/** Writes a right-zero-extended value to {@code out}. */
public static void writeRightZeroExtendedValue(ByteOutput out, int type, long value) {
// Figure out how many bits are needed to represent the value.
int requiredBits = 64 - Long.numberOfTrailingZeros(value);
if (requiredBits == 0) {
requiredBits = 1;
}
// Round up the requiredBits to a number of bytes.
int requiredBytes = (requiredBits + 0x07) >> 3;
// Scootch the first bits to be written down to the low-order bits.
value >>= 64 - (requiredBytes * 8);
/*
* Write the header byte, which includes the type and
* requiredBytes - 1.
*/
out.writeByte(type | ((requiredBytes - 1) << 5));
// Write the value, per se.
while (requiredBytes > 0) {
out.writeByte((byte) value);
value >>= 8;
requiredBytes--;
}
}
/** Writes a signed integral to {@code out}. */
public static void writeSignedIntegralValue(ByteOutput out, int type, long value) {
/*
* Figure out how many bits are needed to represent the value,
* including a sign bit: The bit count is subtracted from 65
* and not 64 to account for the sign bit. The xor operation
* has the effect of leaving non-negative values alone and
* unary complementing negative values (so that a leading zero
* count always returns a useful number for our present
* purpose).
*/
int requiredBits = 65 - Long.numberOfLeadingZeros(value ^ (value >> 63));
// Round up the requiredBits to a number of bytes.
int requiredBytes = (requiredBits + 0x07) >> 3;
/*
* Write the header byte, which includes the type and
* requiredBytes - 1.
*/
out.writeByte(type | ((requiredBytes - 1) << 5));
// Write the value, per se.
while (requiredBytes > 0) {
out.writeByte((byte) value);
value >>= 8;
requiredBytes--;
}
}
/** Writes an unsigned integral to {@code out}. */
public static void writeUnsignedIntegralValue(ByteOutput out, int type, long value) {
// Figure out how many bits are needed to represent the value.
int requiredBits = 64 - Long.numberOfLeadingZeros(value);
if (requiredBits == 0) {
requiredBits = 1;
}
// Round up the requiredBits to a number of bytes.
int requiredBytes = (requiredBits + 0x07) >> 3;
/*
* Write the header byte, which includes the type and
* requiredBytes - 1.
*/
out.writeByte(type | ((requiredBytes - 1) << 5));
// Write the value, per se.
while (requiredBytes > 0) {
out.writeByte((byte) value);
value >>= 8;
requiredBytes--;
}
}
