From fa7b55fc4ba50bde3f1de8e40a56ef70d9116595 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oona=20R=C3=A4is=C3=A4nen?= <oona@kapsi.fi>
Date: Sat, 28 Dec 2024 09:15:00 +0200
Subject: [PATCH] Small improvement to compilation time

Compile the event list into its own object file and forward-declare
---
 .github/workflows/build.yml              |  2 +-
 CHANGES.md                               |  1 +
 README.md                                |  3 +++
 meson.build                              |  1 +
 src/tmc/events.h                         | 16 ++++++++++++++++
 src/tmc/{event_list.h => events_data.cc} |  4 +---
 src/tmc/tmc.cc                           |  2 +-
 7 files changed, 24 insertions(+), 5 deletions(-)
 create mode 100644 src/tmc/events.h
 rename src/tmc/{event_list.h => events_data.cc} (99%)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c611334..544d516 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -2,7 +2,7 @@ name: build
 
 on:
   push:
-    branches: [ master ]
+    branches: [ master, dev-dont-use ]
     tags: [ 'v*' ]
   pull_request:
     branches: [ master ]
diff --git a/CHANGES.md b/CHANGES.md
index bad4e37..8927b17 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -15,6 +15,7 @@
 * Build system fixes:
   * macOS: ask Homebrew about liquid-dsp location instead of hardcoding it
   * Set default installation prefix to /usr/local (all platforms)
+  * Reduce compiler workload somewhat with forward declarations
 
 ## 1.0.1 (2024-07-19)
 
diff --git a/README.md b/README.md
index b45561d..c450656 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,8 @@ line instead of `meson compile` to limit the number of build processes:
 
         $ taskset -c 0 meson compile
 
+The compilation will still require at least 500 MB of free RAM.
+
 ## Usage
 
 Redsea reads an MPX signal from stdin by default. It expects the input
@@ -217,6 +219,7 @@ redsea -f WAVEFILE
 * Linux/macOS/Cygwin/MSYS2+MinGW
 * C++14 compiler
 * meson + ninja
+* 500 MB of free memory for non-parallel build ([breakdown](https://github.com/windytan/redsea/issues/120#issuecomment-2559254338))
 
 ### Testing
 
diff --git a/meson.build b/meson.build
index 7fd67cb..17e2316 100644
--- a/meson.build
+++ b/meson.build
@@ -103,6 +103,7 @@ sources_no_main = [
   'src/rdsstring.cc',
   'src/tables.cc',
   'src/tmc/csv.cc',
+  'src/tmc/events_data.cc',
   'src/tmc/tmc.cc',
   'src/tmc/locationdb.cc',
   'src/util.cc',
diff --git a/src/tmc/events.h b/src/tmc/events.h
new file mode 100644
index 0000000..873beec
--- /dev/null
+++ b/src/tmc/events.h
@@ -0,0 +1,16 @@
+#ifndef TMC_EVENTS_H_
+#define TMC_EVENTS_H_
+
+#include <array>
+#include <string>
+
+namespace redsea {
+namespace tmc {
+
+extern const std::array<std::string, 1553> tmc_data_events;
+extern const std::array<std::string, 233> tmc_data_suppl;
+
+}  // namespace tmc
+}  // namespace redsea
+
+#endif  // TMC_EVENTS_H_
diff --git a/src/tmc/event_list.h b/src/tmc/events_data.cc
similarity index 99%
rename from src/tmc/event_list.h
rename to src/tmc/events_data.cc
index 7d38a5b..1b29260 100644
--- a/src/tmc/event_list.h
+++ b/src/tmc/events_data.cc
@@ -1,5 +1,4 @@
-#ifndef TMC_EVENT_LIST_H_
-#define TMC_EVENT_LIST_H_
+#include "events.h"
 
 #include <array>
 #include <string>
@@ -1801,4 +1800,3 @@ const std::array<std::string, 233> tmc_data_suppl{
 
 }  // namespace tmc
 }  // namespace redsea
-#endif  // TMC_EVENT_LIST_H_
diff --git a/src/tmc/tmc.cc b/src/tmc/tmc.cc
index 85d4699..827f55a 100644
--- a/src/tmc/tmc.cc
+++ b/src/tmc/tmc.cc
@@ -33,7 +33,7 @@
 #include "src/common.h"
 #include "src/tables.h"
 #include "src/tmc/csv.h"
-#include "src/tmc/event_list.h"
+#include "src/tmc/events.h"
 #include "src/tmc/locationdb.h"
 
 namespace redsea {