1 // Copyright (c) 2013 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_BROWSER_STREAMS_STREAM_H_ 6 #define CONTENT_BROWSER_STREAMS_STREAM_H_ 7 8 #include "base/basictypes.h" 9 #include "base/memory/ref_counted.h" 10 #include "base/memory/weak_ptr.h" 11 #include "content/browser/byte_stream.h" 12 #include "content/common/content_export.h" 13 #include "url/gurl.h" 14 15 namespace net { 16 class IOBuffer; 17 } 18 19 namespace content { 20 21 class StreamHandle; 22 class StreamHandleImpl; 23 class StreamReadObserver; 24 class StreamRegistry; 25 class StreamWriteObserver; 26 27 // A stream that sends data from an arbitrary source to an internal URL 28 // that can be read by an internal consumer. It will continue to pull from the 29 // original URL as long as there is data available. It can be read from 30 // multiple clients, but only one can be reading at a time. This allows a 31 // reader to consume part of the stream, then pass it along to another client 32 // to continue processing the stream. 33 class CONTENT_EXPORT Stream : public base::RefCountedThreadSafe<Stream> { 34 public: 35 enum StreamState { 36 STREAM_HAS_DATA, 37 STREAM_COMPLETE, 38 STREAM_EMPTY, 39 STREAM_ABORTED, 40 }; 41 42 // Creates a stream. 43 // 44 // Security origin of Streams is checked in Blink (See BlobRegistry, 45 // BlobURL and SecurityOrigin to understand how it works). There's no security 46 // origin check in Chromium side for now. 47 Stream(StreamRegistry* registry, 48 StreamWriteObserver* write_observer, 49 const GURL& url); 50 51 // Sets the reader of this stream. Returns true on success, or false if there 52 // is already a reader. 53 bool SetReadObserver(StreamReadObserver* observer); 54 55 // Removes the read observer. |observer| must be the current observer. 56 void RemoveReadObserver(StreamReadObserver* observer); 57 58 // Removes the write observer. |observer| must be the current observer. 59 void RemoveWriteObserver(StreamWriteObserver* observer); 60 61 // Stops accepting new data, clears all buffer, unregisters this stream from 62 // |registry_| and make coming ReadRawData() calls return STREAM_ABORTED. 63 void Abort(); 64 65 // Adds the data in |buffer| to the stream. Takes ownership of |buffer|. 66 void AddData(scoped_refptr<net::IOBuffer> buffer, size_t size); 67 // Adds data of |size| at |data| to the stream. This method creates a copy 68 // of the data, and then passes it to |writer_|. 69 void AddData(const char* data, size_t size); 70 71 // Notifies this stream that it will not be receiving any more data. 72 void Finalize(); 73 74 // Reads a maximum of |buf_size| from the stream into |buf|. Sets 75 // |*bytes_read| to the number of bytes actually read. 76 // Returns STREAM_HAS_DATA if data was read, STREAM_EMPTY if no data was read, 77 // and STREAM_COMPLETE if the stream is finalized and all data has been read. 78 StreamState ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read); 79 80 scoped_ptr<StreamHandle> CreateHandle(const GURL& original_url, 81 const std::string& mime_type); 82 void CloseHandle(); 83 84 // Indicates whether there is space in the buffer to add more data. can_add_data()85 bool can_add_data() const { return can_add_data_; } 86 url()87 const GURL& url() const { return url_; } 88 89 // For StreamRegistry to remember the last memory usage reported to it. last_total_buffered_bytes()90 size_t last_total_buffered_bytes() const { 91 return last_total_buffered_bytes_; 92 } 93 94 private: 95 friend class base::RefCountedThreadSafe<Stream>; 96 97 virtual ~Stream(); 98 99 void OnSpaceAvailable(); 100 void OnDataAvailable(); 101 102 // Clears |data_| and related variables. 103 void ClearBuffer(); 104 105 bool can_add_data_; 106 107 GURL url_; 108 109 // Buffer for storing data read from |reader_| but not yet read out from this 110 // Stream by ReadRawData() method. 111 scoped_refptr<net::IOBuffer> data_; 112 // Number of bytes read from |reader_| into |data_| including bytes already 113 // read out. 114 size_t data_length_; 115 // Number of bytes in |data_| that are already read out. 116 size_t data_bytes_read_; 117 118 // Last value returned by writer_->TotalBufferedBytes() in AddData(). Stored 119 // in order to check memory usage. 120 size_t last_total_buffered_bytes_; 121 122 scoped_ptr<ByteStreamWriter> writer_; 123 scoped_ptr<ByteStreamReader> reader_; 124 125 StreamRegistry* registry_; 126 StreamReadObserver* read_observer_; 127 StreamWriteObserver* write_observer_; 128 129 StreamHandleImpl* stream_handle_; 130 131 base::WeakPtrFactory<Stream> weak_ptr_factory_; 132 DISALLOW_COPY_AND_ASSIGN(Stream); 133 }; 134 135 } // namespace content 136 137 #endif // CONTENT_BROWSER_STREAMS_STREAM_H_ 138