Optimize github action cache (#544)

* optimize github action cache

* fix

* refactor: improve github actions cache optimization (#3)

- move ccache configuration logic to dedicated action
- rename conanfile-changed to should-save-conan-cache for clarity

---------

Co-authored-by: Niq Dudfield <ndudfield@gmail.com>

.github/actions/xahau-configure-ccache/action.yml

@@ -14,6 +14,18 @@ inputs:
     description: 'How to check compiler for changes'
     required: false
     default: 'content'
+  is_main_branch:
+    description: 'Whether the current branch is the main branch'
+    required: false
+    default: 'false'
+  main_cache_dir:
+    description: 'Path to the main branch cache directory'
+    required: false
+    default: '~/.ccache-main'
+  current_cache_dir:
+    description: 'Path to the current branch cache directory'
+    required: false
+    default: '~/.ccache-current'
 
 runs:
   using: 'composite'
@@ -21,11 +33,31 @@ runs:
     - name: Configure ccache
       shell: bash
       run: |
+        # Create cache directories
+        mkdir -p ${{ inputs.main_cache_dir }} ${{ inputs.current_cache_dir }}
+        
+        # Set compiler check globally
+        ccache -o compiler_check=${{ inputs.compiler_check }}
+        
+        # Use a single config file location
         mkdir -p ~/.ccache
-        export CONF_PATH="${CCACHE_CONFIGPATH:-${CCACHE_DIR:-$HOME/.ccache}/ccache.conf}"
-        mkdir -p $(dirname "$CONF_PATH")
+        export CONF_PATH="$HOME/.ccache/ccache.conf"
+        
+        # Apply common settings
         echo "max_size = ${{ inputs.max_size }}" > "$CONF_PATH"
         echo "hash_dir = ${{ inputs.hash_dir }}" >> "$CONF_PATH"
         echo "compiler_check = ${{ inputs.compiler_check }}" >> "$CONF_PATH"
+        
+        if [ "${{ inputs.is_main_branch }}" == "true" ]; then
+          # Main branch: use main branch cache
+          ccache --set-config=cache_dir="${{ inputs.main_cache_dir }}"
+          echo "CCACHE_DIR=${{ inputs.main_cache_dir }}" >> $GITHUB_ENV
+        else
+          # Feature branch: use current branch cache with main as secondary
+          ccache --set-config=cache_dir="${{ inputs.current_cache_dir }}"
+          ccache --set-config=secondary_storage="file:${{ inputs.main_cache_dir }}"
+          echo "CCACHE_DIR=${{ inputs.current_cache_dir }}" >> $GITHUB_ENV
+        fi
+        
         ccache -p # Print config for verification
         ccache -z # Zero statistics before the build