Record cache freshness metric per 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 2706 matching lines @@
 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;
   }
 
   bool validation_request = transaction_pattern_ == PATTERN_ENTRY_VALIDATED ||
                             transaction_pattern_ == PATTERN_ENTRY_UPDATED;
+
+  bool stale_request =
+      validation_cause_ == VALIDATION_CAUSE_STALE &&
+      (validation_request ||
+       transaction_pattern_ == PATTERN_ENTRY_CANT_CONDITIONALIZE);
+  int64_t freshness_periods_since_last_used = 0;
+
+  if (stale_request) {
+    // For stale entries, record how many freshness periods have elapsed since
+    // the entry was last used.
+    DCHECK(!open_entry_last_used_.is_null());
+    DCHECK(!stale_entry_freshness_.is_zero());
+    base::TimeDelta time_since_use = base::Time::Now() - open_entry_last_used_;
+    freshness_periods_since_last_used =
+        (time_since_use * 1000) / stale_entry_freshness_;
+
+    UMA_HISTOGRAM_COUNTS("HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed",
+                         freshness_periods_since_last_used);
+  }
+
   std::string mime_type;
   HttpResponseHeaders* response_headers = GetResponseInfo()->headers.get();
   if (response_headers && response_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("HttpCache.Pattern.MainFrameHTML",
                                 transaction_pattern_, PATTERN_MAX);
       if (validation_request) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.MainFrameHTML",
                                   validation_cause_, VALIDATION_CAUSE_MAX);
       }
+      if (stale_request) {
+        UMA_HISTOGRAM_COUNTS(
+            "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.MainFrameHTML",
+            freshness_periods_since_last_used);
+      }
     } else if (mime_type == "text/html") {
       UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.NonMainFrameHTML",
                                 transaction_pattern_, PATTERN_MAX);
       if (validation_request) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.NonMainFrameHTML",
                                   validation_cause_, VALIDATION_CAUSE_MAX);
       }
+      if (stale_request) {
+        UMA_HISTOGRAM_COUNTS(
+            "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed."
+            "NonMainFrameHTML",
+            freshness_periods_since_last_used);
+      }
     } else if (mime_type == "text/css") {
       UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.CSS", transaction_pattern_,
                                 PATTERN_MAX);
       if (validation_request) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.CSS",
                                   validation_cause_, VALIDATION_CAUSE_MAX);
       }
+      if (stale_request) {
+        UMA_HISTOGRAM_COUNTS(
+            "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.CSS",
+            freshness_periods_since_last_used);
+      }
     } else if (base::StartsWith(mime_type, "image/",
                                 base::CompareCase::SENSITIVE)) {
       int64_t content_length = response_headers->GetContentLength();
       if (content_length >= 0 && content_length < 100) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.TinyImage",
                                   transaction_pattern_, PATTERN_MAX);
         if (validation_request) {
           UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.TinyImage",
                                     validation_cause_, VALIDATION_CAUSE_MAX);
         }
+        if (stale_request) {
+          UMA_HISTOGRAM_COUNTS(
+              "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.TinyImage",
+              freshness_periods_since_last_used);
+        }
       } else if (content_length >= 100) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.NonTinyImage",
                                   transaction_pattern_, PATTERN_MAX);
         if (validation_request) {
           UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.NonTinyImage",
                                     validation_cause_, VALIDATION_CAUSE_MAX);
         }
+        if (stale_request) {
+          UMA_HISTOGRAM_COUNTS(
+              "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.NonTinyImage",
+              freshness_periods_since_last_used);
+        }
       }
       UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.Image", transaction_pattern_,
                                 PATTERN_MAX);
       if (validation_request) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.Image",
                                   validation_cause_, VALIDATION_CAUSE_MAX);
       }
+      if (stale_request) {
+        UMA_HISTOGRAM_COUNTS(
+            "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.Image",
+            freshness_periods_since_last_used);
+      }
     } else if (base::EndsWith(mime_type, "javascript",
                               base::CompareCase::SENSITIVE) ||
                base::EndsWith(mime_type, "ecmascript",
                               base::CompareCase::SENSITIVE)) {
       UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.JavaScript",
                                 transaction_pattern_, PATTERN_MAX);
       if (validation_request) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.JavaScript",
                                   validation_cause_, VALIDATION_CAUSE_MAX);
       }
+      if (stale_request) {
+        UMA_HISTOGRAM_COUNTS(
+            "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.JavaScript",
+            freshness_periods_since_last_used);
+      }
     } else if (mime_type.find("font") != std::string::npos) {
       UMA_HISTOGRAM_ENUMERATION("HttpCache.Pattern.Font", transaction_pattern_,
                                 PATTERN_MAX);
       if (validation_request) {
         UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause.Font",
                                   validation_cause_, VALIDATION_CAUSE_MAX);
       }
+      if (stale_request) {
+        UMA_HISTOGRAM_COUNTS(
+            "HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed.Font",
+            freshness_periods_since_last_used);
+      }
     }
   }
 
-  if ((validation_request ||
-       transaction_pattern_ == PATTERN_ENTRY_CANT_CONDITIONALIZE) &&
-      validation_cause_ == VALIDATION_CAUSE_STALE) {
-    // For stale entries, record how many freshness periods have elapsed since
-    // the entry was last used.
-    DCHECK(!open_entry_last_used_.is_null());
-    DCHECK(!stale_entry_freshness_.is_zero());
-
-    base::TimeDelta time_since_use = base::Time::Now() - open_entry_last_used_;
-    UMA_HISTOGRAM_COUNTS("HttpCache.StaleEntry.FreshnessPeriodsSinceLastUsed",
-                         (time_since_use * 1000) / stale_entry_freshness_);
-  }
-
   UMA_HISTOGRAM_ENUMERATION(
       "HttpCache.Pattern", transaction_pattern_, PATTERN_MAX);
 
   if (validation_request) {
     UMA_HISTOGRAM_ENUMERATION("HttpCache.ValidationCause", validation_cause_,
                               VALIDATION_CAUSE_MAX);
   }
 
   if (transaction_pattern_ == PATTERN_ENTRY_CANT_CONDITIONALIZE) {
     UMA_HISTOGRAM_ENUMERATION("HttpCache.CantConditionalizeCause",
@@ skipping 68 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   DoLoop(result);
 }
 
 }  // namespace net