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1 /*
2  * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "config.h"
27 #include "WebKitDLL.h"
28 #include "MemoryStream.h"
29 
30 using std::min;
31 using namespace WebCore;
32 
33 // MemoryStream ---------------------------------------------------------------
34 
MemoryStream(PassRefPtr<SharedBuffer> buffer)35 MemoryStream::MemoryStream(PassRefPtr<SharedBuffer> buffer)
36 : m_refCount(0)
37 , m_buffer(buffer)
38 , m_pos(0)
39 {
40     gClassCount++;
41     gClassNameCount.add("MemoryStream");
42 }
43 
~MemoryStream()44 MemoryStream::~MemoryStream()
45 {
46     gClassCount--;
47     gClassNameCount.remove("MemoryStream");
48 }
49 
createInstance(PassRefPtr<SharedBuffer> buffer)50 COMPtr<MemoryStream> MemoryStream::createInstance(PassRefPtr<SharedBuffer> buffer)
51 {
52     return new MemoryStream(buffer);
53 }
54 
55 // IUnknown -------------------------------------------------------------------
56 
QueryInterface(REFIID riid,void ** ppvObject)57 HRESULT STDMETHODCALLTYPE MemoryStream::QueryInterface(REFIID riid, void** ppvObject)
58 {
59     *ppvObject = 0;
60     if (IsEqualGUID(riid, IID_IUnknown))
61         *ppvObject = static_cast<IUnknown*>(this);
62     else if (IsEqualGUID(riid, IID_ISequentialStream))
63         *ppvObject = static_cast<ISequentialStream*>(this);
64     else if (IsEqualGUID(riid, IID_IStream))
65         *ppvObject = static_cast<IStream*>(this);
66     else
67         return E_NOINTERFACE;
68 
69     AddRef();
70     return S_OK;
71 }
72 
AddRef(void)73 ULONG STDMETHODCALLTYPE MemoryStream::AddRef(void)
74 {
75     return ++m_refCount;
76 }
77 
Release(void)78 ULONG STDMETHODCALLTYPE MemoryStream::Release(void)
79 {
80     ULONG newRef = --m_refCount;
81     if (!newRef)
82         delete(this);
83 
84     return newRef;
85 }
86 
87 // ISequentialStream ----------------------------------------------------------
88 
Read(void * pv,ULONG cb,ULONG * pcbRead)89 HRESULT STDMETHODCALLTYPE MemoryStream::Read(
90     /* [length_is][size_is][out] */ void* pv,
91     /* [in] */ ULONG cb,
92     /* [out] */ ULONG* pcbRead)
93 {
94     *pcbRead = 0;
95 
96     if (!m_buffer)
97         return E_FAIL;
98 
99     if (m_pos >= m_buffer->size())
100         return S_FALSE;
101 
102     if (m_pos + cb < m_buffer->size())
103         *pcbRead = cb;
104     else
105         *pcbRead = (ULONG) (m_buffer->size() - m_pos);
106 
107     memcpy(pv, m_buffer->data() + m_pos, *pcbRead);
108     m_pos += *pcbRead;
109 
110     return S_OK;
111 }
112 
Write(const void *,ULONG,ULONG *)113 HRESULT STDMETHODCALLTYPE MemoryStream::Write(
114     /* [size_is][in] */ const void* /*pv*/,
115     /* [in] */ ULONG /*cb*/,
116     /* [out] */ ULONG* /*pcbWritten*/)
117 {
118     // we use this for read-only streams
119     return STG_E_ACCESSDENIED;
120 }
121 
122 // IStream --------------------------------------------------------------------
123 
Seek(LARGE_INTEGER dlibMove,DWORD dwOrigin,ULARGE_INTEGER * plibNewPosition)124 HRESULT STDMETHODCALLTYPE MemoryStream::Seek(
125     /* [in] */ LARGE_INTEGER dlibMove,
126     /* [in] */ DWORD dwOrigin,
127     /* [out] */ ULARGE_INTEGER* plibNewPosition)
128 {
129     if (!m_buffer)
130         return E_FAIL;
131 
132     size_t proposedPos = m_pos;
133     size_t lowPartNeg;
134     switch (dwOrigin) {
135         case STREAM_SEEK_SET:
136             proposedPos = dlibMove.LowPart;
137             if (dlibMove.HighPart)
138                 return E_FAIL;
139             break;
140         case STREAM_SEEK_CUR:
141             if (!dlibMove.HighPart) {
142                 if (dlibMove.LowPart > (m_buffer->size() - m_pos))
143                     return E_FAIL;
144                 proposedPos += dlibMove.LowPart;
145             } else if (dlibMove.HighPart == -1) {
146                 lowPartNeg = (~dlibMove.LowPart)+1;
147                 if (lowPartNeg > m_pos)
148                     return E_FAIL;
149                 proposedPos = m_pos - lowPartNeg;
150             } else
151                 return E_FAIL;
152             break;
153         case STREAM_SEEK_END:
154             if (dlibMove.HighPart != -1)
155                 return E_FAIL;
156             lowPartNeg = (~dlibMove.LowPart)+1;
157             if (lowPartNeg > m_buffer->size())
158                 return E_FAIL;
159             proposedPos = m_buffer->size() - lowPartNeg;
160             break;
161         default:
162             return E_FAIL;
163     }
164 
165     if (proposedPos >= m_buffer->size())
166         return E_FAIL;
167 
168     if (plibNewPosition) {
169         plibNewPosition->HighPart = 0;
170         plibNewPosition->LowPart = (DWORD) m_pos;
171     }
172 
173     return S_OK;
174 }
175 
SetSize(ULARGE_INTEGER)176 HRESULT STDMETHODCALLTYPE MemoryStream::SetSize(
177     /* [in] */ ULARGE_INTEGER /*libNewSize*/)
178 {
179     return STG_E_INVALIDFUNCTION;
180 }
181 
CopyTo(IStream * pstm,ULARGE_INTEGER cb,ULARGE_INTEGER * pcbRead,ULARGE_INTEGER * pcbWritten)182 HRESULT STDMETHODCALLTYPE MemoryStream::CopyTo(
183     /* [unique][in] */ IStream* pstm,
184     /* [in] */ ULARGE_INTEGER cb,
185     /* [out] */ ULARGE_INTEGER* pcbRead,
186     /* [out] */ ULARGE_INTEGER* pcbWritten)
187 {
188     if (!m_buffer)
189         return E_FAIL;
190     if (cb.HighPart) {
191         cb.HighPart = 0;
192         cb.LowPart = (DWORD)-1;
193     }
194 
195     ULONG written;
196     ULONG read = min(cb.LowPart, (ULONG)(m_buffer->size()-m_pos));
197     HRESULT hr = pstm->Write(m_buffer->data()+m_pos, read, &written);
198     if (pcbWritten) {
199         pcbWritten->HighPart = 0;
200         pcbWritten->LowPart = written;
201     }
202     if (pcbRead) {
203         pcbRead->HighPart = 0;
204         pcbRead->LowPart = read;
205     }
206 
207     return hr;
208 }
209 
Commit(DWORD)210 HRESULT STDMETHODCALLTYPE MemoryStream::Commit(
211     /* [in] */ DWORD /*grfCommitFlags*/)
212 {
213     return S_OK;
214 }
215 
Revert(void)216 HRESULT STDMETHODCALLTYPE MemoryStream::Revert( void)
217 {
218     return S_OK;
219 }
220 
LockRegion(ULARGE_INTEGER,ULARGE_INTEGER,DWORD)221 HRESULT STDMETHODCALLTYPE MemoryStream::LockRegion(
222     /* [in] */ ULARGE_INTEGER /*libOffset*/,
223     /* [in] */ ULARGE_INTEGER /*cb*/,
224     /* [in] */ DWORD /*dwLockType*/)
225 {
226     return STG_E_INVALIDFUNCTION;
227 }
228 
UnlockRegion(ULARGE_INTEGER,ULARGE_INTEGER,DWORD)229 HRESULT STDMETHODCALLTYPE MemoryStream::UnlockRegion(
230     /* [in] */ ULARGE_INTEGER /*libOffset*/,
231     /* [in] */ ULARGE_INTEGER /*cb*/,
232     /* [in] */ DWORD /*dwLockType*/)
233 {
234     return STG_E_INVALIDFUNCTION;
235 }
236 
Stat(STATSTG * pstatstg,DWORD)237 HRESULT STDMETHODCALLTYPE MemoryStream::Stat(
238     /* [out] */ STATSTG* pstatstg,
239     /* [in] */ DWORD /*grfStatFlag*/)
240 {
241     if (!pstatstg)
242         return E_POINTER;
243 
244     if (!m_buffer)
245         return E_FAIL;
246 
247     memset(pstatstg, 0, sizeof(STATSTG));
248     pstatstg->type = STGTY_STREAM;
249     pstatstg->cbSize.LowPart = (DWORD) m_buffer->size();
250     return S_OK;
251 }
252 
Clone(IStream ** ppstm)253 HRESULT STDMETHODCALLTYPE MemoryStream::Clone(
254     /* [out] */ IStream** ppstm)
255 {
256     MemoryStream::createInstance(m_buffer).copyRefTo(ppstm);
257     // FIXME: MSDN says we should be returning STG_E_INSUFFICIENT_MEMORY instead of E_OUTOFMEMORY here.
258     return (*ppstm) ? S_OK : E_OUTOFMEMORY;
259 }
260