Unified callback system.

base/prebind.h.pump

+$$ This is a pump file for generating file templates.  Pump is a python
+$$ script that is part of the Google Test suite of utilities.  Description
+$$ can be found here:
+$$
+$$ http://code.google.com/p/googletest/wiki/PumpManual
+$$
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_PREBIND_H_
+#define BASE_PREBIND_H_
+
+#include "base/uber_callback.h"
+
+namespace base {
+
+namespace internal {
+// These classes are argument wrappers that affect the refcounting, and storage
+// semantics for prebound arguments.
+
+template <typename T>
+class UnretainedWrapper {
+ public:
+  explicit UnretainedWrapper(T* o) : obj_(o) {}
+  T* get() { return obj_; }
+ private:
+  T* obj_;
+};
+
+template <typename T>
+class ConstRefWrapper {
+ public:
+  explicit ConstRefWrapper(const T& o) : ptr_(&o) {}
+  const T* get() { return ptr_; }
+ private:
+  const T* ptr_;
+};
+
+// Unwrap for the wrappers above.
+template <typename T>
+T Unwrap(T o) { return o; }
+
+template <typename T>
+T* Unwrap(UnretainedWrapper<T> unretained) { return unretained.get(); }
+
+template <typename T>
+const T* Unwrap(ConstRefWrapper<T> const_ref) { return const_ref.get(); }
+
+// Optional Refcounting.
+
+template <bool ref, typename O>
+struct MaybeRefcount;
+
+template <typename O>
+struct MaybeRefcount<false, O> {
+  static void AddRef(const O&) {}
+  static void Release(const O&) {}
+};
+
+template <typename O>
+struct MaybeRefcount<true, UnretainedWrapper<O> > {
+  static void AddRef(const UnretainedWrapper<O>&) {}
+  static void Release(const UnretainedWrapper<O>&) {}
+};
+
+template <typename O>
+struct MaybeRefcount<true, ConstRefWrapper<O> > {
+  static void AddRef(ConstRefWrapper<O> o) { o.get()->AddRef(); }
+  static void Release(ConstRefWrapper<O> o) { o.get()->Release(); }
+};
+
+template <typename O>
+struct MaybeRefcount<true, O* > {
+  static void AddRef(O* o) { o->AddRef(); }
+  static void Release(O* o) { o->Release(); }
+};
+
+// The method by which a function is invoked is determined by 3 different
+// dimensions:
+//
+//   1) The type of function (normal, method, const-method)
+//   2) The arity of the function
+//   3) The number of bound parameters.
+//
+// The FunctionTraitsN classes unwrap the function signature type to
+// specialize based on the first two dimensions.  The N in FunctionTraitsN
+// specifies the 3rd dimension.
+
+$var MAX_ARITY = 6
+
+$range PREBOUND 1..MAX_ARITY
+$for PREBOUND [[
+
+template <typename StorageType, typename Sig>
+struct FunctionTraits$(PREBOUND);
+
+$range ARITY 1..MAX_ARITY
+$for ARITY [[
+
+$var UNBOUND = ARITY - PREBOUND
+$if UNBOUND >= 0 [[
+
+$$ Variables for function traits generation.
+$range ARG 1..ARITY
+$range BOUND_ARG 1..PREBOUND
+$range UNBOUND_ARG (ARITY - UNBOUND + 1)..ARITY
+
+$$ Variables for method traits generation. We are always short one arity since
+$$ the first bound parameter is the object.
+$var M_ARITY = ARITY - 1
+$range M_ARG 1..M_ARITY
+$range M_BOUND_ARG 2..PREBOUND
+$range M_UNBOUND_ARG (M_ARITY - UNBOUND + 1)..M_ARITY
+
+// Function: Arity $(ARITY) -> $(UNBOUND).
+template <typename StorageType, typename R, $for ARG , [[typename X$(ARG)]]>
+struct FunctionTraits$(PREBOUND)<StorageType, R(*)($for ARG , [[X$(ARG)]])> {
+  static const bool kShouldRef = false;
+  static R DoInvoke(InvokerStorageBase* base[[]]
+$if UNBOUND != 0 [[, ]] $for UNBOUND_ARG , [[X$(UNBOUND_ARG) x$(UNBOUND_ARG)]]) {
+    StorageType* invoker = static_cast<StorageType*>(base);
+    return invoker->f_($for BOUND_ARG , [[Unwrap(invoker->p$(BOUND_ARG)_)]][[]]
+$if UNBOUND > 0 [[, ]] $for UNBOUND_ARG , [[x$(UNBOUND_ARG)]]);
+  }
+};
+
+// Method: Arity $(M_ARITY) -> $(UNBOUND).
+template <typename StorageType, typename R, typename T[[]]
+$if M_ARITY > 0[[, ]] $for M_ARG , [[typename X$(M_ARG)]]>
+struct FunctionTraits$(PREBOUND)<StorageType, R(T::*)($for M_ARG , [[X$(M_ARG)]])> {
+  static const bool kShouldRef = true;
+  static R DoInvoke(InvokerStorageBase* base[[]]
+$if UNBOUND > 0 [[, ]] $for M_UNBOUND_ARG , [[X$(M_UNBOUND_ARG) x$(M_UNBOUND_ARG)]]) {
+    StorageType* invoker = static_cast<StorageType*>(base);
+    return (Unwrap(invoker->p1_)->*invoker->f_)([[]]
+$for M_BOUND_ARG , [[Unwrap(invoker->p$(M_BOUND_ARG)_)]][[]]
+$if UNBOUND > 0 [[$if PREBOUND > 1 [[, ]]]][[]]
+$for M_UNBOUND_ARG , [[x$(M_UNBOUND_ARG)]]);
+  }
+};
+
+// Const Method: Arity $(M_ARITY) -> $(UNBOUND).
+template <typename StorageType, typename R, typename T[[]]
+$if M_ARITY > 0[[, ]] $for M_ARG , [[typename X$(M_ARG)]]>
+struct FunctionTraits$(PREBOUND)<StorageType, R(T::*)($for M_ARG , [[X$(M_ARG)]]) const> {
+  static const bool kShouldRef = true;
+  static R DoInvoke(InvokerStorageBase* base[[]]
+$if UNBOUND > 0 [[, ]] $for M_UNBOUND_ARG , [[X$(M_UNBOUND_ARG) x$(M_UNBOUND_ARG)]]) {
+    StorageType* invoker = static_cast<StorageType*>(base);
+    return (Unwrap(invoker->p1_)->*invoker->f_)([[]]
+$for M_BOUND_ARG , [[Unwrap(invoker->p$(M_BOUND_ARG)_)]][[]]
+$if UNBOUND > 0 [[$if PREBOUND > 1 [[, ]]]][[]]
+$for M_UNBOUND_ARG , [[x$(M_UNBOUND_ARG)]]);
+  }
+};
+
+]]  $$ if UNBOUND
+]]  $$ for ARITY
+]]  $$ for PREBOUND
+
+
+// These are the actual storage classes for the invokers.
+
+$for PREBOUND [[
+$range BOUND_ARG 1..PREBOUND
+
+template <typename Sig, $for BOUND_ARG , [[typename P$(BOUND_ARG)]]>
+class InvokerStorage$(PREBOUND) : public InvokerStorageBase {
+ public:
+  typedef InvokerStorage$(PREBOUND) StorageType;
+  typedef FunctionTraits$(PREBOUND)<StorageType, Sig> FunctionTraits;
+
+  InvokerStorage$(PREBOUND)(Sig f, [[]]
+$for BOUND_ARG , [[const P$(BOUND_ARG)& p$(BOUND_ARG)]])
+      : f_(f), $for BOUND_ARG , [[p$(BOUND_ARG)_(p$(BOUND_ARG))]] {
+    MaybeRefcount<FunctionTraits::kShouldRef, P1>::AddRef(p1_);
+  }
+
+  virtual ~InvokerStorage$(PREBOUND)() {
+    MaybeRefcount<FunctionTraits::kShouldRef, P1>::Release(p1_);
+  }
+
+  Sig f_;
+
+$for BOUND_ARG [[
+  P$(BOUND_ARG) p$(BOUND_ARG)_;
+
+]]
+};
+
+]]  $$ for PREBOUND
+
+}  // namespace internal
+
+
+$for PREBOUND [[
+$range BOUND_ARG 1..PREBOUND
+
+template <typename Sig, $for BOUND_ARG , [[typename P$(BOUND_ARG)]]>
+InvokerStorageHolder<internal::InvokerStorage$(PREBOUND)<Sig, [[]]
+$for BOUND_ARG , [[P$(BOUND_ARG)]]> >
+Prebind(Sig f, $for BOUND_ARG , [[const P$(BOUND_ARG)& p$(BOUND_ARG)]]) {
+  return MakeInvokerStorageHolder(
+      new internal::InvokerStorage$(PREBOUND)<Sig, [[]]
+$for BOUND_ARG , [[P$(BOUND_ARG)]]>(
+          f, [[]] $for BOUND_ARG , [[p$(BOUND_ARG)]]));
+}
+
+]]  $$ for PREBOUND
+
+template <typename T>
+inline internal::UnretainedWrapper<T> Unretained(T* o) {
+  return internal::UnretainedWrapper<T>(o);
+}
+
+template <typename T>
+inline internal::ConstRefWrapper<T> ConstRef(const T& o) {
+  return internal::ConstRefWrapper<T>(o);
+}
+
+
+}  // namespace base
+
+#endif  // BASE_PREBIND_H_