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1 // Copyright 2015 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 #ifndef STORAGE_BROWSER_BLOB_BLOB_ASYNC_TRANSPORT_STRATEGY_H_ | |
6 #define STORAGE_BROWSER_BLOB_BLOB_ASYNC_TRANSPORT_STRATEGY_H_ | |
7 | |
8 #include <map> | |
9 #include <vector> | |
10 | |
11 #include "base/macros.h" | |
12 #include "base/memory/scoped_ptr.h" | |
13 #include "storage/browser/blob/blob_data_builder.h" | |
14 #include "storage/browser/storage_browser_export.h" | |
15 #include "storage/common/blob_storage/blob_item_bytes_request.h" | |
16 #include "storage/common/data_element.h" | |
17 | |
18 namespace storage { | |
19 | |
20 // This class computes and stores the strategy for asynchronously transporting | |
21 // memory from the renderer to the browser. We take memory constraints of our | |
22 // system and the description of a blob, and figure out: | |
23 // 1) How to store the blob data in the browser process: in memory or on disk. | |
24 // 2) How to transport the data from the renderer: ipc payload, shared memory, | |
25 // or file handles. | |
26 // We then generate data requests for that blob's memory and seed a | |
27 // BlobDataBuilder for storing that data. | |
28 // | |
29 // Note: This class does not compute requests by using the 'shortcut' method, | |
30 // where the data is already present in the blob description, and will | |
31 // always give the caller the full strategy for requesting all data from | |
32 // the renderer. | |
33 class STORAGE_EXPORT BlobAsyncTransportStrategy { | |
34 public: | |
35 enum Error { | |
36 ERROR_NONE = 0, | |
37 ERROR_TOO_LARGE, // This item can't fit in disk or memory | |
38 ERROR_INVALID_PARAMS | |
39 }; | |
40 | |
41 struct RendererMemoryItemRequest { | |
42 RendererMemoryItemRequest(); | |
43 // This is the index of the item in the builder on the browser side. | |
44 size_t browser_item_index; | |
45 // Note: For files this offset should always be 0, as the file offset in | |
46 // segmentation is handled by the handle_offset in the message. This | |
47 // offset is used for populating a chunk when the data comes back to | |
48 // the browser. | |
49 size_t browser_item_offset; | |
50 BlobItemBytesRequest message; | |
51 bool received; | |
52 }; | |
53 | |
54 BlobAsyncTransportStrategy(); | |
55 virtual ~BlobAsyncTransportStrategy(); | |
56 | |
57 // This call does the computation to create the requests and builder for the | |
58 // blob given the memory constraints and blob description. |memory_available| | |
59 // is the total amount of memory we can offer for storing blobs. | |
60 // This method can only be called once. | |
61 void Initialize(size_t max_ipc_memory_size, | |
62 size_t max_shared_memory_size, | |
63 uint64_t max_file_size, | |
64 uint64_t disk_space_left, | |
65 size_t memory_available, | |
66 const std::string& uuid, | |
67 const std::vector<DataElement>& blob_item_infos); | |
68 | |
69 // The sizes of the file handles being used (by handle index) in the async | |
70 // operation. | |
71 const std::vector<uint64_t>& file_handle_sizes() const { | |
72 return file_handle_sizes_; | |
73 } | |
74 | |
75 // The sizes of the shared memory handles being used (by handle index) in the | |
76 // async operation. | |
77 const std::vector<size_t>& shared_memory_handle_sizes() const { | |
78 return shared_memory_handle_sizes_; | |
79 } | |
80 | |
81 // The requests for memory, segmented as described above, along with their | |
82 // destination browser indexes and offsets. | |
83 const std::vector<RendererMemoryItemRequest>& requests() const { | |
84 return requests_; | |
85 } | |
86 | |
87 // Marks the request at the given request number as recieved. | |
88 void MarkRequestAsReceived(size_t request_num) { | |
89 DCHECK_LT(request_num, requests_.size()); | |
90 requests_[request_num].received = true; | |
91 } | |
92 | |
93 // A BlobDataBuilder which can be used to construct the Blob in the | |
94 // BlobStorageContext object after: | |
95 // * The bytes items from AppendFutureData are populated by | |
96 // PopulateFutureData. | |
97 // * The temporary files from AppendFutureFile are populated by | |
98 // PopulateFutureFile. | |
99 BlobDataBuilder* blob_builder() { return builder_.get(); } | |
100 | |
101 // The total bytes size of memory items in the blob. | |
102 uint64_t total_bytes_size() const { return total_bytes_size_; } | |
103 | |
104 Error error() const { return error_; } | |
105 | |
106 static bool ShouldBeShortcut(const std::vector<DataElement>& items, | |
107 size_t memory_available); | |
108 | |
109 private: | |
110 template <typename SizeType> | |
111 static void ComputeHandleSizes(SizeType total_memory_size, | |
112 SizeType max_segment_size, | |
113 std::vector<SizeType>* segment_sizes); | |
114 | |
115 Error error_; | |
116 | |
117 std::vector<uint64_t> file_handle_sizes_; | |
michaeln
2015/11/25 23:34:54
Might be more trouble than its worth to have the t
dmurph
2015/11/26 00:37:07
I don't see why we need to add that restriction, i
michaeln
2015/11/30 21:07:26
Since the source of the data for these files is bl
dmurph
2015/11/30 21:33:28
It was a joke about Bill Gates haha.
I was thinki
michaeln
2015/11/30 21:57:19
I guess its true that crazy api usage can describe
| |
118 std::vector<size_t> shared_memory_handle_sizes_; | |
119 | |
120 uint64_t total_bytes_size_; | |
121 std::vector<RendererMemoryItemRequest> requests_; | |
122 scoped_ptr<BlobDataBuilder> builder_; | |
123 | |
124 DISALLOW_COPY_AND_ASSIGN(BlobAsyncTransportStrategy); | |
125 }; | |
126 | |
127 } // namespace storage | |
128 | |
129 #endif // STORAGE_BROWSER_BLOB_BLOB_ASYNC_TRANSPORT_STRATEGY_H_ | |
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