parse configuration file

config.cpp

@@ -1,3 +1,11 @@
+#include <iostream>
+#include <fstream>
+#include <streambuf>
+#include <iterator>
+#include <functional>
+#include <unordered_map>
+
+#include "utility.h"
 #include "config.h"
 
 #define CA_DIR SUNSHINE_ASSETS_DIR "/demoCA"
@@ -24,4 +32,101 @@ nvhttp_t nvhttp {
   "03904e64-51da-4fb3-9afd-a9f7ff70fea4", // unique_id
   "devices.xml" // file_devices
 };
+
+bool whitespace(char ch) {
+  return ch == ' ' || ch == '\t';
+}
+
+std::string to_string(const char *begin, const char *end) {
+  return { begin, (std::size_t)(end - begin) };
+}
+
+std::optional<std::pair<std::string, std::string>> parse_line(std::string_view::const_iterator begin, std::string_view::const_iterator end) {
+  begin = std::find_if(begin, end, std::not_fn(whitespace));
+  end   = std::find(begin, end, '#');
+  end   = std::find_if(std::make_reverse_iterator(end), std::make_reverse_iterator(begin), std::not_fn(whitespace)).base();
+
+  auto eq = std::find(begin, end, '=');
+  if(eq == end || eq == begin) {
+    return std::nullopt;
+  }
+
+  auto end_name = std::find_if(std::make_reverse_iterator(eq - 1), std::make_reverse_iterator(begin), std::not_fn(whitespace)).base();
+  auto begin_val = std::find_if(eq + 1, end, std::not_fn(whitespace));
+
+  return std::pair { to_string(begin, end_name), to_string(begin_val, end) };
+}
+
+std::unordered_map<std::string, std::string> parse_config(std::string_view file_content) {
+  std::unordered_map<std::string, std::string> vars;
+
+  auto pos = std::begin(file_content) - 1;
+  auto end = std::end(file_content);
+
+  while(pos <= end) {
+    auto newline = std::find(pos, end, '\n');
+    auto var = parse_line(pos, *(newline - 1) == '\r' ? newline - 1 : newline);
+
+    pos = newline + 1;
+    if(!var) {
+      continue;
+    }
+
+    vars.emplace(std::move(*var));
+  }
+
+  return vars;
+}
+
+void string_f(std::unordered_map<std::string, std::string> &vars, const std::string &name, std::string &input) {
+  auto it = vars.find(name);
+  if(it == std::end(vars)) {
+    return;
+  }
+
+  input = std::move(it->second);
+}
+
+void int_f(std::unordered_map<std::string, std::string> &vars, const std::string &name, int &input) {
+  auto it = vars.find(name);
+
+  if(it == std::end(vars)) {
+    return;
+  }
+
+  auto &val = it->second;
+  input = util::from_chars(&val[0], &val[0] + val.size());
+}
+
+void parse_file(const char *file) {
+  std::ifstream in(file);
+
+  auto vars = parse_config(std::string {
+    // Quick and dirty
+    std::istreambuf_iterator<char>(in),
+    std::istreambuf_iterator<char>()
+  });
+
+  for(auto &[name, val] : vars) {
+    std::cout << "["sv << name << "] -- ["sv << val << "]"sv << std::endl;
+  }
+
+  int_f(vars, "max_b_frames", video.max_b_frames);
+  int_f(vars, "gop_size", video.gop_size);
+  int_f(vars, "crf", video.crf);
+
+  string_f(vars, "pkey", nvhttp.pkey);
+  string_f(vars, "cert", nvhttp.cert);
+  string_f(vars, "unique_id", nvhttp.unique_id);
+  string_f(vars, "file_devices", nvhttp.file_devices);
+  string_f(vars, "external_ip", nvhttp.external_ip);
+
+  int to = -1;
+  int_f(vars, "ping_timeout", to);
+  if(to > 0) {
+    stream.ping_timeout = std::chrono::milliseconds(to);
+  }
+}
+
+
 }

config.h

@@ -29,6 +29,8 @@ struct nvhttp_t {
 extern video_t video;
 extern stream_t stream;
 extern nvhttp_t nvhttp;
+
+void parse_file(const char *file);
 }
 
 #endif

main.cpp

@@ -14,8 +14,13 @@ extern "C" {
 
 #include <libavcodec/avcodec.h>
 
+#include "config.h"
 using namespace std::literals;
-int main() {
+int main(int argc, char *argv[]) {
+  if(argc > 1) {
+    config::parse_file(argv[1]);
+  }
+
   reed_solomon_init();
 
   std::thread httpThread { nvhttp::start };