From 4f294285fec6298b2af5495acc3ec812f062e4e4 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Sat, 20 Nov 1999 00:28:30 +0000
Subject: [PATCH] Added a readline(buf) vs. read(buf,len)

---
 src/Network/Makefile.am   |  1 +
 src/Network/fg_file.cxx   | 31 +++++++++-------
 src/Network/fg_file.hxx   |  9 +++--
 src/Network/fg_serial.cxx | 76 ++++++++++++++++++++++++++++++++-------
 src/Network/fg_serial.hxx | 14 +++++---
 src/Network/garmin.cxx    |  4 +--
 src/Network/iochannel.cxx | 12 +++++--
 src/Network/iochannel.hxx |  5 +--
 src/Network/nmea.cxx      |  8 ++++-
 9 files changed, 120 insertions(+), 40 deletions(-)

diff --git a/src/Network/Makefile.am b/src/Network/Makefile.am
index 6d6c76e96..b5ecbb3ca 100644
--- a/src/Network/Makefile.am
+++ b/src/Network/Makefile.am
@@ -4,6 +4,7 @@ libNetwork_a_SOURCES = \
 	iochannel.cxx iochannel.hxx \
 	fg_file.cxx fg_file.hxx \
 	fg_serial.cxx fg_serial.hxx \
+	fg_socket.cxx fg_socket.hxx \
 	protocol.cxx protocol.hxx \
 	garmin.cxx garmin.hxx \
 	nmea.cxx nmea.hxx \
diff --git a/src/Network/fg_file.cxx b/src/Network/fg_file.cxx
index 748e5727d..4adb2b220 100644
--- a/src/Network/fg_file.cxx
+++ b/src/Network/fg_file.cxx
@@ -26,7 +26,6 @@
 #include STL_STRING
 
 #include <Debug/logstream.hxx>
-#include <Time/fg_time.hxx>
 
 #include "fg_file.hxx"
 
@@ -64,40 +63,48 @@ bool FGFile::open( FGProtocol::fgProtocolDir dir ) {
 }
 
 
-// read data from file
-bool FGFile::read( char *buf, int *length ) {
+// read a block of data of specified size
+int FGFile::read( char *buf, int length ) {
+    // read a chunk
+    int result = std::read( fp, buf, length );
+
+    return result;
+}
+
+
+// read a line of data, length is max size of input buffer
+int FGFile::readline( char *buf, int length ) {
     // save our current position
     int pos = lseek( fp, 0, SEEK_CUR );
 
     // read a chunk
-    int result = std::read( fp, buf, FG_MAX_MSG_SIZE );
+    int result = std::read( fp, buf, length );
 
     // find the end of line and reset position
     int i;
     for ( i = 0; i < result && buf[i] != '\n'; ++i );
     if ( buf[i] == '\n' ) {
-	*length = i + 1;
+	result = i + 1;
     } else {
-	*length = i;
+	result = i;
     }
-    lseek( fp, pos + *length, SEEK_SET );
+    lseek( fp, pos + result, SEEK_SET );
     
     // just in case ...
-    buf[ *length ] = '\0';
+    buf[ result ] = '\0';
 
-    return true;
+    return result;
 }
 
 
 // write data to a file
-bool FGFile::write( char *buf, int length ) {
+int FGFile::write( char *buf, int length ) {
     int result = std::write( fp, buf, length );
     if ( result != length ) {
 	FG_LOG( FG_IO, FG_ALERT, "Error writing data: " << file_name );
-	return false;
     }
 
-    return true;
+    return result;
 }
 
 
diff --git a/src/Network/fg_file.hxx b/src/Network/fg_file.hxx
index 852fc4936..469be7b6f 100644
--- a/src/Network/fg_file.hxx
+++ b/src/Network/fg_file.hxx
@@ -57,11 +57,14 @@ public:
     // open the file based on specified direction
     bool open( FGProtocol::fgProtocolDir dir );
 
-    // read data from file
-    bool read( char *buf, int *length );
+    // read a block of data of specified size
+    int read( char *buf, int length );
+
+    // read a line of data, length is max size of input buffer
+    int readline( char *buf, int length );
 
     // write data to a file
-    bool write( char *buf, int length );
+    int write( char *buf, int length );
 
     // close file
     bool close();
diff --git a/src/Network/fg_serial.cxx b/src/Network/fg_serial.cxx
index 87dcb207e..162c62fc6 100644
--- a/src/Network/fg_serial.cxx
+++ b/src/Network/fg_serial.cxx
@@ -27,16 +27,16 @@
 
 #include <Debug/logstream.hxx>
 #include <Aircraft/aircraft.hxx>
-#include <Include/fg_constants.h>
 #include <Serial/serial.hxx>
-#include <Time/fg_time.hxx>
 
 #include "fg_serial.hxx"
 
 FG_USING_STD(string);
 
 
-FGSerial::FGSerial() {
+FGSerial::FGSerial() :
+    save_len(0)
+{
 }
 
 
@@ -62,27 +62,77 @@ bool FGSerial::open( FGProtocol::fgProtocolDir dir ) {
 }
 
 
-// read data from port
-bool FGSerial::read( char *buf, int *length ) {
-    // read a chunk
-    *length = port.read_port( buf );
+// Read data from port.  If we don't get enough data, save what we did
+// get in the save buffer and return 0.  The save buffer will be
+// prepended to subsequent reads until we get as much as is requested.
+
+int FGSerial::read( char *buf, int length ) {
+    int result;
+
+    // read a chunk, keep in the save buffer until we have the
+    // requested amount read
+
+    char *buf_ptr = save_buf + save_len;
+    result = port.read_port( buf_ptr, length - save_len );
     
-    // just in case ...
-    buf[ *length ] = '\0';
+    if ( result + save_len == length ) {
+	strncpy( buf, save_buf, length );
+	save_len = 0;
 
-    return true;
+	return length;
+    }
+    
+    return 0;
+}
+
+
+// read data from port
+int FGSerial::readline( char *buf, int length ) {
+    int result;
+
+    // read a chunk, keep in the save buffer until we have the
+    // requested amount read
+
+    char *buf_ptr = save_buf + save_len;
+    result = port.read_port( buf_ptr, FG_MAX_MSG_SIZE - save_len );
+    save_len += result;
+
+    // look for the end of line in save_buf
+    int i;
+    for ( i = 0; i < save_len && save_buf[i] != '\n'; ++i );
+    if ( save_buf[i] == '\n' ) {
+	result = i + 1;
+    } else {
+	// no end of line yet
+	return 0;
+    }
+
+    // we found an end of line
+
+    // copy to external buffer
+    strncpy( buf, save_buf, result );
+    buf[result] = '\0';
+    cout << "fg_serial line = " << buf << endl;
+
+    // shift save buffer
+    for ( i = result; i < save_len; ++i ) {
+	save_buf[ i - result ] = save_buf[result];
+    }
+    save_len -= result;
+
+    return result;
 }
 
+
 // write data to port
-bool FGSerial::write( char *buf, int length ) {
+int FGSerial::write( char *buf, int length ) {
     int result = port.write_port( buf, length );
 
     if ( result != length ) {
 	FG_LOG( FG_IO, FG_ALERT, "Error writing data: " << device );
-	return false;
     }
 
-    return true;
+    return result;
 }
 
 
diff --git a/src/Network/fg_serial.hxx b/src/Network/fg_serial.hxx
index 34075f762..ba8888113 100644
--- a/src/Network/fg_serial.hxx
+++ b/src/Network/fg_serial.hxx
@@ -53,6 +53,9 @@ class FGSerial : public FGIOChannel {
     string baud;
     FGSerialPort port;
 
+    char save_buf[ 2 * FG_MAX_MSG_SIZE ];
+    int save_len;
+
 public:
 
     FGSerial();
@@ -61,11 +64,14 @@ public:
     // open the serial port based on specified direction
     bool open( FGProtocol::fgProtocolDir dir );
 
-    // read data from port
-    bool read( char *buf, int *length );
+    // read a block of data of specified size
+    int read( char *buf, int length );
+
+    // read a line of data, length is max size of input buffer
+    int readline( char *buf, int length );
 
-    // write data to port
-    bool write( char *buf, int length );
+    // write data to a file
+    int write( char *buf, int length );
 
     // close port
     bool close();
diff --git a/src/Network/garmin.cxx b/src/Network/garmin.cxx
index 56116255c..81b279f04 100644
--- a/src/Network/garmin.cxx
+++ b/src/Network/garmin.cxx
@@ -373,13 +373,13 @@ bool FGGarmin::process() {
 	    return false;
 	}
     } else if ( get_direction() == in ) {
-	if ( io->read( buf, &length ) ) {
+	if ( io->readline( buf, FG_MAX_MSG_SIZE ) ) {
 	    parse_message();
 	} else {
 	    FG_LOG( FG_IO, FG_ALERT, "Error reading data." );
 	    return false;
 	}
-	if ( io->read( buf, &length ) ) {
+	if ( io->readline( buf, FG_MAX_MSG_SIZE ) ) {
 	    parse_message();
 	} else {
 	    FG_LOG( FG_IO, FG_ALERT, "Error reading data." );
diff --git a/src/Network/iochannel.cxx b/src/Network/iochannel.cxx
index c054f2c26..23f6c46e9 100644
--- a/src/Network/iochannel.cxx
+++ b/src/Network/iochannel.cxx
@@ -45,13 +45,19 @@ bool FGIOChannel::open( FGProtocol::fgProtocolDir dir ) {
 
 
 // dummy process routine
-bool FGIOChannel::read( char *buf, int *length ) {
-    return false;
+int FGIOChannel::read( char *buf, int length ) {
+    return 0;
+}
+
+
+// dummy process routine
+int FGIOChannel::readline( char *buf, int length ) {
+    return 0;
 }
 
 
 // dummy process routine
-bool FGIOChannel::write( char *buf, int length ) {
+int FGIOChannel::write( char *buf, int length ) {
     return false;
 }
 
diff --git a/src/Network/iochannel.hxx b/src/Network/iochannel.hxx
index ee125b2d8..aae5c1932 100644
--- a/src/Network/iochannel.hxx
+++ b/src/Network/iochannel.hxx
@@ -48,8 +48,9 @@ public:
     virtual ~FGIOChannel();
 
     virtual bool open( FGProtocol::fgProtocolDir dir );
-    virtual bool read( char *buf, int *length );
-    virtual bool write( char *buf, int length );
+    virtual int read( char *buf, int length );
+    virtual int readline( char *buf, int length );
+    virtual int write( char *buf, int length );
     virtual bool close();
 };
 
diff --git a/src/Network/nmea.cxx b/src/Network/nmea.cxx
index 3da8ce42b..b1755f2e2 100644
--- a/src/Network/nmea.cxx
+++ b/src/Network/nmea.cxx
@@ -476,7 +476,13 @@ bool FGNMEA::process() {
 	    return false;
 	}
     } else if ( get_direction() == in ) {
-	if ( io->read( buf, &length ) ) {
+	if ( io->readline( buf, FG_MAX_MSG_SIZE ) ) {
+	    parse_message();
+	} else {
+	    FG_LOG( FG_IO, FG_ALERT, "Error reading data." );
+	    return false;
+	}
+	if ( io->readline( buf, FG_MAX_MSG_SIZE ) ) {
 	    parse_message();
 	} else {
 	    FG_LOG( FG_IO, FG_ALERT, "Error reading data." );
-- 
2.39.5