prestodb/presto · error · IllegalArgumentException

arrayOffset is negative

Error message

arrayOffset is negative

What it means

The package-private ByteArrayBlock constructor validates its arrayOffset parameter and throws this IllegalArgumentException if it is negative. arrayOffset is the starting index into the shared byte[] values array; a negative offset would make all position math invalid. It is a defensive precondition against malformed construction arguments.

Source

Thrown at presto-common/src/main/java/com/facebook/presto/common/block/ByteArrayBlock.java:66

    public static final int SIZE_IN_BYTES_PER_POSITION = Byte.BYTES + Byte.BYTES;

    private final int arrayOffset;
    private final int positionCount;
    @Nullable
    private final boolean[] valueIsNull;
    private final byte[] values;

    private final long retainedSizeInBytes;

    public ByteArrayBlock(int positionCount, Optional<boolean[]> valueIsNull, byte[] values)
    {
        this(0, positionCount, valueIsNull.orElse(null), values);
    }

    ByteArrayBlock(int arrayOffset, int positionCount, boolean[] valueIsNull, byte[] values)
    {
        if (arrayOffset < 0) {
            throw new IllegalArgumentException("arrayOffset is negative");
        }
        this.arrayOffset = arrayOffset;
        if (positionCount < 0) {
            throw new IllegalArgumentException("positionCount is negative");
        }
        this.positionCount = positionCount;

        if (values.length - arrayOffset < positionCount) {
            throw new IllegalArgumentException("values length is less than positionCount");
        }
        this.values = values;

        if (valueIsNull != null && valueIsNull.length - arrayOffset < positionCount) {
            throw new IllegalArgumentException("isNull length is less than positionCount");
        }
        this.valueIsNull = valueIsNull;

        retainedSizeInBytes = (INSTANCE_SIZE + sizeOf(valueIsNull) + sizeOf(values));

View on GitHub (pinned to 55bb57d202)

Solutions

1. Fix the offset computation so it is never negative; clamp with Math.max(0, offset) only if a negative value is legitimate 'no data' semantics.
2. If the intent was an empty view, pass arrayOffset 0 with positionCount 0 instead of a negative offset.
3. Audit the code that wraps sub-arrays and add an explicit assertion offset >= 0 near the slice computation.

Example fix

// before
int offset = previousEnd - sliceSize; // can go negative
new ByteArrayBlock(offset, count, valueIsNull, values);
// after
int offset = Math.max(0, previousEnd - sliceSize);
checkArgument(offset >= 0, "computed slice offset is negative");
new ByteArrayBlock(offset, count, valueIsNull, values);

if (arrayOffset < 0) {
    throw new IllegalArgumentException("computed arrayOffset is negative: " + arrayOffset);
}
new ByteArrayBlock(arrayOffset, positionCount, valueIsNull, values);

boolean isValidBlockArgs(int arrayOffset, int positionCount) {
    return arrayOffset >= 0 && positionCount >= 0;
}

try {
    block = new ByteArrayBlock(arrayOffset, positionCount, valueIsNull, values);
} catch (IllegalArgumentException e) {
    if (e.getMessage().equals("arrayOffset is negative")) {
        throw new IllegalStateException("negative slice offset from " + offsetSource, e);
    } else {
        throw e;
    }
}

When it happens

Trigger: Constructing ByteArrayBlock (directly in package code, or via the public constructor paths that forward) with a negative arrayOffset, usually from bad offset arithmetic when wrapping a sub-range of a larger byte buffer.

Common situations: Custom connector code slicing a page/buffer with a computed offset that underflowed (offset -= size going negative); reusing offset variables across loops; buggy serialization/deserialization code that reconstructs blocks with incorrect offsets.

Understand the failure class

Background: "must be a positive integer", "cannot be empty", "invalid argument": how invalid-argument errors work across open-source libraries — this error's family across 33 libraries.

Related errors

• positionCount is negative
• array1 and array2 cannot be null and should have same length
• positionCount is negative
• ids length is less than positionCount
• New column does not have same number of rows as old column

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/cb35e9334cf3e8e3. Report an issue: GitHub.