feat: add ability to specify node::SnapshotFlags values MONGOSH-1605 (#54)

Author: addaleax

resources/main-template.cc

@@ -17,6 +17,7 @@
 #include <openssl/rsa.h>
 #include <openssl/rand.h>
 #endif
+#include <type_traits> // injected code may refer to std::underlying_type
 
 using namespace node;
 using namespace v8;
@@ -33,6 +34,11 @@ using namespace v8;
 #define NODE_VERSION_SUPPORTS_EMBEDDER_SNAPSHOT 1
 #endif
 
+// Snapshot config is supported since https://github.com/nodejs/node/pull/50453
+#if NODE_VERSION_AT_LEAST(21, 6, 0) && !defined(BOXEDNODE_SNAPSHOT_CONFIG_FLAGS)
+#define BOXEDNODE_SNAPSHOT_CONFIG_FLAGS (SnapshotFlags::kWithoutCodeCache)
+#endif
+
 // 18.1.0 is the current minimum version that has https://github.com/nodejs/node/pull/42809,
 // which introduced crashes when using workers, and later 18.9.0 is the current
 // minimum version to contain https://github.com/nodejs/node/pull/44252, which
@@ -167,7 +173,15 @@ static int RunNodeInstance(MultiIsolatePlatform* platform,
   int exit_code = 0;
   std::vector<std::string> errors;
   std::unique_ptr<CommonEnvironmentSetup> setup =
-      CommonEnvironmentSetup::CreateForSnapshotting(platform, &errors, args, exec_args);
+      CommonEnvironmentSetup::CreateForSnapshotting(
+          platform,
+          &errors,
+          args,
+          exec_args
+#ifdef BOXEDNODE_SNAPSHOT_CONFIG_FLAGS
+          , SnapshotConfig { BOXEDNODE_SNAPSHOT_CONFIG_FLAGS, std::nullopt }
+#endif
+          );
 
   Isolate* isolate = setup->isolate();
 

src/index.ts

@@ -275,6 +275,7 @@ type CompilationOptions = {
   useLegacyDefaultUvLoop?: boolean;
   useCodeCache?: boolean,
   useNodeSnapshot?: boolean,
+  nodeSnapshotConfigFlags?: string[], // e.g. 'WithoutCodeCache'
   executableMetadata?: ExecutableMetadata,
   preCompileHook?: (nodeSourceTree: string, options: CompilationOptions) => void | Promise<void>
 }
@@ -421,6 +422,14 @@ async function compileJSFileAsBinaryImpl (options: CompilationOptions, logger: L
     if (snapshotMode === 'consume') {
       mainSource = `#define BOXEDNODE_CONSUME_SNAPSHOT 1\n${mainSource}`;
     }
+    if (options.nodeSnapshotConfigFlags) {
+      const flags = [
+        '0',
+        ...options.nodeSnapshotConfigFlags.map(flag =>
+          `static_cast<std::underlying_type<SnapshotFlags>::type>(SnapshotFlags::k${flag})`)
+      ].join(' | ');
+      mainSource = `#define BOXEDNODE_SNAPSHOT_CONFIG_FLAGS (static_cast<SnapshotFlags>(${flags}))\n${mainSource}`;
+    }
     await fs.writeFile(path.join(nodeSourcePath, 'src', 'node_main.cc'), mainSource);
     logger.stepCompleted();
 

test/index.ts

@@ -217,10 +217,11 @@ describe('basic functionality', () => {
     it('works with snapshot support', async function () {
       this.timeout(2 * 60 * 60 * 1000); // 2 hours
       await compileJSFileAsBinary({
-        nodeVersionRange: 'v21.0.0-nightly20230801d396a041f7',
+        nodeVersionRange: '^21.6.2',
         sourceFile: path.resolve(__dirname, 'resources/snapshot-echo-args.js'),
         targetFile: path.resolve(__dirname, `resources/snapshot-echo-args${exeSuffix}`),
         useNodeSnapshot: true,
+        nodeSnapshotConfigFlags: ['WithoutCodeCache'],
         // the nightly path name is too long for Windows...
         tmpdir: process.platform === 'win32' ? path.join(os.tmpdir(), 'bn') : undefined
       });