File: scoped_handle_win.h

package info (click to toggle)
icedove 1:52.3.0-4~deb8u2
  • links: PTS, VCS
  • area: main
  • in suites: jessie
  • size: 1,705,608 kB
  • sloc: cpp: 5,079,451; ansic: 2,051,639; python: 458,782; java: 241,615; xml: 192,378; asm: 178,649; sh: 81,867; makefile: 24,692; perl: 16,874; objc: 4,389; yacc: 1,816; ada: 1,697; lex: 1,257; pascal: 1,251; cs: 879; exp: 499; php: 436; lisp: 258; awk: 152; sed: 51; ruby: 47; csh: 27
file content (219 lines) | stat: -rw-r--r-- 4,506 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2006-2008 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_SCOPED_HANDLE_WIN_H_
#define BASE_SCOPED_HANDLE_WIN_H_

#include <windows.h>

#include "base/basictypes.h"
#include "base/logging.h"

// Used so we always remember to close the handle.
// The class interface matches that of ScopedStdioHandle in  addition to an
// IsValid() method since invalid handles on windows can be either NULL or
// INVALID_HANDLE_VALUE (-1).
//
// Example:
//   ScopedHandle hfile(CreateFile(...));
//   if (!hfile.Get())
//     ...process error
//   ReadFile(hfile.Get(), ...);
//
// To sqirrel the handle away somewhere else:
//   secret_handle_ = hfile.Take();
//
// To explicitly close the handle:
//   hfile.Close();
class ScopedHandle {
 public:
  ScopedHandle() : handle_(NULL) {
  }

  explicit ScopedHandle(HANDLE h) : handle_(NULL) {
    Set(h);
  }

  ~ScopedHandle() {
    Close();
  }

  // Use this instead of comparing to INVALID_HANDLE_VALUE to pick up our NULL
  // usage for errors.
  bool IsValid() const {
    return handle_ != NULL;
  }

  void Set(HANDLE new_handle) {
    Close();

    // Windows is inconsistent about invalid handles, so we always use NULL
    if (new_handle != INVALID_HANDLE_VALUE)
      handle_ = new_handle;
  }

  HANDLE Get() {
    return handle_;
  }

  operator HANDLE() { return handle_; }

  HANDLE Take() {
    // transfers ownership away from this object
    HANDLE h = handle_;
    handle_ = NULL;
    return h;
  }

  void Close() {
    if (handle_) {
      if (!::CloseHandle(handle_)) {
        NOTREACHED();
      }
      handle_ = NULL;
    }
  }

 private:
  HANDLE handle_;
  DISALLOW_EVIL_CONSTRUCTORS(ScopedHandle);
};

// Like ScopedHandle, but for HANDLEs returned from FindFile().
class ScopedFindFileHandle {
 public:
  explicit ScopedFindFileHandle(HANDLE handle) : handle_(handle) {
    // Windows is inconsistent about invalid handles, so we always use NULL
    if (handle_ == INVALID_HANDLE_VALUE)
      handle_ = NULL;
  }

  ~ScopedFindFileHandle() {
    if (handle_)
      FindClose(handle_);
  }

  // Use this instead of comparing to INVALID_HANDLE_VALUE to pick up our NULL
  // usage for errors.
  bool IsValid() const { return handle_ != NULL; }

  operator HANDLE() { return handle_; }

 private:
  HANDLE handle_;

  DISALLOW_EVIL_CONSTRUCTORS(ScopedFindFileHandle);
};

// Like ScopedHandle but for HDC.  Only use this on HDCs returned from
// CreateCompatibleDC.  For an HDC returned by GetDC, use ReleaseDC instead.
class ScopedHDC {
 public:
  ScopedHDC() : hdc_(NULL) { }
  explicit ScopedHDC(HDC h) : hdc_(h) { }

  ~ScopedHDC() {
    Close();
  }

  HDC Get() {
    return hdc_;
  }

  void Set(HDC h) {
    Close();
    hdc_ = h;
  }

  operator HDC() { return hdc_; }

 private:
  void Close() {
#ifdef NOGDI
    assert(false);
#else
    if (hdc_)
      DeleteDC(hdc_);
#endif  // NOGDI
  }

  HDC hdc_;
  DISALLOW_EVIL_CONSTRUCTORS(ScopedHDC);
};

// Like ScopedHandle but for GDI objects.
template<class T>
class ScopedGDIObject {
 public:
  ScopedGDIObject() : object_(NULL) {}
  explicit ScopedGDIObject(T object) : object_(object) {}

  ~ScopedGDIObject() {
    Close();
  }

  T Get() {
    return object_;
  }

  void Set(T object) {
    if (object_ && object != object_)
      Close();
    object_ = object;
  }

  ScopedGDIObject& operator=(T object) {
    Set(object);
    return *this;
  }

  operator T() { return object_; }

 private:
  void Close() {
    if (object_)
      DeleteObject(object_);
  }

  T object_;
  DISALLOW_COPY_AND_ASSIGN(ScopedGDIObject);
};

// Typedefs for some common use cases.
typedef ScopedGDIObject<HBITMAP> ScopedBitmap;
typedef ScopedGDIObject<HRGN> ScopedHRGN;
typedef ScopedGDIObject<HFONT> ScopedHFONT;


// Like ScopedHandle except for HGLOBAL.
template<class T>
class ScopedHGlobal {
 public:
  explicit ScopedHGlobal(HGLOBAL glob) : glob_(glob) {
    data_ = static_cast<T*>(GlobalLock(glob_));
  }
  ~ScopedHGlobal() {
    GlobalUnlock(glob_);
  }

  T* get() { return data_; }

  size_t Size() const { return GlobalSize(glob_); }

  T* operator->() const  {
    assert(data_ != 0);
    return data_;
  }

 private:
  HGLOBAL glob_;

  T* data_;

  DISALLOW_EVIL_CONSTRUCTORS(ScopedHGlobal);
};

#endif // BASE_SCOPED_HANDLE_WIN_H_