Fix range check for character arrays with elements over 32767

This commit is contained in:
Marc Miltenberger 2021-12-22 22:26:26 +01:00 committed by Ben Gruver
parent ec5ae22888
commit 11f71ae481
2 changed files with 25 additions and 4 deletions

View File

@ -220,9 +220,24 @@ public class Preconditions {
}
public static <L extends List<? extends Number>> L checkArrayPayloadElements(int elementWidth, L elements) {
long maxValue = (1L << ((8 * elementWidth) - 1)) - 1;
long minValue = -maxValue - 1;
long maxValue;
long minValue;
if (elementWidth == 2) {
//Could be a short or character.
//Characters are unsigned, Shorts are signed.
//Short.MAX_VALUE = 32767
//Short.MIN_VALUE = -32768
//(int) Character.MAX_VALUE = 65535
//(int) Character.MIN_VALUE = 0
//See https://docs.oracle.com/javase/specs/jvms/se6/html/Overview.doc.html for details
//As such, we use the combined interval range of both.
maxValue = (int) Character.MAX_VALUE;
minValue = Short.MIN_VALUE;
} else {
//Two's complement.
maxValue = (1L << ((8 * elementWidth) - 1)) - 1;
minValue = -maxValue - 1;
}
for (Number element : elements) {
if (element.longValue() < minValue || element.longValue() > maxValue) {
throw new IllegalArgumentException(

View File

@ -28,12 +28,18 @@ public class PreconditionsTest {
verifyArrayPayloadElementIsValid(4, Integer.MIN_VALUE);
verifyArrayPayloadElementIsValid(2, Short.MAX_VALUE);
verifyArrayPayloadElementIsValid(2, Short.MIN_VALUE);
verifyArrayPayloadElementIsValid(2, Character.MAX_VALUE);
verifyArrayPayloadElementIsValid(2, Character.MIN_VALUE);
verifyArrayPayloadElementIsValid(1, Byte.MAX_VALUE);
verifyArrayPayloadElementIsValid(1, Byte.MIN_VALUE);
verifyArrayPayloadElementIsInvalid(4, ((long) Integer.MAX_VALUE) + 1);
verifyArrayPayloadElementIsInvalid(4, ((long) Integer.MIN_VALUE) - 1);
verifyArrayPayloadElementIsInvalid(2, ((long) Short.MAX_VALUE) + 1);
verifyArrayPayloadElementIsInvalid(2, ((long) Short.MIN_VALUE) - 1);
//Since short and character have the same size, but different ranges
// and cannot be distinguished here, the valid interval is
//[Short.MIN_VALUE, Character.MAX_VALUE], i.e. [-32768, 65535]
verifyArrayPayloadElementIsInvalid(2, ((long) Character.MAX_VALUE) + 1);
verifyArrayPayloadElementIsInvalid(2, ((long) Short.MIN_VALUE) - 1);
verifyArrayPayloadElementIsInvalid(1, ((long) Byte.MAX_VALUE) + 1);
verifyArrayPayloadElementIsInvalid(1, ((long) Byte.MIN_VALUE) - 1);