Add Drive.MetadataDBValidityCheckFailureReason UMA histogram

chrome/browser/chromeos/drive/resource_metadata_storage.cc

Index: chrome/browser/chromeos/drive/resource_metadata_storage.cc
diff --git a/chrome/browser/chromeos/drive/resource_metadata_storage.cc b/chrome/browser/chromeos/drive/resource_metadata_storage.cc
index 5453ee3852d6a7906901b33e06db54401cf4dac1..78c43815f43c9d8790b50a5b1dfb11f6c0d87ee7 100644
--- a/chrome/browser/chromeos/drive/resource_metadata_storage.cc
+++ b/chrome/browser/chromeos/drive/resource_metadata_storage.cc
@@ -37,6 +37,19 @@ enum DBInitStatus {
   DB_INIT_MAX_VALUE,
 };
 
+// Enum to describe DB validity check failure reason.
+enum CheckValidityFailureReason {
+  CHECK_VALIDITY_FAILURE_INVALID_HEADER,
+  CHECK_VALIDITY_FAILURE_BROKEN_ID_ENTRY,
+  CHECK_VALIDITY_FAILURE_BROKEN_ENTRY,
+  CHECK_VALIDITY_FAILURE_INVALID_LOCAL_ID,
+  CHECK_VALIDITY_FAILURE_INVALID_PARENT_ID,
+  CHECK_VALIDITY_FAILURE_BROKEN_CHILD_MAP,
+  CHECK_VALIDITY_FAILURE_CHILD_ENTRY_COUNT_MISMATCH,
+  CHECK_VALIDITY_FAILURE_ITERATOR_ERROR,
+  CHECK_VALIDITY_FAILURE_MAX_VALUE,
+};
+
 // The name of the DB which stores the metadata.
 const base::FilePath::CharType kResourceMapDBName[] =
     FILE_PATH_LITERAL("resource_metadata_resource_map.db");
@@ -932,6 +945,9 @@ bool ResourceMetadataStorage::CheckValidity() {
       !header.ParseFromArray(it->value().data(), it->value().size()) ||
       header.version() != kDBVersion) {
     DLOG(ERROR) << "Invalid header detected. version = " << header.version();
+    UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",

[Alexei Svitkine (slow), 2014/08/05 13:18:16]

Nit: Each histogram macro adds a lot of machine code at the callsite. Can you
instead add a helper function that records the macro and takes the enum value to
record and then call it from every place you record this histogram? This will
avoid bloating the binary.

[hashimoto, 2014/08/06 03:52:20]

Done.

+                              CHECK_VALIDITY_FAILURE_INVALID_HEADER,
+                              CHECK_VALIDITY_FAILURE_MAX_VALUE);
     return false;
   }
 
@@ -962,6 +978,9 @@ bool ResourceMetadataStorage::CheckValidity() {
           leveldb::Slice(GetIdEntryKey(entry.resource_id())) == it->key();
       if (!ok) {
         DLOG(ERROR) << "Broken ID entry. status = " << status.ToString();
+        UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                                  CHECK_VALIDITY_FAILURE_BROKEN_ID_ENTRY,
+                                  CHECK_VALIDITY_FAILURE_MAX_VALUE);
         return false;
       }
       continue;
@@ -970,11 +989,17 @@ bool ResourceMetadataStorage::CheckValidity() {
     // Check if stored data is broken.
     if (!entry.ParseFromArray(it->value().data(), it->value().size())) {
       DLOG(ERROR) << "Broken entry detected";
+      UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                                CHECK_VALIDITY_FAILURE_BROKEN_ENTRY,
+                                CHECK_VALIDITY_FAILURE_MAX_VALUE);
       return false;
     }
 
     if (leveldb::Slice(entry.local_id()) != it->key()) {
       DLOG(ERROR) << "Wrong local ID.";
+      UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                                CHECK_VALIDITY_FAILURE_INVALID_LOCAL_ID,
+                                CHECK_VALIDITY_FAILURE_MAX_VALUE);
       return false;
     }
 
@@ -986,6 +1011,9 @@ bool ResourceMetadataStorage::CheckValidity() {
           &serialized_entry);
       if (!status.ok()) {
         DLOG(ERROR) << "Can't get parent entry. status = " << status.ToString();
+        UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                                  CHECK_VALIDITY_FAILURE_INVALID_PARENT_ID,
+                                  CHECK_VALIDITY_FAILURE_MAX_VALUE);
         return false;
       }
 
@@ -997,14 +1025,27 @@ bool ResourceMetadataStorage::CheckValidity() {
           &child_id);
       if (!status.ok() || leveldb::Slice(child_id) != it->key()) {
         DLOG(ERROR) << "Child map is broken. status = " << status.ToString();
+        UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                                  CHECK_VALIDITY_FAILURE_BROKEN_CHILD_MAP,
+                                  CHECK_VALIDITY_FAILURE_MAX_VALUE);
         return false;
       }
       ++num_entries_with_parent;
     }
   }
-  if (!it->status().ok() || num_child_entries != num_entries_with_parent) {
+  if (!it->status().ok()) {
     DLOG(ERROR) << "Error during checking resource map. status = "
                 << it->status().ToString();
+    UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                              CHECK_VALIDITY_FAILURE_ITERATOR_ERROR,
+                              CHECK_VALIDITY_FAILURE_MAX_VALUE);
+    return false;
+  }
+  if (num_child_entries != num_entries_with_parent) {
+    DLOG(ERROR) << "Child entry count mismatch";
+    UMA_HISTOGRAM_ENUMERATION("Drive.MetadataDBValidityCheckFailureReason",
+                              CHECK_VALIDITY_FAILURE_CHILD_ENTRY_COUNT_MISMATCH,
+                              CHECK_VALIDITY_FAILURE_MAX_VALUE);
     return false;
   }
   return true;