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

net/url_request/url_request_http_job.cc

Index: net/url_request/url_request_http_job.cc
diff --git a/net/url_request/url_request_http_job.cc b/net/url_request/url_request_http_job.cc
index 51b690824301e8a7bcdb5cbd1f2333d4469858f6..66a51a05ea516e51c83b263b30eb22c0b2033d7f 100644
--- a/net/url_request/url_request_http_job.cc
+++ b/net/url_request/url_request_http_job.cc
@@ -33,6 +33,7 @@
 #include "net/base/url_util.h"
 #include "net/cert/cert_status_flags.h"
 #include "net/cookies/cookie_store.h"
+#include "net/filter/stream_source_util.h"
 #include "net/http/http_content_disposition.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_request_headers.h"
@@ -161,88 +162,6 @@ void LogChannelIDAndCookieStores(const GURL& url,
 
 namespace net {
 
-class URLRequestHttpJob::HttpFilterContext : public FilterContext {
- public:
-  explicit HttpFilterContext(URLRequestHttpJob* job);
-  ~HttpFilterContext() override;
-
-  // FilterContext implementation.
-  bool GetMimeType(std::string* mime_type) const override;
-  bool GetURL(GURL* gurl) const override;
-  base::Time GetRequestTime() const override;
-  bool IsCachedContent() const override;
-  SdchManager::DictionarySet* SdchDictionariesAdvertised() const override;
-  int64_t GetByteReadCount() const override;
-  int GetResponseCode() const override;
-  const URLRequestContext* GetURLRequestContext() const override;
-  void RecordPacketStats(StatisticSelector statistic) const override;
-  const BoundNetLog& GetNetLog() const override;
-
- private:
-  URLRequestHttpJob* job_;
-
-  // URLRequestHttpJob may be detached from URLRequest, but we still need to
-  // return something.
-  BoundNetLog dummy_log_;
-
-  DISALLOW_COPY_AND_ASSIGN(HttpFilterContext);
-};
-
-URLRequestHttpJob::HttpFilterContext::HttpFilterContext(URLRequestHttpJob* job)
-    : job_(job) {
-  DCHECK(job_);
-}
-
-URLRequestHttpJob::HttpFilterContext::~HttpFilterContext() {
-}
-
-bool URLRequestHttpJob::HttpFilterContext::GetMimeType(
-    std::string* mime_type) const {
-  return job_->GetMimeType(mime_type);
-}
-
-bool URLRequestHttpJob::HttpFilterContext::GetURL(GURL* gurl) const {
-  if (!job_->request())
-    return false;
-  *gurl = job_->request()->url();
-  return true;
-}
-
-base::Time URLRequestHttpJob::HttpFilterContext::GetRequestTime() const {
-  return job_->request() ? job_->request()->request_time() : base::Time();
-}
-
-bool URLRequestHttpJob::HttpFilterContext::IsCachedContent() const {
-  return job_->is_cached_content_;
-}
-
-SdchManager::DictionarySet*
-URLRequestHttpJob::HttpFilterContext::SdchDictionariesAdvertised() const {
-  return job_->dictionaries_advertised_.get();
-}
-
-int64_t URLRequestHttpJob::HttpFilterContext::GetByteReadCount() const {
-  return job_->prefilter_bytes_read();
-}
-
-int URLRequestHttpJob::HttpFilterContext::GetResponseCode() const {
-  return job_->GetResponseCode();
-}
-
-const URLRequestContext*
-URLRequestHttpJob::HttpFilterContext::GetURLRequestContext() const {
-  return job_->request() ? job_->request()->context() : NULL;
-}
-
-void URLRequestHttpJob::HttpFilterContext::RecordPacketStats(
-    StatisticSelector statistic) const {
-  job_->RecordPacketStats(statistic);
-}
-
-const BoundNetLog& URLRequestHttpJob::HttpFilterContext::GetNetLog() const {
-  return job_->request() ? job_->request()->net_log() : dummy_log_;
-}
-
 // TODO(darin): make sure the port blocking code is not lost
 // static
 URLRequestJob* URLRequestHttpJob::Factory(URLRequest* request,
@@ -294,7 +213,6 @@ URLRequestHttpJob::URLRequestHttpJob(
       bytes_observed_in_packets_(0),
       request_time_snapshot_(),
       final_packet_time_(),
-      filter_context_(new HttpFilterContext(this)),
       on_headers_received_callback_(
           base::Bind(&URLRequestHttpJob::OnHeadersReceivedCallback,
                      base::Unretained(this))),
@@ -314,6 +232,8 @@ URLRequestHttpJob::URLRequestHttpJob(
 URLRequestHttpJob::~URLRequestHttpJob() {
   CHECK(!awaiting_callback_);
 
+// FIXME: FilterContext is gone. How should we handle SDCH stats???
+#if 0
   DCHECK(!sdch_test_control_ || !sdch_test_activated_);
   if (!is_cached_content_) {
     if (sdch_test_control_)
@@ -321,9 +241,10 @@ URLRequestHttpJob::~URLRequestHttpJob() {
     if (sdch_test_activated_)
       RecordPacketStats(FilterContext::SDCH_EXPERIMENT_DECODE);
   }
+#endif
   // Make sure SDCH filters are told to emit histogram data while
   // filter_context_ is still alive.
-  DestroyFilters();
+  // DestroyFilters();
 
   DoneWithRequest(ABORTED);
 }
@@ -1228,27 +1149,13 @@ void URLRequestHttpJob::PopulateNetErrorDetails(
   return transaction_->PopulateNetErrorDetails(details);
 }
 
-Filter* URLRequestHttpJob::SetupFilter() const {
+std::unique_ptr<StreamSource> URLRequestHttpJob::SetupSource() {
   DCHECK(transaction_.get());
   if (!response_info_)
-    return NULL;
+    return nullptr;
 
-  std::vector<Filter::FilterType> encoding_types;
-  std::string encoding_type;
-  HttpResponseHeaders* headers = GetResponseHeaders();
-  size_t iter = 0;
-  while (headers->EnumerateHeader(&iter, "Content-Encoding", &encoding_type)) {
-    encoding_types.push_back(Filter::ConvertEncodingToType(encoding_type));
-  }
-
-  // Even if encoding types are empty, there is a chance that we need to add
-  // some decoding, as some proxies strip encoding completely. In such cases,
-  // we may need to add (for example) SDCH filtering (when the context suggests
-  // it is appropriate).
-  Filter::FixupEncodingTypes(*filter_context_, &encoding_types);
-
-  return !encoding_types.empty()
-      ? Filter::Factory(encoding_types, *filter_context_) : NULL;
+  return StreamSourceUtil::BuildSourceChain(URLRequestJob::SetupSource(),
+                                            GetResponseHeaders());
 }
 
 bool URLRequestHttpJob::CopyFragmentOnRedirect(const GURL& location) const {
@@ -1543,44 +1450,6 @@ void URLRequestHttpJob::UpdatePacketReadTimes() {
   bytes_observed_in_packets_ = prefilter_bytes_read();
 }
 
-void URLRequestHttpJob::RecordPacketStats(
-    FilterContext::StatisticSelector statistic) const {
-  if (!packet_timing_enabled_ || (final_packet_time_ == base::Time()))
-    return;
-
-  base::TimeDelta duration = final_packet_time_ - request_time_snapshot_;
-  switch (statistic) {
-    case FilterContext::SDCH_DECODE: {
-      UMA_HISTOGRAM_CUSTOM_COUNTS("Sdch3.Network_Decode_Bytes_Processed_b",
-          static_cast<int>(bytes_observed_in_packets_), 500, 100000, 100);
-      return;
-    }
-    case FilterContext::SDCH_PASSTHROUGH: {
-      // Despite advertising a dictionary, we handled non-sdch compressed
-      // content.
-      return;
-    }
-
-    case FilterContext::SDCH_EXPERIMENT_DECODE: {
-      UMA_HISTOGRAM_CUSTOM_TIMES("Sdch3.Experiment3_Decode",
-                                  duration,
-                                  base::TimeDelta::FromMilliseconds(20),
-                                  base::TimeDelta::FromMinutes(10), 100);
-      return;
-    }
-    case FilterContext::SDCH_EXPERIMENT_HOLDBACK: {
-      UMA_HISTOGRAM_CUSTOM_TIMES("Sdch3.Experiment3_Holdback",
-                                  duration,
-                                  base::TimeDelta::FromMilliseconds(20),
-                                  base::TimeDelta::FromMinutes(10), 100);
-      return;
-    }
-    default:
-      NOTREACHED();
-      return;
-  }
-}
-
 void URLRequestHttpJob::RecordPerfHistograms(CompletionCause reason) {
   if (start_time_.is_null())
     return;