ngscopeclient · Mar 11, 2020
diff --git a/scopehal/LeCroyOscilloscope.cpp b/scopehal/LeCroyOscilloscope.cpp
@@ -955,38 +955,14 @@ Oscilloscope::TriggerMode LeCroyOscilloscope::PollTrigger()
 
 bool LeCroyOscilloscope::ReadWaveformBlock(string& data)
 {
-	//First packet is just a header "DAT1,\n" or "DESC,\n". Throw it away.
-	//In some rare circumstances, such as when the user touches front panel controls,
-	//it appears we can get a blank line before this. Ignore that.
-	string header = ReadData();
-
-	//Second block is a header including the message length. Parse that.
-	string lhdr = ReadSingleBlockString();
-	unsigned int num_bytes = atoi(lhdr.c_str() + 2);
-	if(num_bytes == 0)
-	{
-		ReadData();
-		return true;
-	}
-
-	//Read the data
-	data.clear();
-	while(true)
-	{
-		string payload = ReadData();
-		data += payload;
-		if(data.size() >= num_bytes)
-			break;
-	}
-
-	//Throw away the newline at the end
-	ReadData();
-
-	if(data.size() != num_bytes)
-	{
-		LogError("bad rx block size (got %zu, expected %u)\n", data.size(), num_bytes);
-		return false;
-	}
+	//Prefix "DESC,\n" or "DAT1,\n". Always seems to be 6 chars and start with a D.
+	//Next is the length header. Looks like #9000000346. #9 followed by nine ASCII length digits.
+	//Ignore that too.
+	string tmp = ReadSingleBlockString();
+	size_t offset = tmp.find("D");
+
+	//Copy the rest of the block
+	data = tmp.substr(offset + 16);
 
 	return true;
 }

diff --git a/scopehal/LeCroyOscilloscope.h b/scopehal/LeCroyOscilloscope.h
@@ -164,7 +164,6 @@ class LeCroyOscilloscope
 	void BulkCheckChannelEnableState();
 
 	virtual bool SendCommand(std::string cmd, bool eoi=true) = 0;
-	virtual std::string ReadData() =0;
 	virtual std::string ReadSingleBlockString(bool trimNewline = false) =0;
 
 	bool ReadWaveformBlock(std::string& data);

diff --git a/scopehal/LeCroyVICPOscilloscope.cpp b/scopehal/LeCroyVICPOscilloscope.cpp
@@ -65,32 +65,17 @@ bool LeCroyVICPOscilloscope::SendCommand(string cmd, bool eoi)
 	return true;
 }
 
-/**
-	@brief Read exactly one packet from the socket
- */
-string LeCroyVICPOscilloscope::ReadData()
-{
-	return m_transport->ReadReply();
-}
-
 string LeCroyVICPOscilloscope::ReadSingleBlockString(bool trimNewline)
 {
-	while(true)
-	{
-		string payload = ReadData();
+	string payload = m_transport->ReadReply();
 
-		//Skip empty blocks
-		if(payload.empty() || payload == "\n")
-			continue;
-
-		if(trimNewline && (payload.length() > 0) )
-		{
-			int iend = payload.length() - 1;
-			if(trimNewline && (payload[iend] == '\n'))
-				payload.resize(iend);
-		}
-
-		payload += "\0";
-		return payload;
+	if(trimNewline && (payload.length() > 0) )
+	{
+		int iend = payload.length() - 1;
+		if(trimNewline && (payload[iend] == '\n'))
+			payload.resize(iend);
 	}
+
+	payload += "\0";
+	return payload;
 }
diff --git a/scopehal/LeCroyVICPOscilloscope.h b/scopehal/LeCroyVICPOscilloscope.h
@@ -48,7 +48,6 @@ class LeCroyVICPOscilloscope
 
 protected:
 	virtual bool SendCommand(std::string cmd, bool eoi=true);
-	virtual std::string ReadData();
 	virtual std::string ReadSingleBlockString(bool trimNewline = false);
 
 	VICPSocketTransport* m_transport;

diff --git a/scopehal/SiglentSCPIOscilloscope.h b/scopehal/SiglentSCPIOscilloscope.h
@@ -55,7 +55,7 @@ class SiglentSCPIOscilloscope
 protected:
 	virtual void DetectAnalogChannels();
 	virtual bool SendCommand(std::string cmd, bool eoi=true);
-	virtual std::string ReadData();
+	std::string ReadData();
 	virtual std::string ReadSingleBlockString(bool trimNewline = false);
 
 	void ReadWaveDescriptorBlock(SiglentWaveformDesc_t *descriptor, unsigned int channel);

diff --git a/scopehal/VICPSocketTransport.cpp b/scopehal/VICPSocketTransport.cpp
@@ -41,11 +41,11 @@ using namespace std;
 // Construction / destruction
 
 VICPSocketTransport::VICPSocketTransport(string hostname, unsigned short port)
-	: m_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
+	: m_nextSequence(1)
+	, m_lastSequence(1)
+	, m_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
 	, m_hostname(hostname)
 	, m_port(port)
-	, m_nextSequence(1)
-	, m_lastSequence(1)
 {
 	LogDebug("Connecting to VICP oscilloscope at %s:%d\n", hostname.c_str(), port);
 
@@ -111,39 +111,50 @@ bool VICPSocketTransport::SendCommand(string cmd)
 
 string VICPSocketTransport::ReadReply()
 {
-	//Read the header
-	unsigned char header[8];
-	ReadRawData(8, header);
-
-	uint8_t op = header[0];
-	//OP_EOI terminates a block
-
-	//Sanity check
-	if(header[1] != 1)
-	{
-		LogError("Bad VICP protocol version\n");
-		return "";
-	}
-	if(header[2] != m_lastSequence)
-	{
-		//LogError("Bad VICP sequence number %d (expected %d)\n", header[2], m_lastSequence);
-		//return "";
-	}
-	if(header[3] != 0)
+	string payload;
+	while(true)
 	{
-		LogError("Bad VICP reserved field\n");
-		return "";
+		//Read the header
+		unsigned char header[8];
+		ReadRawData(8, header);
+
+		//Sanity check
+		if(header[1] != 1)
+		{
+			LogError("Bad VICP protocol version\n");
+			return "";
+		}
+		if(header[2] != m_lastSequence)
+		{
+			//LogError("Bad VICP sequence number %d (expected %d)\n", header[2], m_lastSequence);
+			//return "";
+		}
+		if(header[3] != 0)
+		{
+			LogError("Bad VICP reserved field\n");
+			return "";
+		}
+
+		//Read the message data
+		uint32_t len = (header[4] << 24) | (header[5] << 16) | (header[6] << 8) | header[7];
+		string rxbuf;
+		rxbuf.resize(len);
+		ReadRawData(len, (unsigned char*)&rxbuf[0]);
+
+		//Skip empty blocks, or just newlines
+		if( (len == 0) || (rxbuf == "\n"))
+		{}
+
+		//Actual frame data
+		else
+			payload += rxbuf;
+
+		//Check EOI flag
+		if(header[0] & OP_EOI)
+			break;
 	}
 
-	//TODO: pay attention to header?
-
-	//Read the message data
-	uint32_t len = (header[4] << 24) | (header[5] << 16) | (header[6] << 8) | header[7];
-	string ret;
-	ret.resize(len);
-	ReadRawData(len, (unsigned char*)&ret[0]);
-
-	return ret;
+	return payload;
 }
 
 void VICPSocketTransport::SendRawData(size_t len, const unsigned char* buf)