[ON HOLD] Implement pull-based design for content decoding

net/url_request/url_request_job.h

Index: net/url_request/url_request_job.h
diff --git a/net/url_request/url_request_job.h b/net/url_request/url_request_job.h
index 9555b67f0f2b7ac4ced49e411d34f59ac34cd5fa..8bc3d52a7a654849c1268ccdf5a7a5be928ea082 100644
--- a/net/url_request/url_request_job.h
+++ b/net/url_request/url_request_job.h
@@ -22,6 +22,7 @@
 #include "net/base/request_priority.h"
 #include "net/base/upload_progress.h"
 #include "net/cookies/canonical_cookie.h"
+#include "net/filter/stream_source.h"
 #include "net/socket/connection_attempts.h"
 #include "net/url_request/redirect_info.h"
 #include "net/url_request/url_request.h"
@@ -47,6 +48,7 @@ class X509Certificate;
 
 class NET_EXPORT URLRequestJob : public base::PowerObserver {
  public:
+  typedef base::Callback<void(net::Error, size_t)> ReadRawCompleteCallback;
   explicit URLRequestJob(URLRequest* request,
                          NetworkDelegate* network_delegate);
   ~URLRequestJob() override;
@@ -155,7 +157,9 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
   // This class takes ownership of the returned Filter.
   //
   // The default implementation returns NULL.
-  virtual Filter* SetupFilter() const;
+  // virtual Filter* SetupFilter() const;
+
+  virtual scoped_ptr<StreamSource> SetupSource();
 
   // Called to determine if this response is a redirect.  Only makes sense
   // for some types of requests.  This method returns true if the response
@@ -252,6 +256,10 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
                                          const GURL& redirect_destination);
 
  protected:
+  // Call: req->NotifyReadCompleted
+  // By: NotifyReadComplete
+  void SourceReadComplete(Error error, size_t bytes_read);
+
   // Notifies the job that a certificate is requested.
   void NotifyCertificateRequested(SSLCertRequestInfo* cert_request_info);
 
@@ -312,15 +320,6 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
   // 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);
-
   // Whether the response is being filtered in this job.
   // Only valid after NotifyHeadersComplete() has been called.
   bool HasFilter() { return filter_ != NULL; }
@@ -342,11 +341,11 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
 
   // The number of bytes read before passing to the filter. This value reflects
   // bytes read even when there is no filter.
-  int64_t prefilter_bytes_read() const { return prefilter_bytes_read_; }
+  int64_t prefilter_bytes_read() const;
 
   // The number of bytes read after passing through the filter. This value
   // reflects bytes read even when there is no filter.
-  int64_t postfilter_bytes_read() const { return postfilter_bytes_read_; }
+  int64_t postfilter_bytes_read() const;
 
   // Turns an integer result code into an Error and a count of bytes read.
   // The semantics are:
@@ -363,21 +362,20 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
   URLRequest* request_;
 
  private:
+  friend class URLRequestJobStreamSource;

[mmenke, 2016/02/18 22:58:28]

Seems like this should just be an inner class instead.  Then you don't need it
to be a friend, or in the global namespace.

[xunjieli, 2016/03/03 23:00:09]

Done.

   // Set the status of the associated URLRequest.
   // TODO(mmenke): Make the URLRequest manage its own status.
   void SetStatus(const URLRequestStatus& status);
 
-  // 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);
 
   // Invokes ReadRawData and records bytes read if the read completes
   // synchronously.
-  Error ReadRawDataHelper(IOBuffer* buf, int buf_size, int* bytes_read);
+  Error ReadRawDataHelper(IOBuffer* buf,
+                          int buf_size,
+                          int* bytes_read,
+                          const StreamSource::OnReadCompleteCallback& callback);
 
   // 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
@@ -427,11 +425,10 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
   // NotifyDone so that it is kept in sync with the request.
   bool done_;
 
-  int64_t prefilter_bytes_read_;
-  int64_t postfilter_bytes_read_;
-
   // The data stream filter which is enabled on demand.
   scoped_ptr<Filter> filter_;
+  // TODO doc
+  scoped_ptr<StreamSource> source_;
 
   // If the filter filled its output buffer, then there is a change that it
   // still has internal data to emit, and this flag is set.
@@ -471,6 +468,11 @@ class NET_EXPORT URLRequestJob : public base::PowerObserver {
   // notification.
   int64_t last_notified_total_sent_bytes_;
 
+  ReadRawCompleteCallback read_raw_callback_;
+
+  // Raw network bytes read from job subclass.
+  size_t raw_bytes_read_;
+
   base::WeakPtrFactory<URLRequestJob> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestJob);