From c47b0765a8605b9afcc6205a6d2396ccbe3d5e05 Mon Sep 17 00:00:00 2001
From: cbdev <cb@cbcdn.com>
Date: Sun, 4 Jun 2017 22:49:27 +0200
Subject: Implement channel mapping

---
 midimonster.h | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

(limited to 'midimonster.h')

diff --git a/midimonster.h b/midimonster.h
index 9026222..b2af7a3 100644
--- a/midimonster.h
+++ b/midimonster.h
@@ -13,6 +13,7 @@ struct _backend_instance;
 typedef int (*mmbackend_handle_event)(size_t channels, struct _backend_channel* c, struct _channel_value* v);
 typedef struct _backend_instance* (*mmbackend_create_instance)();
 typedef struct _backend_channel* (*mmbackend_parse_channel)(struct _backend_instance* instance, char* spec);
+typedef void (*mmbackend_free_channel)(struct _backend_channel* c);
 typedef int (*mmbackend_configure)(char* option, char* value);
 typedef int (*mmbackend_configure_instance)(struct _backend_instance* instance, char* option, char* value);
 typedef int (*mmbackend_process_fd)(size_t fds, int* fd, void** impl);
@@ -36,6 +37,7 @@ typedef struct /*_mm_backend*/ {
 	mmbackend_process_fd process;
 	mmbackend_start start;
 	mmbackend_shutdown shutdown;
+	mmbackend_free_channel channel_free;
 } backend;
 
 typedef struct _backend_instance {
@@ -58,9 +60,48 @@ typedef struct /*_mm_managed_fd*/ {
 	void* impl;
 } managed_fd;
 
+typedef struct /*_mm_channel_mapping*/ {
+	channel* from;
+	size_t destinations;
+	channel** to;
+} channel_mapping;
+
+/*
+ * Register a new backend.
+ */
 int mm_backend_register(backend b);
+
+/*
+ * Provides a pointer to a newly (zero-)allocated instance.
+ * All instance pointers need to be allocated via this API
+ * in order to be assignable from the configuration parser.
+ * This API should be called from the mmbackend_create_instance
+ * call of your backend.
+ *
+ * Instances returned from this call are freed by midimonster.
+ * The contents of the impl members should be freed in the
+ * mmbackend_shutdown procedure of the backend, eg. by querying
+ * all instances for the backend.
+ */
 instance* mm_instance();
+/*
+ * Provides a pointer to a channel structure, pre-filled with
+ * the provided instance reference and identifier.
+ * Will return previous allocations if the provided fields
+ * match.
+ * This API is just a convenience function. The array
+ * of channels is only used for mapping internally,
+ * creating and managing your own channel store is
+ * possible.
+ * For each channel with a non-NULL impl field, the backend
+ * will receive a call to its channel_free function.
+ */
+channel* mm_channel(instance* i, uint64_t ident);
 int mm_manage_fd(int fd, char* backend, int manage, void* impl);
 int mm_channel_event(channel* c, channel_value v);
+/*
+ * Query all active instances for a given backend.
+ */
 int mm_backend_instances(char* backend, size_t* n, instance*** i);
+int mm_map_channel(channel* from, channel* to);
 #endif
-- 
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