private static boolean valueEquals(
Type type, Slice leftSlice, int leftOffset, Slice rightSlice, int rightOffset) {
// check if null flags are the same
boolean leftIsNull = leftSlice.getByte(leftOffset) != 0;
boolean rightIsNull = rightSlice.getByte(rightOffset) != 0;
if (leftIsNull != rightIsNull) {
return false;
}
// if values are both null, they are equal
if (leftIsNull) {
return true;
}
if (type == Type.FIXED_INT_64 || type == Type.DOUBLE) {
long leftValue = leftSlice.getLong(leftOffset + SIZE_OF_BYTE);
long rightValue = rightSlice.getLong(rightOffset + SIZE_OF_BYTE);
return leftValue == rightValue;
} else if (type == Type.BOOLEAN) {
boolean leftValue = leftSlice.getByte(leftOffset + SIZE_OF_BYTE) != 0;
boolean rightValue = rightSlice.getByte(rightOffset + SIZE_OF_BYTE) != 0;
return leftValue == rightValue;
} else if (type == Type.VARIABLE_BINARY) {
int leftLength = getVariableBinaryLength(leftSlice, leftOffset);
int rightLength = getVariableBinaryLength(rightSlice, rightOffset);
return leftSlice.equals(
leftOffset + SIZE_OF_BYTE + SIZE_OF_INT,
leftLength,
rightSlice,
rightOffset + SIZE_OF_BYTE + SIZE_OF_INT,
rightLength);
} else {
throw new IllegalArgumentException("Unsupported type " + type);
}
}
@Description("returns index of first occurrence of a substring (or 0 if not found)")
@ScalarFunction("strpos")
@SqlType(BigintType.class)
public static long stringPosition(
@SqlType(VarcharType.class) Slice string, @SqlType(VarcharType.class) Slice substring) {
if (substring.length() > string.length()) {
return 0;
}
for (int i = 0; i <= (string.length() - substring.length()); i++) {
if (string.equals(i, substring.length(), substring, 0, substring.length())) {
return i + 1;
}
}
return 0;
}
// TODO: Implement a more efficient string search
@Nullable
@Description("splits a string by a delimiter and returns the specified field (counting from one)")
@ScalarFunction
@SqlType(VarcharType.class)
public static Slice splitPart(
@SqlType(VarcharType.class) Slice string,
@SqlType(VarcharType.class) Slice delimiter,
@SqlType(BigintType.class) long index) {
checkArgument(index > 0, "Index must be greater than zero");
if (delimiter.length() == 0) {
if (index > string.length()) {
// index is too big, null is returned
return null;
}
return string.slice((int) (index - 1), 1);
}
int previousIndex = 0;
int matchCount = 0;
for (int i = 0; i <= (string.length() - delimiter.length()); i++) {
if (string.equals(i, delimiter.length(), delimiter, 0, delimiter.length())) {
matchCount++;
if (matchCount == index) {
return string.slice(previousIndex, i - previousIndex);
}
// noinspection AssignmentToForLoopParameter
i += (delimiter.length() - 1);
previousIndex = i + 1;
}
}
if (matchCount == index - 1) {
// returns last section of the split
return string.slice(previousIndex, string.length() - previousIndex);
}
// index is too big, null is returned
return null;
}