Adding support for the SpeechRecognition.maxAlternatives JS API parameter (Speech CL2.5)

content/browser/speech/google_streaming_remote_engine.cc

 // 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.
 
 #include "content/browser/speech/google_streaming_remote_engine.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 17 matching lines @@
 
 using content::BrowserThread;
 using content::SpeechRecognitionError;
 using content::SpeechRecognitionErrorCode;
 using content::SpeechRecognitionHypothesis;
 using content::SpeechRecognitionResult;
 using net::URLFetcher;
 
 namespace {
 
-// TODO(primiano) This shouldn't be a const, rather it should be taken from
-// maxNBest property (which is not yet implemented in WebKit).
-const int kMaxResults = 5;
 const char kDownstreamUrl[] = "/down?";
 const char kUpstreamUrl[] = "/up?";
 const speech::AudioEncoder::Codec kDefaultAudioCodec =
     speech::AudioEncoder::CODEC_FLAC;
 
 // TODO(primiano) /////////// Remove this after debug stage. /////////////////
 void DumpResponse(const std::string& response) {
   bool parse_ok;
   speech::HttpStreamingResult res;
   parse_ok = res.ParseFromString(response);
@@ skipping 264 matching lines @@
   encoder_.reset(AudioEncoder::Create(kDefaultAudioCodec,
                                       config_.audio_sample_rate,
                                       config_.audio_num_bits_per_sample));
   DCHECK(encoder_.get());
   const std::string request_key = GenerateRequestKey();
 
   // Setup downstream fetcher.
   std::vector<std::string> downstream_args;
   downstream_args.push_back("sky=" + GetWebserviceKey());
   downstream_args.push_back("pair=" + request_key);
-  downstream_args.push_back("maxresults=" + base::IntToString(kMaxResults));
-
   GURL downstream_url(GetWebserviceBaseURL() + std::string(kDownstreamUrl) +
                       JoinString(downstream_args, '&'));
   // TODO(primiano) /////////// Remove this after debug stage. /////////////
   DVLOG(1) << "Opening downstream: " + downstream_url.PathForRequest();
 
   downstream_fetcher_.reset(URLFetcher::Create(
       kDownstreamUrlFetcherIdForTests, downstream_url, URLFetcher::GET, this));
   downstream_fetcher_->SetRequestContext(url_context_);
   downstream_fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                                     net::LOAD_DO_NOT_SEND_COOKIES |
                                     net::LOAD_DO_NOT_SEND_AUTH_DATA);
   downstream_fetcher_->Start();
 
   // Setup upstream fetcher.
   // TODO(primiano) Handle config_.grammar array when it will be implemented by
   // the speech recognition webservice.
   std::vector<std::string> upstream_args;
   upstream_args.push_back("sky=" + GetWebserviceKey());
   upstream_args.push_back("pair=" + request_key);
   upstream_args.push_back(
       "lang=" + net::EscapeQueryParamValue(GetAcceptedLanguages(), true));
   upstream_args.push_back(
       config_.filter_profanities ? "pfilter=2" : "pfilter=0");
-  upstream_args.push_back("maxresults=" + base::IntToString(kMaxResults));
+  if (config_.max_hypotheses > 0U) {
+    upstream_args.push_back("maxresults=" +
+                            base::UintToString(config_.max_hypotheses));
+  }
+  // TODO(primiano) What is this client= parameter? Check with speech team.
   upstream_args.push_back("client=myapp.mycompany.com");
-  // TODO(primiano) Can we remove this feature sending audio HW information?
   if (!config_.hardware_info.empty()) {
     upstream_args.push_back(
         "xhw=" + net::EscapeQueryParamValue(config_.hardware_info, true));
   }
 
   GURL upstream_url(GetWebserviceBaseURL() + std::string(kUpstreamUrl) +
                     JoinString(upstream_args, '&'));
 
   // TODO(primiano) /////////// Remove this after debug stage. /////////////////
   DVLOG(1) << "Opening upstream: " + upstream_url.PathForRequest();
@@ skipping 216 matching lines @@
 }
 
 GoogleStreamingRemoteEngine::FSMEventArgs::FSMEventArgs(FSMEvent event_value)
     : event(event_value) {
 }
 
 GoogleStreamingRemoteEngine::FSMEventArgs::~FSMEventArgs() {
 }
 
 }  // namespace speech