CI: Trim cache before saving

.github/actions/godot-build/action.yml

@@ -19,11 +19,6 @@ inputs:
   scons-cache:
     description: The SCons cache path.
     default: ${{ github.workspace }}/.scons_cache/
-  scons-cache-limit:
-    description: The SCons cache size limit.
-    # actions/cache has 10 GiB limit, and GitHub runners have a 14 GiB disk.
-    # Limit to 7 GiB to avoid having the extracted cache fill the disk.
-    default: 7
 
 runs:
   using: composite
@@ -33,7 +28,7 @@ runs:
       env:
         SCONSFLAGS: ${{ inputs.sconsflags }}
       run: |
-        echo "Building with flags:" platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }} "cache_path=${{ inputs.scons-cache }}" cache_limit=${{ inputs.scons-cache-limit }}
+        echo "Building with flags:" platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }} "cache_path=${{ inputs.scons-cache }}"
 
         if [ "${{ inputs.target }}" != "editor" ]; then
           # Ensure we don't include editor code in export template builds.
@@ -47,5 +42,5 @@ runs:
           export BUILD_NAME="gh"
         fi
 
-        scons platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }} "cache_path=${{ inputs.scons-cache }}" cache_limit=${{ inputs.scons-cache-limit }}
+        scons platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }} "cache_path=${{ inputs.scons-cache }}"
         ls -l bin/

.github/actions/godot-cache-restore/action.yml

@@ -11,42 +11,29 @@ inputs:
 runs:
   using: composite
   steps:
-    # Because all branches can refer to the repository's default branch's cache, we want it to
-    # persist as the de-facto fallback. However, it easily expunges in a matter of hours if
-    # nothing explicitly calls to it, so we work around that by ensuring it's *always* pinged
-    # prior to any cache operations.
-    - name: Ping main cache
+    - name: Restore default cache
       uses: actions/cache/restore@v4
       id: cache-ping
       with:
         path: ${{ inputs.scons-cache }}
-        key: ${{ github.sha }} # Dummy key; we have to rely on the fallback value.
+        key: ${{ inputs.cache-name }}|${{ github.event.repository.default_branch }}|${{ github.sha }}
         restore-keys: ${{ inputs.cache-name }}|${{ github.event.repository.default_branch }}
-        lookup-only: true
 
-    # Fallback access isn't logged, so register an explicit cache-hit if found.
-    - name: Ping main cache (exact)
-      if: steps.cache-ping.outputs.cache-matched-key
-      uses: actions/cache/restore@v4
-      with:
-        path: ${{ inputs.scons-cache }}
-        key: ${{ steps.cache-ping.outputs.cache-matched-key }}
-        lookup-only: true
+    - name: Log default cache files
+      if: github.ref_name != github.event.repository.default_branch
+      shell: sh
+      run: find "${{ inputs.scons-cache }}" >> redundant.txt
 
-    # We try to match an existing cache to restore from it. Each potential key is checked against
-    # all existing caches as a prefix. E.g. 'linux-template-minimal' would match any cache that
-    # starts with "linux-template-minimal", such as
-    # "linux-template-minimal|master|6588a4a29af1621086feac0117d5d4d37af957fd".
-    #
-    # We check these prefixes in this order:
-    #   1. An exact match for the base branch, reference name, and SHA hash.
-    #   2. A partial match for the same cache name and reference name.
-    #   3. A partial match for the same cache name and default branch name.
-    - name: Restore SCons cache directory
+    # This is done after pulling the default cache so that PRs can integrate any potential changes
+    # from the default branch without conflicting with whatever local changes were already made.
+    - name: Restore local cache
       uses: actions/cache/restore@v4
+      if: github.ref_name != github.event.repository.default_branch
       with:
         path: ${{ inputs.scons-cache }}
         key: ${{ inputs.cache-name }}|${{ github.ref_name }}|${{ github.sha }}
-        restore-keys: |
-          ${{ inputs.cache-name }}|${{ github.ref_name }}
-          ${{ inputs.cache-name }}|${{ github.event.repository.default_branch }}
+        restore-keys: ${{ inputs.cache-name }}|${{ github.ref_name }}
+
+    - name: Store unix timestamp
+      shell: sh
+      run: echo "CACHE_TIMESTAMP=$(date +%s)" >> $GITHUB_ENV

.github/actions/godot-cache-save/action.yml

@@ -11,6 +11,10 @@ inputs:
 runs:
   using: composite
   steps:
+    - name: Purge files before timestamp
+      shell: sh
+      run: misc/scripts/purge_cache.py ${{ env.CACHE_TIMESTAMP }} "${{ inputs.scons-cache }}"
+
     - name: Save SCons cache directory
       uses: actions/cache/save@v4
       with: