QUIC - track disk cache API calls and failure reasons in separate

net/http/disk_cache_based_quic_server_info.cc

 // Copyright 2014 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/disk_cache_based_quic_server_info.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "net/base/completion_callback.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_network_session.h"
 #include "net/quic/quic_server_id.h"
 
 namespace net {
 
-// Histogram that tracks number of times data read/parse/write API calls of
-// QuicServerInfo to and from disk cache is called.
-enum QuicServerInfoAPICall {
-  QUIC_SERVER_INFO_START = 0,
-  QUIC_SERVER_INFO_WAIT_FOR_DATA_READY = 1,
-  QUIC_SERVER_INFO_PARSE = 2,
-  QUIC_SERVER_INFO_WAIT_FOR_DATA_READY_CANCEL = 3,
-  QUIC_SERVER_INFO_READY_TO_PERSIST = 4,
-  QUIC_SERVER_INFO_PERSIST = 5,
-  QUIC_SERVER_INFO_NUM_OF_API_CALLS = 6,
-};
-
-// Histogram that tracks failure reasons to read/load/write of QuicServerInfo to
-// and from disk cache.
-enum FailureReason {
-  WAIT_FOR_DATA_READY_INVALID_ARGUMENT_FAILURE = 0,
-  GET_BACKEND_FAILURE = 1,
-  OPEN_FAILURE = 2,
-  CREATE_OR_OPEN_FAILURE = 3,
-  PARSE_NO_DATA_FAILURE = 4,
-  PARSE_FAILURE = 5,
-  READ_FAILURE = 6,
-  READY_TO_PERSIST_FAILURE = 7,
-  PERSIST_NO_BACKEND_FAILURE = 8,
-  WRITE_FAILURE = 9,
-  NUM_OF_FAILURES = 10,
-};
-
-void RecordQuicServerInfoStatus(QuicServerInfoAPICall call) {
-  UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall", call,
-                            QUIC_SERVER_INFO_NUM_OF_API_CALLS);
-}
-
-void RecordQuicServerInfoFailure(FailureReason failure) {
-  UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason", failure,
-                            NUM_OF_FAILURES);
-}
-
 // Some APIs inside disk_cache take a handle that the caller must keep alive
 // until the API has finished its asynchronous execution.
 //
 // Unfortunately, DiskCacheBasedQuicServerInfo may be deleted before the
 // operation completes causing a use-after-free.
 //
 // This data shim struct is meant to provide a location for the disk_cache
 // APIs to write into even if the originating DiskCacheBasedQuicServerInfo
 // object has been deleted.  The lifetime for instances of this struct
 // should be bound to the CompletionCallback that is passed to the disk_cache
@@ skipping 306 matching lines @@
 
 int DiskCacheBasedQuicServerInfo::DoSetDone() {
   if (entry_)
     entry_->Close();
   entry_ = NULL;
   new_data_.clear();
   state_ = NONE;
   return OK;
 }
 
+void DiskCacheBasedQuicServerInfo::RecordQuicServerInfoStatus(
+    QuicServerInfoAPICall call) {
+  if (!backend_) {
+    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall", call,
+                              QUIC_SERVER_INFO_NUM_OF_API_CALLS);
+  } else if (backend_->GetCacheType() == net::MEMORY_CACHE) {
+    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall.MemoryCache", call,
+                              QUIC_SERVER_INFO_NUM_OF_API_CALLS);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.APICall.DiskCache", call,
+                              QUIC_SERVER_INFO_NUM_OF_API_CALLS);
+  }
+}
+
+void DiskCacheBasedQuicServerInfo::RecordQuicServerInfoFailure(
+    FailureReason failure) {
+  if (!backend_) {
+    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason", failure,

[Alexei Svitkine (slow), 2014/11/07 16:00:36]

Generally, the practice is to keep the non suffixed histogram log in both cases.

Since that's not what you're doing now, I think it's worth updating the comments
for the base histogram to specify when the base version is logged.
Alternatively, give this case a suffix too.

[ramant (doing other things), 2014/11/07 17:53:04]

Wanted to give it a new suffix, but made the wrong call and didn't do it. Thanks
for the above suggested. Added a new suffix "NoBackend".

Done.

+                              NUM_OF_FAILURES);
+  } else if (backend_->GetCacheType() == net::MEMORY_CACHE) {
+    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.MemoryCache",
+                              failure, NUM_OF_FAILURES);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.DiskCache",
+                              failure, NUM_OF_FAILURES);
+  }
+}
+
 }  // namespace net