@Override
public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
final B64 b64 = toB64(exprs[0], qc, true);
long by = toLong(exprs[1], qc);
if (b64 == null) return null;
if (by == 0) return b64;
byte[] bytes = b64.binary(info);
final int bl = bytes.length;
byte[] tmp = new byte[bl];
int r = 0;
if (by > 7) {
tmp = new BigInteger(bytes).shiftLeft((int) by).toByteArray();
if (tmp.length != bl) {
bytes = tmp;
tmp = new byte[bl];
System.arraycopy(bytes, bytes.length - bl, tmp, 0, bl);
}
} else if (by > 0) {
for (int i = bl - 1; i >= 0; i--) {
final byte b = bytes[i];
tmp[i] = (byte) (b << by | r);
r = b >>> 32 - by;
}
} else if (by > -8) {
by = -by;
for (int i = 0; i < bl; i++) {
final int b = bytes[i] & 0xFF;
tmp[i] = (byte) (b >>> by | r);
r = b << 32 - by;
}
} else {
by = -by;
BigInteger bi = new BigInteger(bytes);
if (bi.signum() >= 0) {
bi = bi.shiftRight((int) by);
} else {
final BigInteger o = BigInteger.ONE.shiftLeft(bl * 8 + 1);
final BigInteger m = o.subtract(BigInteger.ONE).shiftRight((int) by + 1);
bi = bi.subtract(o).shiftRight((int) by).and(m);
}
tmp = bi.toByteArray();
final int tl = tmp.length;
if (tl != bl) {
bytes = tmp;
tmp = new byte[bl];
System.arraycopy(bytes, 0, tmp, bl - tl, tl);
}
}
return new B64(tmp);
}
private void decryptTabelEntry(BigInteger[] cLabels) {
int col = 0;
for (int i = 0; i < nCIBits; i++) if (cLabels[i].testBit(0)) col |= (1 << i);
BigInteger target = EGTable[col];
BigInteger colKey = BigInteger.ZERO;
for (int k = nCIBits - 1; k >= 0; k--)
colKey = colKey.shiftLeft(Wire.labelBitLength).xor(cLabels[k]);
BigInteger res = Cipher.decrypt(colKey, target, nBits * Wire.labelBitLength);
BigInteger mask = BigInteger.ONE.shiftLeft(Wire.labelBitLength).subtract(BigInteger.ONE);
for (int k = nBits - 1; k >= 0; k--)
outputLabels[k] = res.shiftRight(Wire.labelBitLength * k).and(mask);
}
public static void main(String argv[]) {
for (int i = -10; i < 10; i++) {
BigDecimal bd = BigDecimal.ONE.scaleByPowerOfTen(i);
BigDecimal expected;
if (!bd.equals(expected = new BigDecimal(BigInteger.ONE, -i))) {
throw new RuntimeException(
"Unexpected result " + bd.toString() + "; expected " + expected.toString());
}
bd = BigDecimal.ONE.negate().scaleByPowerOfTen(i);
if (!bd.equals(expected = new BigDecimal(BigInteger.ONE.negate(), -i))) {
throw new RuntimeException(
"Unexpected result " + bd.toString() + "; expected " + expected.toString());
}
}
}
