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encode_unsigned

cqlite_core::storage::serialization::vint

Function encode_unsigned 

Source 
pub fn encode_unsigned(value: u64, buf: &mut Vec<u8>)
Expand description

Encode an unsigned u64 to VInt bytes

Encoding format (standard Cassandra unsigned VInt):

  • 1 byte: 0xxxxxxx (values 0-127)
  • 2 bytes: 10xxxxxx xxxxxxxx (values 128-16383, 14 bits total: 6+8)
  • 3 bytes: 110xxxxx xxxxxxxx xxxxxxxx (values 16384-2097151, 21 bits: 5+8+8)
  • … up to 9 bytes total

The first byte encodes the number of extra bytes via leading 1-bits, followed by a 0 separator bit, then data bits.

§Arguments

  • value - Unsigned 64-bit integer to encode
  • buf - Target buffer to write VInt bytes

§Examples

let mut buf = Vec::new();
encode_unsigned(0, &mut buf);
assert_eq!(buf, vec![0x00]);

buf.clear();
encode_unsigned(127, &mut buf);
assert_eq!(buf, vec![0x7F]);

buf.clear();
encode_unsigned(128, &mut buf);
assert_eq!(buf, vec![0x80, 0x80]); // 10xxxxxx xxxxxxxx