ecore_file_monitor: add kevent backend.

Summary:
This is a very simple kevent backend, very similar to the eio_monitor
implementation. On BSD systems, some core features within in E and
other applications are always using the poll engine, which is not
ideal.  This is better, and simpler.

Reviewers: devilhorns, raster, bu5hm4n, vtorri

Reviewed By: vtorri

Subscribers: vtorri, cedric, #reviewers, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D12239

2 files changed, 292 insertions, 0 deletions

diff --git a/src/lib/ecore_file/ecore_file_monitor_kevent.c b/src/lib/ecore_file/ecore_file_monitor_kevent.c
new file mode 100644
index 0000000000..e8c4c1e238
--- /dev/null
+++ b/src/lib/ecore_file/ecore_file_monitor_kevent.c
@@ -0,0 +1,290 @@
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include "ecore_file_private.h"
+
+#define KEVENT_NUM_EVENTS 5
+
+typedef struct _Ecore_File_Monitor_Kevent Ecore_File_Monitor_Kevent;
+
+#define ECORE_FILE_MONITOR_KEVENT(x) ((Ecore_File_Monitor_Kevent *)(x))
+
+struct _Ecore_File_Monitor_Kevent
+{
+   Ecore_File_Monitor  monitor;
+   Eina_List          *prev;
+   int                 fd;
+};
+
+typedef struct _File_Info File_Info;
+struct _File_Info
+{
+   const char *path;
+   Eina_Stat   st;
+};
+
+static Ecore_Fd_Handler   *_kevent_fdh = NULL;
+static Eina_Hash          *_kevent_monitors = NULL;
+
+static Eina_Bool           _ecore_file_monitor_kevent_handler(void *data, Ecore_Fd_Handler *fdh);
+static int                 _ecore_file_monitor_kevent_monitor(Ecore_File_Monitor *em, const char *path);
+static void                _ecore_file_monitor_kevent_find(Ecore_File_Monitor *em);
+static void                _ecore_file_monitor_kevent_hash_del_cb(void *data);
+static Eina_List *         _ecore_file_monitor_kevent_ls(const char *directory);
+static void                _ecore_file_monitor_kevent_ls_free(Eina_List *);
+
+int
+ecore_file_monitor_backend_init(void)
+{
+   int fd;
+
+   if (_kevent_fdh != NULL) return 0;
+
+   fd = kqueue();
+   if (fd < 0)
+     return 0;
+
+   _kevent_fdh = ecore_main_fd_handler_add(fd, ECORE_FD_READ, _ecore_file_monitor_kevent_handler,
+                                           NULL, NULL, NULL);
+   if (!_kevent_fdh)
+     {
+        close(fd);
+        return 0;
+     }
+
+   _kevent_monitors = eina_hash_int32_new(_ecore_file_monitor_kevent_hash_del_cb);
+   return 1;
+}
+
+int
+ecore_file_monitor_backend_shutdown(void)
+{
+   int fd;
+
+   if (!_kevent_fdh) return 1;
+
+   eina_hash_free(_kevent_monitors);
+
+   fd = ecore_main_fd_handler_fd_get(_kevent_fdh);
+   ecore_main_fd_handler_del(_kevent_fdh);
+   _kevent_fdh = NULL;
+
+   if (fd != -1)
+     close(fd);
+
+   return 1;
+}
+
+Ecore_File_Monitor *
+ecore_file_monitor_backend_add(const char *path,
+                               void (*func) (void *data, Ecore_File_Monitor *em,
+                                             Ecore_File_Event event,
+                                             const char *path),
+                               void *data)
+{
+   Ecore_File_Monitor *em;
+   char *path2;
+   size_t len;
+
+   if (!path) return NULL;
+   if (!func) return NULL;
+
+   em = (Ecore_File_Monitor *)calloc(1, sizeof(Ecore_File_Monitor_Kevent));
+   if (!em) return NULL;
+
+   em->func = func;
+   em->data = data;
+
+   len = strlen(path);
+   path2 = alloca(len + 1);
+   strcpy(path2, path);
+   if (path2[len - 1] == '/' && strcmp(path2, "/")) path2[len - 1] = 0;
+   em->path = eina_stringshare_add(path2);
+
+   if (!_ecore_file_monitor_kevent_monitor(em, em->path))
+     return NULL;
+
+   return em;
+}
+
+static Eina_List *
+_ecore_file_monitor_kevent_ls(const char *directory)
+{
+   Eina_Iterator *it;
+   Eina_File_Direct_Info *info;
+   Eina_List *files = NULL;
+
+   it = eina_file_direct_ls(directory);
+   if (!it) return NULL;
+
+   EINA_ITERATOR_FOREACH(it, info)
+     {
+        File_Info *file = malloc(sizeof(File_Info));
+        if (eina_file_statat(eina_iterator_container_get(it), info, &file->st))
+          {
+             free(file);
+             continue;
+          }
+        file->path = eina_stringshare_add(info->path);
+        files = eina_list_append(files, file);
+     }
+
+   eina_iterator_free(it);
+
+   return files;
+}
+
+static void
+_ecore_file_monitor_kevent_ls_free(Eina_List *list)
+{
+   File_Info *file;
+
+   EINA_LIST_FREE(list, file)
+     {
+        eina_stringshare_del(file->path);
+        free(file);
+     }
+}
+
+static void
+_ecore_file_monitor_kevent_hash_del_cb(void *data)
+{
+   Ecore_File_Monitor *em = data;
+
+   if (ECORE_FILE_MONITOR_KEVENT(em)->fd >= 0)
+     close(ECORE_FILE_MONITOR_KEVENT(em)->fd);
+   eina_stringshare_del(em->path);
+   _ecore_file_monitor_kevent_ls_free(ECORE_FILE_MONITOR_KEVENT(em)->prev);
+
+   free(em);
+}
+
+void
+ecore_file_monitor_backend_del(Ecore_File_Monitor *em)
+{
+   eina_hash_del(_kevent_monitors, &(ECORE_FILE_MONITOR_KEVENT(em)->fd), em);
+}
+
+static Eina_Bool
+_ecore_file_monitor_kevent_handler(void *data EINA_UNUSED, Ecore_Fd_Handler *fdh)
+{
+   Ecore_File_Monitor *em;
+   struct kevent evs[KEVENT_NUM_EVENTS];
+   int fd;
+   const struct timespec timeout = { 0, 0 };
+
+   fd = ecore_main_fd_handler_fd_get(fdh);
+   if (fd < 0) return ECORE_CALLBACK_RENEW;
+
+   int res = kevent(fd, 0, 0, evs, KEVENT_NUM_EVENTS, &timeout);
+   for (int i = 0; i < res; i++)
+     {
+        em = eina_hash_find(_kevent_monitors, &evs[i].ident);
+        if (evs[i].fflags & NOTE_DELETE)
+          {
+             em->func(em->data, em, ECORE_FILE_EVENT_DELETED_SELF, em->path);
+          }
+        if ((evs[i].fflags & NOTE_WRITE) || (evs[i].fflags & NOTE_ATTRIB))
+          {
+             _ecore_file_monitor_kevent_find(em);
+          }
+     }
+
+   return ECORE_CALLBACK_RENEW;
+}
+
+static void
+_ecore_file_monitor_kevent_find(Ecore_File_Monitor *em)
+{
+   Eina_List *l, *l2;
+   File_Info *file, *file2;
+   Eina_List *files;
+
+   files = _ecore_file_monitor_kevent_ls(em->path);
+
+   EINA_LIST_FOREACH(ECORE_FILE_MONITOR_KEVENT(em)->prev, l, file)
+     {
+        Eina_Bool exists = EINA_FALSE;
+        EINA_LIST_FOREACH(files, l2, file2)
+          {
+             if (file->st.ino == file2->st.ino)
+               {
+                  if (file->path == file2->path)
+                    exists = EINA_TRUE;
+
+                  if (file->st.mtime != file2->st.mtime)
+                    em->func(em->data, em, ECORE_FILE_EVENT_MODIFIED, file->path);
+               }
+          }
+
+        if (!exists)
+          {
+             if (S_ISDIR(file->st.mode))
+               em->func(em->data, em, ECORE_FILE_EVENT_DELETED_DIRECTORY, file->path);
+             else
+               em->func(em->data, em, ECORE_FILE_EVENT_DELETED_FILE, file->path);
+          }
+     }
+
+   EINA_LIST_FOREACH(files, l, file)
+     {
+        Eina_Bool exists = EINA_FALSE;
+        EINA_LIST_FOREACH(ECORE_FILE_MONITOR_KEVENT(em)->prev, l2, file2)
+          {
+             if ((file->path == file2->path) && (file->st.ino == file2->st.ino))
+               {
+                  exists = EINA_TRUE;
+                  break;
+               }
+          }
+
+        if (!exists)
+          {
+             if (S_ISDIR(file->st.mode))
+               em->func(em->data, em, ECORE_FILE_EVENT_CREATED_DIRECTORY, file->path);
+             else
+               em->func(em->data, em, ECORE_FILE_EVENT_CREATED_FILE, file->path);
+          }
+     }
+
+   _ecore_file_monitor_kevent_ls_free(ECORE_FILE_MONITOR_KEVENT(em)->prev);
+   ECORE_FILE_MONITOR_KEVENT(em)->prev = files;
+}
+
+static int
+_ecore_file_monitor_kevent_monitor(Ecore_File_Monitor *em, const char *path)
+{
+   struct kevent ev;
+   int fd, res = 0;
+
+   if ((!ecore_file_exists(path)) || (!ecore_file_is_dir(path)))
+     return 0;
+
+   fd = open(path, O_RDONLY);
+   if (fd < 0)
+     {
+        INF("open failed, %s", strerror(errno));
+        ecore_file_monitor_backend_del(em);
+        return 0;
+     }
+
+   eina_file_close_on_exec(fd, EINA_TRUE);
+
+   ECORE_FILE_MONITOR_KEVENT(em)->fd = fd;
+   ECORE_FILE_MONITOR_KEVENT(em)->prev = _ecore_file_monitor_kevent_ls(em->path);
+
+   eina_hash_direct_add(_kevent_monitors, &(ECORE_FILE_MONITOR_KEVENT(em)->fd), em);
+
+   EV_SET(&ev, fd, EVFILT_VNODE, EV_ADD | EV_CLEAR,
+          NOTE_DELETE | NOTE_WRITE | NOTE_ATTRIB, 0, NULL);
+   res = kevent(ecore_main_fd_handler_fd_get(_kevent_fdh), &ev, 1, 0, 0, 0);
+   if (res)
+     eina_hash_del(_kevent_monitors, &(ECORE_FILE_MONITOR_KEVENT(em)->fd), em);
+
+   return 1;
+}
diff --git a/src/lib/ecore_file/meson.build b/src/lib/ecore_file/meson.build
index 9e0212d6c0..a25d98dffb 100644
--- a/src/lib/ecore_file/meson.build
+++ b/src/lib/ecore_file/meson.build
@@ -14,6 +14,8 @@ if sys_windows == true
   ecore_file_src += files([ 'ecore_file_monitor_win32.c'])
 elif sys_linux == true
   ecore_file_src += files([ 'ecore_file_monitor_inotify.c'])
+elif sys_bsd == true
+  ecore_file_src += files([ 'ecore_file_monitor_kevent.c'])
 else
   ecore_file_src += files([ 'ecore_file_monitor_poll.c'])
 endif