/**
* Like {@link #readRawVarint32(InputStream)}, but expects that the caller has already read one
* byte. This allows the caller to determine if EOF has been reached before attempting to read.
*/
public static int readRawVarint32(final int firstByte, final InputStream input)
throws IOException {
if ((firstByte & 0x80) == 0) {
return firstByte;
}
int result = firstByte & 0x7f;
int offset = 7;
for (; offset < 32; offset += 7) {
final int b = input.read();
if (b == -1) {
throw InvalidProtocolBufferException.truncatedMessage();
}
result |= (b & 0x7f) << offset;
if ((b & 0x80) == 0) {
return result;
}
}
// Keep reading up to 64 bits.
for (; offset < 64; offset += 7) {
final int b = input.read();
if (b == -1) {
throw InvalidProtocolBufferException.truncatedMessage();
}
if ((b & 0x80) == 0) {
return result;
}
}
throw InvalidProtocolBufferException.malformedVarint();
}
private void skipRawVarintSlowPath() throws IOException {
for (int i = 0; i < 10; i++) {
if (readRawByte() >= 0) {
return;
}
}
throw InvalidProtocolBufferException.malformedVarint();
}
/* Visible for testing */
long readRawVarint64SlowPath() throws IOException {
long result = 0;
for (int shift = 0; shift < 64; shift += 7) {
final byte b = readRawByte();
result |= (long) (b & 0x7F) << shift;
if ((b & 0x80) == 0) {
return result;
}
}
throw InvalidProtocolBufferException.malformedVarint();
}
/** Tests readRawVarint32() and readRawVarint64(). */
public void testReadVarint() throws Exception {
assertReadVarint(bytes(0x00), 0);
assertReadVarint(bytes(0x01), 1);
assertReadVarint(bytes(0x7f), 127);
// 14882
assertReadVarint(bytes(0xa2, 0x74), (0x22 << 0) | (0x74 << 7));
// 2961488830
assertReadVarint(
bytes(0xbe, 0xf7, 0x92, 0x84, 0x0b),
(0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) | (0x0bL << 28));
// 64-bit
// 7256456126
assertReadVarint(
bytes(0xbe, 0xf7, 0x92, 0x84, 0x1b),
(0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) | (0x1bL << 28));
// 41256202580718336
assertReadVarint(
bytes(0x80, 0xe6, 0xeb, 0x9c, 0xc3, 0xc9, 0xa4, 0x49),
(0x00 << 0)
| (0x66 << 7)
| (0x6b << 14)
| (0x1c << 21)
| (0x43L << 28)
| (0x49L << 35)
| (0x24L << 42)
| (0x49L << 49));
// 11964378330978735131
assertReadVarint(
bytes(0x9b, 0xa8, 0xf9, 0xc2, 0xbb, 0xd6, 0x80, 0x85, 0xa6, 0x01),
(0x1b << 0)
| (0x28 << 7)
| (0x79 << 14)
| (0x42 << 21)
| (0x3bL << 28)
| (0x56L << 35)
| (0x00L << 42)
| (0x05L << 49)
| (0x26L << 56)
| (0x01L << 63));
// Failures
assertReadVarintFailure(
InvalidProtocolBufferException.malformedVarint(),
bytes(0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x00));
assertReadVarintFailure(InvalidProtocolBufferException.truncatedMessage(), bytes(0x80));
}
