1 files changed, 132 insertions, 0 deletions
diff --git a/src/source.c b/src/source.c
new file mode 100644
index 0000000..6203dfe
--- /dev/null
+++ b/src/source.c
@@ -0,0 +1,132 @@
+#include "source.h"
+#include "source_private.h"
+
+#include <pthread.h>
+#include <stdlib.h>
+
+struct imv_source {
+  /* pointers to implementation's functions */
+  const struct imv_source_vtable *vtable;
+
+  /* pointer to implementation data */
+  void *private;
+
+  /* Attempted to be locked by load_first_frame or load_next_frame.
+   * If the mutex can't be locked, the call is aborted.
+   * Used to prevent the source from having multiple worker threads at once.
+   * Released by the source before calling the message callback with a result.
+   */
+  pthread_mutex_t busy;
+
+  /* callback function */
+  imv_source_callback callback;
+  /* callback data */
+  void *callback_data;
+};
+
+struct imv_source *imv_source_create(const struct imv_source_vtable *vtable, void *private)
+{
+  struct imv_source *source = calloc(1, sizeof *source);
+  source->vtable = vtable;
+  source->private = private;
+  pthread_mutex_init(&source->busy, NULL);
+  return source;
+}
+
+static void *free_thread(void *src)
+{
+  imv_source_free(src);
+  return NULL;
+}
+
+void imv_source_async_free(struct imv_source *src)
+{
+  pthread_t thread;
+  pthread_create(&thread, NULL, free_thread, src);
+  pthread_detach(thread);
+}
+
+static void *first_frame_thread(void *src)
+{
+  imv_source_load_first_frame(src);
+  return NULL;
+}
+
+void imv_source_async_load_first_frame(struct imv_source *src)
+{
+  pthread_t thread;
+  pthread_create(&thread, NULL, first_frame_thread, src);
+  pthread_detach(thread);
+}
+
+static void *next_frame_thread(void *src)
+{
+  imv_source_load_next_frame(src);
+  return NULL;
+}
+void imv_source_async_load_next_frame(struct imv_source *src)
+{
+  pthread_t thread;
+  pthread_create(&thread, NULL, next_frame_thread, src);
+  pthread_detach(thread);
+}
+
+void imv_source_free(struct imv_source *src)
+{
+  pthread_mutex_lock(&src->busy);
+  src->vtable->free(src->private);
+  pthread_mutex_unlock(&src->busy);
+  pthread_mutex_destroy(&src->busy);
+  free(src);
+}
+
+void imv_source_load_first_frame(struct imv_source *src)
+{
+  if (!src->vtable->load_first_frame) {
+    return;
+  }
+
+  if (pthread_mutex_trylock(&src->busy)) {
+    return;
+  }
+
+  struct imv_source_message msg = {
+    .source = src,
+    .user_data = src->callback_data
+  };
+
+  src->vtable->load_first_frame(src->private, &msg.image, &msg.frametime);
+
+  pthread_mutex_unlock(&src->busy);
+
+  src->callback(&msg);
+}
+
+void imv_source_load_next_frame(struct imv_source *src)
+{
+  if (!src->vtable->load_next_frame) {
+    return;
+  }
+
+  if (pthread_mutex_trylock(&src->busy)) {
+    return;
+  }
+
+  struct imv_source_message msg = {
+    .source = src,
+    .user_data = src->callback_data
+  };
+
+  src->vtable->load_next_frame(src->private, &msg.image, &msg.frametime);
+
+  pthread_mutex_unlock(&src->busy);
+
+  src->callback(&msg);
+}
+
+void imv_source_set_callback(struct imv_source *src, imv_source_callback callback,
+    void *data)
+{
+  src->callback = callback;
+  src->callback_data = data;
+}