| // Copyright 2016 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 NET_FILTER_FILTER_SOURCE_STREAM_H_ |
| #define NET_FILTER_FILTER_SOURCE_STREAM_H_ |
| |
| #include <memory> |
| #include <string> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "net/base/completion_callback.h" |
| #include "net/base/net_errors.h" |
| #include "net/base/net_export.h" |
| #include "net/filter/source_stream.h" |
| |
| namespace net { |
| |
| class DrainableIOBuffer; |
| class IOBuffer; |
| |
| // FilterSourceStream represents SourceStreams that always have an upstream |
| // from which undecoded input can be read. Except the ultimate upstream in |
| // the filter chain, all other streams should implement FilterSourceStream |
| // instead of SourceStream. |
| class NET_EXPORT_PRIVATE FilterSourceStream : public SourceStream { |
| public: |
| // |upstream| is the SourceStream from which |this| will read data. |
| // |upstream| cannot be null. |
| FilterSourceStream(SourceType type, std::unique_ptr<SourceStream> upstream); |
| |
| ~FilterSourceStream() override; |
| |
| int Read(IOBuffer* read_buffer, |
| int read_buffer_size, |
| const CompletionCallback& callback) override; |
| |
| std::string Description() const override; |
| |
| private: |
| enum State { |
| STATE_NONE, |
| // Reading data from |upstream_| into |input_buffer_|. |
| STATE_READ_DATA, |
| // Reading data from |upstream_| completed. |
| STATE_READ_DATA_COMPLETE, |
| // Filtering data contained in |input_buffer_|. |
| STATE_FILTER_DATA, |
| // Filtering data contained in |input_buffer_| completed. |
| STATE_FILTER_DATA_COMPLETE, |
| STATE_DONE, |
| }; |
| |
| int DoLoop(int result); |
| int DoReadData(); |
| int DoReadDataComplete(int result); |
| int DoFilterData(); |
| |
| // Helper method used as a callback argument passed to |upstream_->Read()|. |
| void OnIOComplete(int result); |
| |
| // Subclasses should implement this method to filter data from |
| // |input_buffer| and write to |output_buffer|. |
| // This method must complete synchronously (i.e. It cannot return |
| // ERR_IO_PENDING). If an unrecoverable error occurred, this should return |
| // ERR_CONTENT_DECODING_FAILED or a more specific error code. |
| // |
| // If FilterData() returns 0, *|consumed_bytes| must be equal to |
| // |input_buffer_size|. Upstream EOF is reached when FilterData() is called |
| // with |upstream_eof_reached| = true. |
| // TODO(xunjieli): consider allowing asynchronous response via callback |
| // to support off-thread decompression. |
| virtual int FilterData(IOBuffer* output_buffer, |
| int output_buffer_size, |
| IOBuffer* input_buffer, |
| int input_buffer_size, |
| int* consumed_bytes, |
| bool upstream_eof_reached) = 0; |
| |
| // Returns a string representation of the type of this FilterSourceStream. |
| // This is for UMA logging. |
| virtual std::string GetTypeAsString() const = 0; |
| |
| // Returns whether |this| still needs more input data from |upstream_|. |
| // By default, |this| will continue reading until |upstream_| returns an error |
| // or EOF. Subclass can override this to return false to skip reading all the |
| // input from |upstream_|. |
| virtual bool NeedMoreData() const; |
| |
| // The SourceStream from which |this| will read data from. Data flows from |
| // |upstream_| to |this_|. |
| std::unique_ptr<SourceStream> upstream_; |
| |
| State next_state_; |
| |
| // Buffer for reading data out of |upstream_| and then for use by |this| |
| // before the filtered data is returned through Read(). |
| scoped_refptr<IOBuffer> input_buffer_; |
| |
| // Wrapper around |input_buffer_| that makes visible only the unread data. |
| // Keep this as a member because subclass might not drain everything in a |
| // single FilterData(). |
| scoped_refptr<DrainableIOBuffer> drainable_input_buffer_; |
| |
| // Not null if there is a pending Read. |
| scoped_refptr<IOBuffer> output_buffer_; |
| int output_buffer_size_; |
| CompletionCallback callback_; |
| |
| // Reading from |upstream_| has returned 0 byte or an error code. |
| bool upstream_end_reached_; |
| |
| DISALLOW_COPY_AND_ASSIGN(FilterSourceStream); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_FILTER_FILTER_SOURCE_STREAM_H_ |