Restructure SDCH layering to allow more separation (observer/1->[0,n]

net/base/sdch_manager.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 "net/base/sdch_manager.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "crypto/sha2.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "net/base/sdch_observer.h"
 #include "net/url_request/url_request_http_job.h"
 
 namespace {
 
 void StripTrailingDot(GURL* gurl) {
   std::string host(gurl->host());
 
   if (host.empty())
     return;
 
@@ skipping 215 matching lines @@
 }
 
 // static
 bool SdchManager::Dictionary::DomainMatch(const GURL& gurl,
                                           const std::string& restriction) {
   // TODO(jar): This is not precisely a domain match definition.
   return gurl.DomainIs(restriction.data(), restriction.size());
 }
 
 //------------------------------------------------------------------------------
-SdchManager::SdchManager()
-    : fetches_count_for_testing_(0) {
-  DCHECK(CalledOnValidThread());
+SdchManager::SdchManager() {
+  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 SdchManager::~SdchManager() {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   while (!dictionaries_.empty()) {
     DictionaryMap::iterator it = dictionaries_.begin();
     dictionaries_.erase(it->first);
   }
 }
 
 void SdchManager::ClearData() {
   blacklisted_domains_.clear();
   allow_latency_experiment_.clear();
-  if (fetcher_.get())
-    fetcher_->Cancel();
 
   // Note that this may result in not having dictionaries we've advertised
   // for incoming responses.  The window is relatively small (as ClearData()
   // is not expected to be called frequently), so we rely on meta-refresh
   // to handle this case.
   dictionaries_.clear();
+
+  FOR_EACH_OBSERVER(SdchObserver, observers_, OnClearDictionaries(this));
 }
 
 // static
 void SdchManager::SdchErrorRecovery(ProblemCodes problem) {
   UMA_HISTOGRAM_ENUMERATION("Sdch3.ProblemCodes_4", problem, MAX_PROBLEM_CODE);
 }
 
-void SdchManager::set_sdch_fetcher(scoped_ptr<SdchFetcher> fetcher) {
-  DCHECK(CalledOnValidThread());
-  fetcher_ = fetcher.Pass();
-}
-
 // static
 void SdchManager::EnableSdchSupport(bool enabled) {
   g_sdch_enabled_ = enabled;
 }
 
 // static
 void SdchManager::EnableSecureSchemeSupport(bool enabled) {
   g_secure_scheme_supported_ = enabled;
 }
 
@@ skipping 50 matching lines @@
 
 int SdchManager::BlacklistDomainExponential(const std::string& domain) {
   std::string domain_lower(base::StringToLowerASCII(domain));
 
   if (blacklisted_domains_.end() == blacklisted_domains_.find(domain_lower))
     return 0;
   return blacklisted_domains_[domain_lower].exponential_count;
 }
 
 bool SdchManager::IsInSupportedDomain(const GURL& url) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   if (!g_sdch_enabled_ )
     return false;
 
   if (!secure_scheme_supported() && url.SchemeIsSecure())
     return false;
 
   if (blacklisted_domains_.empty())
     return true;
 
   DomainBlacklistInfo::iterator it =
       blacklisted_domains_.find(base::StringToLowerASCII(url.host()));
   if (blacklisted_domains_.end() == it || it->second.count == 0)
     return true;
 
   UMA_HISTOGRAM_ENUMERATION("Sdch3.BlacklistReason", it->second.reason,
                             MAX_PROBLEM_CODE);
   SdchErrorRecovery(DOMAIN_BLACKLIST_INCLUDES_TARGET);
 
   int count = it->second.count - 1;
   if (count > 0) {
     it->second.count = count;
   } else {
     it->second.count = 0;
     it->second.reason = MIN_PROBLEM_CODE;
   }
 
   return false;
 }
 
-void SdchManager::FetchDictionary(const GURL& request_url,
+void SdchManager::OnGetDictionary(const GURL& request_url,
                                   const GURL& dictionary_url) {
-  DCHECK(CalledOnValidThread());
-  if (CanFetchDictionary(request_url, dictionary_url) && fetcher_.get()) {
-    ++fetches_count_for_testing_;
-    fetcher_->Schedule(dictionary_url);
-  }
+  if (!CanFetchDictionary(request_url, dictionary_url))
+    return;
+
+  FOR_EACH_OBSERVER(SdchObserver,
+                    observers_,
+                    OnGetDictionary(this, request_url, dictionary_url));
 }
 
 bool SdchManager::CanFetchDictionary(const GURL& referring_url,
                                      const GURL& dictionary_url) const {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   /* The user agent may retrieve a dictionary from the dictionary URL if all of
      the following are true:
        1 The dictionary URL host name matches the referrer URL host name and
            scheme.
        2 The dictionary URL host name domain matches the parent domain of the
            referrer URL host name
        3 The parent domain of the referrer URL host name is not a top level
            domain
-       4 The dictionary URL is not an HTTPS URL.
    */
   // Item (1) above implies item (2).  Spec should be updated.
   // I take "host name match" to be "is identical to"
   if (referring_url.host() != dictionary_url.host() ||
       referring_url.scheme() != dictionary_url.scheme()) {
     SdchErrorRecovery(DICTIONARY_LOAD_ATTEMPT_FROM_DIFFERENT_HOST);
     return false;
   }
   if (!secure_scheme_supported() && referring_url.SchemeIsSecure()) {
     SdchErrorRecovery(DICTIONARY_SELECTED_FOR_SSL);
     return false;
   }
 
   // TODO(jar): Remove this failsafe conservative hack which is more restrictive
   // than current SDCH spec when needed, and justified by security audit.
   if (!referring_url.SchemeIsHTTPOrHTTPS()) {
     SdchErrorRecovery(DICTIONARY_SELECTED_FROM_NON_HTTP);
     return false;
   }
 
   return true;
 }
 
 void SdchManager::GetVcdiffDictionary(
     const std::string& server_hash,
     const GURL& referring_url,
     scoped_refptr<Dictionary>* dictionary) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   *dictionary = NULL;
   DictionaryMap::iterator it = dictionaries_.find(server_hash);
   if (it == dictionaries_.end()) {
     return;
   }
   scoped_refptr<Dictionary> matching_dictionary = it->second;
   if (!IsInSupportedDomain(referring_url))
     return;
   if (!matching_dictionary->CanUse(referring_url))
     return;
   *dictionary = matching_dictionary;
 }
 
 // TODO(jar): If we have evictions from the dictionaries_, then we need to
 // change this interface to return a list of reference counted Dictionary
 // instances that can be used if/when a server specifies one.
 void SdchManager::GetAvailDictionaryList(const GURL& target_url,
                                          std::string* list) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   int count = 0;
   for (DictionaryMap::iterator it = dictionaries_.begin();
        it != dictionaries_.end(); ++it) {
     if (!IsInSupportedDomain(target_url))
       continue;
     if (!it->second->CanAdvertise(target_url))
       continue;
     ++count;
     if (!list->empty())
       list->append(",");
@@ skipping 16 matching lines @@
   UrlSafeBase64Encode(second_48_bits, server_hash);
 
   DCHECK_EQ(server_hash->length(), 8u);
   DCHECK_EQ(client_hash->length(), 8u);
 }
 
 //------------------------------------------------------------------------------
 // Methods for supporting latency experiments.
 
 bool SdchManager::AllowLatencyExperiment(const GURL& url) const {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   return allow_latency_experiment_.end() !=
       allow_latency_experiment_.find(url.host());
 }
 
 void SdchManager::SetAllowLatencyExperiment(const GURL& url, bool enable) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   if (enable) {
     allow_latency_experiment_.insert(url.host());
     return;
   }
   ExperimentSet::iterator it = allow_latency_experiment_.find(url.host());
   if (allow_latency_experiment_.end() == it)
     return;  // It was already erased, or never allowed.
   SdchErrorRecovery(LATENCY_TEST_DISALLOWED);
   allow_latency_experiment_.erase(it);
 }
 
+void SdchManager::AddObserver(SdchObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void SdchManager::RemoveObserver(SdchObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 void SdchManager::AddSdchDictionary(const std::string& dictionary_text,
     const GURL& dictionary_url) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   std::string client_hash;
   std::string server_hash;
   GenerateHash(dictionary_text, &client_hash, &server_hash);
   if (dictionaries_.find(server_hash) != dictionaries_.end()) {
     SdchErrorRecovery(DICTIONARY_ALREADY_LOADED);
     return;                             // Already loaded.
   }
 
   std::string domain, path;
   std::set<int> ports;
@@ skipping 94 matching lines @@
 void SdchManager::UrlSafeBase64Encode(const std::string& input,
                                       std::string* output) {
   // Since this is only done during a dictionary load, and hashes are only 8
   // characters, we just do the simple fixup, rather than rewriting the encoder.
   base::Base64Encode(input, output);
   std::replace(output->begin(), output->end(), '+', '-');
   std::replace(output->begin(), output->end(), '/', '_');
 }
 
 }  // namespace net