commit 5cf14e365281378ecbfc6a0d5ead9c9772bc2533
Author: Nam Tran <daq@g2quad-02>
Date:   Wed Nov 4 20:25:50 2020 -0600

    socket read with timeout, logging

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..964ad22
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+r
+build
+old
+dump
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..b912cdb
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,22 @@
+target = r
+CXX = g++
+CXX_FLAGS := -std=c++14 -Iloguru
+LD_FLAGS := -lpthread -ldl
+BUILD := ./build
+OBJS := $(BUILD)/client.o $(BUILD)/loguru.o
+
+all: $(target)
+
+$(BUILD)/%.o: %.cc
+	@mkdir -p $(BUILD)
+	g++ -c $< -o $@ $(CXX_FLAGS) 
+
+$(BUILD)/loguru.o:
+	@mkdir -p $(BUILD)
+	g++ -c loguru/loguru.cpp -Iloguru -o $@ $(CXX_FLAGS) 
+
+r: $(OBJS)
+	g++ -o $@ $^ $(LD_FLAGS)
+
+clean:
+	rm -rf $(BUILD) r
diff --git a/client.cc b/client.cc
new file mode 100644
index 0000000..af0edae
--- /dev/null
+++ b/client.cc
@@ -0,0 +1,134 @@
+#include <iostream>
+#include <sys/socket.h>
+#include <stdlib.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <errno.h>
+#include <functional>
+#include <fstream>
+#include <chrono>
+#include <thread>
+#include <ctime>
+#include <iomanip>
+#include <csignal>
+#include <loguru.hpp>
+
+const char * HOST = "192.168.30.89";
+const uint32_t PORT = 9999;
+const size_t MAX_EVENT_SIZE = 33484; // in bytes
+const size_t MIN_EVENT_SIZE = 204; // in bytes
+const bool verbose = true;
+
+int sock = 0;
+bool running = true;
+int open_socket();
+void signalHandler( int signum );
+
+bool bad_data = true;
+
+int main(int argc, char const* argv[])
+{
+   signal(SIGINT, signalHandler);
+   int ret = open_socket();
+   if (ret != 0)
+      return -1;
+
+   char char_buffer[MAX_EVENT_SIZE];
+   uint32_t * wordData = (uint32_t*) char_buffer;
+   ssize_t nread;
+
+   fd_set select_fds;                // fd's used by select
+   struct timeval timeout;           // Time value for time out
+   //Timeout set for 0 sec + 200 millisec
+   timeout.tv_sec = 0;         
+   timeout.tv_usec = 200*1000;
+   std::chrono::duration<int, std::milli> polling_period(2);
+
+   while (running) {
+      // Setup the descriptor set for select()
+      FD_ZERO(&select_fds);            
+      FD_SET(sock, &select_fds);           
+      if ( select(sock + 1, &select_fds, NULL, NULL, &timeout) == 0 ){
+         std::this_thread::sleep_for(polling_period);
+      }
+      else{
+         // read in first 4 bytes
+         nread = recv(sock, char_buffer, 4, 0);
+         LOG_IF_F(INFO, verbose, "read in %u bytes: 0x%08X", nread, wordData[0]);
+         // if not A5 marker, go to next iteration (read in 4 more bytes)
+         if ((char_buffer[0] & 0xFF) != 0xA5){
+            bad_data = true;
+            continue;
+         }
+         else {
+            bad_data = false;
+            size_t frameSize = 4 * (wordData[0] >> 8);
+            nread = recv(sock, char_buffer, frameSize - 4, 0);
+            // nread + 4 must be between MIN_EVENT_SIZE and MAX_EVENT_SIZE, and equal to frameSize.
+            if ((nread != frameSize - 4) || (frameSize < MIN_EVENT_SIZE)|| (frameSize > MAX_EVENT_SIZE)){
+               bad_data = true;
+               continue;
+            }
+            else {
+               // ok, this seems to be good data
+               LOG_IF_F(INFO, verbose, "next %u bytes (expecting %u): 0x%08X",
+                     nread, frameSize - 4, wordData[0]);
+               uint8_t board_id = (wordData[0] >> 24) & 0xFF;
+               uint8_t version = wordData[0] & 0xFF;
+               uint16_t spill_id = (wordData[1] & 0x00FFFF00) >> 8;
+               uint8_t channel_count = (wordData[1]) & 0x000000FF;
+               if (verbose) {
+                  std::cout << "board " << static_cast<uint32_t>(board_id) <<
+                     ", version " << static_cast<uint32_t>(version) <<
+                     ", spill " << static_cast<uint32_t>(spill_id) <<
+                     ", channel_count " << static_cast<uint32_t>(channel_count)<< std::endl;
+               }
+
+               if ((board_id > 4) || (board_id < 1) || (version != 1) || (channel_count > 8) || (channel_count < 1)) {
+                  bad_data = true;
+                  continue;
+               }
+               else {
+
+               }
+
+            }
+         }
+      }
+   }
+
+   close(sock);
+   return 0;
+}
+
+void signalHandler( int signum ) {
+   std::cout << "Interrupt signal (" << signum << ") received, exiting..."
+      << std::endl;
+   running = false;
+}
+
+int open_socket(){
+   struct sockaddr_in serv_addr;
+   if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
+      std::cerr << "Cannot create socket" << std::endl;
+      return -1;
+   }
+
+   memset(&serv_addr, '0', sizeof(serv_addr));
+   serv_addr.sin_family = AF_INET;
+   serv_addr.sin_port = htons(PORT);
+
+   if(inet_pton(AF_INET, HOST, &serv_addr.sin_addr)<=0) {
+      std::cerr << "Invalid address or Address not supported" << std::endl;
+      return -1;
+   }
+
+   if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
+      std::cerr << "Cannot connect to " << HOST << ":" << PORT << std::endl;
+      return -1;
+   }
+
+   return 0;
+}