medfall

commit 69773421b1cd453d0df49dd451af871b3e618118
parent ab147445a06bad9f12327610187c63f9dd681916
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Tue Nov 22 21:39:11 +0200

Refactor stream API a bit

Diffstat:
server/main.cc
 | 
10
++++------
stream.h
 | 
66
+++++++++++++++++++++++++++++++++++++++++++++++++-----------------
2 files changed, 53 insertions(+), 23 deletions(-)
diff --git a/server/main.cc b/server/main.cc
@@ -152,12 +152,10 @@ int main() {
 		memset( buf, 0, sizeof( buf ) );
 		size_t len;
 		while( receive( server_fd_ipv4, buf, &len, sizeof( buf ) ) ) {
-			Stream stream;
-			stream.ptr = buf;
-			// stream.len = len
+			ReadStream stream( buf, len );;
 
-			u64 sid;
-			stream = read_u64( stream, &sid );
+			u64 sid = read_u64( &stream );
+			if( !stream.ok ) continue;
 
 			if( sid == u64( -1 ) ) {
 				u64 new_sid = rng_next_u64( &rng );
@@ -174,7 +172,7 @@ int main() {
 				}
 			}
 		}
-		while( receive( server_fd_ipv6, buf, &len, sizeof( buf ) ) );
+		// while( receive( server_fd_ipv6, buf, &len, sizeof( buf ) ) );
 
 		printf( "frame\n" );
 		for( size_t i = 0; i < ARRAY_COUNT( states ); i++ ) {
diff --git a/stream.h b/stream.h
@@ -1,37 +1,69 @@
+// TODO: need to come up with something for writers though
+
 #ifndef _STREAM_H_
 #define _STREAM_H_
 
 #include "intrinsics.h"
 #include "platform_inline.h"
 
-struct Stream {
+struct ReadStream {
+	ReadStream( char * buf, size_t len ) {
+		ptr = buf;
+		one_past_end = buf + len;
+		ok = true;
+	}
+
+	char * ptr;
+	char * one_past_end;
+	bool ok;
+};
+
+struct WriteStream {
+	WriteStream( char * buf, size_t len ) {
+		start = buf;
+		ptr = buf;
+		one_past_end = buf + len;
+		ok = true;
+	}
+
+	char * start;
 	char * ptr;
+	char * one_past_end;
+	bool ok;
 };
 
-static forceinline bool cpu_is_little_endian() {
-#if FORCE_LITTLE_ENDIAN
-	return true;
-#else
+static bool cpu_is_little_endian() {
 	u16 i = 1;
 	char * c = ( char * ) &i;
 	return c[ 0 ] == 1;
-#endif
 }
 
-// TODO: https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
-// maybe use __builtin_bswap16/32/64 and http://stackoverflow.com/a/13208789
-#define DEF_READ_WRITE( type ) \
-	inline Stream read_##type( Stream stream, type * v ) { \
+#define DEF_READ_WRITE( T ) \
+	inline void read( ReadStream * stream, T * x ) { \
 		ASSERT( cpu_is_little_endian() ); \
-		*v = *( type * ) stream.ptr; \
-		stream.ptr += sizeof( type ); \
-		return stream; \
+		if( !stream->ok || checked_cast< size_t >( stream->one_past_end - stream->ptr ) < sizeof( T ) ) { \
+			stream->ok = false; \
+			*x = T(); \
+		} \
+		memcpy( x, stream->ptr, sizeof( T ) ); \
+		stream->ptr += sizeof( T ); \
 	} \
-	inline Stream write_##type( Stream stream, const type * v ) { \
+	inline T read_##T( ReadStream * stream ) { \
+		T x; \
+		read( stream, &x ); \
+		return x; \
+	} \
+	inline void write( WriteStream * stream, const T & x ) { \
 		ASSERT( cpu_is_little_endian() ); \
-		*( type * ) stream.ptr = *v; \
-		stream.ptr += sizeof( type ); \
-		return stream; \
+		if( !stream->ok || checked_cast< size_t >( stream->one_past_end - stream->ptr ) < sizeof( T ) ) { \
+			stream->ok = false; \
+			return; \
+		} \
+		memcpy( stream->ptr, &x, sizeof( T ) ); \
+		stream->ptr += sizeof( T ); \
+	} \
+	inline void write_##T( WriteStream * stream, const T & x ) { \
+		write( stream, x ); \
 	}
 
 DEF_READ_WRITE( u8 )