Improve conan package caching in CI

.github/actions/cmake-project-finalize/action.yaml

@@ -0,0 +1,27 @@
+name: CMake project finalize
+description: Finalize conan packages in cache
+inputs:
+  conan-cache-key-prefix:
+    description: Prefix for the conan cache key
+    required: true
+  conan-cache-matched-key:
+    description: Matched cache used to restore conan cache
+    required: true
+
+runs:
+  using: composite
+  steps:
+    - env:
+        CONAN_CACHE_MATCHED_KEY: ${{ inputs.conan-cache-matched-key }}
+      id: init
+      run: |
+        # Initialize cmake-project-finalize action
+        "${GITHUB_ACTION_PATH}/init.sh"
+      shell: bash
+
+    - if: steps.init.outputs.save-cache == 'true'
+      name: Cache Conan packages
+      uses: actions/cache/save@9255dc7a253b0ccc959486e2bca901246202afeb # v5.0.1
+      with:
+        key: ${{ inputs.conan-cache-key-prefix }}-${{ hashFiles('solvers/cpp/conan.lock') }}-${{ steps.init.outputs.packages-hash }}
+        path: ${{ steps.init.outputs.conan-cache-path }}

.github/actions/cmake-project-finalize/init.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# Validate required environment variables
+if [[ -z "${CONAN_HOME}" ]]; then
+  echo "::error::CONAN_HOME is not set"
+  exit 1
+fi
+
+pushd solvers/cpp
+
+echo "::group::List existing recipes and binaries"
+conan list --cache '*/*#*:*' -f=compact
+echo "::endgroup::"
+
+# Remove all recipes that have not been used in the last 1 hour
+# (with their binaries). In practice, this will remove all recipes that have
+# not been used in the last build.
+echo "::group::Remove unused recipes and binaries"
+conan remove "*" --lru=1h --confirm
+echo "::endgroup::"
+
+# Remove all binaries (but not recipes) not used in the last 1 hour
+echo "::group::Remove unused binaries"
+conan remove "*:*" --lru=1h --confirm
+echo "::endgroup::"
+
+# Remove non-critical folders from the cache for the remaining recipes
+echo "::group::Remove non-critical folders from the cache"
+conan cache clean
+echo "::endgroup::"
+
+# Generate file about existing recipes and binaries
+
+echo "::group::List remaining recipes and binaries"
+conan list --cache '*/*#*:*' -f=compact | tee "${RUNNER_TEMP}/existing_packages.txt"
+echo "::endgroup::"
+
+packagesHash=$(sha256sum "${RUNNER_TEMP}/existing_packages.txt" | cut -d ' ' -f 1)
+
+popd
+
+matchedKeyPackagesHash=${CONAN_CACHE_MATCHED_KEY##*-}
+
+if [[ "${packagesHash}" != "${matchedKeyPackagesHash}" ]]; then
+  saveCache=true
+else
+  saveCache=false
+fi
+
+
+echo "::group::Outputs from init"
+{
+  echo "conan-cache-path=${CONAN_HOME}/p"
+  echo "packages-hash=${packagesHash}"
+  echo "save-cache=${saveCache}"
+} | tee -a "${GITHUB_OUTPUT}"
+echo "::endgroup::"

.github/actions/cmake-project-setup/action.yaml

@@ -1,19 +1,39 @@
 name: CMake project setup
 description: Setup cmake, conan and CMakeUserPresets.json
+inputs:
+  conan-cache-key-prefix:
+    description: Prefix for the conan cache key
+    required: true
+outputs:
+  conan-cache-matched-key:
+    description: Cache restore key used to restore Conan packages
+    value: ${{ steps.cache-conan-packages.outputs.cache-matched-key }}
 
 runs:
   using: composite
   steps:
+    - id: init
+      run: |
+        # Initialize cmake-project-setup action
+        "${GITHUB_ACTION_PATH}/init.sh"
+      shell: bash
+
+    - id: cache-conan-packages
+      name: Restore Conan packages cache
+      uses: actions/cache/restore@9255dc7a253b0ccc959486e2bca901246202afeb # v5.0.1
+      with:
+        # Use an intentionally non-matching suffix so that restores only use the prefixes below.
+        # The full key is only used when saving a new cache entry.
+        key: ${{ inputs.conan-cache-key-prefix }}-${{ hashFiles('solvers/cpp/conan.lock') }}-partial-match-only
+        path: ${{ steps.init.outputs.conan-cache-path }}
+        restore-keys: |
+          ${{ inputs.conan-cache-key-prefix }}-${{ hashFiles('solvers/cpp/conan.lock') }}-
+          ${{ inputs.conan-cache-key-prefix }}-
+
     - name: Install CMake
       # TODO: Install cmake through mise
       uses: lukka/get-cmake@9e07ecdcee1b12e5037e42f410b67f03e2f626e1 # v4.2.1
 
-    - name: Setup Conan Client
-      # TODO: Setup only conan package cache here and use conan through mise
-      uses: conan-io/setup-conan@2f4bd34e8e0af00e1a77a66e1d284e06d71d703f # v1.3.0
-      with:
-        cache_packages: true
-
     - name: Prepare files
       run: |
         cp .github/files/CMakeUserPresets.json solvers/cpp/

.github/actions/cmake-project-setup/init.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+set -euo pipefail
+
+conanHome=${RUNNER_TEMP}/aoc-conan-home
+
+export CONAN_HOME="${conanHome}"
+
+echo "::group::Detect Conan profile"
+pushd solvers/cpp
+conan profile detect
+popd
+echo "::endgroup::"
+
+echo "::group::Environment variable changes"
+{
+  echo -n "CONAN_HOME="
+  echo "${conanHome}" | tr -d '\n'
+  echo
+} | tee -a "${GITHUB_ENV}"
+echo "::endgroup::"
+
+echo "::group::Outputs from init"
+{
+  echo "conan-cache-path=${conanHome}/p"
+} | tee -a "${GITHUB_OUTPUT}"
+echo "::endgroup::"

.github/workflows/cpp-build-test-run.yaml

@@ -69,8 +69,16 @@ jobs:
           cache-mode: use
           downloads-hash-from-prepare: ${{ matrix.homebrew-downloads-hash-from-prepare }}
 
-      - name: Setup CMake project
+      - name: Setup tools through mise
+        uses: ./.github/actions/mise-project-setup
+        with:
+          directory: solvers/cpp
+
+      - id: setup-cmake-project
+        name: Setup CMake project
         uses: ./.github/actions/cmake-project-setup
+        with:
+          conan-cache-key-prefix: conan-${{ steps.preset-name.outputs.name }}
 
       - if: matrix.os == 'ubuntu'
         name: Specify HOMEBREW_PREFIX
@@ -85,11 +93,6 @@ jobs:
           cmakeListsTxtPath: solvers/cpp/CMakeLists.txt
           workflowPreset: ${{ steps.preset-name.outputs.name }}
 
-      - name: Restore aoc-main mise project
-        uses: ./.github/actions/mise-project-setup
-        with:
-          directory: aoc-main
-
       - name: Restore aoc-main uv project
         uses: ./.github/actions/uv-project-setup
         with:
@@ -100,3 +103,9 @@ jobs:
           AOC_CPP_SKIP_PREPARE: "1"
           AOC_CPP_WORKFLOW_PRESET: ${{ steps.preset-name.outputs.name }}
         run: mise run aoc:all -- --solver cpp -vv
+
+      - name: Finalize cmake project
+        uses: ./.github/actions/cmake-project-finalize
+        with:
+          conan-cache-key-prefix: conan-${{ steps.preset-name.outputs.name }}
+          conan-cache-matched-key: ${{ steps.setup-cmake-project.outputs.conan-cache-matched-key }}