diff -r 000000000000 -r 6474c204b198 storage/src/mozStorageStatementJSHelper.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/storage/src/mozStorageStatementJSHelper.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,236 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIXPConnect.h"
+#include "mozStorageStatement.h"
+#include "mozStorageService.h"
+
+#include "nsMemory.h"
+#include "nsString.h"
+#include "nsServiceManagerUtils.h"
+
+#include "mozStorageStatementJSHelper.h"
+
+#include "mozStorageStatementRow.h"
+#include "mozStorageStatementParams.h"
+
+#include "jsapi.h"
+
+namespace mozilla {
+namespace storage {
+
+////////////////////////////////////////////////////////////////////////////////
+//// Global Functions
+
+static
+bool
+stepFunc(JSContext *aCtx,
+         uint32_t,
+         jsval *_vp)
+{
+  nsCOMPtr<nsIXPConnect> xpc(Service::getXPConnect());
+  nsCOMPtr<nsIXPConnectWrappedNative> wrapper;
+  JSObject *obj = JS_THIS_OBJECT(aCtx, _vp);
+  if (!obj) {
+    return false;
+  }
+
+  nsresult rv =
+    xpc->GetWrappedNativeOfJSObject(aCtx, obj, getter_AddRefs(wrapper));
+  if (NS_FAILED(rv)) {
+    ::JS_ReportError(aCtx, "mozIStorageStatement::step() could not obtain native statement");
+    return false;
+  }
+
+#ifdef DEBUG
+  {
+    nsCOMPtr<mozIStorageStatement> isStatement(
+      do_QueryInterface(wrapper->Native())
+    );
+    NS_ASSERTION(isStatement, "How is this not a statement?!");
+  }
+#endif
+
+  Statement *stmt = static_cast<Statement *>(
+    static_cast<mozIStorageStatement *>(wrapper->Native())
+  );
+
+  bool hasMore = false;
+  rv = stmt->ExecuteStep(&hasMore);
+  if (NS_SUCCEEDED(rv) && !hasMore) {
+    *_vp = JSVAL_FALSE;
+    (void)stmt->Reset();
+    return true;
+  }
+
+  if (NS_FAILED(rv)) {
+    ::JS_ReportError(aCtx, "mozIStorageStatement::step() returned an error");
+    return false;
+  }
+
+  *_vp = BOOLEAN_TO_JSVAL(hasMore);
+  return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// StatementJSHelper
+
+nsresult
+StatementJSHelper::getRow(Statement *aStatement,
+                          JSContext *aCtx,
+                          JSObject *aScopeObj,
+                          jsval *_row)
+{
+  nsresult rv;
+
+#ifdef DEBUG
+  int32_t state;
+  (void)aStatement->GetState(&state);
+  NS_ASSERTION(state == mozIStorageStatement::MOZ_STORAGE_STATEMENT_EXECUTING,
+               "Invalid state to get the row object - all calls will fail!");
+#endif
+
+  if (!aStatement->mStatementRowHolder) {
+    JS::RootedObject scope(aCtx, aScopeObj);
+    nsCOMPtr<mozIStorageStatementRow> row(new StatementRow(aStatement));
+    NS_ENSURE_TRUE(row, NS_ERROR_OUT_OF_MEMORY);
+
+    nsCOMPtr<nsIXPConnect> xpc(Service::getXPConnect());
+    rv = xpc->WrapNative(
+      aCtx,
+      ::JS_GetGlobalForObject(aCtx, scope),
+      row,
+      NS_GET_IID(mozIStorageStatementRow),
+      getter_AddRefs(aStatement->mStatementRowHolder)
+    );
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  JS::Rooted<JSObject*> obj(aCtx);
+  obj = aStatement->mStatementRowHolder->GetJSObject();
+  NS_ENSURE_STATE(obj);
+
+  *_row = OBJECT_TO_JSVAL(obj);
+  return NS_OK;
+}
+
+nsresult
+StatementJSHelper::getParams(Statement *aStatement,
+                             JSContext *aCtx,
+                             JSObject *aScopeObj,
+                             jsval *_params)
+{
+  nsresult rv;
+
+#ifdef DEBUG
+  int32_t state;
+  (void)aStatement->GetState(&state);
+  NS_ASSERTION(state == mozIStorageStatement::MOZ_STORAGE_STATEMENT_READY,
+               "Invalid state to get the params object - all calls will fail!");
+#endif
+
+  if (!aStatement->mStatementParamsHolder) {
+    JS::RootedObject scope(aCtx, aScopeObj);
+    nsCOMPtr<mozIStorageStatementParams> params =
+      new StatementParams(aStatement);
+    NS_ENSURE_TRUE(params, NS_ERROR_OUT_OF_MEMORY);
+
+    nsCOMPtr<nsIXPConnect> xpc(Service::getXPConnect());
+    rv = xpc->WrapNative(
+      aCtx,
+      ::JS_GetGlobalForObject(aCtx, scope),
+      params,
+      NS_GET_IID(mozIStorageStatementParams),
+      getter_AddRefs(aStatement->mStatementParamsHolder)
+    );
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  JS::Rooted<JSObject*> obj(aCtx);
+  obj = aStatement->mStatementParamsHolder->GetJSObject();
+  NS_ENSURE_STATE(obj);
+
+  *_params = OBJECT_TO_JSVAL(obj);
+  return NS_OK;
+}
+
+NS_IMETHODIMP_(MozExternalRefCountType) StatementJSHelper::AddRef() { return 2; }
+NS_IMETHODIMP_(MozExternalRefCountType) StatementJSHelper::Release() { return 1; }
+NS_INTERFACE_MAP_BEGIN(StatementJSHelper)
+  NS_INTERFACE_MAP_ENTRY(nsIXPCScriptable)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+////////////////////////////////////////////////////////////////////////////////
+//// nsIXPCScriptable
+
+#define XPC_MAP_CLASSNAME StatementJSHelper
+#define XPC_MAP_QUOTED_CLASSNAME "StatementJSHelper"
+#define XPC_MAP_WANT_GETPROPERTY
+#define XPC_MAP_WANT_NEWRESOLVE
+#define XPC_MAP_FLAGS nsIXPCScriptable::ALLOW_PROP_MODS_DURING_RESOLVE
+#include "xpc_map_end.h"
+
+NS_IMETHODIMP
+StatementJSHelper::GetProperty(nsIXPConnectWrappedNative *aWrapper,
+                               JSContext *aCtx,
+                               JSObject *aScopeObj,
+                               jsid aId,
+                               jsval *_result,
+                               bool *_retval)
+{
+  if (!JSID_IS_STRING(aId))
+    return NS_OK;
+
+  JS::Rooted<JSObject*> scope(aCtx, aScopeObj);
+  JS::Rooted<jsid> id(aCtx, aId);
+
+#ifdef DEBUG
+  {
+    nsCOMPtr<mozIStorageStatement> isStatement(
+                                     do_QueryInterface(aWrapper->Native()));
+    NS_ASSERTION(isStatement, "How is this not a statement?!");
+  }
+#endif
+
+  Statement *stmt = static_cast<Statement *>(
+    static_cast<mozIStorageStatement *>(aWrapper->Native())
+  );
+
+  JSFlatString *str = JSID_TO_FLAT_STRING(id);
+  if (::JS_FlatStringEqualsAscii(str, "row"))
+    return getRow(stmt, aCtx, scope, _result);
+
+  if (::JS_FlatStringEqualsAscii(str, "params"))
+    return getParams(stmt, aCtx, scope, _result);
+
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+StatementJSHelper::NewResolve(nsIXPConnectWrappedNative *aWrapper,
+                              JSContext *aCtx,
+                              JSObject *aScopeObj,
+                              jsid aId,
+                              JSObject **_objp,
+                              bool *_retval)
+{
+  if (!JSID_IS_STRING(aId))
+    return NS_OK;
+
+  JS::RootedObject scope(aCtx, aScopeObj);
+  if (::JS_FlatStringEqualsAscii(JSID_TO_FLAT_STRING(aId), "step")) {
+    *_retval = ::JS_DefineFunction(aCtx, scope, "step", stepFunc,
+                                   0, 0) != nullptr;
+    *_objp = scope.get();
+    return NS_OK;
+  }
+  return NS_OK;
+}
+
+} // namespace storage
+} // namespace mozilla