From c6b0e934857170f786eebb740db666005ab00aa0 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 20 Apr 2013 17:18:23 +0300
Subject: [PATCH] Encapsulate serial device state into a struct

---
 source/io/serial.cpp | 73 +++++++++++++++++++++++---------------------
 source/io/serial.h   |  2 ++
 2 files changed, 40 insertions(+), 35 deletions(-)

diff --git a/source/io/serial.cpp b/source/io/serial.cpp
index 26ef92e..dc623e2 100644
--- a/source/io/serial.cpp
+++ b/source/io/serial.cpp
@@ -12,18 +12,26 @@
 
 using namespace std;
 
-namespace {
-
-using namespace Msp;
-using namespace Msp::IO;
+namespace Msp {
+namespace IO {
 
+struct Serial::DeviceState
+{
 #ifdef WIN32
-typedef DCB DeviceState;
+	DCB state;
 #else
-typedef termios DeviceState;
+	termios state;
 #endif
 
-void get_state(const Handle &handle, DeviceState &state)
+	void get_from(const Handle &);
+	void apply_to(const Handle &);
+	void set_baud_rate(unsigned);
+	void set_data_bits(unsigned);
+	void set_parity(Parity);
+	void set_stop_bits(unsigned);
+};
+
+void Serial::DeviceState::get_from(const Handle &handle)
 {
 #ifdef WIN32
 	GetCommState(*handle, &state);
@@ -32,7 +40,7 @@ void get_state(const Handle &handle, DeviceState &state)
 #endif
 }
 
-void set_state(const Handle &handle, DeviceState &state)
+void Serial::DeviceState::apply_to(const Handle &handle)
 {
 #ifdef WIN32
 	if(SetCommState(*handle, &state)==0)
@@ -43,7 +51,7 @@ void set_state(const Handle &handle, DeviceState &state)
 #endif
 }
 
-void set_baud_rate(DeviceState &state, unsigned baud)
+void Serial::DeviceState::set_baud_rate(unsigned baud)
 {
 #ifdef WIN32
 	state.BaudRate = baud;
@@ -78,7 +86,7 @@ void set_baud_rate(DeviceState &state, unsigned baud)
 #endif
 }
 
-void set_data_bits(DeviceState &state, unsigned bits)
+void Serial::DeviceState::set_data_bits(unsigned bits)
 {
 #ifdef WIN32
 	state.ByteSize = bits;
@@ -97,7 +105,7 @@ void set_data_bits(DeviceState &state, unsigned bits)
 #endif
 }
 
-void set_parity(DeviceState &state, Serial::Parity par)
+void Serial::DeviceState::set_parity(Serial::Parity par)
 {
 #ifdef WIN32
 	switch(par)
@@ -121,7 +129,7 @@ void set_parity(DeviceState &state, Serial::Parity par)
 #endif
 }
 
-void set_stop_bits(DeviceState &state, unsigned bits)
+void Serial::DeviceState::set_stop_bits(unsigned bits)
 {
 #ifdef WIN32
 	switch(bits)
@@ -143,11 +151,6 @@ void set_stop_bits(DeviceState &state, unsigned bits)
 #endif
 }
 
-}
-
-
-namespace Msp {
-namespace IO {
 
 Serial::Serial(const string &descr):
 	reader(handle, 1024)
@@ -231,33 +234,33 @@ void Serial::set_block(bool b)
 void Serial::set_baud_rate(unsigned rate)
 {
 	DeviceState state;
-	get_state(handle, state);
-	::set_baud_rate(state, rate);
-	set_state(handle, state);
+	state.get_from(handle);
+	state.set_baud_rate(rate);
+	state.apply_to(handle);
 }
 
 void Serial::set_data_bits(unsigned bits)
 {
 	DeviceState state;
-	get_state(handle, state);
-	::set_data_bits(state, bits);
-	set_state(handle, state);
+	state.get_from(handle);
+	state.set_data_bits(bits);
+	state.apply_to(handle);
 }
 
 void Serial::set_parity(Parity par)
 {
 	DeviceState state;
-	get_state(handle, state);
-	::set_parity(state, par);
-	set_state(handle, state);
+	state.get_from(handle);
+	state.set_parity(par);
+	state.apply_to(handle);
 }
 
 void Serial::set_stop_bits(unsigned bits)
 {
 	DeviceState state;
-	get_state(handle, state);
-	::set_stop_bits(state, bits);
-	set_state(handle, state);
+	state.get_from(handle);
+	state.set_stop_bits(bits);
+	state.apply_to(handle);
 }
 
 void Serial::set_parameters(const string &params)
@@ -274,12 +277,12 @@ void Serial::set_parameters(const string &params)
 		throw invalid_argument("Serial::set_parameters stop_bits");
 
 	DeviceState state;
-	get_state(handle, state);
-	::set_baud_rate(state, lexical_cast<unsigned>(params.substr(0, i)));
-	::set_data_bits(state, params[i+1]-'0');
-	::set_parity(state, (params[i+2]=='E' ? EVEN : params[i+2]=='O' ? ODD : NONE));
-	::set_stop_bits(state, params[i+3]-'0');
-	set_state(handle, state);
+	state.get_from(handle);
+	state.set_baud_rate(lexical_cast<unsigned>(params.substr(0, i)));
+	state.set_data_bits(params[i+1]-'0');
+	state.set_parity((params[i+2]=='E' ? EVEN : params[i+2]=='O' ? ODD : NONE));
+	state.set_stop_bits(params[i+3]-'0');
+	state.apply_to(handle);
 }
 
 unsigned Serial::do_write(const char *buf, unsigned size)
diff --git a/source/io/serial.h b/source/io/serial.h
index 39ca27a..49ecefb 100644
--- a/source/io/serial.h
+++ b/source/io/serial.h
@@ -19,6 +19,8 @@ public:
 	};
 
 private:
+	struct DeviceState;
+
 	Handle handle;
 	EventReader reader;
 
-- 
2.43.0