Lots of refactoring to move the SDR-type-specific bits out of the

main code and make them optionally buildable.

sdr.c

@@ -0,0 +1,145 @@
+#include "dump1090.h"
+#include "sdr.h"
+
+#define ENABLE_RTLSDR
+
+#include "sdr_ifile.h"
+#ifdef ENABLE_RTLSDR
+#  include "sdr_rtlsdr.h"
+#endif
+
+typedef struct {
+    const char *name;
+    sdr_type_t sdr_type;
+    void (*initConfig)();
+    void (*showHelp)();
+    bool (*handleOption)(int, char**, int*);
+    bool (*open)();
+    void (*run)();
+    void (*close)();
+} sdr_handler;
+
+static void noInitConfig()
+{
+}
+
+static void noShowHelp()
+{
+}
+
+static bool noHandleOption(int argc, char **argv, int *jptr)
+{
+    MODES_NOTUSED(argc);
+    MODES_NOTUSED(argv);
+    MODES_NOTUSED(jptr);
+
+    return false;
+}
+
+static bool noOpen()
+{
+    fprintf(stderr, "Net-only mode, no SDR device or file open.\n");
+    return true;
+}
+
+static void noRun()
+{
+}
+
+static void noClose()
+{
+}
+
+static bool unsupportedOpen()
+{
+    fprintf(stderr, "Support for this SDR type was not enabled in this build.\n");
+    return false;
+}
+
+static sdr_handler sdr_handlers[] = {
+#ifdef ENABLE_RTLSDR
+    { "rtlsdr", SDR_RTLSDR, rtlsdrInitConfig, rtlsdrShowHelp, rtlsdrHandleOption, rtlsdrOpen, rtlsdrRun, rtlsdrClose },
+#endif
+
+    { "ifile", SDR_IFILE, ifileInitConfig, ifileShowHelp, ifileHandleOption, ifileOpen, ifileRun, ifileClose },
+    { "none", SDR_NONE, noInitConfig, noShowHelp, noHandleOption, noOpen, noRun, noClose },
+
+    { NULL, SDR_NONE, NULL, NULL, NULL, NULL, NULL, NULL } /* must come last */
+};
+
+void sdrInitConfig()
+{
+    // Default SDR is the first type available in the handlers array.
+    Modes.sdr_type = sdr_handlers[0].sdr_type;
+
+    for (int i = 0; sdr_handlers[i].name; ++i) {
+        sdr_handlers[i].initConfig();
+    }
+}
+
+void sdrShowHelp()
+{
+    printf("--device-type <type>     Select SDR type (default: %s)\n", sdr_handlers[0].name);
+    printf("\n");
+
+    for (int i = 0; sdr_handlers[i].name; ++i) {
+        sdr_handlers[i].showHelp();
+    }
+}
+
+bool sdrHandleOption(int argc, char **argv, int *jptr)
+{
+    int j = *jptr;
+    if (!strcmp(argv[j], "--device-type") && (j+1) < argc) {
+        ++j;
+        for (int i = 0; sdr_handlers[i].name; ++i) {
+            if (!strcasecmp(sdr_handlers[i].name, argv[j])) {
+                Modes.sdr_type = sdr_handlers[i].sdr_type;
+                *jptr = j;
+                return true;
+            }
+        }
+
+        fprintf(stderr, "SDR type '%s' not recognized; supported SDR types are:\n", argv[j]);
+        for (int i = 0; sdr_handlers[i].name; ++i) {
+            fprintf(stderr, "  %s\n", sdr_handlers[i].name);
+        }
+
+        return false;
+    }
+
+    for (int i = 0; sdr_handlers[i].name; ++i) {
+        if (sdr_handlers[i].handleOption(argc, argv, jptr))
+            return true;
+    }
+
+    return false;
+}
+
+static sdr_handler *current_handler()
+{
+    static sdr_handler unsupported_handler = { "unsupported", SDR_NONE, noInitConfig, noShowHelp, noHandleOption, unsupportedOpen, noRun, noClose };
+
+    for (int i = 0; sdr_handlers[i].name; ++i) {
+        if (Modes.sdr_type == sdr_handlers[i].sdr_type) {
+            return &sdr_handlers[i];
+        }
+    }
+
+    return &unsupported_handler;
+}
+
+bool sdrOpen()
+{
+    return current_handler()->open();
+}
+
+void sdrRun()
+{
+    return current_handler()->run();
+}
+
+void sdrClose()
+{
+    current_handler()->close();
+}