feat(CI): enable cache in dashboard checks (#23432)

.github/workflows/dashboard-ci.yml

@@ -19,6 +19,10 @@ concurrency:
   group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
   cancel-in-progress: true
 
+permissions:
+  actions: write
+  contents: read
+
 env:
   CONTINUOUS_INTEGRATION: true
   MYSQL_ROOT_PASSWORD: root
@@ -72,6 +76,113 @@ jobs:
         with:
           fetch-depth: 1
 
+      - name: Install ccache
+        shell: bash
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y ccache
+          ccache --version
+
+      # Detect the compilers that acore.sh / CMake will end up using.
+      # We record both the binary name and a short version tag for the cache key.
+      - name: Detect compiler
+        id: detect
+        shell: bash
+        run: |
+          set -euo pipefail
+          CC_BIN="${CC:-}"
+          CXX_BIN="${CXX:-}"
+          [[ -z "$CC_BIN"  ]] && CC_BIN="$(command -v clang || command -v gcc)"
+          [[ -z "$CXX_BIN" ]] && CXX_BIN="$(command -v clang++ || command -v g++)"
+
+          make_ver_id() {
+            local bin="$1"; local base="$(basename "$bin")"
+            case "$base" in
+              clang)
+                maj="$("$bin" -dumpversion 2>/dev/null | cut -d. -f1)"; [[ -z "$maj" ]] && maj="$( "$bin" --version | sed -n 's/.*version \([0-9][0-9]*\).*/\1/p' | head -1 )"
+                echo "clang-${maj:-unknown}"
+                ;;
+              clang++)
+                maj="$("$bin" -dumpversion 2>/dev/null | cut -d. -f1)"; [[ -z "$maj" ]] && maj="$( "$bin" --version | sed -n 's/.*version \([0-9][0-9]*\).*/\1/p' | head -1 )"
+                echo "clang++-${maj:-unknown}"
+                ;;
+              gcc)
+                maj="$("$bin" -dumpfullversion -dumpversion 2>/dev/null || "$bin" -dumpversion 2>/dev/null)"; maj="${maj%%.*}"
+                echo "gcc-${maj:-unknown}"
+                ;;
+              g++)
+                maj="$("$bin" -dumpfullversion -dumpversion 2>/dev/null || "$bin" -dumpversion 2>/dev/null)"; maj="${maj%%.*}"
+                echo "g++-${maj:-unknown}"
+                ;;
+              *)
+                echo "$base"
+                ;;
+            esac
+          }
+
+          echo "cc_id=$(make_ver_id "$CC_BIN")"   >> "$GITHUB_OUTPUT"
+          echo "cxx_id=$(make_ver_id "$CXX_BIN")" >> "$GITHUB_OUTPUT"
+          echo "Detected: $CC_BIN, $CXX_BIN"
+
+      - name: Prepare ccache dir
+        shell: bash
+        run: mkdir -p "${{ github.workspace }}/var/ccache"
+
+      - name: Echo cache key
+        shell: bash
+        run: echo "Cache key -> ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:${{ github.ref_name }}"
+
+      - name: Restore ccache
+        id: restore_ccache
+        uses: actions/cache/restore@v4
+        with:
+          path: ${{ github.workspace }}/var/ccache
+          key: ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:${{ github.ref_name }}
+          restore-keys: |
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:true:pch=false:
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:false:pch=false:
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:true:pch=true:
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:false:pch=true:
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:true:
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:false:
+            ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:
+
+      - name: Setup ccache env
+        shell: bash
+        env:
+          CCACHE_DIR: ${{ github.workspace }}/var/ccache
+        run: |
+          mkdir -p "$CCACHE_DIR"
+          cat <<EOF >> "$GITHUB_ENV"
+          CCACHE_BASEDIR=${{ github.workspace }}
+          CCACHE_DIR=${{ github.workspace }}/var/ccache
+          CCACHE_HASHDIR=1
+          CCACHE_MAXSIZE=5G
+          CCACHE_SLOPPINESS=pch_defines,time_macros,include_file_mtime
+          CCACHE_COMPRESS=1
+          CCACHE_COMPRESSLEVEL=9
+          CCACHE_COMPILERCHECK=content
+          CCACHE_LOGFILE=${{ github.workspace }}/var/ccache/cache.debug
+          CMAKE_C_COMPILER_LAUNCHER=ccache
+          CMAKE_CXX_COMPILER_LAUNCHER=ccache
+          EOF
+
+      - name: ccache snapshot (before)
+        shell: bash
+        run: |
+          echo "==== Effective ccache configuration ===="
+          ccache -p | egrep 'base_dir|hash_dir|compiler_check|sloppiness|max_size' || true
+          echo
+          echo "==== Previous cache stats ===="
+          ccache -s || true
+          echo
+          echo "==== Top cache results (from prior runs) ===="
+          grep -o 'result: .*' "${{ github.workspace }}/var/ccache/cache.debug" 2>/dev/null | sort | uniq -c | sort -nr | head || true
+
+      - name: Reset ccache stats
+        shell: bash
+        run: ccache -z || true
+
       - name: Configure AzerothCore settings
         run: |
             touch conf/config.sh
@@ -154,3 +265,15 @@ jobs:
           ./acore.sh sm delete authserver
         timeout-minutes: 30
         continue-on-error: false
+
+      # save only if we didn't hit the cache
+      - name: Save ccache
+        if: steps.restore_ccache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@v4
+        with:
+          path: ${{ github.workspace }}/var/ccache
+          key: ccache:${{ runner.os }}:${{ steps.detect.outputs.cc_id }}_${{ steps.detect.outputs.cxx_id }}:${{ github.ref_name }}
+
+      - name: ccache stats (after)
+        shell: bash
+        run: ccache -s || true