Implement caching

.github/workflows/test.yml

@@ -14,10 +14,34 @@ jobs:
 
     steps:
     - uses: actions/checkout@main
-    - uses: './'
+
+    - name: Build Lua
+      uses: './'
       with:
         luaVersion: ${{ matrix.luaVersion }}
+        buildCache: false
 
-    - name: test lua
+    - name: Test Lua
       run: lua -e 'print("hi from lua")'
 
+  test-cache:
+    needs: test
+
+    strategy:
+      fail-fast: false
+      matrix:
+        luaVersion: ["5.1.5", "5.2.4", "5.3.5", "5.4.1", "luajit-2.0.5", "luajit-2.1.0-beta3", "luajit-openresty", "5.1", "5.4"]
+        machineTag: ["ubuntu-latest", "macos-latest"]
+
+    runs-on: ${{ matrix.machineTag }}
+
+    steps:
+    - uses: actions/checkout@main
+
+    - name: Get Lua from cache
+      uses: './'
+      with:
+        luaVersion: ${{ matrix.luaVersion }}
+
+    - name: Test Lua
+      run: lua -e 'print("hi from lua")'

action.yml

@@ -14,6 +14,10 @@ inputs:
   luaCompileFlags:
     description: "Command line flags passed to make when building Lua"
     required: false
+  buildCache:
+    description: "Set to 'false' to skip restoring .lua from cache and always compile it"
+    required: false
+    default: 'true'
 
 runs:
   using: 'node12'

main.js

@@ -3,6 +3,8 @@ const core = require("@actions/core")
 const exec = require("@actions/exec")
 const io = require("@actions/io")
 const tc = require("@actions/tool-cache")
+const ch = require("@actions/cache")
+const fsp = require("fs").promises
 
 const path = require("path")
 
@@ -19,8 +21,7 @@ const VERSION_ALIASES = {
 
 const isMacOS = () => (process.platform || "").startsWith("darwin")
 
-async function install_luajit_openresty() {
-  const luaInstallPath = path.join(process.cwd(), LUA_PREFIX)
+async function install_luajit_openresty(luaInstallPath) {
   const installPath = path.join(process.cwd(), INSTALL_PREFIX)
   const luaCompileFlags = core.getInput('luaCompileFlags')
 
@@ -48,17 +49,13 @@ async function install_luajit_openresty() {
     cwd: path.join(installPath, "luajit2")
   })
 
-
-  core.addPath(path.join(luaInstallPath, "bin"));
-
   await exec.exec("ln -s luajit lua", undefined, {
     cwd: path.join(luaInstallPath, "bin")
   })
 }
 
-async function install_luajit(luajitVersion) {
+async function install_luajit(luaInstallPath, luajitVersion) {
   const luaExtractPath = path.join(process.cwd(), INSTALL_PREFIX, `LuaJIT-${luajitVersion}`)
-  const luaInstallPath = path.join(process.cwd(), LUA_PREFIX)
 
   const luaCompileFlags = core.getInput('luaCompileFlags')
 
@@ -84,33 +81,14 @@ async function install_luajit(luajitVersion) {
     cwd: luaExtractPath
   })
 
-  core.addPath(path.join(luaInstallPath, "bin"));
-
   await exec.exec(`ln -s luajit-${luajitVersion} lua`, undefined, {
     cwd: path.join(luaInstallPath, "bin")
   })
-
 }
 
-async function main() {
-  let luaVersion = core.getInput('luaVersion', { required: true })
-  let luaCompileFlags = core.getInput('luaCompileFlags')
-
-  if (VERSION_ALIASES[luaVersion]) {
-    luaVersion = VERSION_ALIASES[luaVersion]
-  }
-
-  if (luaVersion == "luajit-openresty") {
-    return await install_luajit_openresty()
-  }
-
-  if (luaVersion.startsWith("luajit-")) {
-    const luajitVersion = luaVersion.substr("luajit-".length)
-    return await install_luajit(luajitVersion)
-  }
-
+async function install_plain_lua(luaInstallPath, luaVersion) {
   const luaExtractPath = path.join(process.cwd(), INSTALL_PREFIX, `lua-${luaVersion}`)
-  const luaInstallPath = path.join(process.cwd(), LUA_PREFIX)
+  const luaCompileFlags = core.getInput('luaCompileFlags')
 
   const luaSourceTar = await tc.downloadTool(`https://www.lua.org/ftp/lua-${luaVersion}.tar.gz`)
   await io.mkdirP(luaExtractPath)
@@ -144,8 +122,66 @@ async function main() {
   await exec.exec(`make -j INSTALL_TOP="${luaInstallPath}" install`, undefined, {
     cwd: luaExtractPath
   })
+}
+
+async function install(luaInstallPath, luaVersion) {
+  if (luaVersion == "luajit-openresty") {
+    return await install_luajit_openresty(luaInstallPath)
+  }
+
+  if (luaVersion.startsWith("luajit-")) {
+    const luajitVersion = luaVersion.substr("luajit-".length)
+    return await install_luajit(luaInstallPath, luajitVersion)
+  }
+
+  return await install_plain_lua(luaInstallPath, luaVersion)
+}
+
+const makeCacheKey = luaVersion=> `setup-lua-${luaVersion}-${process.platform}-${process.arch}`
+const exists = (filename, mode) => fsp.access(filename, mode).then(() => true, () => false)
+
+async function main() {
+  let luaVersion = core.getInput('luaVersion', { required: true })
+  let luaCompileFlags = core.getInput('luaCompileFlags')
+
+  if (VERSION_ALIASES[luaVersion]) {
+    luaVersion = VERSION_ALIASES[luaVersion]
+  }
+
+  const luaInstallPath = path.join(process.cwd(), LUA_PREFIX)
+
+  // The tool cache is mostly useful on self-hosted runners. It doesn't persist across jobs in Github's runners
+  let toolCacheDir = tc.find('lua', luaVersion)
+
+  if (!toolCacheDir) {
+    const cacheKey = makeCacheKey(luaVersion)
+    if (core.getInput('buildCache') == 'true') {
+      await ch.restoreCache([luaInstallPath], cacheKey) // @actions/cache does persist across jobs
+    }
+
+    if (!(await exists(luaInstallPath))) {
+      await install(luaInstallPath, luaVersion)
+      try {
+        await ch.saveCache([luaInstallPath], cacheKey)
+      } catch (ex) {
+        // This could happen due to a race condition, in which case it should be safe to ignore saving the cache
+        if (ex instanceof ch.ReserveCacheError) {
+          console.log(`Cannot save cache. (${ex.message}) Skipping...`)
+        } else { 
+          throw ex
+        }
+      }
+    }
+
+    toolCacheDir = await tc.cacheDir(luaInstallPath, 'lua', luaVersion)
+  }
+
+  // If .lua doesn't exist, symlink it to the tool cache dir
+  if (toolCacheDir && !(await exists(luaInstallPath))) {
+    await fsp.symlink(toolCacheDir, luaInstallPath);
+  }
 
-  core.addPath(path.join(luaInstallPath, "bin"));
+  core.addPath(path.join(luaInstallPath, "bin"))
 }
 
 main().catch(err => {