Utils for file change reload

[Pikachuxxxx]

Overview

We want to look for timestamp and directory changes and have a callback installed on files to indicate changes.

Windows - ReadDirectoryChangesW
MacOS -

FSEventStreamCreate(
    NULL,
    &Callback,
    NULL,
    paths,
    kFSEventStreamEventIdSinceNow,
    0.1,
    kFSEventStreamCreateFlagFileEvents
);

Unix -

int fd = inotify_init1(IN_NONBLOCK);
int wd = inotify_add_watch(
    fd,
    "assets",
    IN_MODIFY | IN_CREATE | IN_DELETE | IN_MOVED_TO
);

Register OS functions and poll them eveyrframe to drain the file changes queue.

typedef enum RZ_FileChangeType
{
    RZ_FILE_CHANGE_MODIFIED,
    RZ_FILE_CHANGE_ADDED,
    RZ_FILE_CHANGE_REMOVED
} RZ_FileChangeType;

typedef struct RZ_FileChange
{
    const char* path;
    RZ_FileChangeType type;
} RZ_FileChange;

typedef struct RZ_FileWatcher RZ_FileWatcher;

typedef void (*RZ_FileWatcherPollFn)(
    RZ_FileWatcher* watcher,
    RZ_FileChange*  outChanges,
    int*            inOutCount,
    int             maxChanges
);

typedef void (*RZ_FileWatcherDestroyFn)(RZ_FileWatcher* watcher);

struct RZ_FileWatcher
{
    void* platform;                 // OS-specific state
    RZ_FileWatcherPollFn poll;
    RZ_FileWatcherDestroyFn destroy;
};

RZ_FileWatcher* RZ_CreateFileWatcher_Windows(const char* path);
RZ_FileWatcher* RZ_CreateFileWatcher_Linux(const char* path);
RZ_FileWatcher* RZ_CreateFileWatcher_Mac(const char* path);
RZ_FileWatcher* RZ_CreateFileWatcher_Polling(const char* path);

  RZ_FileChange changes[64];
    int changeCount = 0;

    fileWatcher->poll(
        fileWatcher,
        changes,
        &changeCount,
        64
    );

    for (int i = 0; i < changeCount; i++)
    {
        AssetSystem_OnFileChanged(&changes[i]);
    }