
forEach.attachInput(res);
// pull output tuple from ForEach
Result forEachResult = forEach.getNext(t1);
{
switch (forEachResult.returnStatus) {
case POStatus.STATUS_OK:
case POStatus.STATUS_NULL:
case POStatus.STATUS_ERR:
return forEachResult;
case POStatus.STATUS_EOP:
break;
}
}
}
}
/**
* From the inputs, constructs the output tuple for this co-group in the required format which is
* (key, {bag of tuples from input 1}, {bag of tuples from input 2}, ...)
*/
@Override
public Result getNext(Tuple t) throws ExecException {
Tuple res;
if (firstTime) {
firstTime = false;
if (PigMapReduce.sJobConf != null) {
String bagType = PigMapReduce.sJobConf.get("pig.cachedbag.type");
if (bagType != null && bagType.equalsIgnoreCase("default")) {
useDefaultBag = true;
}
}
}
if (distinct) {
// only set the key which has the whole
// tuple
res = mTupleFactory.newTuple(1);
res.set(0, key);
} else {
// Create numInputs bags
DataBag[] dbs = null;
dbs = new DataBag[numInputs];
if (isAccumulative()) {
// create bag wrapper to pull tuples in many batches
// all bags have reference to the sample tuples buffer
// which contains tuples from one batch
POPackageTupleBuffer buffer = new POPackageTupleBuffer();
for (int i = 0; i < numInputs; i++) {
dbs[i] = new AccumulativeBag(buffer, i);
}
} else {
// create bag to pull all tuples out of iterator
for (int i = 0; i < numInputs; i++) {
dbs[i] =
useDefaultBag
? BagFactory.getInstance().newDefaultBag()
// In a very rare case if there is a POStream after this
// POPackage in the pipeline and is also blocking the pipeline;
// constructor argument should be 2 * numInputs. But for one obscure
// case we don't want to pay the penalty all the time.
: new InternalCachedBag(numInputs);
}
// For each indexed tup in the inp, sort them
// into their corresponding bags based
// on the index
while (tupIter.hasNext()) {
NullableTuple ntup = tupIter.next();
int index = ntup.getIndex();
Tuple copy = getValueTuple(ntup, index);
if (numInputs == 1) {
// this is for multi-query merge where
// the numInputs is always 1, but the index
// (the position of the inner plan in the
// enclosed operator) may not be 1.
dbs[0].add(copy);
} else {
dbs[index].add(copy);
}
if (reporter != null) reporter.progress();
}
}
// Construct the output tuple by appending
// the key and all the above constructed bags
// and return it.
res = mTupleFactory.newTuple(numInputs + 1);
res.set(0, key);
int i = -1;
for (DataBag bag : dbs) {
i++;
if (inner[i] && !isAccumulative()) {
if (bag.size() == 0) {
detachInput();
Result r = new Result();
r.returnStatus = POStatus.STATUS_NULL;
return r;
}
}
res.set(i + 1, bag);
}
}
detachInput();
Result r = new Result();
r.result = res;
r.returnStatus = POStatus.STATUS_OK;
return r;
}
