Break down HTTPCache.Result metric by resource type

net/http/http_cache_transaction.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/http/http_cache_transaction.h"
 
 #include "build/build_config.h"  // For OS_POSIX
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 2686 matching lines @@
   transaction_pattern_ = new_transaction_pattern;
 }
 
 void HttpCache::Transaction::RecordHistograms() {
   DCHECK_NE(PATTERN_UNDEFINED, transaction_pattern_);
   if (!cache_.get() || !cache_->GetCurrentBackend() ||
       cache_->GetCurrentBackend()->GetCacheType() != DISK_CACHE ||
       cache_->mode() != NORMAL || request_->method != "GET") {
     return;
   }
+
+  std::string mime_type;
+  if (GetResponseInfo()->headers &&

[Deprecated (see juliatuttle), 2016/03/23 19:28:48]

Do you have a sense from local testing that these are covering things well?

[jkarlin, 2016/03/24 11:09:00]

Nothing extensive, but it seems to have good coverage on my local build.

+      GetResponseInfo()->headers->GetMimeType(&mime_type)) {
+    // Record the cache pattern by resource type. The type is inferred by
+    // response header mime type, which could be incorrect, so this is just an
+    // estimate.
+    if (mime_type == "text/html" && (request_->load_flags & LOAD_MAIN_FRAME)) {
+      UMA_HISTOGRAM_ENUMERATION(std::string("HttpCache.Pattern.MainFrameHTML"),
+                                transaction_pattern_, PATTERN_MAX);
+    } else if (mime_type == "text/html") {
+      UMA_HISTOGRAM_ENUMERATION(
+          std::string("HttpCache.Pattern.NonMainFrameHTML"),
+          transaction_pattern_, PATTERN_MAX);
+    } else if (mime_type == "text/css") {
+      UMA_HISTOGRAM_ENUMERATION(std::string("HttpCache.Pattern.CSS"),
+                                transaction_pattern_, PATTERN_MAX);
+    } else if (base::StartsWith(mime_type, "image/",
+                                base::CompareCase::SENSITIVE)) {
+      UMA_HISTOGRAM_ENUMERATION(std::string("HttpCache.Pattern.Image"),
+                                transaction_pattern_, PATTERN_MAX);
+    } else if (base::EndsWith(mime_type, "javascript",

[Deprecated (see juliatuttle), 2016/03/23 19:28:48]

Did you want to check for ecmascript as well?

[jkarlin, 2016/03/24 11:09:00]

Done.

+                              base::CompareCase::SENSITIVE)) {
+      UMA_HISTOGRAM_ENUMERATION(std::string("HttpCache.Pattern.JavaScript"),
+                                transaction_pattern_, PATTERN_MAX);
+    } else if (mime_type.find("font") != std::string::npos) {
+      UMA_HISTOGRAM_ENUMERATION(std::string("HttpCache.Pattern.Font"),
+                                transaction_pattern_, PATTERN_MAX);
+    }
+  }
+
   UMA_HISTOGRAM_ENUMERATION(
       "HttpCache.Pattern", transaction_pattern_, PATTERN_MAX);
   if (transaction_pattern_ == PATTERN_NOT_COVERED)
     return;
   DCHECK(!range_requested_);
   DCHECK(!first_cache_access_since_.is_null());
 
   TimeDelta total_time = base::TimeTicks::Now() - first_cache_access_since_;
 
   UMA_HISTOGRAM_TIMES("HttpCache.AccessToDone", total_time);
@@ skipping 57 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   DoLoop(result);
 }
 
 }  // namespace net