Revert "Reland: URLRequestJob: change ReadRawData contract"

net/url_request/url_request_job.h

 // Copyright (c) 2012 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_URL_REQUEST_URL_REQUEST_JOB_H_
 #define NET_URL_REQUEST_URL_REQUEST_JOB_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/power_monitor/power_observer.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/load_states.h"
-#include "net/base/net_errors.h"
 #include "net/base/net_export.h"
 #include "net/base/request_priority.h"
 #include "net/base/upload_progress.h"
 #include "net/cookies/canonical_cookie.h"
 #include "net/socket/connection_attempts.h"
 #include "net/url_request/redirect_info.h"
 #include "net/url_request/url_request.h"
 #include "url/gurl.h"
 
 namespace net {
@@ skipping 239 matching lines @@
 
   // Delegates to URLRequest::Delegate.
   bool CanEnablePrivacyMode() const;
 
   // Notifies the job that the network is about to be used.
   void NotifyBeforeNetworkStart(bool* defer);
 
   // Notifies the job that headers have been received.
   void NotifyHeadersComplete();
 
+  // Notifies the request that the job has completed a Read operation.
+  void NotifyReadComplete(int bytes_read);
+
   // Notifies the request that a start error has occurred.
   void NotifyStartError(const URLRequestStatus& status);
 
+  // NotifyDone marks when we are done with a request.  It is really
+  // a glorified set_status, but also does internal state checking and
+  // job tracking.  It should be called once per request, when the job is
+  // finished doing all IO.
+  void NotifyDone(const URLRequestStatus& status);
+
+  // Some work performed by NotifyDone must be completed on a separate task
+  // so as to avoid re-entering the delegate.  This method exists to perform
+  // that work.
+  void CompleteNotifyDone();
+
   // Used as an asynchronous callback for Kill to notify the URLRequest
   // that we were canceled.
   void NotifyCanceled();
 
   // Notifies the job the request should be restarted.
   // Should only be called if the job has not started a response.
   void NotifyRestartRequired();
 
   // See corresponding functions in url_request.h.
   void OnCallToDelegate();
   void OnCallToDelegateComplete();
 
-  // Called to read raw (pre-filtered) data from this Job. Reads at most
-  // |buf_size| bytes into |buf|.
-  // Possible return values:
-  //   >= 0: Read completed synchronously. Return value is the number of bytes
-  //         read. 0 means eof.
-  //   ERR_IO_PENDING: Read pending asynchronously.
-  //                   When the read completes, |ReadRawDataComplete| should be
-  //                   called.
-  //   Any other negative number: Read failed synchronously. Return value is a
-  //                   network error code.
-  // This method might hold onto a reference to |buf| (by incrementing the
-  // refcount) until the method completes or is cancelled.
-  virtual int ReadRawData(IOBuffer* buf, int buf_size);
+  // Called to read raw (pre-filtered) data from this Job.
+  // If returning true, data was read from the job.  buf will contain
+  // the data, and bytes_read will receive the number of bytes read.
+  // If returning true, and bytes_read is returned as 0, there is no
+  // additional data to be read.
+  // If returning false, an error occurred or an async IO is now pending.
+  // If async IO is pending, the status of the request will be
+  // URLRequestStatus::IO_PENDING, and buf must remain available until the
+  // operation is completed.  See comments on URLRequest::Read for more
+  // info.
+  virtual bool ReadRawData(IOBuffer* buf, int buf_size, int* bytes_read);
 
   // Called to tell the job that a filter has successfully reached the end of
   // the stream.
   virtual void DoneReading();
 
   // Called to tell the job that the body won't be read because it's a redirect.
   // This is needed so that redirect headers can be cached even though their
   // bodies are never read.
   virtual void DoneReadingRedirectResponse();
 
-  // Reads filtered data from the request. Returns OK if immediately successful,
-  // ERR_IO_PENDING if the request couldn't complete synchronously, and some
-  // other error code if the request failed synchronously. Note that this
-  // function can issue new asynchronous requests if needed, in which case it
-  // returns ERR_IO_PENDING. If this method completes synchronously,
-  // |*bytes_read| is the number of bytes output by the filter chain if this
-  // method returns OK, or zero if this method returns an error.
-  Error ReadFilteredData(int* bytes_read);
+  // Informs the filter that data has been read into its buffer
+  void FilteredDataRead(int bytes_read);
+
+  // Reads filtered data from the request.  Returns true if successful,
+  // false otherwise.  Note, if there is not enough data received to
+  // return data, this call can issue a new async IO request under
+  // the hood.
+  bool ReadFilteredData(int* bytes_read);
 
   // Whether the response is being filtered in this job.
   // Only valid after NotifyHeadersComplete() has been called.
   bool HasFilter() { return filter_ != NULL; }
 
   // At or near destruction time, a derived class may request that the filters
   // be destroyed so that statistics can be gathered while the derived class is
   // still present to assist in calculations.  This is used by URLRequestHttpJob
   // to get SDCH to emit stats.
   void DestroyFilters();
@@ skipping 11 matching lines @@
   void SetProxyServer(const HostPortPair& proxy_server);
 
   // The number of bytes read before passing to the filter. This value reflects
   // bytes read even when there is no filter.
   int64 prefilter_bytes_read() const { return prefilter_bytes_read_; }
 
   // The number of bytes read after passing through the filter. This value
   // reflects bytes read even when there is no filter.
   int64 postfilter_bytes_read() const { return postfilter_bytes_read_; }
 
-  // Turns an integer result code into an Error and a count of bytes read.
-  // The semantics are:
-  //   |result| >= 0: |*error| == OK, |*count| == |result|
-  //   |result| < 0: |*error| = |result|, |*count| == 0
-  static void ConvertResultToError(int result, Error* error, int* count);
-
-  // Completion callback for raw reads. See |ReadRawData| for details.
-  // |bytes_read| is either >= 0 to indicate a successful read and count of
-  // bytes read, or < 0 to indicate an error.
-  void ReadRawDataComplete(int bytes_read);
-
   // The request that initiated this job. This value MAY BE NULL if the
   // request was released by DetachRequest().
   URLRequest* request_;
 
  private:
   // When data filtering is enabled, this function is used to read data
-  // for the filter. Returns a net error code to indicate if raw data was
-  // successfully read,  an error happened, or the IO is pending.
-  Error ReadRawDataForFilter(int* bytes_read);
-
-  // Informs the filter chain that data has been read into its buffer.
-  void PushInputToFilter(int bytes_read);
+  // for the filter.  Returns true if raw data was read.  Returns false if
+  // an error occurred (or we are waiting for IO to complete).
+  bool ReadRawDataForFilter(int* bytes_read);
 
   // Invokes ReadRawData and records bytes read if the read completes
   // synchronously.
-  Error ReadRawDataHelper(IOBuffer* buf, int buf_size, int* bytes_read);
+  bool ReadRawDataHelper(IOBuffer* buf, int buf_size, int* bytes_read);
 
   // Called in response to a redirect that was not canceled to follow the
   // redirect. The current job will be replaced with a new job loading the
   // given redirect destination.
   void FollowRedirect(const RedirectInfo& redirect_info);
 
   // Called after every raw read. If |bytes_read| is > 0, this indicates
   // a successful read of |bytes_read| unfiltered bytes. If |bytes_read|
-  // is 0, this indicates that there is no additional data to read. |error|
-  // specifies whether an error occurred and no bytes were read.
-  void GatherRawReadStats(Error error, int bytes_read);
+  // is 0, this indicates that there is no additional data to read. If
+  // |bytes_read| is < 0, an error occurred and no bytes were read.
+  void OnRawReadComplete(int bytes_read);
 
   // Updates the profiling info and notifies observers that an additional
   // |bytes_read| unfiltered bytes have been read for this job.
   void RecordBytesRead(int bytes_read);
 
   // Called to query whether there is data available in the filter to be read
   // out.
   bool FilterHasData();
 
-  // NotifyDone marks that request is done. It is really a glorified
-  // set_status, but also does internal state checking and job tracking. It
-  // should be called once per request, when the job is finished doing all IO.
-  void NotifyDone(const URLRequestStatus& status);
-
-  // Some work performed by NotifyDone must be completed asynchronously so
-  // as to avoid re-entering URLRequest::Delegate. This method performs that
-  // work.
-  void CompleteNotifyDone();
-
   // Subclasses may implement this method to record packet arrival times.
   // The default implementation does nothing.  Only invoked when bytes have been
   // read since the last invocation.
   virtual void UpdatePacketReadTimes();
 
   // Computes a new RedirectInfo based on receiving a redirect response of
   // |location| and |http_status_code|.
   RedirectInfo ComputeRedirectInfo(const GURL& location, int http_status_code);
 
   // Notify the network delegate that more bytes have been received or sent over
@@ skipping 51 matching lines @@
   int64_t last_notified_total_sent_bytes_;
 
   base::WeakPtrFactory<URLRequestJob> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestJob);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_JOB_H_