Expire appcaches that fail to update for "too long".

content/browser/appcache/appcache_update_job.cc

Index: content/browser/appcache/appcache_update_job.cc
diff --git a/content/browser/appcache/appcache_update_job.cc b/content/browser/appcache/appcache_update_job.cc
index 4848c9a5f15019ae07ff5a5c0dc7d26e7239e3b0..74c4dbbd70422239cca6ac93ead0b15b359963d4 100644
--- a/content/browser/appcache/appcache_update_job.cc
+++ b/content/browser/appcache/appcache_update_job.cc
@@ -251,6 +251,13 @@ void AppCacheUpdateJob::URLFetcher::AddConditionalHeaders(
   DCHECK(request_.get() && headers);
   net::HttpRequestHeaders extra_headers;
 
+  // TODO(michaeln): skip condition headers on manifest fetches if its been 24 hours
+  // since the last update check
+  // TODO: store date of last update check even that busted the cache
+  // if (firstManifestFetch &&
+  //     now > newest_successful_unconditional_update_check_time + 24hours)
+  //    performing_unconditional_update_check_ = true;
+
   // Add If-Modified-Since header if response info has Last-Modified header.
   const std::string last_modified = "Last-Modified";
   std::string last_modified_value;
@@ -478,6 +485,17 @@ void AppCacheUpdateJob::HandleCacheFailure(
   DiscardInprogressCache();
   internal_state_ = COMPLETED;
   DeleteSoon();  // To unwind the stack prior to deletion.
+
+    // TODO(michaeln): Evict the cache under other cicrumstances too
+    // if we've been getting srvr errors for "too long"
+    // if we've been getting srvr redirects for "too long"
+    // if we've been getting an invalid manifest for "too long"
+    // maybe "too long" for http is less than it is for https?

[palmer, 2015/04/21 19:56:34]

Good idea.

+    // TODO: store date of first evictable error since last successfull update check
+    // if (is_an_evictable_error &&
+    //       now > first_evictable_error_since_successfull_check + kTooLong)
+    //   evict();
+    // else if (!first_evictable_error_since_successfull_check) set it to now
 }
 
 void AppCacheUpdateJob::FetchManifest(bool is_first_fetch) {
@@ -541,6 +559,8 @@ void AppCacheUpdateJob::HandleManifestFetchCompleted(
              update_type_ == UPGRADE_ATTEMPT) {
     storage_->MakeGroupObsolete(group_, this, response_code);  // async
   } else {
+    // TODO(michaeln): Evict the cache under other cicrumstances too.
+    // APPCACHE_MANIFEST_ERROR + networkresponsecde is an evictable error
     const char* kFormatString = "Manifest fetch failed (%d) %s";
     std::string message = FormatUrlErrorMessage(
         kFormatString, manifest_url_, fetcher->result(), response_code);
@@ -587,6 +607,7 @@ void AppCacheUpdateJob::ContinueHandleManifestFetchCompleted(bool changed) {
   DCHECK(internal_state_ == FETCH_MANIFEST);
 
   if (!changed) {
+    // if unconditional_check, set time to now
     DCHECK(update_type_ == UPGRADE_ATTEMPT);
     internal_state_ = NO_UPDATE;
 
@@ -603,6 +624,8 @@ void AppCacheUpdateJob::ContinueHandleManifestFetchCompleted(bool changed) {
                         PARSE_MANIFEST_ALLOWING_INTERCEPTS :
                         PARSE_MANIFEST_PER_STANDARD,
                      manifest)) {
+    // TODO(michaeln): Evict the cache under other cicrumstances too.
+    // APPCACHE_SIGNATURE_ERROR is an evictable error
     const char* kFormatString = "Failed to parse manifest %s";
     const std::string message = base::StringPrintf(kFormatString,
         manifest_url_.spec().c_str());