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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 CONTENT_CHILD_BLOB_STORAGE_BLOB_CONSOLIDATION_H_ |
| 6 #define CONTENT_CHILD_BLOB_STORAGE_BLOB_CONSOLIDATION_H_ |
| 7 |
| 8 #include <string> |
| 9 #include <vector> |
| 10 |
| 11 #include "base/logging.h" |
| 12 #include "base/macros.h" |
| 13 #include "base/memory/scoped_ptr.h" |
| 14 #include "content/common/content_export.h" |
| 15 #include "storage/common/data_element.h" |
| 16 #include "third_party/WebKit/public/platform/WebThreadSafeData.h" |
| 17 |
| 18 namespace content { |
| 19 |
| 20 // This class facilitates the consolidation of memory items in blobs. No memory |
| 21 // is copied to store items in this object. Instead, the memory is copied into |
| 22 // the external char* array given to the ReadMemory method. |
| 23 // Features: |
| 24 // * Add_Item methods for building the blob. |
| 25 // * consolidated_items for getting the consolidated items. This is |
| 26 // used to describe the blob to the browser. |
| 27 // * total_memory to get the total memory size of the blob. |
| 28 // * ReadMemory for reading arbitrary memory from any consolidated item. |
| 29 // |
| 30 // NOTE: this class does not do memory accounting or garbage collecting. The |
| 31 // memory for the blob sticks around until this class is destructed. |
| 32 class CONTENT_EXPORT BlobConsolidation { |
| 33 public: |
| 34 enum class ReadStatus { |
| 35 ERROR_UNKNOWN, |
| 36 ERROR_WRONG_TYPE, |
| 37 ERROR_OUT_OF_BOUNDS, |
| 38 OK |
| 39 }; |
| 40 struct ConsolidatedItem { |
| 41 ConsolidatedItem(); |
| 42 ConsolidatedItem(storage::DataElement::Type type, |
| 43 uint64_t offset, |
| 44 uint64_t length); |
| 45 ~ConsolidatedItem(); |
| 46 |
| 47 storage::DataElement::Type type; |
| 48 uint64_t offset; |
| 49 uint64_t length; |
| 50 |
| 51 base::FilePath path; // For TYPE_FILE. |
| 52 GURL filesystem_url; // For TYPE_FILE_FILESYSTEM. |
| 53 double expected_modification_time; // For TYPE_FILE, TYPE_FILE_FILESYSTEM. |
| 54 std::string blob_uuid; // For TYPE_BLOB. |
| 55 // Only populated if len(items) > 1. Used for binary search. |
| 56 // Since the offset of the first item is always 0, we exclude this. |
| 57 std::vector<size_t> offsets; // For TYPE_BYTES. |
| 58 std::vector<blink::WebThreadSafeData> data; // For TYPE_BYTES. |
| 59 }; |
| 60 |
| 61 BlobConsolidation(); |
| 62 ~BlobConsolidation(); |
| 63 |
| 64 void AddDataItem(const blink::WebThreadSafeData& data); |
| 65 void AddFileItem(const base::FilePath& path, |
| 66 uint64_t offset, |
| 67 uint64_t length, |
| 68 double expected_modification_time); |
| 69 void AddBlobItem(const std::string& uuid, uint64_t offset, uint64_t length); |
| 70 void AddFileSystemItem(const GURL& url, |
| 71 uint64_t offset, |
| 72 uint64_t length, |
| 73 double expected_modification_time); |
| 74 |
| 75 // These are the resulting consolidated items, constructed from the Add* |
| 76 // methods. This configuration is used to describe the data to the browser, |
| 77 // even though one consolidated memory items can contain multiple data parts. |
| 78 const std::vector<ConsolidatedItem>& consolidated_items() const { |
| 79 return consolidated_items_; |
| 80 } |
| 81 |
| 82 size_t total_memory() const { return total_memory_; } |
| 83 |
| 84 // Reads memory from the given item into the given buffer. Returns: |
| 85 // * ReadStatus::ERROR if the state or arguments are invalid (see error log), |
| 86 // * ReadStatus::ERROR_WRONG_TYPE if the item at the index isn't memory, |
| 87 // * ReadStatus::ERROR_OUT_OF_BOUNDS if index, offset, or size are invalid, |
| 88 // * ReadStatus::DONE if the memory has been successfully read. |
| 89 // Precondition: memory_out must be a valid pointer to memory with a size of |
| 90 // at least consolidated_size. |
| 91 ReadStatus ReadMemory(size_t consolidated_item_index, |
| 92 size_t consolidated_offset, |
| 93 size_t consolidated_size, |
| 94 void* memory_out); |
| 95 |
| 96 private: |
| 97 size_t total_memory_; |
| 98 std::vector<ConsolidatedItem> consolidated_items_; |
| 99 |
| 100 DISALLOW_COPY_AND_ASSIGN(BlobConsolidation); |
| 101 }; |
| 102 |
| 103 } // namespace content |
| 104 #endif // CONTENT_CHILD_BLOB_STORAGE_BLOB_CONSOLIDATION_H_ |
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