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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* 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/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#pragma once
#include <string>
#include <string_view>
#include <stdexcept>
#include <type_traits>
#include <utility>
#include <prewin.h>
#include <objbase.h>
#include <postwin.h>
namespace sal::systools
{
/* Simple exception class for propagating COM errors */
class ComError : public std::runtime_error
{
public:
ComError(const std::string& message, HRESULT hr) :
std::runtime_error(message),
hr_(hr)
{}
HRESULT GetHresult() const { return hr_; }
private:
HRESULT hr_;
};
/* Convert failed HRESULT to thrown ComError */
inline void ThrowIfFailed(HRESULT hr, std::string_view msg)
{
if (FAILED(hr))
throw ComError(std::string(msg), hr);
}
/* A guard class to call CoInitializeEx/CoUninitialize in proper pairs
* See also: o3tl::safeCoInitializeEx doing dangerous re-initialization
*/
class CoInitializeGuard
{
public:
enum class WhenFailed
{
NoThrow, // do not throw
Throw, // throw on failure
Abort, // std::abort on failure
};
explicit CoInitializeGuard(DWORD dwCoInit, bool failChangeMode = false,
WhenFailed whenFailed = WhenFailed::Throw)
{
HRESULT hr = ::CoInitializeEx(nullptr, dwCoInit);
if (whenFailed != WhenFailed::NoThrow && FAILED(hr)
&& (failChangeMode || hr != RPC_E_CHANGED_MODE))
{
if (whenFailed == WhenFailed::Throw)
throw ComError("CoInitializeEx failed", hr);
else // if (whenFailed == Abort)
std::abort();
}
mbUninit = SUCCEEDED(hr);
}
CoInitializeGuard(const CoInitializeGuard&) = delete; // non-construction-copyable
void operator=(const CoInitializeGuard&) = delete; // non-copyable
~CoInitializeGuard()
{
if (mbUninit)
::CoUninitialize();
}
private:
bool mbUninit;
};
struct COM_QUERY_TAG {} constexpr COM_QUERY;
struct COM_QUERY_THROW_TAG {} constexpr COM_QUERY_THROW;
template <typename TAG>
constexpr bool is_COM_query_tag
= std::is_same_v<TAG, COM_QUERY_TAG> || std::is_same_v<TAG, COM_QUERY_THROW_TAG>;
/* A simple COM smart pointer template */
template <typename T>
class COMReference
{
public:
/* Explicitly controllable whether AddRef will be called or not */
COMReference(T* comptr = nullptr, bool bAddRef = true) :
com_ptr_(comptr)
{
if (bAddRef)
addRef(com_ptr_);
}
COMReference(const COMReference<T>& other) :
COMReference(other.com_ptr_)
{
}
COMReference(COMReference<T>&& other) :
COMReference(std::exchange(other.com_ptr_, nullptr), false)
{
}
// Query from IUnknown*, using COM_QUERY or COM_QUERY_THROW tags
template <typename T2, typename TAG>
COMReference(const COMReference<T2>& p, TAG t)
: COMReference(p.template QueryInterface<T>(t))
{
}
// Using CoCreateInstance
COMReference(REFCLSID clsid, IUnknown* pOuter = nullptr, DWORD nCtx = CLSCTX_ALL)
: com_ptr_(nullptr)
{
ThrowIfFailed(CoCreateInstance(clsid, pOuter, nCtx), "CoCreateInstance failed");
}
COMReference<T>& operator=(const COMReference<T>& other)
{
return operator=(other.com_ptr_);
}
COMReference<T>& operator=(COMReference<T>&& other)
{
if (com_ptr_ != other.com_ptr_)
{
clear();
std::swap(com_ptr_, other.com_ptr_);
}
return *this;
}
COMReference<T>& operator=(T* comptr)
{
assign(comptr);
return *this;
}
~COMReference() { release(com_ptr_); }
template <typename T2, typename TAG, std::enable_if_t<is_COM_query_tag<TAG>, int> = 0>
COMReference<T2> QueryInterface(TAG) const
{
T2* ip = nullptr;
HRESULT hr = E_POINTER;
if (com_ptr_)
hr = com_ptr_->QueryInterface(&ip);
if constexpr (std::is_same_v<TAG, COM_QUERY_THROW_TAG>)
ThrowIfFailed(hr, "QueryInterface failed");
return { ip, false };
}
template <typename T2, typename TAG>
COMReference<T>& set(const COMReference<T2>& p, TAG t)
{
return operator=(p.template QueryInterface<T>(t));
}
HRESULT CoCreateInstance(REFCLSID clsid, IUnknown* pOuter = nullptr,
DWORD nCtx = CLSCTX_ALL)
{
T* ip;
HRESULT hr = ::CoCreateInstance(clsid, pOuter, nCtx, IID_PPV_ARGS(&ip));
if (SUCCEEDED(hr))
release(std::exchange(com_ptr_, ip));
return hr;
}
HRESULT CoGetClassObject(REFCLSID clsid, DWORD nCtx = CLSCTX_ALL)
{
T* ip;
HRESULT hr = ::CoGetClassObject(clsid, nCtx, nullptr, IID_PPV_ARGS(&ip));
if (SUCCEEDED(hr))
release(std::exchange(com_ptr_, ip));
return hr;
}
T* operator->() const { return com_ptr_; }
T& operator*() const { return *com_ptr_; }
/* Necessary for assigning com_ptr_ from functions like
CoCreateInstance which require a 'void**' */
T** operator&()
{
clear();
return &com_ptr_;
}
T* get() const { return com_ptr_; }
operator T* () const { return get(); }
void clear() { assign(nullptr); }
bool is() const { return (com_ptr_ != nullptr); }
operator bool() const { return is(); }
private:
static void addRef(T* ptr)
{
if (ptr)
ptr->AddRef();
}
static void release(T* ptr)
{
if (ptr)
ptr->Release();
}
void assign(T* ptr)
{
if (com_ptr_ == ptr)
return;
addRef(ptr);
release(std::exchange(com_ptr_, ptr));
}
T* com_ptr_;
};
} // sal::systools
/* Typedefs for some popular COM interfaces */
typedef sal::systools::COMReference<IDataObject> IDataObjectPtr;
typedef sal::systools::COMReference<IStream> IStreamPtr;
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
