move the libevent2 <> CURL stuff into the library

libdc/include/dc/loop.h

@@ -0,0 +1,48 @@
+#ifndef DC_LOOP_H
+#define DC_LOOP_H
+
+#include <dc/api.h>
+
+#include <event.h>
+#include <curl/curl.h>
+
+#include <stdint.h>
+
+struct dc_loop_;
+typedef struct dc_loop_ *dc_loop_t;
+
+/**
+ * A simple CURLM <--> libevent2 loop and handler if you don't want
+ * to bother rolling your own.
+ */
+dc_loop_t dc_loop_new(void);
+
+/**
+ * If you already have either the CURL multi handle, or the event
+ * base handle, use this function. Either can be NULL. If both are
+ * NULL both are allocated for you.
+ */
+dc_loop_t dc_loop_new_full(struct event_base *base, CURLM *multi);
+
+/**
+ * Returns the CURL multi handle in use by this loop.
+ */
+CURLM *dc_loop_curl(dc_loop_t l);
+
+/**
+ * Returns the event base used by this loop.
+ */
+struct event_base *dc_loop_event_base(dc_loop_t l);
+
+/**
+ * Add an API handle that this loop should feed.
+ */
+void dc_loop_add_api(dc_loop_t loop, dc_api_t api);
+
+/**
+ * Loop once, and process one message in the queues of the event
+ * base, and one message from the queue of the CURL multi events.
+ */
+bool dc_loop_once(dc_loop_t l);
+
+#endif