ircd::js: Add trap_function alternative to full object trap.

include/ircd/js/js.h

@@ -79,3 +79,4 @@ inline JSVersion version(const char *const &v)   { return JS_StringToVersion(v);
 #include "for_each.h"
 #include "args.h"
 #include "trap.h"
+#include "trap_function.h"

include/ircd/js/trap_function.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2016 Charybdis Development Team
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+#define HAVE_IRCD_JS_TRAP_FUNCTION
+
+namespace ircd {
+namespace js   {
+
+struct trap_function
+{
+	std::string name;
+	uint arity;
+	uint flags;
+
+  protected:
+	virtual value on_call(object::handle, const args &);
+
+  private:
+	static trap_function &from(JSObject *const &);
+	static bool handle_call(JSContext *, unsigned, JS::Value *) noexcept;
+
+  public:
+	function operator()(const object::handle &);
+
+	trap_function(std::string name,
+	              const uint &arity = 0,
+	              const uint &flags = 0);
+
+	trap_function(trap_function &&) = delete;
+	trap_function(const trap_function &) = delete;
+	virtual ~trap_function() noexcept;
+};
+
+} // namespace js
+} // namespace ircd

ircd/js.cc

@@ -138,6 +138,98 @@ js::ReportOutOfMemory(ExclusiveContext *const c)
 // ircd/js/js.h - With 3rd party (JSAPI) symbols
 //
 
+///////////////////////////////////////////////////////////////////////////////
+//
+// ircd/js/trap_function.h
+//
+
+ircd::js::trap_function::trap_function(std::string name,
+                                       const uint &arity,
+                                       const uint &flags)
+:name{std::move(name)}
+,arity{arity}
+,flags{flags}
+{
+}
+
+ircd::js::trap_function::~trap_function()
+noexcept
+{
+}
+
+ircd::js::function
+ircd::js::trap_function::operator()(const object::handle &obj)
+{
+	const auto jsf(::js::DefineFunctionWithReserved(*cx,
+	                                                obj,
+	                                                name.c_str(),
+	                                                handle_call,
+	                                                arity,
+	                                                flags));
+	if(unlikely(!jsf))
+		throw internal_error("Failed to create trap_function");
+
+	function ret(jsf);
+	::js::SetFunctionNativeReserved(ret, 0, pointer_value(this));
+	return ret;
+}
+
+bool
+ircd::js::trap_function::handle_call(JSContext *const c,
+                                     const unsigned argc,
+                                     JS::Value *const argv)
+noexcept try
+{
+	assert(&our(c) == cx);
+
+	const struct args args(argc, argv);
+	//const auto that(args.computeThis(c));
+	const object func(args.callee());
+	auto &trap(from(func));
+	log.debug("trap_function(%p) \"%s\": call",
+	          (const void *)&trap,
+	          trap.name.c_str());
+
+	args.rval().set(trap.on_call(func, args));
+	return true;
+}
+catch(const jserror &e)
+{
+	e.set_pending();
+	return false;
+}
+catch(const std::exception &e)
+{
+	const struct args args(argc, argv);
+	auto &func(args.callee());
+	auto &trap(from(&func));
+
+	log.error("trap_function(%p) \"%s\": %s",
+	          reinterpret_cast<const void *>(&trap),
+	          trap.name.c_str(),
+	          e.what());
+
+	JS_ReportError(*cx, "BUG: trap_function(%p) \"%s\": %s",
+	               reinterpret_cast<const void *>(&trap),
+	               trap.name.c_str(),
+	               e.what());
+	return false;
+}
+
+ircd::js::trap_function &
+ircd::js::trap_function::from(JSObject *const &func)
+{
+	const auto tval(::js::GetFunctionNativeReserved(func, 0));
+	return *pointer_value<trap_function>(tval);
+}
+
+ircd::js::value
+ircd::js::trap_function::on_call(object::handle,
+                                 const args &)
+{
+	return {};
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // ircd/js/trap.h