libuuu: implement a basic retry strategy for usb transfer

libuuu/trans.cpp

@@ -46,6 +46,44 @@ TransBase::~TransBase()
 {
 }
 
+int TransBase::write(void *buff, size_t size)
+{
+	int ret;
+
+	for (int retry = 0; retry < m_retry; retry++) {
+		ret = write_simple(buff, size);
+		switch (ret) {
+			case 0:
+				return 0;
+			case LIBUSB_ERROR_TIMEOUT:
+				continue;
+			default:
+				return ret;
+		}
+	}
+
+	return LIBUSB_ERROR_TIMEOUT;
+}
+
+int TransBase::read(void *buff, size_t size, size_t *return_size)
+{
+	int ret;
+
+	for (int retry = 0; retry < m_retry; retry++) {
+		ret = read_simple(buff, size, return_size);
+		switch (ret) {
+			case 0:
+				return 0;
+			case LIBUSB_ERROR_TIMEOUT:
+				continue;
+			default:
+				return ret;
+		}
+	}
+
+	return LIBUSB_ERROR_TIMEOUT;
+}
+
 int TransBase::read(vector<uint8_t> &buff)
 {
 	size_t size;
@@ -117,7 +155,7 @@ int HIDTrans::open(void *p)
 	return 0;
 }
 
-int HIDTrans::write(void *buff, size_t size)
+int HIDTrans::write_simple(void *buff, size_t size)
 {
 	int ret;
 	uint8_t *p = (uint8_t *)buff;
@@ -160,7 +198,7 @@ int HIDTrans::write(void *buff, size_t size)
 	return ret;
 }
 
-int HIDTrans::read(void *buff, size_t size, size_t *rsize)
+int HIDTrans::read_simple(void *buff, size_t size, size_t *rsize)
 {
 	int ret;
 	int actual;
@@ -188,7 +226,7 @@ int HIDTrans::read(void *buff, size_t size, size_t *rsize)
 	return 0;
 }
 
-int BulkTrans::write(void *buff, size_t size)
+int BulkTrans::write_simple(void *buff, size_t size)
 {
 	int ret = 0;
 	int actual_length;
@@ -264,7 +302,7 @@ int BulkTrans::open(void *p)
 	}
 	return 0;
 }
-int BulkTrans::read(void *buff, size_t size, size_t *rsize)
+int BulkTrans::read_simple(void *buff, size_t size, size_t *rsize)
 {
 	int ret;
 	int actual_length;

libuuu/trans.h

@@ -37,20 +37,24 @@
 class TransBase
 {
 public:
-	TransBase() = default;
+	TransBase(int retry = 1) : m_retry{retry} {}
 	TransBase(const TransBase&) = delete;
 	TransBase& operator=(const TransBase&) = delete;
 	virtual ~TransBase();
 
 	virtual int open(void *) { return 0; }
 	virtual int close() { return 0; }
-	virtual int write(void *buff, size_t size) = 0;
-	virtual int read(void *buff, size_t size, size_t *return_size) = 0;
+	int write(void *buff, size_t size);
+	int read(void *buff, size_t size, size_t *return_size);
 	int write(std::vector<uint8_t> & buff) { return write(buff.data(), buff.size()); }
 	int read(std::vector<uint8_t> &buff);
 
 protected:
 	void * m_devhandle = nullptr;
+	int m_retry = 1;
+
+	virtual int write_simple(void *buff, size_t size) = 0;
+	virtual int read_simple(void *buff, size_t size, size_t *return_size) = 0;
 };
 
 class EPInfo
@@ -65,6 +69,7 @@ class EPInfo
 class USBTrans : public TransBase
 {
 public:
+	USBTrans(int retry = 1) : TransBase(retry) {}
 	int open(void *p) override;
 	int close() override;
 
@@ -74,13 +79,15 @@ class USBTrans : public TransBase
 class HIDTrans : public USBTrans
 {
 public:
-	HIDTrans(int timeout = 1000) : m_timeout{timeout} {}
+	HIDTrans(int timeout = 1000) : USBTrans(2), m_timeout{timeout} {}
 	~HIDTrans() override { if (m_devhandle) close();  m_devhandle = nullptr; }
 
 	int open(void *p) override;
 	void set_hid_out_ep(int ep) noexcept { m_outEP = ep; }
-	int write(void *buff, size_t size) override;
-	int read(void *buff, size_t size, size_t *return_size) override;
+
+protected:
+	int write_simple(void *buff, size_t size) override;
+	int read_simple(void *buff, size_t size, size_t *return_size) override;
 
 private:
 	int m_outEP = 0;
@@ -91,12 +98,14 @@ class HIDTrans : public USBTrans
 class BulkTrans : public USBTrans
 {
 public:
-	BulkTrans(int timeout = 2000) : m_timeout{timeout} {}
+	BulkTrans(int timeout = 2000) : USBTrans(2), m_timeout{timeout} {}
 	~BulkTrans() override { if (m_devhandle) close();  m_devhandle = nullptr; }
 
 	int open(void *p) override;
-	int write(void *buff, size_t size) override;
-	int read(void *buff, size_t size, size_t *return_size) override;
+
+protected:
+	int write_simple(void *buff, size_t size) override;
+	int read_simple(void *buff, size_t size, size_t *return_size) override;
 
 private:
 	size_t m_MaxTransPreRequest = 0x100000;