Live reloading;

Use -w or --watch to watch source directory for changes and call
lovr.filechanged when a file is changed.

By default lovr.filechanged will restart lovr.

It's powered by lovr.filesystem.watch/lovr.filesystem.unwatch functions,
but these are currently hardcoded to only watch the whole source folder.

Currently there is a bug where it only restarts on the first change,
this is seemingly a problem with dmon.

CMakeLists.txt

@@ -421,6 +421,7 @@ if(LOVR_ENABLE_FILESYSTEM)
     src/modules/filesystem/filesystem.c
     src/api/l_filesystem.c
     src/api/l_filesystem_file.c
+    src/lib/dmon/dmon.c
     src/lib/miniz/miniz_tinfl.c
   )
 else()

Tupfile.lua

@@ -393,6 +393,7 @@ src += 'src/lib/miniz/*.c'
 src += (config.modules.audio or config.modules.data) and 'src/lib/miniaudio/*.c' or nil
 src += config.modules.data and 'src/lib/jsmn/*.c' or nil
 src += config.modules.data and 'src/lib/minimp3/*.c' or nil
+src += config.modules.filesystem and 'src/lib/dmon/*.c' or nil
 src += config.modules.math and 'src/lib/noise/*.c' or nil
 src += config.modules.thread and 'src/core/job.c' or nil
 

etc/boot.lua

@@ -282,6 +282,10 @@ function lovr.threaderror(thread, err)
   error('Thread error\n\n' .. err, 0)
 end
 
+function lovr.filechanged(path, action, oldpath)
+  lovr.event.restart()
+end
+
 function lovr.log(message, level, tag)
   message = message:gsub('\n$', '')
   print(message)

etc/nogame/arg.lua

@@ -3,7 +3,8 @@ function lovr.arg(arg)
     _help = { short = '-h', long = '--help', help = 'Show help and exit' },
     _version = { short = '-v', long = '--version', help = 'Show version and exit' },
     console = { long = '--console', help = 'Attach Windows console' },
-    debug = { long = '--debug', help = 'Enable debugging checks and logging' }
+    debug = { long = '--debug', help = 'Enable debugging checks and logging' },
+    watch = { short = '-w', long = '--watch', help = 'Watch files and restart on change' }
   }
 
   local shift
@@ -68,5 +69,9 @@ function lovr.arg(arg)
     if arg.debug then
       conf.graphics.debug = true
     end
+
+    if arg.watch then
+      lovr.filesystem.watch()
+    end
   end
 end

src/api/api.h

@@ -38,6 +38,7 @@ extern StringEntry lovrDrawMode[];
 extern StringEntry lovrDrawStyle[];
 extern StringEntry lovrEffect[];
 extern StringEntry lovrEventType[];
+extern StringEntry lovrFileAction[];
 extern StringEntry lovrFilterMode[];
 extern StringEntry lovrHeadsetDriver[];
 extern StringEntry lovrHorizontalAlign[];

src/api/l_event.c

@@ -22,6 +22,7 @@ StringEntry lovrEventType[] = {
 #ifndef LOVR_DISABLE_THREAD
   [EVENT_THREAD_ERROR] = ENTRY("threaderror"),
 #endif
+  [EVENT_FILECHANGED] = ENTRY("filechanged"),
   [EVENT_PERMISSION] = ENTRY("permission"),
   { 0 }
 };
@@ -207,6 +208,14 @@ static int nextEvent(lua_State* L) {
       return 3;
 #endif
 
+    case EVENT_FILECHANGED:
+      lua_pushstring(L, event.data.file.path);
+      luax_pushenum(L, FileAction, event.data.file.action);
+      lua_pushstring(L, event.data.file.oldpath);
+      free(event.data.file.path);
+      free(event.data.file.oldpath);
+      return 4;
+
     case EVENT_PERMISSION:
       luax_pushenum(L, Permission, event.data.permission.permission);
       lua_pushboolean(L, event.data.permission.granted);

src/api/l_filesystem.c

@@ -5,6 +5,14 @@
 #include <stdlib.h>
 #include <string.h>
 
+StringEntry lovrFileAction[] = {
+  [FILE_CREATE] = ENTRY("create"),
+  [FILE_DELETE] = ENTRY("delete"),
+  [FILE_MODIFY] = ENTRY("modify"),
+  [FILE_RENAME] = ENTRY("rename"),
+  { 0 }
+};
+
 StringEntry lovrOpenMode[] = {
   [OPEN_READ] = ENTRY("r"),
   [OPEN_WRITE] = ENTRY("w"),
@@ -349,6 +357,16 @@ static int l_lovrFilesystemUnmount(lua_State* L) {
   return 1;
 }
 
+static int l_lovrFilesystemUnwatch(lua_State* L) {
+  lovrFilesystemUnwatch();
+  return 0;
+}
+
+static int l_lovrFilesystemWatch(lua_State* L) {
+  lovrFilesystemWatch();
+  return 0;
+}
+
 static int l_lovrFilesystemWrite(lua_State* L) {
   const char* path = luaL_checkstring(L, 1);
   size_t size;
@@ -411,6 +429,8 @@ static const luaL_Reg lovrFilesystem[] = {
   { "setRequirePath", l_lovrFilesystemSetRequirePath },
   { "setSource", l_lovrFilesystemSetSource },
   { "unmount", l_lovrFilesystemUnmount },
+  { "unwatch", l_lovrFilesystemUnwatch },
+  { "watch", l_lovrFilesystemWatch },
   { "write", l_lovrFilesystemWrite },
   { "newFile", l_lovrFilesystemNewFile },
   { NULL, NULL }

src/lib/dmon/dmon.c

@@ -0,0 +1,2 @@
+#define DMON_IMPL
+#include "dmon.h"

src/modules/event/event.c

@@ -51,13 +51,26 @@ void lovrEventPush(Event event) {
   if (event.type == EVENT_THREAD_ERROR) {
     lovrRetain(event.data.thread.thread);
     size_t length = strlen(event.data.thread.error);
-    char* copy = lovrMalloc(length + 1);
-    memcpy(copy, event.data.thread.error, length);
-    copy[length] = '\0';
+    char* copy = malloc(length + 1);
+    memcpy(copy, event.data.thread.error, length + 1);
     event.data.thread.error = copy;
   }
 #endif
 
+  if (event.type == EVENT_FILECHANGED) {
+    size_t length = strlen(event.data.file.path);
+    char* copy = malloc(length + 1);
+    memcpy(copy, event.data.file.path, length + 1);
+    event.data.file.path = copy;
+
+    if (event.data.file.oldpath) {
+      length = strlen(event.data.file.oldpath);
+      copy = malloc(length + 1);
+      memcpy(copy, event.data.file.oldpath, length + 1);
+      event.data.file.oldpath = copy;
+    }
+  }
+
   arr_push(&state.events, event);
 }
 

src/modules/event/event.h

@@ -25,6 +25,7 @@ typedef enum {
 #ifndef LOVR_DISABLE_THREAD
   EVENT_THREAD_ERROR,
 #endif
+  EVENT_FILECHANGED,
   EVENT_PERMISSION,
   EVENT_CUSTOM
 } EventType;
@@ -115,16 +116,22 @@ typedef struct {
 } ThreadEvent;
 
 typedef struct {
-  char name[MAX_EVENT_NAME_LENGTH];
-  Variant data[4];
-  uint32_t count;
-} CustomEvent;
+  char* path;
+  char* oldpath;
+  int action;
+} FileEvent;
 
 typedef struct {
   uint32_t permission;
   bool granted;
 } PermissionEvent;
 
+typedef struct {
+  char name[MAX_EVENT_NAME_LENGTH];
+  Variant data[4];
+  uint32_t count;
+} CustomEvent;
+
 typedef union {
   QuitEvent quit;
   BoolEvent boolean;
@@ -134,8 +141,9 @@ typedef union {
   MouseEvent mouse;
   MouseWheelEvent wheel;
   ThreadEvent thread;
-  CustomEvent custom;
+  FileEvent file;
   PermissionEvent permission;
+  CustomEvent custom;
 } EventData;
 
 typedef struct {

src/modules/filesystem/filesystem.c

@@ -1,7 +1,9 @@
 #include "filesystem/filesystem.h"
+#include "event/event.h"
 #include "core/fs.h"
 #include "core/os.h"
 #include "util.h"
+#include "lib/dmon/dmon.h"
 #include "lib/miniz/miniz_tinfl.h"
 #include <stdatomic.h>
 #include <string.h>
@@ -75,6 +77,8 @@ struct File {
 
 static struct {
   uint32_t ref;
+  bool watching;
+  dmon_watch_id watchId;
   Archive* archives;
   size_t savePathLength;
   char savePath[1024];
@@ -175,6 +179,7 @@ void lovrFilesystemDestroy(void) {
     lovrRelease(archive, lovrArchiveDestroy);
     archive = next;
   }
+  lovrFilesystemUnwatch();
   memset(&state, 0, sizeof(state));
 }
 
@@ -190,6 +195,41 @@ const char* lovrFilesystemGetSource(void) {
   return state.source[0]  ? state.source : NULL;
 }
 
+static void onFileEvent(dmon_watch_id id, dmon_action action, const char* dir, const char* path, const char* oldpath, void* ctx) {
+  static const FileAction map[] = {
+    [DMON_ACTION_CREATE] = FILE_CREATE,
+    [DMON_ACTION_DELETE] = FILE_DELETE,
+    [DMON_ACTION_MODIFY] = FILE_MODIFY,
+    [DMON_ACTION_MOVE] = FILE_RENAME
+  };
+
+  lovrEventPush((Event) {
+    .type = EVENT_FILECHANGED,
+    .data.file = {
+      .path = (char*) path,
+      .action = map[action],
+      .oldpath = (char*) oldpath
+    }
+  });
+}
+
+void lovrFilesystemWatch(void) {
+  FileInfo info;
+  if (!state.watching && fs_stat(state.source, &info) && info.type == FILE_DIRECTORY) {
+    state.watching = true;
+    dmon_init();
+    state.watchId = dmon_watch(state.source, onFileEvent, DMON_WATCHFLAGS_RECURSIVE, NULL);
+  }
+}
+
+void lovrFilesystemUnwatch(void) {
+  if (state.watching) {
+    state.watching = false;
+    dmon_unwatch(state.watchId);
+    dmon_deinit();
+  }
+}
+
 bool lovrFilesystemIsFused(void) {
   char path[LOVR_PATH_MAX];
   const char* root;

src/modules/filesystem/filesystem.h

@@ -9,11 +9,20 @@
 typedef struct Archive Archive;
 typedef struct File File;
 
+typedef enum {
+  FILE_CREATE,
+  FILE_DELETE,
+  FILE_MODIFY,
+  FILE_RENAME
+} FileAction;
+
 bool lovrFilesystemInit(void);
 void lovrFilesystemDestroy(void);
 void lovrFilesystemSetSource(const char* source);
 const char* lovrFilesystemGetSource(void);
 bool lovrFilesystemIsFused(void);
+void lovrFilesystemWatch(void);
+void lovrFilesystemUnwatch(void);
 bool lovrFilesystemMount(const char* path, const char* mountpoint, bool append, const char *root);
 bool lovrFilesystemUnmount(const char* path);
 const char* lovrFilesystemGetRealDirectory(const char* path);