Index: content/child/blob_storage/blob_consolidation.h |
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+// Copyright 2015 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#ifndef CONTENT_CHILD_BLOB_STORAGE_BLOB_CONSOLIDATION_H_ |
+#define CONTENT_CHILD_BLOB_STORAGE_BLOB_CONSOLIDATION_H_ |
+ |
+#include <string> |
+#include <vector> |
+ |
+#include "base/logging.h" |
+#include "base/macros.h" |
+#include "base/memory/scoped_ptr.h" |
+#include "content/common/content_export.h" |
+#include "storage/common/data_element.h" |
+#include "third_party/WebKit/public/platform/WebBlobData.h" |
+#include "third_party/WebKit/public/platform/WebString.h" |
+#include "third_party/WebKit/public/platform/WebThreadSafeData.h" |
+#include "third_party/WebKit/public/platform/WebURL.h" |
+ |
+namespace content { |
+ |
+// This class facilitates the consolidation of memory items in blobs. No memory |
+// is copied to store items in this object. Instead, the memory is copied into |
+// the external char* array given to the ReadMemory method. |
+// Features: |
+// * Add_Item methods for building the blob. |
+// * consolidated_items for getting the consolidated items. This is |
+// used to describe the blob to the browser. |
+// * total_memory to get the total memory size of the blob. |
+// * ReadMemory for reading arbitrary memory from any consolidated item. |
+// * RecordMemoryRead for recording that an amount of memory has been read from |
+// a given consolidated item. This allows this class to release memory |
+// resources once an item has been read. |
+// |
+// TODO(dmurph): Keep memory accounting per item instead of globally so we can |
+// free resources while reading instead of all at the end. |
+class CONTENT_EXPORT BlobConsolidation { |
michaeln
2015/06/17 03:17:55
Seeing the heavy use of blink:WebTypes in here, i
dmurph
2015/06/17 18:29:50
This class is going to be used elsewhere in later
michaeln
2015/06/18 00:10:48
Got it, makes sense to leave it as a separate clas
dmurph
2015/06/22 18:17:46
Whoops, missed this comment.
As discussed in pers
|
+ public: |
+ enum class ReadStatus { |
+ ERROR = 0, |
+ ERROR_WRONG_TYPE, |
+ ERROR_OUT_OF_BOUNDS, |
+ BLOB_BYTES_PENDING, |
+ DONE |
+ }; |
+ struct ConsolidatedItem { |
+ ConsolidatedItem(); |
+ ConsolidatedItem(storage::DataElement::Type type, uint64_t offset, |
+ uint64_t length); |
+ ~ConsolidatedItem(); |
+ |
+ storage::DataElement::Type type; |
+ uint64_t offset; |
+ uint64_t length; |
+ |
+ blink::WebString path; // For TYPE_FILE. |
+ blink::WebURL filesystem_url; // For TYPE_FILE_FILESYSTEM. |
+ double expected_modification_time; // For TYPE_FILE, TYPE_FILE_FILESYSTEM. |
+ blink::WebString blob_uuid; // For TYPE_BLOB. |
+ // Only populated if len(items) > 1. Used for binary search. |
+ // Since the offset of the first item is always 0, we exclude this. |
+ std::vector<size_t> offsets; // For TYPE_BYTES. |
+ std::vector<blink::WebThreadSafeData> data; // For TYPE_BYTES. |
+ }; |
+ |
+ BlobConsolidation(); |
+ ~BlobConsolidation(); |
+ |
+ void AddDataItem(const blink::WebThreadSafeData& data); |
+ void AddFileItem(const blink::WebString& path, uint64_t offset, |
+ uint64_t length, double expected_modification_time); |
+ void AddBlobItem(const blink::WebString& uuid, uint64_t offset, |
+ uint64_t length); |
+ void AddFileSystemItem(const blink::WebURL& url, uint64_t offset, |
+ uint64_t length, double expected_modification_time); |
+ |
+ // This gets the consolidated items constructed from the WebBlobData. This |
+ // is used to describe the blob to the browser. |
+ const std::vector<ConsolidatedItem>& consolidated_items() const { |
+ return consolidated_items_; |
+ } |
+ |
+ const size_t total_memory() const { return total_memory_; } |
+ |
+ // Reads memory from the given item into the given buffer. Returns: |
+ // * ReadStatus::ERROR if the state or arguments are invalid (see error log), |
+ // * ReadStatus::ERROR_WRONG_TYPE if the item at the index isn't memory, |
+ // * ReadStatus::ERROR_OUT_OF_BOUNDS if index, offset, or size are invalid, |
+ // * ReadStatus::DONE if the memory has been successfully read. |
+ ReadStatus ReadMemory(size_t consolidated_item_index, |
+ size_t consolidated_offset, size_t consolidated_size, |
+ char* memory_out); |
michaeln
2015/06/17 03:17:55
maybe void* memory_out to avoid casting at callsit
dmurph
2015/06/17 18:29:50
Done. This has the side effect of me needing to c
michaeln
2015/06/18 00:10:48
That's a fair trade, better to make life easier fo
|
+ |
+ // Records an amount of memory has been read from a given item and is no |
+ // longer needed. |
+ // * ReadStatus::ERROR if we have read more than the blob's total memory. |
+ // * ReadStatus::ERROR_WRONG_TYPE if the item at the index isn't memory, |
+ // * ReadStatus::ERROR_OUT_OF_BOUNDS if index or size are invalid, |
+ // * ReadStatus::BLOB_BYTES_PENDING if there are still bytes to be read from |
+ // this blob (not only the given item). |
+ // * ReadStatus::DONE if all bytes have been read from this blob. This object |
+ // can now be destroyed, as all bytes have been read. |
+ // TODO(dmurph): do per-item accounting, and error if we exceed per-item size. |
michaeln
2015/06/17 03:17:55
How do you anticipate using the accounting? I'm wo
dmurph
2015/06/17 18:29:50
There are two cases where the memory is read:
1. o
michaeln
2015/06/18 00:10:48
Incremental cleanup might be "nice", but I'd vote
|
+ ReadStatus RecordMemoryRead(size_t consolidated_item_index, |
+ size_t memory_size); |
+ |
+ private: |
+ size_t total_memory_; |
+ size_t total_memory_read_; |
+ std::vector<ConsolidatedItem> consolidated_items_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(BlobConsolidation); |
+}; |
+ |
+} // namespace content |
+#endif // CONTENT_CHILD_BLOB_STORAGE_BLOB_CONSOLIDATION_H_ |