acquisition: drive a DataSource from the registry; --source and --source-opt

src/config.cpp

@@ -6,6 +6,7 @@
 // For `RowSet::kMaxRows`: `--plots` names a row count, and one constant for the ceiling
 // is what stops the message and the clamp from drifting apart.
 #include "plot_host.hpp"
+#include "source/registry.hpp"
 
 #include <cstdio>
 #include <cstdlib>
@@ -40,14 +41,35 @@ double parse_double(const char* name, const std::string& v) {
 
 }  // namespace
 
+SourceConfig Config::source_config() const {
+  SourceConfig out;
+  if (source_kind == "udps") {
+    out.set("server", server);
+    out.set("port", std::to_string(port));
+    if (!multicast.empty()) out.set("multicast", multicast);
+    if (!interface_addr.empty()) out.set("interface", interface_addr);
+    out.set("recv_buffer", std::to_string(recv_buffer_bytes));
+  }
+  for (const auto& kv : source_opts.items()) out.set(kv.first, kv.second);
+  return out;
+}
+
+std::string Config::session_host() const { return udpscope::session_host(source_kind, source_config()); }
+std::uint16_t Config::session_port() const { return udpscope::session_port(source_kind, source_config()); }
+
 void print_usage(std::FILE* out, const char* argv0) {
+  std::string names;
+  for (const SourceKind* k : kinds()) names += (names.empty() ? "" : ", ") + k->id();
   std::fprintf(out,
-               "usage: %s --server ADDR --port PORT [options]\n"
+               "usage: %s --server ADDR --port PORT [--source NAME] [options]\n"
                "\n"
                "  --server ADDR        stream source IPv4 address (default 127.0.0.1)\n"
                "  --port PORT          UDP port (unicast) or TCP port (multicast) (default 8000)\n"
                "  --multicast GROUP    join GROUP for DATA instead of unicast\n"
                "  --interface ADDR     local IPv4 of the interface to join on\n"
+               "  --source NAME        source kind (%s; default udps). --server/--port/\n"
+               "                       --multicast/--interface configure udps\n"
+               "  --source-opt K=V     a setting for the source kind; repeatable\n"
                "  --buffer-mb MB       size of each of the two sample buffers (default 200)\n"
                "  --max-window SEC     largest time window the toolbar offers (default 600)\n"
                "  --holdoff SEC        default trigger hold-off (default 0.010)\n"
@@ -69,7 +91,7 @@ void print_usage(std::FILE* out, const char* argv0) {
                "                       and the GL area has no hardware context, so the window\n"
                "                       never paints or allocates\n"
                "  -h, --help           this text\n",
-               argv0);
+               argv0, names.c_str());
 }
 
 Config parse_args(int argc, char** argv) {
@@ -91,6 +113,18 @@ Config parse_args(int argc, char** argv) {
       c.multicast = value_of(argc, argv, i, "--multicast");
     } else if (a == "--interface" || a.rfind("--interface=", 0) == 0) {
       c.interface_addr = value_of(argc, argv, i, "--interface");
+    } else if (a == "--source" || a.rfind("--source=", 0) == 0) {
+      const std::string v = value_of(argc, argv, i, "--source");
+      if (find_kind(v) == nullptr) {
+        std::string names;
+        for (const SourceKind* k : kinds()) names += (names.empty() ? "" : ", ") + k->id();
+        fail("unknown source '" + v + "' (available: " + names + ")");
+      }
+      c.source_kind = v;
+      c.source_specified = true;
+    } else if (a == "--source-opt" || a.rfind("--source-opt=", 0) == 0) {
+      const std::string v = value_of(argc, argv, i, "--source-opt");
+      if (!c.source_opts.parse_assignment(v)) fail("--source-opt must be key=value: " + v);
     } else if (a == "--buffer-mb" || a.rfind("--buffer-mb=", 0) == 0) {
       c.buffer_mb = parse_double("--buffer-mb", value_of(argc, argv, i, "--buffer-mb"));
       c.buffer_mb_specified = true;