Disk: Read driver for Plasion

disk/plasiondiskreaddriver.cpp

@@ -0,0 +1,74 @@
+#include "icsneo/disk/plasiondiskreaddriver.h"
+#include "icsneo/communication/message/neoreadmemorysdmessage.h"
+#include "icsneo/communication/multichannelcommunication.h"
+#include <cstring>
+
+using namespace icsneo;
+using namespace icsneo::Disk;
+
+optional<uint64_t> PlasionDiskReadDriver::readLogicalDiskAligned(Communication& com, device_eventhandler_t report,
+	uint64_t pos, uint8_t* into, uint64_t amount, std::chrono::milliseconds timeout) {
+	static std::shared_ptr<MessageFilter> NeoMemorySDRead = std::make_shared<MessageFilter>(Network::NetID::NeoMemorySDRead);
+
+	if(amount > getBlockSizeBounds().second)
+		return nullopt;
+
+	if(amount % getBlockSizeBounds().first != 0)
+		return nullopt;
+
+	if(pos % getBlockSizeBounds().first != 0)
+		return nullopt;
+
+	if(cachePos != pos || std::chrono::steady_clock::now() > cachedAt + CacheTime) {
+		// The cache does not have this data, go get it
+		std::mutex m;
+		std::condition_variable cv;
+		uint32_t copied = 0;
+		bool error = false;
+		std::unique_lock<std::mutex> lk(m);
+		auto cb = com.addMessageCallback(MessageCallback([&](std::shared_ptr<Message> msg) {
+			std::unique_lock<std::mutex> lk(m);
+
+			const auto sdmsg = std::dynamic_pointer_cast<NeoReadMemorySDMessage>(msg);
+			if(!sdmsg || cache.size() < copied + sdmsg->data.size()) {
+				error = true;
+				lk.unlock();
+				cv.notify_all();
+				return;
+			}
+
+			// Invalidate the cache here in case we fail half-way through
+			cachedAt = std::chrono::steady_clock::time_point();
+
+			memcpy(cache.data() + copied, sdmsg->data.data(), sdmsg->data.size());
+			copied += sdmsg->data.size();
+			if(copied == amount) {
+				lk.unlock();
+				cv.notify_all();
+			}
+		}, NeoMemorySDRead));
+
+		uint32_t sector = pos / SectorSize;
+		com.rawWrite({
+			uint8_t(MultiChannelCommunication::CommandType::HostPC_from_SDCC1),
+			uint8_t(sector & 0xFF),
+			uint8_t((sector >> 8) & 0xFF),
+			uint8_t((sector >> 16) & 0xFF),
+			uint8_t((sector >> 24) & 0xFF),
+			uint8_t(amount & 0xFF),
+			uint8_t((amount >> 8) & 0xFF),
+		});
+
+		bool hitTimeout = !cv.wait_for(lk, timeout, [&copied, &error, &amount] { return error || copied == amount; });
+		com.removeMessageCallback(cb);
+
+		if(hitTimeout)
+			return nullopt;
+
+		cachedAt = std::chrono::steady_clock::now();
+		cachePos = pos;
+	}
+
+	memcpy(into, cache.data(), amount);
+	return amount;
+}