Tencent/matrix · error · std::runtime_error

Invalid type size.

Error message

Invalid type size.

What it means

ReadTyped<T>() in the hprof reader reads a multi-byte value sized via ReadU2/ReadU4/ReadU8 depending on sizeof(T). If sizeof(T) is 1, 3, or anything other than 4 or 8 bytes, the reader cannot know which primitive read to use and throws std::runtime_error("Invalid type size.") to prevent misaligned/incorrect deserialization of the HPROF heap dump.

Solutions

1. Use ReadU1()/ReadU2() for 1- and 2-byte fields instead of ReadTyped
2. Instantiate ReadTyped only with 4- or 8-byte types (uint32_t, int32_t, uint64_t, float, double)
3. Add a static_assert(sizeof(T)==4||sizeof(T)==8) to catch bad instantiations at compile time
4. Check the HPROF spec for the exact field size of the record being parsed

Example fix

// before
uint8_t flags = ReadTyped<uint8_t>(); // throws Invalid type size.
// after
uint8_t flags = ReadU1();

template <typename T>
bool isReadableSize() { return sizeof(T) == 4 || sizeof(T) == 8; }
// assert before calling:
static_assert(isReadableSize<MyType>(), "ReadTyped requires 4- or 8-byte types");

template <typename T>
constexpr bool valid_read_type_v = (sizeof(T) == 4 || sizeof(T) == 8);

try {
  auto v = reader.ReadTyped<uint32_t>();
} catch (const std::runtime_error &e) {
  if (strcmp(e.what(), "Invalid type size.") == 0) {
    // fix template instantiation / use ReadU2() for small fields
  }
  throw;
}

When it happens

Trigger: Calling ReadTyped with a template type whose size is not 4 or 8 bytes (e.g. ReadTyped<uint8_t>, ReadTyped<bool>, ReadTyped<Some3ByteStruct>) while parsing an HPROF record.

Common situations: Adding new HPROF record parsers that read single-byte or 2-byte fields using the generic ReadTyped helper instead of the dedicated U1/U2 readers; refactors changing a field's type to char/bool.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Unable to obtained scaled bitmap's dimensions
• Could not find char array in
• Field does not exists
• Unexpected type for
• Unknown root type:

AI-assisted analysis of Tencent/matrix@3b8293bd65 (2026-09-08). Data as JSON: /api/errors/7bde3022b6e5f6b0. Report an issue: GitHub.

Appendix: source

Thrown at matrix/matrix-android/matrix-hprof-analyzer/lib/reader/include/reader.h:62

            Skip(sizeof(uint64_t));
        }

        template<typename T>
        T ReadTyped(size_t size) {
            if (size == sizeof(uint8_t)) {
                const uint8_t value = ReadU1();
                return *reinterpret_cast<const T *>(&value);
            } else if (size == sizeof(uint16_t)) {
                const uint16_t value = ReadU2();
                return *reinterpret_cast<const T *>(&value);
            } else if (size == sizeof(uint32_t)) {
                const uint32_t value = ReadU4();
                return *reinterpret_cast<const T *>(&value);
            } else if (size == sizeof(uint64_t)) {
                const uint64_t value = ReadU8();
                return *reinterpret_cast<const T *>(&value);
            } else {
                throw std::runtime_error("Invalid type size.");
            }
        }

        std::string ReadString(size_t length);

        std::string ReadNullTerminatedString();

        uint64_t Read(size_t size);

        void Skip(size_t size);

        void ResetCursor();

        const void *Extract(size_t size);

    private:
        const size_t buffer_size_;
        const uint8_t *buffer_;

View on GitHub (pinned to 3b8293bd65)