Expose clearKeptObjects function, kriszyp/weak-lru-cache#4

external.js

@@ -1,9 +1,10 @@
-export let Env, Compression, Cursor, getAddress, getAddressShared, setGlobalBuffer,
+export let Env, Compression, Cursor, getAddress, clearKeptObjects, setGlobalBuffer,
     require, arch, fs, lmdbError, path, EventEmitter, orderedBinary, MsgpackrEncoder, WeakLRUCache;
 export function setNativeFunctions(externals) {
 	Env = externals.Env;
 	Compression = externals.Compression;
 	getAddress = externals.getAddress;
+    clearKeptObjects = externals.clearKeptObjects;
     setGlobalBuffer = externals.setGlobalBuffer;
     Cursor = externals.Cursor;
     lmdbError = externals.lmdbError;

node-index.js

@@ -20,6 +20,7 @@ setExternals({
 export { toBufferKey as keyValueToBuffer, compareKeys, compareKeys as compareKey, fromBufferKey as bufferToKeyValue } from 'ordered-binary';
 export { ABORT, IF_EXISTS, asBinary } from './write.js';
 export { levelup } from './level.js';
+export { clearKeptObjects } from './external.js';
 export { open, getLastVersion, getLastEntrySize, setLastVersion, allDbs } from './open.js';
 import { toBufferKey as keyValueToBuffer, compareKeys as compareKey, fromBufferKey as bufferToKeyValue } from 'ordered-binary';
 import { open, getLastVersion } from './open.js';

src/lmdb-js.h

@@ -147,6 +147,7 @@ NAN_METHOD(lmdbError);
 //NAN_METHOD(getBufferForAddress);
 NAN_METHOD(getViewAddress);
 NAN_METHOD(getAddress);
+NAN_METHOD(clearKeptObjects);
 NAN_METHOD(lmdbNativeFunctions);
 
 #ifndef thread_local

src/misc.cpp

@@ -21,6 +21,7 @@ void setupExportMisc(Local<Object> exports) {
     Nan::SetMethod(exports, "lmdbError", lmdbError);
     //Nan::SetMethod(exports, "getBufferForAddress", getBufferForAddress);
     Nan::SetMethod(exports, "getAddress", getViewAddress);
+    Nan::SetMethod(exports, "clearKeptObjects", clearKeptObjects);
     // this is set solely for the purpose of giving a good name to the set of native functions for the profiler since V8
     // often just uses the name of the last exported native function:
     Nan::SetMethod(exports, "lmdbNativeFunctions", lmdbNativeFunctions);
@@ -201,6 +202,10 @@ NAN_METHOD(getViewAddress) {
     void* address = length > 0 ? node::Buffer::Data(info[0]) : nullptr;
     info.GetReturnValue().Set(Nan::New<Number>((size_t) address));
 }
+NAN_METHOD(clearKeptObjects) {
+    Isolate::GetCurrent()->ClearKeptObjects();
+}
+
 NAN_METHOD(lmdbNativeFunctions) {
     // no-op, just doing this to give a label to the native functions
 }