SiyaoIsHiding commented on code in PR #1952:
URL:
https://github.com/apache/cassandra-java-driver/pull/1952#discussion_r1919982845
##########
core/src/main/java/com/datastax/oss/driver/internal/core/type/util/VIntCoding.java:
##########
@@ -174,10 +175,84 @@ public static int computeVIntSize(final long param) {
}
/** Compute the number of bytes that would be needed to encode an unsigned
varint. */
- private static int computeUnsignedVIntSize(final long value) {
+ public static int computeUnsignedVIntSize(final long value) {
int magnitude =
Long.numberOfLeadingZeros(
value | 1); // | with 1 to ensure magnitude <= 63, so (63 - 1) / 7
<= 8
return (639 - magnitude * 9) >> 6;
}
+
+ public static void writeUnsignedVInt32(int value, ByteBuffer output) {
+ writeUnsignedVInt((long) value, output);
+ }
+
+ public static void writeUnsignedVInt(long value, ByteBuffer output) {
+ int size = VIntCoding.computeUnsignedVIntSize(value);
+ if (size == 1) {
+ output.put((byte) value);
+ return;
+ }
+
+ output.put(VIntCoding.encodeVInt(value, size), 0, size);
+ }
+
+ /**
+ * Read up to a 32-bit integer back, using the unsigned (no zigzag) encoding.
+ *
+ * <p>Note this method is the same as {@link #readUnsignedVInt(DataInput)},
except that we do
+ * *not* block if there are not enough bytes in the buffer to reconstruct
the value.
+ *
+ * @throws VIntOutOfRangeException If the vint doesn't fit into a 32-bit
integer
+ */
+ public static int getUnsignedVInt32(ByteBuffer input, int readerIndex) {
+ return checkedCast(getUnsignedVInt(input, readerIndex));
+ }
+
+ public static long getUnsignedVInt(ByteBuffer input, int readerIndex) {
+ return getUnsignedVInt(input, readerIndex, input.limit());
+ }
+
+ public static long getUnsignedVInt(ByteBuffer input, int readerIndex, int
readerLimit) {
+ if (readerIndex < 0)
+ throw new IllegalArgumentException(
+ "Reader index should be non-negative, but was " + readerIndex);
+
+ if (readerIndex >= readerLimit) return -1;
+
+ int firstByte = input.get(readerIndex++);
+
+ // Bail out early if this is one byte, necessary or it fails later
+ if (firstByte >= 0) return firstByte;
+
+ int size = numberOfExtraBytesToRead(firstByte);
+ if (readerIndex + size > readerLimit) return -1;
+
+ long retval = firstByte & firstByteValueMask(size);
+ for (int ii = 0; ii < size; ii++) {
+ byte b = input.get(readerIndex++);
+ retval <<= 8;
+ retval |= b & 0xff;
+ }
+
+ return retval;
+ }
+
+ public static int checkedCast(long value) {
+ int result = (int) value;
+ if ((long) result != value) throw new VIntOutOfRangeException(value);
+ return result;
+ }
+
+ /**
+ * Throw when attempting to decode a vint and the output type doesn't have
enough space to fit the
+ * value that was decoded
+ */
+ public static class VIntOutOfRangeException extends RuntimeException {
+ public final long value;
+
+ private VIntOutOfRangeException(long value) {
+ super(value + " is out of range for a 32-bit integer");
+ this.value = value;
+ }
+ }
Review Comment:
Added tests copied from the server side
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