Add base to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 402 insertions, 0 deletions

diff --git a/base/scoped_ptr.h b/base/scoped_ptr.h
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+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "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 COPYRIGHT
+// OWNER OR CONTRIBUTORS 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.
+// All Rights Reserved.
+
+#ifndef BASE_SCOPED_PTR_H__
+#define BASE_SCOPED_PTR_H__
+
+//  This is an implementation designed to match the anticipated future TR2
+//  implementation of the scoped_ptr class, and its closely-related brethren,
+//  scoped_array, scoped_ptr_malloc, and make_scoped_ptr.
+//
+//  See http://wiki/Main/ScopedPointerInterface for the spec that drove this
+//  file.
+
+#include <assert.h>
+#include <stdlib.h>
+#include <cstddef>
+
+
+template <class C> class scoped_ptr;
+template <class C, class Free> class scoped_ptr_malloc;
+template <class C> class scoped_array;
+
+template <class C>
+scoped_ptr<C> make_scoped_ptr(C *);
+
+// A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
+// automatically deletes the pointer it holds (if any).
+// That is, scoped_ptr<T> owns the T object that it points to.
+// Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
+// Also like T*, scoped_ptr<T> is thread-compatible, and once you
+// dereference it, you get the threadsafety guarantees of T.
+//
+// The size of a scoped_ptr is small:
+// sizeof(scoped_ptr<C>) == sizeof(C*)
+template <class C>
+class scoped_ptr {
+ public:
+
+  // The element type
+  typedef C element_type;
+
+  // Constructor.  Defaults to intializing with NULL.
+  // There is no way to create an uninitialized scoped_ptr.
+  // The input parameter must be allocated with new.
+  explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
+
+  // Destructor.  If there is a C object, delete it.
+  // We don't need to test ptr_ == NULL because C++ does that for us.
+  ~scoped_ptr() {
+    enum { type_must_be_complete = sizeof(C) };
+    delete ptr_;
+  }
+
+  // Reset.  Deletes the current owned object, if any.
+  // Then takes ownership of a new object, if given.
+  // this->reset(this->get()) works.
+  void reset(C* p = NULL) {
+    if (p != ptr_) {
+      enum { type_must_be_complete = sizeof(C) };
+      delete ptr_;
+      ptr_ = p;
+    }
+  }
+
+  // Accessors to get the owned object.
+  // operator* and operator-> will assert() if there is no current object.
+  C& operator*() const {
+    assert(ptr_ != NULL);
+    return *ptr_;
+  }
+  C* operator->() const  {
+    assert(ptr_ != NULL);
+    return ptr_;
+  }
+  C* get() const { return ptr_; }
+
+  // Comparison operators.
+  // These return whether two scoped_ptr refer to the same object, not just to
+  // two different but equal objects.
+  bool operator==(C* p) const { return ptr_ == p; }
+  bool operator!=(C* p) const { return ptr_ != p; }
+
+  // Swap two scoped pointers.
+  void swap(scoped_ptr& p2) {
+    C* tmp = ptr_;
+    ptr_ = p2.ptr_;
+    p2.ptr_ = tmp;
+  }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  C* release() {
+    C* retVal = ptr_;
+    ptr_ = NULL;
+    return retVal;
+  }
+
+ private:
+  C* ptr_;
+
+  friend scoped_ptr<C> make_scoped_ptr<C>(C *p);
+
+  // Forbid comparison of scoped_ptr types.  If C2 != C, it totally doesn't
+  // make sense, and if C2 == C, it still doesn't make sense because you should
+  // never have the same object owned by two different scoped_ptrs.
+  template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
+  template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
+
+  // Disallow evil constructors
+  scoped_ptr(const scoped_ptr&);
+  void operator=(const scoped_ptr&);
+};
+
+// Free functions
+template <class C>
+void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
+  p1.swap(p2);
+}
+
+template <class C>
+bool operator==(C* p1, const scoped_ptr<C>& p2) {
+  return p1 == p2.get();
+}
+
+template <class C>
+bool operator!=(C* p1, const scoped_ptr<C>& p2) {
+  return p1 != p2.get();
+}
+
+template <class C>
+scoped_ptr<C> make_scoped_ptr(C *p) {
+  // This does nothing but to return a scoped_ptr of the type that the passed
+  // pointer is of.  (This eliminates the need to specify the name of T when
+  // making a scoped_ptr that is used anonymously/temporarily.)  From an
+  // access control point of view, we construct an unnamed scoped_ptr here
+  // which we return and thus copy-construct.  Hence, we need to have access
+  // to scoped_ptr::scoped_ptr(scoped_ptr const &).  However, it is guaranteed
+  // that we never actually call the copy constructor, which is a good thing
+  // as we would call the temporary's object destructor (and thus delete p)
+  // if we actually did copy some object, here.
+  return scoped_ptr<C>(p);
+}
+
+// scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
+// with new [] and the destructor deletes objects with delete [].
+//
+// As with scoped_ptr<C>, a scoped_array<C> either points to an object
+// or is NULL.  A scoped_array<C> owns the object that it points to.
+// scoped_array<T> is thread-compatible, and once you index into it,
+// the returned objects have only the threadsafety guarantees of T.
+//
+// Size: sizeof(scoped_array<C>) == sizeof(C*)
+template <class C>
+class scoped_array {
+ public:
+
+  // The element type
+  typedef C element_type;
+
+  // Constructor.  Defaults to intializing with NULL.
+  // There is no way to create an uninitialized scoped_array.
+  // The input parameter must be allocated with new [].
+  explicit scoped_array(C* p = NULL) : array_(p) { }
+
+  // Destructor.  If there is a C object, delete it.
+  // We don't need to test ptr_ == NULL because C++ does that for us.
+  ~scoped_array() {
+    enum { type_must_be_complete = sizeof(C) };
+    delete[] array_;
+  }
+
+  // Reset.  Deletes the current owned object, if any.
+  // Then takes ownership of a new object, if given.
+  // this->reset(this->get()) works.
+  void reset(C* p = NULL) {
+    if (p != array_) {
+      enum { type_must_be_complete = sizeof(C) };
+      delete[] array_;
+      array_ = p;
+    }
+  }
+
+  // Get one element of the current object.
+  // Will assert() if there is no current object, or index i is negative.
+  C& operator[](std::ptrdiff_t i) const {
+    assert(i >= 0);
+    assert(array_ != NULL);
+    return array_[i];
+  }
+
+  // Get a pointer to the zeroth element of the current object.
+  // If there is no current object, return NULL.
+  C* get() const {
+    return array_;
+  }
+
+  // Comparison operators.
+  // These return whether two scoped_array refer to the same object, not just to
+  // two different but equal objects.
+  bool operator==(C* p) const { return array_ == p; }
+  bool operator!=(C* p) const { return array_ != p; }
+
+  // Swap two scoped arrays.
+  void swap(scoped_array& p2) {
+    C* tmp = array_;
+    array_ = p2.array_;
+    p2.array_ = tmp;
+  }
+
+  // Release an array.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  C* release() {
+    C* retVal = array_;
+    array_ = NULL;
+    return retVal;
+  }
+
+ private:
+  C* array_;
+
+  // Forbid comparison of different scoped_array types.
+  template <class C2> bool operator==(scoped_array<C2> const& p2) const;
+  template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
+
+  // Disallow evil constructors
+  scoped_array(const scoped_array&);
+  void operator=(const scoped_array&);
+};
+
+// Free functions
+template <class C>
+void swap(scoped_array<C>& p1, scoped_array<C>& p2) {
+  p1.swap(p2);
+}
+
+template <class C>
+bool operator==(C* p1, const scoped_array<C>& p2) {
+  return p1 == p2.get();
+}
+
+template <class C>
+bool operator!=(C* p1, const scoped_array<C>& p2) {
+  return p1 != p2.get();
+}
+
+// This class wraps the c library function free() in a class that can be
+// passed as a template argument to scoped_ptr_malloc below.
+class ScopedPtrMallocFree {
+ public:
+  inline void operator()(void* x) const {
+    free(x);
+  }
+};
+
+// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
+// second template argument, the functor used to free the object.
+
+template<class C, class FreeProc = ScopedPtrMallocFree>
+class scoped_ptr_malloc {
+ public:
+
+  // The element type
+  typedef C element_type;
+
+  // Constructor.  Defaults to intializing with NULL.
+  // There is no way to create an uninitialized scoped_ptr.
+  // The input parameter must be allocated with an allocator that matches the
+  // Free functor.  For the default Free functor, this is malloc, calloc, or
+  // realloc.
+  explicit scoped_ptr_malloc(C* p = NULL): ptr_(p) {}
+
+  // Destructor.  If there is a C object, call the Free functor.
+  ~scoped_ptr_malloc() {
+    free_(ptr_);
+  }
+
+  // Reset.  Calls the Free functor on the current owned object, if any.
+  // Then takes ownership of a new object, if given.
+  // this->reset(this->get()) works.
+  void reset(C* p = NULL) {
+    if (ptr_ != p) {
+      free_(ptr_);
+      ptr_ = p;
+    }
+  }
+
+  // Get the current object.
+  // operator* and operator-> will cause an assert() failure if there is
+  // no current object.
+  C& operator*() const {
+    assert(ptr_ != NULL);
+    return *ptr_;
+  }
+
+  C* operator->() const {
+    assert(ptr_ != NULL);
+    return ptr_;
+  }
+
+  C* get() const {
+    return ptr_;
+  }
+
+  // Comparison operators.
+  // These return whether a scoped_ptr_malloc and a plain pointer refer
+  // to the same object, not just to two different but equal objects.
+  // For compatibility wwith the boost-derived implementation, these
+  // take non-const arguments.
+  bool operator==(C* p) const {
+    return ptr_ == p;
+  }
+
+  bool operator!=(C* p) const {
+    return ptr_ != p;
+  }
+
+  // Swap two scoped pointers.
+  void swap(scoped_ptr_malloc & b) {
+    C* tmp = b.ptr_;
+    b.ptr_ = ptr_;
+    ptr_ = tmp;
+  }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  C* release() {
+    C* tmp = ptr_;
+    ptr_ = NULL;
+    return tmp;
+  }
+
+ private:
+  C* ptr_;
+
+  // no reason to use these: each scoped_ptr_malloc should have its own object
+  template <class C2, class GP>
+  bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
+  template <class C2, class GP>
+  bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
+
+  static FreeProc const free_;
+
+  // Disallow evil constructors
+  scoped_ptr_malloc(const scoped_ptr_malloc&);
+  void operator=(const scoped_ptr_malloc&);
+};
+
+template<class C, class FP>
+FP const scoped_ptr_malloc<C, FP>::free_ = FP();
+
+template<class C, class FP> inline
+void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
+  a.swap(b);
+}
+
+template<class C, class FP> inline
+bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
+  return p == b.get();
+}
+
+template<class C, class FP> inline
+bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
+  return p != b.get();
+}
+
+#endif  // BASE_SCOPED_PTR_H__