Function ReadScope

code/AssetLib/FBX/FBXBinaryTokenizer.cpp:305–388

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// ------------------------------------------------------------------------------------------------
bool ReadScope(TokenList &output_tokens, StackAllocator &token_allocator, const char *input, const char *&cursor, const char *end, bool const is64bits) {
    // the first word contains the offset at which this block ends
	const uint64_t end_offset = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);

    // we may get 0 if reading reached the end of the file -
    // fbx files have a mysterious extra footer which I don't know
    // how to extract any information from, but at least it always
    // starts with a 0.
    if(!end_offset) {
        return false;
    }

    if(end_offset > Offset(input, end)) {
        TokenizeError("block offset is out of range",input, cursor);
    }
    else if(end_offset < Offset(input, cursor)) {
        TokenizeError("block offset is negative out of range",input, cursor);
    }

    // the second data word contains the number of properties in the scope
	const uint64_t prop_count = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);

    // the third data word contains the length of the property list
	const uint64_t prop_length = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);

    // now comes the name of the scope/key
    const char* sbeg, *send;
    ReadString(sbeg, send, input, cursor, end);

    output_tokens.push_back(new_Token(sbeg, send, TokenType_KEY, Offset(input, cursor) ));

    // now come the individual properties
    const char* begin_cursor = cursor;

    if ((begin_cursor + prop_length) > end) {
        TokenizeError("property length out of bounds reading length ", input, cursor);
    }

    for (unsigned int i = 0; i < prop_count; ++i) {
        ReadData(sbeg, send, input, cursor, begin_cursor + prop_length);

        output_tokens.push_back(new_Token(sbeg, send, TokenType_DATA, Offset(input, cursor) ));

        if(i != prop_count-1) {
            output_tokens.push_back(new_Token(cursor, cursor + 1, TokenType_COMMA, Offset(input, cursor) ));
        }
    }

    if (Offset(begin_cursor, cursor) != prop_length) {
        TokenizeError("property length not reached, something is wrong",input, cursor);
    }

    // at the end of each nested block, there is a NUL record to indicate
    // that the sub-scope exists (i.e. to distinguish between P: and P : {})
    // this NUL record is 13 bytes long on 32 bit version and 25 bytes long on 64 bit.
	const size_t sentinel_block_length = is64bits ? (sizeof(uint64_t)* 3 + 1) : (sizeof(uint32_t)* 3 + 1);

    if (Offset(input, cursor) < end_offset) {