public static Block intersect(Type type, Block leftArray, Block rightArray) {
int leftPositionCount = leftArray.getPositionCount();
int rightPositionCount = rightArray.getPositionCount();
if (leftPositionCount == 0) {
return leftArray;
}
if (rightPositionCount == 0) {
return rightArray;
}
int[] leftPositions = new int[leftPositionCount];
int[] rightPositions = new int[rightPositionCount];
for (int i = 0; i < leftPositionCount; i++) {
leftPositions[i] = i;
}
for (int i = 0; i < rightPositionCount; i++) {
rightPositions[i] = i;
}
IntArrays.quickSort(leftPositions, IntBlockCompare(type, leftArray));
IntArrays.quickSort(rightPositions, IntBlockCompare(type, rightArray));
int entrySize;
if (leftPositionCount < rightPositionCount) {
entrySize = (int) Math.ceil(leftArray.getSizeInBytes() / (double) leftPositionCount);
} else {
entrySize = (int) Math.ceil(rightArray.getSizeInBytes() / (double) rightPositionCount);
}
BlockBuilder resultBlockBuilder =
type.createBlockBuilder(
new BlockBuilderStatus(),
Math.min(leftArray.getPositionCount(), rightArray.getPositionCount()),
entrySize);
int leftCurrentPosition = 0;
int rightCurrentPosition = 0;
int leftBasePosition;
int rightBasePosition;
while (leftCurrentPosition < leftPositionCount && rightCurrentPosition < rightPositionCount) {
leftBasePosition = leftCurrentPosition;
rightBasePosition = rightCurrentPosition;
int compareValue =
type.compareTo(
leftArray,
leftPositions[leftCurrentPosition],
rightArray,
rightPositions[rightCurrentPosition]);
if (compareValue > 0) {
rightCurrentPosition++;
} else if (compareValue < 0) {
leftCurrentPosition++;
} else {
type.appendTo(leftArray, leftPositions[leftCurrentPosition], resultBlockBuilder);
leftCurrentPosition++;
rightCurrentPosition++;
while (leftCurrentPosition < leftPositionCount
&& type.equalTo(
leftArray,
leftPositions[leftBasePosition],
leftArray,
leftPositions[leftCurrentPosition])) {
leftCurrentPosition++;
}
while (rightCurrentPosition < rightPositionCount
&& type.equalTo(
rightArray,
rightPositions[rightBasePosition],
rightArray,
rightPositions[rightCurrentPosition])) {
rightCurrentPosition++;
}
}
}
return resultBlockBuilder.build();
}
