Fix LevelDB histogram code.

third_party/leveldatabase/env_chromium.cc

 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #include <deque>
 #include <errno.h>
 #include <stdio.h>
 #include "base/at_exit.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 108 matching lines @@
   kRenamefile,
   kLockFile,
   kUnlockFile,
   kGetTestDirectory,
   kNewLogger,
   kNumEntries
 };
 
 class UMALogger {
  public:
-  UMALogger(std::string uma_title);
-  void RecordErrorAt(UmaEntry entry) const;
-  void LogRandomAccessFileError(base::PlatformFileError error_code) const;
-
- private:
-  std::string uma_title_;
+  virtual void RecordErrorAt(UmaEntry entry) const = 0;
+  virtual void LogRandomAccessFileError(base::PlatformFileError error_code)
+      const = 0;
 };
 
-UMALogger::UMALogger(std::string uma_title) : uma_title_(uma_title) {}
-
-void UMALogger::RecordErrorAt(UmaEntry entry) const {
-  std::string uma_name(uma_title_);
-  uma_name.append(".IOError");
-  UMA_HISTOGRAM_ENUMERATION(uma_name, entry, kNumEntries);
-}
-
-void UMALogger::LogRandomAccessFileError(base::PlatformFileError error_code)
-    const {
-  DCHECK(error_code < 0);
-  std::string uma_name(uma_title_);
-  uma_name.append(".IOError.RandomAccessFile");
-  UMA_HISTOGRAM_ENUMERATION(uma_name,
-                            -error_code,
-                            -base::PLATFORM_FILE_ERROR_MAX);
-}
-
 }  // namespace
 
 namespace leveldb {
 
 namespace {
 
 class Thread;
 
 static const ::FilePath::CharType kLevelDBTestDirectoryPrefix[]
     = FILE_PATH_LITERAL("leveldb-test-");
@@ skipping 166 matching lines @@
     }
     return result;
   }
 };
 
 class ChromiumFileLock : public FileLock {
  public:
   ::base::PlatformFile file_;
 };
 
-class ChromiumEnv : public Env {
+class ChromiumEnv : public Env, public UMALogger {
  public:
   ChromiumEnv();
   virtual ~ChromiumEnv() {
     NOTREACHED();
   }
 
   virtual Status NewSequentialFile(const std::string& fname,
                                    SequentialFile** result) {
     FILE* f = fopen_internal(fname.c_str(), "rb");
     if (f == NULL) {
       *result = NULL;
-      uma_logger_->RecordErrorAt(kNewSequentialFile);
+      RecordErrorAt(kNewSequentialFile);
       return Status::IOError(fname, strerror(errno));
     } else {
-      *result = new ChromiumSequentialFile(fname, f, uma_logger_.get());
+      *result = new ChromiumSequentialFile(fname, f, this);
       return Status::OK();
     }
   }
 
   virtual Status NewRandomAccessFile(const std::string& fname,
                                      RandomAccessFile** result) {
     int flags = ::base::PLATFORM_FILE_READ | ::base::PLATFORM_FILE_OPEN;
     bool created;
     ::base::PlatformFileError error_code;
     ::base::PlatformFile file = ::base::CreatePlatformFile(
         CreateFilePath(fname), flags, &created, &error_code);
     if (error_code != ::base::PLATFORM_FILE_OK) {
       *result = NULL;
-      uma_logger_->RecordErrorAt(kNewRandomAccessFile);
-      uma_logger_->LogRandomAccessFileError(error_code);
+      RecordErrorAt(kNewRandomAccessFile);
+      LogRandomAccessFileError(error_code);
       return Status::IOError(fname, PlatformFileErrorString(error_code));
     }
-    *result = new ChromiumRandomAccessFile(fname, file, uma_logger_.get());
+    *result = new ChromiumRandomAccessFile(fname, file, this);
     return Status::OK();
   }
 
   virtual Status NewWritableFile(const std::string& fname,
                                  WritableFile** result) {
     *result = NULL;
     FILE* f = fopen_internal(fname.c_str(), "wb");
     if (f == NULL) {
-      uma_logger_->RecordErrorAt(kNewWritableFile);
+      RecordErrorAt(kNewWritableFile);
       return Status::IOError(fname, strerror(errno));
     } else {
       if (!sync_parent(fname)) {
         fclose(f);
         return Status::IOError(fname, strerror(errno));
       }
-      *result = new ChromiumWritableFile(fname, f, uma_logger_.get());
+      *result = new ChromiumWritableFile(fname, f, this);
       return Status::OK();
     }
   }
 
   virtual bool FileExists(const std::string& fname) {
     return ::file_util::PathExists(CreateFilePath(fname));
   }
 
   virtual Status GetChildren(const std::string& dir,
                              std::vector<std::string>* result) {
     result->clear();
     ::file_util::FileEnumerator iter(
         CreateFilePath(dir), false, ::file_util::FileEnumerator::FILES);
     ::FilePath current = iter.Next();
     while (!current.empty()) {
       result->push_back(FilePathToString(current.BaseName()));
       current = iter.Next();
     }
     // TODO(jorlow): Unfortunately, the FileEnumerator swallows errors, so
     //               we'll always return OK. Maybe manually check for error
     //               conditions like the file not existing?
     return Status::OK();
   }
 
   virtual Status DeleteFile(const std::string& fname) {
     Status result;
     // TODO(jorlow): Should we assert this is a file?
     if (!::file_util::Delete(CreateFilePath(fname), false)) {
       result = Status::IOError(fname, "Could not delete file.");
-      uma_logger_->RecordErrorAt(kDeleteFile);
+      RecordErrorAt(kDeleteFile);
     }
     return result;
   };
 
   virtual Status CreateDir(const std::string& name) {
     Status result;
     if (!::file_util::CreateDirectory(CreateFilePath(name))) {
       result = Status::IOError(name, "Could not create directory.");
-      uma_logger_->RecordErrorAt(kCreateDir);
+      RecordErrorAt(kCreateDir);
     }
     return result;
   };
 
   virtual Status DeleteDir(const std::string& name) {
     Status result;
     // TODO(jorlow): Should we assert this is a directory?
     if (!::file_util::Delete(CreateFilePath(name), false)) {
       result = Status::IOError(name, "Could not delete directory.");
-      uma_logger_->RecordErrorAt(kDeleteDir);
+      RecordErrorAt(kDeleteDir);
     }
     return result;
   };
 
   virtual Status GetFileSize(const std::string& fname, uint64_t* size) {
     Status s;
     int64_t signed_size;
     if (!::file_util::GetFileSize(CreateFilePath(fname), &signed_size)) {
       *size = 0;
       s = Status::IOError(fname, "Could not determine file size.");
-      uma_logger_->RecordErrorAt(kGetFileSize);
+      RecordErrorAt(kGetFileSize);
     } else {
       *size = static_cast<uint64_t>(signed_size);
     }
     return s;
   }
 
   virtual Status RenameFile(const std::string& src, const std::string& dst) {
     Status result;
     if (!::file_util::ReplaceFile(CreateFilePath(src), CreateFilePath(dst))) {
       result = Status::IOError(src, "Could not rename file.");
-      uma_logger_->RecordErrorAt(kRenamefile);
+      RecordErrorAt(kRenamefile);
     } else {
       sync_parent(dst);
       if (src != dst)
         sync_parent(src);
     }
     return result;
   }
 
   virtual Status LockFile(const std::string& fname, FileLock** lock) {
     *lock = NULL;
     Status result;
     int flags = ::base::PLATFORM_FILE_OPEN_ALWAYS |
                 ::base::PLATFORM_FILE_READ |
                 ::base::PLATFORM_FILE_WRITE |
                 ::base::PLATFORM_FILE_EXCLUSIVE_READ |
                 ::base::PLATFORM_FILE_EXCLUSIVE_WRITE;
     bool created;
     ::base::PlatformFileError error_code;
     ::base::PlatformFile file = ::base::CreatePlatformFile(
         CreateFilePath(fname), flags, &created, &error_code);
     if (error_code != ::base::PLATFORM_FILE_OK) {
       result = Status::IOError(fname, PlatformFileErrorString(error_code));
-      uma_logger_->RecordErrorAt(kLockFile);
+      RecordErrorAt(kLockFile);
     } else {
       ChromiumFileLock* my_lock = new ChromiumFileLock;
       my_lock->file_ = file;
       *lock = my_lock;
     }
     return result;
   }
 
   virtual Status UnlockFile(FileLock* lock) {
     ChromiumFileLock* my_lock = reinterpret_cast<ChromiumFileLock*>(lock);
     Status result;
     if (!::base::ClosePlatformFile(my_lock->file_)) {
       result = Status::IOError("Could not close lock file.");
-      uma_logger_->RecordErrorAt(kUnlockFile);
+      RecordErrorAt(kUnlockFile);
     }
     delete my_lock;
     return result;
   }
 
   virtual void Schedule(void (*function)(void*), void* arg);
 
   virtual void StartThread(void (*function)(void* arg), void* arg);
 
   virtual std::string UserIdentifier() {
 #if defined(OS_WIN)
     std::wstring user_sid;
     bool ret = ::base::win::GetUserSidString(&user_sid);
     DCHECK(ret);
     return UTF16ToUTF8(user_sid);
 #else
     char buf[100];
     snprintf(buf, sizeof(buf), "%d", int(geteuid()));
     return buf;
 #endif
   }
 
   virtual Status GetTestDirectory(std::string* path) {
     mu_.Acquire();
     if (test_directory_.empty()) {
       if (!::file_util::CreateNewTempDirectory(kLevelDBTestDirectoryPrefix,
                                                &test_directory_)) {
         mu_.Release();
-        uma_logger_->RecordErrorAt(kGetTestDirectory);
+        RecordErrorAt(kGetTestDirectory);
         return Status::IOError("Could not create temp directory.");
       }
     }
     *path = FilePathToString(test_directory_);
     mu_.Release();
     return Status::OK();
   }
 
   virtual Status NewLogger(const std::string& fname, Logger** result) {
     FILE* f = fopen_internal(fname.c_str(), "w");
     if (f == NULL) {
       *result = NULL;
-      uma_logger_->RecordErrorAt(kNewLogger);
+      RecordErrorAt(kNewLogger);
       return Status::IOError(fname, strerror(errno));
     } else {
       if (!sync_parent(fname)) {
         fclose(f); 
         return Status::IOError(fname, strerror(errno));
       }
       *result = new ChromiumLogger(f);
       return Status::OK();
     }
   }
 
   virtual uint64_t NowMicros() {
     return ::base::TimeTicks::Now().ToInternalValue();
   }
 
   virtual void SleepForMicroseconds(int micros) {
     // Round up to the next millisecond.
     ::base::PlatformThread::Sleep(::base::TimeDelta::FromMicroseconds(micros));
   }
 
+  void RecordErrorAt(UmaEntry entry) const {
+    io_error_histogram_->Add(entry);
+  }
+
+  void LogRandomAccessFileError(base::PlatformFileError error_code) const {
+    DCHECK(error_code < 0);
+    random_access_file_histogram_->Add(-error_code);
+  }
+
  protected:
-  scoped_ptr<UMALogger> uma_logger_;
+  void InitHistograms(const std::string& uma_title);
 
  private:
   // BGThread() is the body of the background thread
   void BGThread();
   static void BGThreadWrapper(void* arg) {
     reinterpret_cast<ChromiumEnv*>(arg)->BGThread();
   }
 
   FilePath test_directory_;
 
   size_t page_size_;
   ::base::Lock mu_;
   ::base::ConditionVariable bgsignal_;
   bool started_bgthread_;
 
   // Entry per Schedule() call
   struct BGItem { void* arg; void (*function)(void*); };
   typedef std::deque<BGItem> BGQueue;
   BGQueue queue_;
+
+  base::Histogram* io_error_histogram_;
+  base::Histogram* random_access_file_histogram_;
 };
 
 ChromiumEnv::ChromiumEnv()
     : page_size_(::base::SysInfo::VMAllocationGranularity()),
       bgsignal_(&mu_),
-      started_bgthread_(false),
-      uma_logger_(new UMALogger("LevelDBEnv")) {
+      started_bgthread_(false) {
+  InitHistograms("LevelDBEnv");
+}
+
+void ChromiumEnv::InitHistograms(const std::string& uma_title) {
+  std::string uma_name(uma_title);
+  uma_name.append(".IOError");
+  // Note: The calls to FactoryGet aren't thread-safe. It's ok to call them here
+  // because this method is only called from LazyInstance, which provides
+  // thread-safety.
+  io_error_histogram_ = base::LinearHistogram::FactoryGet(uma_name, 1,
+      kNumEntries, kNumEntries + 1, base::Histogram::kUmaTargetedHistogramFlag);
+
+  uma_name.append(".RandomAccessFile");
+  random_access_file_histogram_ = base::LinearHistogram::FactoryGet(uma_name, 1,
+      -base::PLATFORM_FILE_ERROR_MAX, -base::PLATFORM_FILE_ERROR_MAX + 1,
+      base::Histogram::kUmaTargetedHistogramFlag);
 }
 
 class Thread : public ::base::PlatformThread::Delegate {
  public:
   Thread(void (*function)(void* arg), void* arg)
       : function_(function), arg_(arg) {
     ::base::PlatformThreadHandle handle;
     bool success = ::base::PlatformThread::Create(0, this, &handle);
     DCHECK(success);
   }
@@ skipping 48 matching lines @@
   }
 }
 
 void ChromiumEnv::StartThread(void (*function)(void* arg), void* arg) {
   new Thread(function, arg); // Will self-delete.
 }
 
 class IDBEnv : public ChromiumEnv {
  public:
   IDBEnv() : ChromiumEnv() {
-    uma_logger_.reset(new UMALogger("LevelDBEnv.IDB"));
+    InitHistograms("LevelDBEnv.IDB");
   }
 };
 
 ::base::LazyInstance<IDBEnv>::Leaky
     idb_env = LAZY_INSTANCE_INITIALIZER;
 
 ::base::LazyInstance<ChromiumEnv>::Leaky
     default_env = LAZY_INSTANCE_INITIALIZER;
 
 }
 
 Env* IDBEnv() {
   return idb_env.Pointer();
 }
 
 Env* Env::Default() {
   return default_env.Pointer();
 }
 
 }