UMA counts for corrupt cache db.

chrome/browser/chromeos/gdata/drive_cache_metadata.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 "chrome/browser/chromeos/gdata/drive_cache_metadata.h"
 
 #include <leveldb/db.h>
 
 #include "base/callback.h"
 #include "base/file_util.h"
+#include "base/metrics/histogram.h"
 #include "base/sequenced_task_runner.h"
 #include "chrome/browser/chromeos/gdata/drive.pb.h"
 #include "chrome/browser/chromeos/gdata/drive_file_system_util.h"
 
 namespace gdata {
 
 namespace {
 
+enum DBOpenStatus {
+  DB_OPEN_SUCCESS,
+  DB_OPEN_FAILURE_CORRUPTION,
+  DB_OPEN_FAILURE_OTHER,
+  DB_OPEN_MAX_VALUE,
+};
+
 // A map table of resource ID to file path.
 typedef std::map<std::string, FilePath> ResourceIdToFilePathMap;
 
 // Returns true if |file_path| is a valid symbolic link as |sub_dir_type|.
 // Otherwise, returns false with the reason.
 bool IsValidSymbolicLink(const FilePath& file_path,
                          DriveCache::CacheSubDirectoryType sub_dir_type,
                          const std::vector<FilePath>& cache_paths,
                          std::string* reason) {
   DCHECK(sub_dir_type == DriveCache::CACHE_TYPE_PINNED ||
@@ skipping 430 matching lines @@
   bool scan_cache = !file_util::PathExists(db_path);
 
   leveldb::DB* level_db = NULL;
   leveldb::Options options;
   options.create_if_missing = true;
   leveldb::Status db_status = leveldb::DB::Open(options, db_path.value(),
                                                 &level_db);
 
   // Delete the db and scan the physical cache. This will fix a corrupt db, but
   // perhaps not other causes of failed DB::Open.
+  DBOpenStatus uma_status = DB_OPEN_SUCCESS;
   if (!db_status.ok()) {
-    DVLOG(1) << "Detected corrupt db";
+    LOG(WARNING) << "Cache db failed to open: " << db_status.ToString();

[satorux1, 2012/09/25 23:09:03]

ToString() is neat!

+    uma_status = db_status.IsCorruption() ?
+                 DB_OPEN_FAILURE_CORRUPTION : DB_OPEN_FAILURE_OTHER;
     const bool deleted = file_util::Delete(db_path, true);
     DCHECK(deleted);
     db_status = leveldb::DB::Open(options, db_path.value(), &level_db);
     // TODO(satorux): Handle the situation where DB::Open fails because of lack
     // of disk space, permissions, or other causes. crbug.com/150840.
     CHECK(db_status.ok());  // Must succeed or we'll crash later.
     scan_cache = true;
   }
   DCHECK(level_db);
   level_db_.reset(level_db);
 
+  UMA_HISTOGRAM_ENUMERATION(
+      "Drive.CacheMetadataDBOpen", uma_status, DB_OPEN_MAX_VALUE);
+
   // We scan the cache directories to initialize the cache database if we
   // were previously using the cache map.
   if (scan_cache) {
     CacheMap cache_map;
     ScanCachePaths(cache_paths, &cache_map);
     InsertMapIntoDB(cache_map);
   }
 }
 
 void DriveCacheMetadataDB::InsertMapIntoDB(const CacheMap& cache_map) {
@@ skipping 120 matching lines @@
   return scoped_ptr<DriveCacheMetadata>(
       new FakeDriveCacheMetadata(blocking_task_runner));
 }
 
 void DriveCacheMetadata::AssertOnSequencedWorkerPool() {
   DCHECK(!blocking_task_runner_ ||
          blocking_task_runner_->RunsTasksOnCurrentThread());
 }
 
 }  // namespace gdata