Method scanSource

Sming/Core/Data/Stream/SectionStream.cpp:20–70

* Scan through entire source stream to map location and size of sections. * Called once by constructor. */

 * Called once by constructor.
 */
void SectionStream::scanSource(uint8_t maxSections)
{
	constexpr size_t bufSize{512};
	char buffer[bufSize];

	sections = std::make_unique<Section[]>(maxSections);

	size_t offset{0};
	while(sectionCount < maxSections && !stream->isFinished()) {
		auto& sect = sections[sectionCount];
		stream->seekFrom(offset, SeekOrigin::Start);
		size_t bytesRead = stream->readMemoryBlock(buffer, bufSize);
		if(sect.start == 0) {
			auto tag = (char*)memmem(buffer, bytesRead, startTag.c_str(), startTag.length());
			if(tag == nullptr) {
				if(bytesRead < bufSize) {
					break;
				}
				// If tag starts near end of buffer, this ensures it'll be contained in next read
				offset += bytesRead - startTag.length();
				continue;
			}

			offset += (tag - buffer) + startTag.length();
			sect.start = offset;
			continue;
		}

		auto tag = (char*)memmem(buffer, bytesRead, endTag.c_str(), endTag.length());
		if(tag == nullptr) {
			if(bytesRead < bufSize) {
				break;
			}
			offset += bytesRead - endTag.length();
			continue;
		}
		offset += (tag - buffer);
		sect.size = offset - sect.start;
		offset += endTag.length();
		++sectionCount;
	}

	// No sections? Then consider the entire stream as a single section
	if(sectionCount == 0) {
		sections[0].start = 0;
		sections[0].size = stream->seekFrom(0, SeekOrigin::End);
		sectionCount = 1;
	}

	stream->seekFrom(0, SeekOrigin::Start);
}

bool SectionStream::gotoSection(uint8_t index)
{