OLD | NEW |
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "content/browser/loader/resource_buffer.h" | 5 #include "content/browser/loader/resource_buffer.h" |
6 | 6 |
7 #include <math.h> | 7 #include <math.h> |
8 | 8 |
9 #include "base/logging.h" | 9 #include "base/logging.h" |
10 | 10 |
(...skipping 26 matching lines...) Expand all Loading... |
37 alloc_start_(-1), | 37 alloc_start_(-1), |
38 alloc_end_(-1) { | 38 alloc_end_(-1) { |
39 } | 39 } |
40 | 40 |
41 ResourceBuffer::~ResourceBuffer() { | 41 ResourceBuffer::~ResourceBuffer() { |
42 } | 42 } |
43 | 43 |
44 bool ResourceBuffer::Initialize(int buffer_size, | 44 bool ResourceBuffer::Initialize(int buffer_size, |
45 int min_allocation_size, | 45 int min_allocation_size, |
46 int max_allocation_size) { | 46 int max_allocation_size) { |
47 DCHECK(!IsInitialized()); | 47 CHECK(!IsInitialized()); |
48 | 48 |
49 // It would be wasteful if these are not multiples of min_allocation_size. | 49 // It would be wasteful if these are not multiples of min_allocation_size. |
50 DCHECK_EQ(0, buffer_size % min_allocation_size); | 50 CHECK_EQ(0, buffer_size % min_allocation_size); |
51 DCHECK_EQ(0, max_allocation_size % min_allocation_size); | 51 CHECK_EQ(0, max_allocation_size % min_allocation_size); |
52 | 52 |
53 buf_size_ = buffer_size; | 53 buf_size_ = buffer_size; |
54 min_alloc_size_ = min_allocation_size; | 54 min_alloc_size_ = min_allocation_size; |
55 max_alloc_size_ = max_allocation_size; | 55 max_alloc_size_ = max_allocation_size; |
56 | 56 |
57 return shared_mem_.CreateAndMapAnonymous(buf_size_); | 57 return shared_mem_.CreateAndMapAnonymous(buf_size_); |
58 } | 58 } |
59 | 59 |
60 bool ResourceBuffer::IsInitialized() const { | 60 bool ResourceBuffer::IsInitialized() const { |
61 return shared_mem_.memory() != NULL; | 61 return shared_mem_.memory() != NULL; |
62 } | 62 } |
63 | 63 |
64 bool ResourceBuffer::ShareToProcess( | 64 bool ResourceBuffer::ShareToProcess( |
65 base::ProcessHandle process_handle, | 65 base::ProcessHandle process_handle, |
66 base::SharedMemoryHandle* shared_memory_handle, | 66 base::SharedMemoryHandle* shared_memory_handle, |
67 int* shared_memory_size) { | 67 int* shared_memory_size) { |
68 DCHECK(IsInitialized()); | 68 CHECK(IsInitialized()); |
69 | 69 |
70 if (!shared_mem_.ShareToProcess(process_handle, shared_memory_handle)) | 70 if (!shared_mem_.ShareToProcess(process_handle, shared_memory_handle)) |
71 return false; | 71 return false; |
72 | 72 |
73 *shared_memory_size = buf_size_; | 73 *shared_memory_size = buf_size_; |
74 return true; | 74 return true; |
75 } | 75 } |
76 | 76 |
77 bool ResourceBuffer::CanAllocate() const { | 77 bool ResourceBuffer::CanAllocate() const { |
78 DCHECK(IsInitialized()); | 78 CHECK(IsInitialized()); |
79 | 79 |
80 if (alloc_start_ == -1) | 80 if (alloc_start_ == -1) |
81 return true; | 81 return true; |
82 | 82 |
83 int diff = alloc_end_ - alloc_start_; | 83 int diff = alloc_end_ - alloc_start_; |
84 if (diff > 0) | 84 if (diff > 0) |
85 return (buf_size_ - diff) >= min_alloc_size_; | 85 return (buf_size_ - diff) >= min_alloc_size_; |
86 | 86 |
87 return -diff >= min_alloc_size_; | 87 return -diff >= min_alloc_size_; |
88 } | 88 } |
89 | 89 |
90 char* ResourceBuffer::Allocate(int* size) { | 90 char* ResourceBuffer::Allocate(int* size) { |
91 DCHECK(CanAllocate()); | 91 CHECK(CanAllocate()); |
92 | 92 |
93 int alloc_offset = 0; | 93 int alloc_offset = 0; |
94 int alloc_size; | 94 int alloc_size; |
95 | 95 |
96 if (alloc_start_ == -1) { | 96 if (alloc_start_ == -1) { |
97 // This is the first allocation. | 97 // This is the first allocation. |
98 alloc_start_ = 0; | 98 alloc_start_ = 0; |
99 alloc_end_ = buf_size_; | 99 alloc_end_ = buf_size_; |
100 alloc_size = buf_size_; | 100 alloc_size = buf_size_; |
101 } else if (alloc_start_ < alloc_end_) { | 101 } else if (alloc_start_ < alloc_end_) { |
102 // Append the next allocation if it fits. Otherwise, wraparound. | 102 // Append the next allocation if it fits. Otherwise, wraparound. |
103 // | 103 // |
104 // NOTE: We could look to see if a larger allocation is possible by | 104 // NOTE: We could look to see if a larger allocation is possible by |
105 // wrapping around sooner, but instead we just look to fill the space at | 105 // wrapping around sooner, but instead we just look to fill the space at |
106 // the end of the buffer provided that meets the min_alloc_size_ | 106 // the end of the buffer provided that meets the min_alloc_size_ |
107 // requirement. | 107 // requirement. |
108 // | 108 // |
109 if ((buf_size_ - alloc_end_) >= min_alloc_size_) { | 109 if ((buf_size_ - alloc_end_) >= min_alloc_size_) { |
110 alloc_offset = alloc_end_; | 110 alloc_offset = alloc_end_; |
111 alloc_size = buf_size_ - alloc_end_; | 111 alloc_size = buf_size_ - alloc_end_; |
112 alloc_end_ = buf_size_; | 112 alloc_end_ = buf_size_; |
113 } else { | 113 } else { |
114 // It must be possible to allocate a least min_alloc_size_. | 114 // It must be possible to allocate a least min_alloc_size_. |
115 DCHECK(alloc_start_ >= min_alloc_size_); | 115 CHECK(alloc_start_ >= min_alloc_size_); |
116 alloc_size = alloc_start_; | 116 alloc_size = alloc_start_; |
117 alloc_end_ = alloc_start_; | 117 alloc_end_ = alloc_start_; |
118 } | 118 } |
119 } else { | 119 } else { |
120 // This is the wraparound case. | 120 // This is the wraparound case. |
121 DCHECK(alloc_end_ < alloc_start_); | 121 CHECK(alloc_end_ < alloc_start_); |
122 alloc_offset = alloc_end_; | 122 alloc_offset = alloc_end_; |
123 alloc_size = alloc_start_ - alloc_end_; | 123 alloc_size = alloc_start_ - alloc_end_; |
124 alloc_end_ = alloc_start_; | 124 alloc_end_ = alloc_start_; |
125 } | 125 } |
126 | 126 |
127 // Make sure alloc_size does not exceed max_alloc_size_. We store the | 127 // Make sure alloc_size does not exceed max_alloc_size_. We store the |
128 // current value of alloc_size, so that we can use ShrinkLastAllocation to | 128 // current value of alloc_size, so that we can use ShrinkLastAllocation to |
129 // trim it back. This allows us to reuse the alloc_end_ adjustment logic. | 129 // trim it back. This allows us to reuse the alloc_end_ adjustment logic. |
130 | 130 |
131 alloc_sizes_.push(alloc_size); | 131 alloc_sizes_.push(alloc_size); |
132 | 132 |
133 if (alloc_size > max_alloc_size_) { | 133 if (alloc_size > max_alloc_size_) { |
134 alloc_size = max_alloc_size_; | 134 alloc_size = max_alloc_size_; |
135 ShrinkLastAllocation(alloc_size); | 135 ShrinkLastAllocation(alloc_size); |
136 } | 136 } |
137 | 137 |
138 *size = alloc_size; | 138 *size = alloc_size; |
139 return static_cast<char*>(shared_mem_.memory()) + alloc_offset; | 139 return static_cast<char*>(shared_mem_.memory()) + alloc_offset; |
140 } | 140 } |
141 | 141 |
142 int ResourceBuffer::GetLastAllocationOffset() const { | 142 int ResourceBuffer::GetLastAllocationOffset() const { |
143 DCHECK(!alloc_sizes_.empty()); | 143 CHECK(!alloc_sizes_.empty()); |
144 DCHECK(alloc_end_ >= alloc_sizes_.back()); | 144 CHECK(alloc_end_ >= alloc_sizes_.back()); |
145 return alloc_end_ - alloc_sizes_.back(); | 145 return alloc_end_ - alloc_sizes_.back(); |
146 } | 146 } |
147 | 147 |
148 void ResourceBuffer::ShrinkLastAllocation(int new_size) { | 148 void ResourceBuffer::ShrinkLastAllocation(int new_size) { |
149 DCHECK(!alloc_sizes_.empty()); | 149 CHECK(!alloc_sizes_.empty()); |
150 | 150 |
151 int aligned_size = (new_size / min_alloc_size_) * min_alloc_size_; | 151 int aligned_size = (new_size / min_alloc_size_) * min_alloc_size_; |
152 if (aligned_size < new_size) | 152 if (aligned_size < new_size) |
153 aligned_size += min_alloc_size_; | 153 aligned_size += min_alloc_size_; |
154 | 154 |
155 DCHECK_LE(new_size, aligned_size); | 155 CHECK_LE(new_size, aligned_size); |
156 DCHECK_GE(alloc_sizes_.back(), aligned_size); | 156 CHECK_GE(alloc_sizes_.back(), aligned_size); |
157 | 157 |
158 int* last_allocation_size = &alloc_sizes_.back(); | 158 int* last_allocation_size = &alloc_sizes_.back(); |
159 alloc_end_ -= (*last_allocation_size - aligned_size); | 159 alloc_end_ -= (*last_allocation_size - aligned_size); |
160 *last_allocation_size = aligned_size; | 160 *last_allocation_size = aligned_size; |
161 } | 161 } |
162 | 162 |
163 void ResourceBuffer::RecycleLeastRecentlyAllocated() { | 163 void ResourceBuffer::RecycleLeastRecentlyAllocated() { |
164 DCHECK(!alloc_sizes_.empty()); | 164 CHECK(!alloc_sizes_.empty()); |
165 int allocation_size = alloc_sizes_.front(); | 165 int allocation_size = alloc_sizes_.front(); |
166 alloc_sizes_.pop(); | 166 alloc_sizes_.pop(); |
167 | 167 |
168 alloc_start_ += allocation_size; | 168 alloc_start_ += allocation_size; |
169 DCHECK(alloc_start_ <= buf_size_); | 169 CHECK(alloc_start_ <= buf_size_); |
170 | 170 |
171 if (alloc_start_ == alloc_end_) { | 171 if (alloc_start_ == alloc_end_) { |
172 DCHECK(alloc_sizes_.empty()); | 172 CHECK(alloc_sizes_.empty()); |
173 alloc_start_ = -1; | 173 alloc_start_ = -1; |
174 alloc_end_ = -1; | 174 alloc_end_ = -1; |
175 } else if (alloc_start_ == buf_size_) { | 175 } else if (alloc_start_ == buf_size_) { |
176 DCHECK(!alloc_sizes_.empty()); | 176 CHECK(!alloc_sizes_.empty()); |
177 alloc_start_ = 0; | 177 alloc_start_ = 0; |
178 } | 178 } |
179 } | 179 } |
180 | 180 |
181 } // namespace content | 181 } // namespace content |
OLD | NEW |