1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "mojo/embedder/simple_platform_shared_buffer.h"
6
7 #include "base/logging.h"
8 #include "mojo/embedder/platform_handle_utils.h"
9
10 namespace mojo {
11 namespace embedder {
12
13 // static
Create(size_t num_bytes)14 SimplePlatformSharedBuffer* SimplePlatformSharedBuffer::Create(
15 size_t num_bytes) {
16 DCHECK_GT(num_bytes, 0u);
17
18 SimplePlatformSharedBuffer* rv = new SimplePlatformSharedBuffer(num_bytes);
19 if (!rv->Init()) {
20 // We can't just delete it directly, due to the "in destructor" (debug)
21 // check.
22 scoped_refptr<SimplePlatformSharedBuffer> deleter(rv);
23 return nullptr;
24 }
25
26 return rv;
27 }
28
29 // static
30 SimplePlatformSharedBuffer*
CreateFromPlatformHandle(size_t num_bytes,ScopedPlatformHandle platform_handle)31 SimplePlatformSharedBuffer::CreateFromPlatformHandle(
32 size_t num_bytes,
33 ScopedPlatformHandle platform_handle) {
34 DCHECK_GT(num_bytes, 0u);
35
36 SimplePlatformSharedBuffer* rv = new SimplePlatformSharedBuffer(num_bytes);
37 if (!rv->InitFromPlatformHandle(platform_handle.Pass())) {
38 // We can't just delete it directly, due to the "in destructor" (debug)
39 // check.
40 scoped_refptr<SimplePlatformSharedBuffer> deleter(rv);
41 return nullptr;
42 }
43
44 return rv;
45 }
46
GetNumBytes() const47 size_t SimplePlatformSharedBuffer::GetNumBytes() const {
48 return num_bytes_;
49 }
50
Map(size_t offset,size_t length)51 scoped_ptr<PlatformSharedBufferMapping> SimplePlatformSharedBuffer::Map(
52 size_t offset,
53 size_t length) {
54 if (!IsValidMap(offset, length))
55 return scoped_ptr<PlatformSharedBufferMapping>();
56
57 return MapNoCheck(offset, length);
58 }
59
IsValidMap(size_t offset,size_t length)60 bool SimplePlatformSharedBuffer::IsValidMap(size_t offset, size_t length) {
61 if (offset > num_bytes_ || length == 0)
62 return false;
63
64 // Note: This is an overflow-safe check of |offset + length > num_bytes_|
65 // (that |num_bytes >= offset| is verified above).
66 if (length > num_bytes_ - offset)
67 return false;
68
69 return true;
70 }
71
MapNoCheck(size_t offset,size_t length)72 scoped_ptr<PlatformSharedBufferMapping> SimplePlatformSharedBuffer::MapNoCheck(
73 size_t offset,
74 size_t length) {
75 DCHECK(IsValidMap(offset, length));
76 return MapImpl(offset, length);
77 }
78
DuplicatePlatformHandle()79 ScopedPlatformHandle SimplePlatformSharedBuffer::DuplicatePlatformHandle() {
80 return mojo::embedder::DuplicatePlatformHandle(handle_.get());
81 }
82
PassPlatformHandle()83 ScopedPlatformHandle SimplePlatformSharedBuffer::PassPlatformHandle() {
84 DCHECK(HasOneRef());
85 return handle_.Pass();
86 }
87
SimplePlatformSharedBuffer(size_t num_bytes)88 SimplePlatformSharedBuffer::SimplePlatformSharedBuffer(size_t num_bytes)
89 : num_bytes_(num_bytes) {
90 }
91
~SimplePlatformSharedBuffer()92 SimplePlatformSharedBuffer::~SimplePlatformSharedBuffer() {
93 }
94
~SimplePlatformSharedBufferMapping()95 SimplePlatformSharedBufferMapping::~SimplePlatformSharedBufferMapping() {
96 Unmap();
97 }
98
GetBase() const99 void* SimplePlatformSharedBufferMapping::GetBase() const {
100 return base_;
101 }
102
GetLength() const103 size_t SimplePlatformSharedBufferMapping::GetLength() const {
104 return length_;
105 }
106
107 } // namespace embedder
108 } // namespace mojo
109