Add ccache

.github/workflows/build-and-test.yml

@@ -1,4 +1,7 @@
 on: [ push, pull_request ]
+env:
+  CCACHE_COMPRESS: exists means true
+  CCACHE_SLOPPINESS: include_file_ctime,include_file_mtime,time_macros
 jobs:
   test-release:
     name: Build and run tests in Release mode
@@ -7,6 +10,7 @@ jobs:
     - name: Install dependencies
       run: |
         sudo apt-get install -y \
+                     ccache \
                      parallel \
                      libboost-thread-dev \
                      libboost-iostreams-dev \
@@ -29,11 +33,24 @@ jobs:
         cmake -D CMAKE_BUILD_TYPE=Release \
               -D CMAKE_CXX_OUTPUT_EXTENSION_REPLACE=ON \
               -D CMAKE_C_COMPILER=gcc \
+              -D CMAKE_C_COMPILER_LAUNCHER=ccache \
               -D CMAKE_CXX_COMPILER=g++ \
+              -D CMAKE_CXX_COMPILER_LAUNCHER=ccache \
               ..
         popd
+    - name: Load Cache
+      uses: actions/cache@v1
+      with:
+        path: ccache
+        key: ccache-release-${{ github.ref }}-${{ github.sha }}
+        restore-keys: |
+          ccache-release-${{ github.ref }}-
+          ccache-release-
+          ccache-
     - name: Build
       run: |
+        export CCACHE_DIR="$GITHUB_WORKSPACE/ccache"
+        mkdir -p "$CCACHE_DIR"
         make -j 2 -C _build
     - name: Test
       run: |
@@ -51,6 +68,7 @@ jobs:
     - name: Install dependencies
       run: |
         sudo apt-get install -y \
+                     ccache \
                      parallel \
                      libboost-thread-dev \
                      libboost-iostreams-dev \
@@ -73,11 +91,24 @@ jobs:
         cmake -D CMAKE_BUILD_TYPE=Debug \
               -D CMAKE_CXX_OUTPUT_EXTENSION_REPLACE=ON \
               -D CMAKE_C_COMPILER=gcc \
+              -D CMAKE_C_COMPILER_LAUNCHER=ccache \
               -D CMAKE_CXX_COMPILER=g++ \
+              -D CMAKE_CXX_COMPILER_LAUNCHER=ccache \
               ..
         popd
+    - name: Load Cache
+      uses: actions/cache@v1
+      with:
+        path: ccache
+        key: ccache-debug-${{ github.ref }}-${{ github.sha }}
+        restore-keys: |
+          ccache-debug-${{ github.ref }}-
+          ccache-debug-
+          ccache-
     - name: Build
       run: |
+        export CCACHE_DIR="$GITHUB_WORKSPACE/ccache"
+        mkdir -p "$CCACHE_DIR"
         make -j 2 -C _build
     - name: Test
       run: |