Examples with Constraint com.facebook.presto.type.Constraint used on opensource projects

Example 1 with Constraint

use of com.facebook.presto.type.Constraint in project presto by prestodb.

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 2 with Constraint

use of com.facebook.presto.type.Constraint in project presto by prestodb.

the class StringFunctions method replace.

@Description("greedily replaces occurrences of a pattern with a string")
@ScalarFunction
@LiteralParameters({ "x", "y", "z", "u" })
@Constraint(variable = "u", expression = "min(2147483647, x + z * (x + 1))")
@SqlType("varchar(u)")
public static Slice replace(@SqlType("varchar(x)") Slice str, @SqlType("varchar(y)") Slice search, @SqlType("varchar(z)") Slice replace) {
    // Empty search?
    if (search.length() == 0) {
        // With empty `search` we insert `replace` in front of every character and at the end
        int resultLength;
        try {
            resultLength = Math.addExact(Math.multiplyExact(countCodePoints(str) + 1, replace.length()), str.length());
        } catch (ArithmeticException e) {
            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, "inputs to \"replace\" function are too large: when \"search\" parameter is empty, length of \"string\" times length of \"replace\" must not exceed " + Integer.MAX_VALUE);
        }
        Slice buffer = Slices.allocate(resultLength);
        // Always start with replace
        buffer.setBytes(0, replace);
        int indexBuffer = replace.length();
        // After every code point insert `replace`
        int index = 0;
        while (index < str.length()) {
            int codePointLength = lengthOfCodePointSafe(str, index);
            // Append current code point
            buffer.setBytes(indexBuffer, str, index, codePointLength);
            indexBuffer += codePointLength;
            // Append `replace`
            buffer.setBytes(indexBuffer, replace);
            indexBuffer += replace.length();
            // Advance pointer to current code point
            index += codePointLength;
        }
        return buffer;
    }
    // Allocate a reasonable buffer
    Slice buffer = Slices.allocate(str.length());
    int index = 0;
    int indexBuffer = 0;
    while (index < str.length()) {
        int matchIndex = str.indexOf(search, index);
        // Found a match?
        if (matchIndex < 0) {
            // No match found so copy the rest of string
            int bytesToCopy = str.length() - index;
            buffer = Slices.ensureSize(buffer, indexBuffer + bytesToCopy);
            buffer.setBytes(indexBuffer, str, index, bytesToCopy);
            indexBuffer += bytesToCopy;
            break;
        }
        int bytesToCopy = matchIndex - index;
        buffer = Slices.ensureSize(buffer, indexBuffer + bytesToCopy + replace.length());
        // Non empty match?
        if (bytesToCopy > 0) {
            buffer.setBytes(indexBuffer, str, index, bytesToCopy);
            indexBuffer += bytesToCopy;
        }
        // Non empty replace?
        if (replace.length() > 0) {
            buffer.setBytes(indexBuffer, replace);
            indexBuffer += replace.length();
        }
        // Continue searching after match
        index = matchIndex + search.length();
    }
    return buffer.slice(0, indexBuffer);
}

Example 3 with Constraint

use of com.facebook.presto.type.Constraint in project presto by prestodb.

the class JoniRegexpFunctions method regexpReplace.

@Description("replaces substrings matching a regular expression by given string")
@ScalarFunction
@LiteralParameters({ "x", "y", "z" })
// to get the formula: x + max(x * y / 2, y) * (x + 1)
@Constraint(variable = "z", expression = "min(2147483647, x + max(x * y / 2, y) * (x + 1))")
@SqlType("varchar(z)")
public static Slice regexpReplace(@SqlType("varchar(x)") Slice source, @SqlType(JoniRegexpType.NAME) Regex pattern, @SqlType("varchar(y)") Slice replacement) {
    Matcher matcher = pattern.matcher(source.getBytes());
    SliceOutput sliceOutput = new DynamicSliceOutput(source.length() + replacement.length() * 5);
    int lastEnd = 0;
    // nextStart is the same as lastEnd, unless the last match was zero-width. In such case, nextStart is lastEnd + 1.
    int nextStart = 0;
    while (true) {
        int offset = getMatchingOffset(matcher, nextStart, source.length());
        if (offset == -1) {
            break;
        }
        if (matcher.getEnd() == matcher.getBegin()) {
            nextStart = matcher.getEnd() + 1;
        } else {
            nextStart = matcher.getEnd();
        }
        Slice sliceBetweenReplacements = source.slice(lastEnd, matcher.getBegin() - lastEnd);
        lastEnd = matcher.getEnd();
        sliceOutput.appendBytes(sliceBetweenReplacements);
        appendReplacement(sliceOutput, source, pattern, matcher.getEagerRegion(), replacement);
    }
    sliceOutput.appendBytes(source.slice(lastEnd, source.length() - lastEnd));
    return sliceOutput.slice();
}