Function read_primitive_sequence_indexed

python/pyfory/cpp/pyfory.cc:1242–1466

template <typename SetItemFn>
static int read_primitive_sequence_indexed(Buffer *buffer, Py_ssize_t size,
                                           uint8_t type_id,
                                           SetItemFn set_item) {
  Error error;
  switch (static_cast<TypeId>(type_id)) {
  case TypeId::STRING:
    for (Py_ssize_t i = 0; i < size; ++i) {
      PyObject *item = read_python_string(buffer);
      if (FORY_PREDICT_FALSE(item == nullptr)) {
        return -1;
      }
      set_item(i, item);
    }
    return 0;
  case TypeId::VARINT64: {
    const uint8_t *data = buffer->data();
    const uint8_t *ptr = data + buffer->reader_index();
    const uint8_t *end = data + buffer->size();
    for (Py_ssize_t i = 0; i < size; ++i) {
      if (FORY_PREDICT_FALSE(ptr >= end)) {
        PyErr_SetString(PyExc_BufferError,
                        "buffer out of bound while reading varint64");
        return -1;
      }
      uint64_t raw = 0;
      const uint8_t b0 = *ptr++;
      if ((b0 & 0x80) == 0) {
        raw = b0;
      } else {
        if (FORY_PREDICT_FALSE(ptr >= end)) {
          PyErr_SetString(PyExc_BufferError,
                          "buffer out of bound while reading varint64");
          return -1;
        }
        const uint8_t b1 = *ptr++;
        raw = static_cast<uint64_t>(b0 & 0x7F) |
              (static_cast<uint64_t>(b1 & 0x7F) << 7);
        if (FORY_PREDICT_FALSE((b1 & 0x80) != 0)) {
          const uint32_t offset = static_cast<uint32_t>((ptr - data) - 2);
          uint32_t read_bytes = 0;
          raw = buffer->get_var_uint64(offset, &read_bytes);
          if (FORY_PREDICT_FALSE(read_bytes == 0)) {
            PyErr_SetString(PyExc_BufferError,
                            "buffer out of bound while reading varint64");
            return -1;
          }
          ptr = data + offset + read_bytes;
        }
      }
      const int64_t v =
          static_cast<int64_t>((raw >> 1) ^ -static_cast<int64_t>(raw & 1ULL));
      PyObject *item = PyLong_FromLongLong(v);
      if (FORY_PREDICT_FALSE(item == nullptr)) {
        return -1;
      }
      set_item(i, item);
    }
    buffer->reader_index(static_cast<uint32_t>(ptr - data));