uorb: compress format definitions

Reduces flash usage by ~16KB.

- compress formats at build-time into a single string with all formats
- then at runtime iteratively decompress using
  https://github.com/atomicobject/heatshrink

Tools/msg/templates/uorb/msg.cpp.em

@@ -14,6 +14,7 @@
 @#  - spec (msggen.MsgSpec) Parsed specification of the .msg file
 @#  - search_path (dict) search paths for genmsg
 @#  - topics (List of String) topic names
+@#  - all_topics (List of String) all generated topic names (sorted)
 @###############################################
 /****************************************************************************
  *
@@ -59,7 +60,6 @@ uorb_struct = '%s_s'%name_snake_case
 
 sorted_fields = sorted(spec.parsed_fields(), key=sizeof_field_type, reverse=True)
 struct_size, padding_end_size = add_padding_bytes(sorted_fields, search_path)
-topic_fields = ["%s %s" % (convert_type(field.type, True), field.name) for field in sorted_fields]
 }@
 
 #include <inttypes.h>
@@ -72,12 +72,9 @@ topic_fields = ["%s %s" % (convert_type(field.type, True), field.name) for field
 #include <lib/matrix/matrix/math.hpp>
 #include <lib/mathlib/mathlib.h>
 
-@# join all msg files in one line e.g: "float[3] position;float[3] velocity;bool armed"
-@# This is used for the logger
-constexpr char __orb_@(name_snake_case)_fields[] = "@( ";".join(topic_fields) );";
-
 @[for topic in topics]@
-ORB_DEFINE(@topic, struct @uorb_struct, @(struct_size-padding_end_size), __orb_@(name_snake_case)_fields, static_cast<orb_id_size_t>(ORB_ID::@topic));
+static_assert(static_cast<orb_id_size_t>(ORB_ID::@topic) == @(all_topics.index(topic)), "ORB_ID index mismatch");
+ORB_DEFINE(@topic, struct @uorb_struct, @(struct_size-padding_end_size), static_cast<orb_id_size_t>(ORB_ID::@topic));
 @[end for]
 
 void print_message(const orb_metadata *meta, const @uorb_struct& message)

Tools/msg/templates/uorb/msg.json.em

@@ -0,0 +1,49 @@
+@###############################################
+@#
+@# PX4 ROS compatible message source code
+@# generation for C++
+@#
+@# EmPy template for generating <msg>.h files
+@# Based on the original template for ROS
+@#
+@###############################################
+@# Start of Template
+@#
+@# Context:
+@#  - file_name_in (String) Source file
+@#  - spec (msggen.MsgSpec) Parsed specification of the .msg file
+@#  - search_path (dict) search paths for genmsg
+@#  - topics (List of String) topic names
+@#  - all_topics (List of String) all generated topic names (sorted)
+@###############################################
+
+@{
+import genmsg.msgs
+import json
+
+from px_generate_uorb_topic_helper import * # this is in Tools/
+
+uorb_struct = '%s_s'%name_snake_case
+
+sorted_fields = sorted(spec.parsed_fields(), key=sizeof_field_type, reverse=True)
+struct_size, padding_end_size = add_padding_bytes(sorted_fields, search_path)
+topic_fields = ["%s %s" % (convert_type(field.type, True), field.name) for field in sorted_fields]
+
+dependencies = []
+for field in spec.parsed_fields():
+    if not field.is_header:
+        type_name = field.type
+        # detect embedded types
+        sl_pos = type_name.find('/')
+        if sl_pos >= 0: # nested type
+            dependencies.append(field.base_type)
+}@
+
+{
+@# join all msg files in one line e.g: "float[3] position;float[3] velocity;bool armed;"
+		"fields": @( json.dumps(bytearray(";".join(topic_fields)+";", 'utf-8').decode('unicode_escape')) ),
+		"orb_ids": @( json.dumps([ all_topics.index(topic) for topic in topics]) ),
+		"main_orb_id": @( all_topics.index(name_snake_case) if name_snake_case in all_topics else -1 ),
+		"dependencies": @( json.dumps(list(set(dependencies))) ),
+		"name": "@( spec.full_name )"
+}

Tools/msg/templates/uorb/uORBTopics.cpp.em

@@ -8,7 +8,7 @@
 @#
 @# Context:
 @#  - msgs (List) list of all msg files
-@#  - multi_topics (List) list of all multi-topic names
+@#  - all_topics (List) list of all topic names (sorted)
 @###############################################
 /****************************************************************************
  *
@@ -50,9 +50,7 @@ msg_names = list(set([mn.replace(".msg", "") for mn in msgs])) # set() filters d
 msg_names.sort()
 msgs_count = len(msg_names)
 
-topic_names = list(set(topics)) # set() filters duplicates
-topic_names.sort()
-topics_count = len(topics)
+topics_count = len(all_topics)
 
 }@
 @[for msg_name in msg_names]@
@@ -60,8 +58,8 @@ topics_count = len(topics)
 @[end for]
 
 const constexpr struct orb_metadata *const uorb_topics_list[ORB_TOPICS_COUNT] = {
-@[for idx, topic_name in enumerate(topic_names, 1)]@
-	ORB_ID(@(topic_name))@[if idx != topic_names], @[end if]
+@[for idx, topic_name in enumerate(all_topics, 1)]@
+	ORB_ID(@(topic_name))@[if idx != all_topics], @[end if]
 @[end for]
 };
 

Tools/msg/templates/uorb/uORBTopics.hpp.em

@@ -7,7 +7,8 @@
 @# Start of Template
 @#
 @# Context:
-@#  - topics (List) list of all topic names
+@#  - msgs (List) list of all msg files
+@#  - all_topics (List) list of all topic names (sorted)
 @###############################################
 /****************************************************************************
  *
@@ -43,9 +44,7 @@
  ****************************************************************************/
 
 @{
-topics_count = len(topics)
-topic_names_all = list(set(topics)) # set() filters duplicates
-topic_names_all.sort()
+topics_count = len(all_topics)
 }@
 
 #pragma once
@@ -63,7 +62,7 @@ static constexpr size_t orb_topics_count() { return ORB_TOPICS_COUNT; }
 extern const struct orb_metadata *const *orb_get_topics() __EXPORT;
 
 enum class ORB_ID : orb_id_size_t {
-@[for idx, topic_name in enumerate(topic_names_all)]@
+@[for idx, topic_name in enumerate(all_topics)]@
 	@(topic_name) = @(idx),
 @[end for]
 	INVALID