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 HttpResponseHeaders; 17 class IOBuffer; 18 } 19 20 namespace content { 21 22 class StreamHandle; 23 class StreamHandleImpl; 24 class StreamReadObserver; 25 class StreamRegistry; 26 class StreamWriteObserver; 27 28 // A stream that sends data from an arbitrary source to an internal URL 29 // that can be read by an internal consumer. It will continue to pull from the 30 // original URL as long as there is data available. It can be read from 31 // multiple clients, but only one can be reading at a time. This allows a 32 // reader to consume part of the stream, then pass it along to another client 33 // to continue processing the stream. 34 class CONTENT_EXPORT Stream : public base::RefCountedThreadSafe<Stream> { 35 public: 36 enum StreamState { 37 STREAM_HAS_DATA, 38 STREAM_COMPLETE, 39 STREAM_EMPTY, 40 STREAM_ABORTED, 41 }; 42 43 // Creates a stream. 44 // 45 // Security origin of Streams is checked in Blink (See BlobRegistry, 46 // BlobURL and SecurityOrigin to understand how it works). There's no security 47 // origin check in Chromium side for now. 48 Stream(StreamRegistry* registry, 49 StreamWriteObserver* write_observer, 50 const GURL& url); 51 52 // Sets the reader of this stream. Returns true on success, or false if there 53 // is already a reader. 54 bool SetReadObserver(StreamReadObserver* observer); 55 56 // Removes the read observer. |observer| must be the current observer. 57 void RemoveReadObserver(StreamReadObserver* observer); 58 59 // Removes the write observer. |observer| must be the current observer. 60 void RemoveWriteObserver(StreamWriteObserver* observer); 61 62 // Stops accepting new data, clears all buffer, unregisters this stream from 63 // |registry_| and make coming ReadRawData() calls return STREAM_ABORTED. 64 void Abort(); 65 66 // Adds the data in |buffer| to the stream. Takes ownership of |buffer|. 67 void AddData(scoped_refptr<net::IOBuffer> buffer, size_t size); 68 // Adds data of |size| at |data| to the stream. This method creates a copy 69 // of the data, and then passes it to |writer_|. 70 void AddData(const char* data, size_t size); 71 72 // Notifies this stream that it will not be receiving any more data. 73 void Finalize(); 74 75 // Reads a maximum of |buf_size| from the stream into |buf|. Sets 76 // |*bytes_read| to the number of bytes actually read. 77 // Returns STREAM_HAS_DATA if data was read, STREAM_EMPTY if no data was read, 78 // and STREAM_COMPLETE if the stream is finalized and all data has been read. 79 StreamState ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read); 80 81 scoped_ptr<StreamHandle> CreateHandle( 82 const GURL& original_url, 83 const std::string& mime_type, 84 scoped_refptr<net::HttpResponseHeaders> response_headers); 85 void CloseHandle(); 86 87 // Indicates whether there is space in the buffer to add more data. can_add_data()88 bool can_add_data() const { return can_add_data_; } 89 url()90 const GURL& url() const { return url_; } 91 92 // For StreamRegistry to remember the last memory usage reported to it. last_total_buffered_bytes()93 size_t last_total_buffered_bytes() const { 94 return last_total_buffered_bytes_; 95 } 96 97 private: 98 friend class base::RefCountedThreadSafe<Stream>; 99 100 virtual ~Stream(); 101 102 void OnSpaceAvailable(); 103 void OnDataAvailable(); 104 105 // Clears |data_| and related variables. 106 void ClearBuffer(); 107 108 bool can_add_data_; 109 110 GURL url_; 111 112 // Buffer for storing data read from |reader_| but not yet read out from this 113 // Stream by ReadRawData() method. 114 scoped_refptr<net::IOBuffer> data_; 115 // Number of bytes read from |reader_| into |data_| including bytes already 116 // read out. 117 size_t data_length_; 118 // Number of bytes in |data_| that are already read out. 119 size_t data_bytes_read_; 120 121 // Last value returned by writer_->TotalBufferedBytes() in AddData(). Stored 122 // in order to check memory usage. 123 size_t last_total_buffered_bytes_; 124 125 scoped_ptr<ByteStreamWriter> writer_; 126 scoped_ptr<ByteStreamReader> reader_; 127 128 StreamRegistry* registry_; 129 StreamReadObserver* read_observer_; 130 StreamWriteObserver* write_observer_; 131 132 StreamHandleImpl* stream_handle_; 133 134 base::WeakPtrFactory<Stream> weak_ptr_factory_; 135 DISALLOW_COPY_AND_ASSIGN(Stream); 136 }; 137 138 } // namespace content 139 140 #endif // CONTENT_BROWSER_STREAMS_STREAM_H_ 141