@Override
public int getInt(int ordinal) {
assertIndexIsValid(ordinal);
final int offset = getElementOffset(ordinal);
if (offset < 0) return 0;
return PlatformDependent.UNSAFE.getInt(baseObject, baseOffset + offset);
}
/** Returns a 64-bit integer that can be used as the prefix used in sorting. */
public long getPrefix() {
// Since JVMs are either 4-byte aligned or 8-byte aligned, we check the size of the string.
// If size is 0, just return 0.
// If size is between 0 and 4 (inclusive), assume data is 4-byte aligned under the hood and
// use a getInt to fetch the prefix.
// If size is greater than 4, assume we have at least 8 bytes of data to fetch.
// After getting the data, we use a mask to mask out data that is not part of the string.
long p;
long mask = 0;
if (byteOrder == ByteOrder.LITTLE_ENDIAN) {
if (numBytes >= 8) {
p = PlatformDependent.UNSAFE.getLong(base, offset);
} else if (numBytes > 4) {
p = PlatformDependent.UNSAFE.getLong(base, offset);
mask = (1L << (8 - numBytes) * 8) - 1;
} else if (numBytes > 0) {
p = (long) PlatformDependent.UNSAFE.getInt(base, offset);
mask = (1L << (8 - numBytes) * 8) - 1;
} else {
p = 0;
}
p = java.lang.Long.reverseBytes(p);
} else {
// byteOrder == ByteOrder.BIG_ENDIAN
if (numBytes >= 8) {
p = PlatformDependent.UNSAFE.getLong(base, offset);
} else if (numBytes > 4) {
p = PlatformDependent.UNSAFE.getLong(base, offset);
mask = (1L << (8 - numBytes) * 8) - 1;
} else if (numBytes > 0) {
p = ((long) PlatformDependent.UNSAFE.getInt(base, offset)) << 32;
mask = (1L << (8 - numBytes) * 8) - 1;
} else {
p = 0;
}
}
p &= ~mask;
return p;
}
private int getElementOffset(int ordinal) {
return PlatformDependent.UNSAFE.getInt(baseObject, baseOffset + ordinal * 4L);
}