Method decodeFromByteSource

bolt/common/encode/Coding.h:216–245

Decode a value from a ByteSource, and advance the ByteSource.

  // Decode a value from a ByteSource, and advance the ByteSource.
  static uint64_t decodeFromByteSource(strings::ByteSource* src) {
    uint64_t val = 0;
    int32_t shift = 0;
    int32_t max_size = kMaxSize64;
    folly::StringPiece chunk;
    int32_t remaining = 0;
    const char* p = nullptr;
    for (;;) {
      if (remaining == 0) {
        CHECK(src->next(&chunk));
        p = chunk.start();
        remaining = chunk.size();
        DCHECK_GT(remaining, 0);
      }
      --remaining;
      if (*p & 0x80) {
        CHECK_GT(max_size, 1); // We must have room for the last byte, too
        --max_size;
        val |= static_cast<uint64_t>(*p++ & 0x7f) << shift;
        shift += 7;
      } else {
        val |= static_cast<uint64_t>(*p++) << shift;
        break;
      }
    }
    if (remaining) {
      src->backUp(remaining);
    }
    return val;
  }
  static UInt128 decode128FromByteSource(strings::ByteSource* src) {
    UInt128 val = 0;
    int32_t shift = 0;