Function UpdateUnsignedLeb128

Bcore/src/main/cpp/base/leb128.h:273–282

Overwrite encoded Leb128 with a new value. The new value must be less than or equal to the old value to ensure that it fits the allocated space.

// Overwrite encoded Leb128 with a new value. The new value must be less than
// or equal to the old value to ensure that it fits the allocated space.
static inline void UpdateUnsignedLeb128(uint8_t* dest, uint32_t value) {
  const uint8_t* old_end = dest;
  uint32_t old_value = DecodeUnsignedLeb128(&old_end);
  DCHECK_LE(UnsignedLeb128Size(value), UnsignedLeb128Size(old_value));
  for (uint8_t* end = EncodeUnsignedLeb128(dest, value); end < old_end; end++) {
    // Use longer encoding than necessary to fill the allocated space.
    end[-1] |= 0x80;
    end[0] = 0;
  }
}

static inline uint8_t* EncodeSignedLeb128(uint8_t* dest, int32_t value) {
  uint32_t extra_bits = static_cast<uint32_t>(value ^ (value >> 31)) >> 6;