Examples with Description io.prestosql.spi.function.Description used on opensource projects

Example 41 with Description

use of io.prestosql.spi.function.Description in project hetu-core by openlookeng.

the class StringFunctions method concat.

// TODO: implement N arguments char concat
@Description("concatenates given character strings")
@ScalarFunction
@LiteralParameters({ "x", "y", "u" })
@Constraint(variable = "u", expression = "x + y")
@SqlType("char(u)")
public static Slice concat(@LiteralParameter("x") Long x, @SqlType("char(x)") Slice left, @SqlType("char(y)") Slice right) {
    int rightLength = right.length();
    if (rightLength == 0) {
        return left;
    }
    Slice paddedLeft = padSpaces(left, x.intValue());
    int leftLength = paddedLeft.length();
    Slice result = Slices.allocate(leftLength + rightLength);
    result.setBytes(0, paddedLeft);
    result.setBytes(leftLength, right);
    return result;
}

Example 42 with Description

use of io.prestosql.spi.function.Description in project hetu-core by openlookeng.

the class StringFunctions method hammingDistance.

@Description("computes Hamming distance between two strings")
@ScalarFunction
@LiteralParameters({ "x", "y" })
@SqlType(StandardTypes.BIGINT)
public static long hammingDistance(@SqlType("varchar(x)") Slice left, @SqlType("varchar(y)") Slice right) {
    int distance = 0;
    int leftPosition = 0;
    int rightPosition = 0;
    while (leftPosition < left.length() && rightPosition < right.length()) {
        int codePointLeft = tryGetCodePointAt(left, leftPosition);
        int codePointRight = tryGetCodePointAt(right, rightPosition);
        // the following code treats them as equal if they happen to be of the same length
        if (codePointLeft != codePointRight) {
            distance++;
        }
        leftPosition += codePointLeft > 0 ? lengthOfCodePoint(codePointLeft) : -codePointLeft;
        rightPosition += codePointRight > 0 ? lengthOfCodePoint(codePointRight) : -codePointRight;
    }
    checkCondition(leftPosition == left.length() && rightPosition == right.length(), INVALID_FUNCTION_ARGUMENT, "The input strings to hamming_distance function must have the same length");
    return distance;
}

Example 43 with Description

use of io.prestosql.spi.function.Description in project hetu-core by openlookeng.

the class QuantileDigestFunctions method valuesAtQuantilesDouble.

@ScalarFunction("values_at_quantiles")
@Description("For each input q between [0, 1], find the value whose rank in the sorted sequence of the n values represented by the qdigest is qn.")
@SqlType("array(double)")
public static Block valuesAtQuantilesDouble(@SqlType("qdigest(double)") Slice input, @SqlType("array(double)") Block percentilesArrayBlock) {
    QuantileDigest digest = new QuantileDigest(input);
    BlockBuilder output = DOUBLE.createBlockBuilder(null, percentilesArrayBlock.getPositionCount());
    for (int i = 0; i < percentilesArrayBlock.getPositionCount(); i++) {
        DOUBLE.writeDouble(output, sortableLongToDouble(digest.getQuantile(DOUBLE.getDouble(percentilesArrayBlock, i))));
    }
    return output.build();
}

Example 44 with Description

use of io.prestosql.spi.function.Description in project hetu-core by openlookeng.

the class QuantileDigestFunctions method valuesAtQuantilesReal.

@ScalarFunction("values_at_quantiles")
@Description("For each input q between [0, 1], find the value whose rank in the sorted sequence of the n values represented by the qdigest is qn.")
@SqlType("array(real)")
public static Block valuesAtQuantilesReal(@SqlType("qdigest(real)") Slice input, @SqlType("array(double)") Block percentilesArrayBlock) {
    QuantileDigest digest = new QuantileDigest(input);
    BlockBuilder output = REAL.createBlockBuilder(null, percentilesArrayBlock.getPositionCount());
    for (int i = 0; i < percentilesArrayBlock.getPositionCount(); i++) {
        REAL.writeLong(output, floatToRawIntBits(sortableIntToFloat((int) digest.getQuantile(DOUBLE.getDouble(percentilesArrayBlock, i)))));
    }
    return output.build();
}

Example 45 with Description

use of io.prestosql.spi.function.Description in project hetu-core by openlookeng.

the class JoniRegexpFunctions method regexpExtractAll.

@Description("group(s) extracted using the given pattern")
@ScalarFunction
@LiteralParameters("x")
@SqlType("array(varchar(x))")
public static Block regexpExtractAll(@SqlType("varchar(x)") Slice source, @SqlType(JoniRegexpType.NAME) Regex pattern, @SqlType(StandardTypes.BIGINT) long groupIndex) {
    Matcher matcher = pattern.matcher(source.getBytes());
    validateGroup(groupIndex, matcher.getEagerRegion());
    BlockBuilder blockBuilder = VARCHAR.createBlockBuilder(null, 32);
    int group = toIntExact(groupIndex);
    int nextStart = 0;
    while (true) {
        int offset = matcher.search(nextStart, source.length(), Option.DEFAULT);
        if (offset == -1) {
            break;
        }
        if (matcher.getEnd() == matcher.getBegin()) {
            nextStart = matcher.getEnd() + 1;
        } else {
            nextStart = matcher.getEnd();
        }
        Region region = matcher.getEagerRegion();
        int beg = region.beg[group];
        int end = region.end[group];
        if (beg == -1 || end == -1) {
            blockBuilder.appendNull();
        } else {
            Slice slice = source.slice(beg, end - beg);
            VARCHAR.writeSlice(blockBuilder, slice);
        }
    }
    return blockBuilder.build();
}