From 84dc93c0c82c9dee9ebbc445d1cc7eed899f1ce7 Mon Sep 17 00:00:00 2001
From: "Alejandro R. Mosteo" <amosteo@unizar.es>
Date: Thu, 27 Jun 2024 18:48:18 +0200
Subject: [PATCH] Minimal cache experiment

---
 .github/workflows/cache-minimal.yml | 51 +++++++++++++++++++++++++++++
 .github/workflows/selftest.yml      |  5 ++-
 .github/workflows/test-cache.yml    | 17 ++++++----
 action.yml                          | 42 ++++++++++++++----------
 4 files changed, 89 insertions(+), 26 deletions(-)
 create mode 100644 .github/workflows/cache-minimal.yml

diff --git a/.github/workflows/cache-minimal.yml b/.github/workflows/cache-minimal.yml
new file mode 100644
index 00000000..db32ba6f
--- /dev/null
+++ b/.github/workflows/cache-minimal.yml
@@ -0,0 +1,51 @@
+# Test minimal save/restore of a cache
+
+name: Minimal cache test
+
+on:
+  push:
+    branches:
+      - disabled
+
+jobs:
+  minimal-cache:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Create fake data
+        run: |
+          mkdir mydata
+          touch mydata/thedata.txt
+
+      - name: Create unique key
+        id: cache-key
+        run: |
+          echo "key=cache test $(date -u)" >> $GITHUB_OUTPUT
+
+      - name: Verify cache miss
+        id: miss
+        uses: actions/cache/restore@v4
+        with:
+          path: mydata
+          key: ${{ steps.cache-key.outputs.key }}
+          lookup-only: true
+
+      - name: Save cache
+        uses: actions/cache/save@v4
+        with:
+          path: mydata
+          key: ${{ steps.cache-key.outputs.key }}
+
+      - name: Query cache hit
+        id: hit
+        uses: actions/cache/restore@v4
+        with:
+          path: mydata
+          key: ${{ steps.cache-key.outputs.key }}
+          fail-on-cache-miss: true
+          lookup-only: true
+
+      - name: Print both cache hit and miss
+        run: |
+          echo "Cache miss? ${{ steps.miss.outputs.cache-hit }}"
+          echo "Cache hit? ${{ steps.hit.outputs.cache-hit }}"
diff --git a/.github/workflows/selftest.yml b/.github/workflows/selftest.yml
index 9bd1e0de..92468fe1 100644
--- a/.github/workflows/selftest.yml
+++ b/.github/workflows/selftest.yml
@@ -4,7 +4,10 @@
 
 name: Selftest
 
-on: pull_request
+on:
+  pull_request:
+    branches:
+      - disabled
 
 jobs:
   setup-alire:
diff --git a/.github/workflows/test-cache.yml b/.github/workflows/test-cache.yml
index dbeab342..85a5ad31 100644
--- a/.github/workflows/test-cache.yml
+++ b/.github/workflows/test-cache.yml
@@ -12,16 +12,19 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os:
+          # - macos-latest
+          - ubuntu-latest
+          # - windows-latest
         config:
           - version: '2.0.1'
             branch:  ''
-          - version: '1.2.2'
-            branch:  ''
-          - version: 'nightly'
-            branch:  ''
-          - version: ''
-            branch:  'master'
+          # - version: '1.2.2'
+          #   branch:  ''
+          # - version: 'nightly'
+          #   branch:  ''
+          # - version: ''
+          #   branch:  'master'
 
     runs-on: ${{ matrix.os }}
 
diff --git a/action.yml b/action.yml
index e645c081..be1d6e2f 100644
--- a/action.yml
+++ b/action.yml
@@ -46,11 +46,28 @@ runs:
           echo "version=${{ inputs.version }}" >> $GITHUB_OUTPUT
         fi
 
+    # This is to avoid repeating these paths. Turns out, they're used
+    # internally by the cache action for a unique hash of the cache, and even
+    # if we give the same paths but in different order, save/restore misbehave
+    # (restore misses but save hits). I should report this eventually...
+    - name: Generate cached paths
+      id: cached-paths
+      shell: bash
+      env:
+        CACHED_PATHS: |
+          ~/.cache/alire
+          ~/.config/alire
+          ~/.local/share/alire
+          ./alire_install
+          ~/AppData/Local/alire
+      run:
+        echo "paths=xxx" >> GITHUB_OUTPUT
+
     - name: Generate cache key
       id: cache-key
       shell: bash
       run: |
-        echo "key=alr[${{ steps.find-hash.outputs.version }}][${{ inputs.toolchain }}][${{ runner.os }}][${{ steps.find-hash.outputs.hash }}][c]" >> $GITHUB_OUTPUT
+        echo "key=alr[${{ steps.find-hash.outputs.version }}][${{ inputs.toolchain }}][${{ runner.os }}][${{ steps.find-hash.outputs.hash }}][e]" >> $GITHUB_OUTPUT
       # The last value in square brackets is to make the key unique for debugging
 
     - name: Reuse cached installation
@@ -58,12 +75,7 @@ runs:
       id: cache-alr
       uses: actions/cache/restore@v4
       with:
-        path: |
-          ~/.cache/alire
-          ~/.config/alire
-          ./alire_install
-          ~/.local/share/alire
-          ~/AppData/Local/alire
+        path: ${{steps.cached-paths.outputs.paths}}
         key: ${{steps.cache-key.outputs.key}}
         # .cache contains msys64 install on Windows
         # .config contains the toolchain at the default location, besides index config
@@ -175,23 +187,17 @@ runs:
       if: ${{ inputs.cache == 'true' && steps.cache-alr.outputs.cache-hit != 'true' }}
       uses: actions/cache/save@v4
       with:
-        path: |
-          ~/.cache/alire
-          ~/.config/alire
-          ~/.local/share/alire
-          ./alire_install
-          ~/AppData/Local/alire
-        key: ${{ steps.cache-alr.outputs.cache-primary-key }}
-        # Note that '~' is recommended on Windows too:
-        # https://github.com/actions/cache
+        path: ${{ env.CACHED_PATHS }}
+        key: ${{ steps.cache-key.outputs.key }}
+        # Note that '~' is recommended on Windows too: https://github.com/actions/cache
 
     # Verify cache was saved properly
     - name: Cache verify
       if: ${{ inputs.cache == 'true' && steps.cache-alr.outputs.cache-hit != 'true' }}
       uses: actions/cache/restore@v4
       with:
-        path: unused # Forced to provide it
+        path: ${{ env.CACHED_PATHS }}
         key: ${{steps.cache-key.outputs.key}}
         lookup-only: true
-        fail-on-cache-miss: true
+        fail-on-cache-miss: true # REMOVE BEFORE MERGE