Record UMA statistics for file_stream operations.

net/base/file_stream_posix.cc

 // Copyright (c) 2011 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.
 
 // For 64-bit file access (off_t = off64_t, lseek64, etc).
 #define _FILE_OFFSET_BITS 64
 
 #include "net/base/file_stream.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/eintr_wrapper.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/task.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/worker_pool.h"
 #include "base/synchronization/waitable_event.h"
+#include "net/base/file_stream_metrics.h"
 #include "net/base/net_errors.h"
 
 #if defined(OS_ANDROID)
 // Android's bionic libc only supports the LFS transitional API.
 #define off_t off64_t
 #define lseek lseek64
 #define stat stat64
 #define fstat fstat64
 #endif
 
@@ skipping 17 matching lines @@
     case EACCES:
       return ERR_ACCESS_DENIED;
     default:
       LOG(WARNING) << "Unknown error " << err << " mapped to net::ERR_FAILED";
       return ERR_FAILED;
   }
 }
 
 // ReadFile() is a simple wrapper around read() that handles EINTR signals and
 // calls MapErrorCode() to map errno to net error codes.
-int ReadFile(base::PlatformFile file, char* buf, int buf_len) {
+int ReadFile(base::PlatformFile file, char* buf, int buf_len, bool record_uma) {
   base::ThreadRestrictions::AssertIOAllowed();
   // read(..., 0) returns 0 to indicate end-of-file.
 
   // Loop in the case of getting interrupted by a signal.
   ssize_t res = HANDLE_EINTR(read(file, buf, static_cast<size_t>(buf_len)));
-  if (res == static_cast<ssize_t>(-1))
-    return MapErrorCode(errno);
+  if (res == static_cast<ssize_t>(-1)) {
+    int error = errno;

[cbentzel, 2011/08/18 13:31:28]

Why don't you call RecordAndMapErrorCode(errno, FILE_ERROR_SOURCE_READ,
record_uma) here?

[ahendrickson, 2011/08/18 15:56:45]

Now that RecordAndMapErrorCode is no longer a member function of FileStream,
that is possible.

Done.

+    RecordFileError(error, FILE_ERROR_SOURCE_READ, record_uma);
+    return MapErrorCode(error);
+  }
   return static_cast<int>(res);
 }
 
 void ReadFileTask(base::PlatformFile file,
                   char* buf,
                   int buf_len,
+                  bool record_uma,
                   CompletionCallback* callback) {
-  callback->Run(ReadFile(file, buf, buf_len));
+  callback->Run(ReadFile(file, buf, buf_len, record_uma));
 }
 
 // WriteFile() is a simple wrapper around write() that handles EINTR signals and
 // calls MapErrorCode() to map errno to net error codes.  It tries to write to
 // completion.
-int WriteFile(base::PlatformFile file, const char* buf, int buf_len) {
+int WriteFile(base::PlatformFile file, const char* buf, int buf_len,
+              bool record_uma) {
   base::ThreadRestrictions::AssertIOAllowed();
   ssize_t res = HANDLE_EINTR(write(file, buf, buf_len));
-  if (res == -1)
-    return MapErrorCode(errno);
+  if (res == -1) {
+    int error = errno;
+    RecordFileError(error, FILE_ERROR_SOURCE_WRITE, record_uma);
+    return MapErrorCode(error);
+  }
   return res;
 }
 
 void WriteFileTask(base::PlatformFile file,
                    const char* buf,
-                   int buf_len,
+                   int buf_len, bool record_uma,
                    CompletionCallback* callback) {
-  callback->Run(WriteFile(file, buf, buf_len));
+  callback->Run(WriteFile(file, buf, buf_len, record_uma));
 }
 
 // FlushFile() is a simple wrapper around fsync() that handles EINTR signals and
 // calls MapErrorCode() to map errno to net error codes.  It tries to flush to
 // completion.
-int FlushFile(base::PlatformFile file) {
+int FlushFile(base::PlatformFile file, bool record_uma) {
   base::ThreadRestrictions::AssertIOAllowed();
   ssize_t res = HANDLE_EINTR(fsync(file));
-  if (res == -1)
-    return MapErrorCode(errno);
+  if (res == -1) {
+    int error = errno;
+    RecordFileError(error, FILE_ERROR_SOURCE_FLUSH, record_uma);
+    return MapErrorCode(error);
+  }
   return res;
 }
 
 }  // namespace
 
 // CancelableCallbackTask takes ownership of the Callback.  This task gets
 // posted to the MessageLoopForIO instance.
 class CancelableCallbackTask : public CancelableTask {
  public:
   explicit CancelableCallbackTask(Callback0::Type* callback)
@@ skipping 31 matching lines @@
   CompletionCallback* callback() const { return callback_; }
 
   // Called by the WorkerPool thread executing the IO after the IO completes.
   // This method queues RunAsynchronousCallback() on the MessageLoop and signals
   // |background_io_completed_callback_|, in case the destructor is waiting.  In
   // that case, the destructor will call RunAsynchronousCallback() instead, and
   // cancel |message_loop_task_|.
   // |result| is the result of the Read/Write task.
   void OnBackgroundIOCompleted(int result);
 
+  void EnableErrorStatistics() {
+    record_uma_ = true;
+  }
+
  private:
   // Always called on the IO thread, either directly by a task on the
   // MessageLoop or by ~AsyncContext().
   void RunAsynchronousCallback();
 
   // The MessageLoopForIO that this AsyncContext is running on.
   MessageLoopForIO* const message_loop_;
   CompletionCallback* callback_;  // The user provided callback.
 
   // A callback wrapper around OnBackgroundIOCompleted().  Run by the WorkerPool
   // thread doing the background IO on our behalf.
   CompletionCallbackImpl<AsyncContext> background_io_completed_callback_;
 
   // This is used to synchronize between the AsyncContext destructor (which runs
   // on the IO thread and OnBackgroundIOCompleted() which runs on the WorkerPool
   // thread.
   base::WaitableEvent background_io_completed_;
 
   // These variables are only valid when background_io_completed is signaled.
   int result_;
   CancelableCallbackTask* message_loop_task_;
 
   bool is_closing_;
+  bool record_uma_;
 
   DISALLOW_COPY_AND_ASSIGN(AsyncContext);
 };
 
 FileStream::AsyncContext::AsyncContext()
     : message_loop_(MessageLoopForIO::current()),
       callback_(NULL),
       background_io_completed_callback_(
           this, &AsyncContext::OnBackgroundIOCompleted),
       background_io_completed_(true, false),
       message_loop_task_(NULL),
-      is_closing_(false) {}
+      is_closing_(false),
+      record_uma_(false) {}
 
 FileStream::AsyncContext::~AsyncContext() {
   is_closing_ = true;
   if (callback_) {
     // If |callback_| is non-NULL, that implies either the worker thread is
     // still running the IO task, or the completion callback is queued up on the
     // MessageLoopForIO, but AsyncContext() got deleted before then.
     const bool need_to_wait = !background_io_completed_.IsSignaled();
     base::TimeTicks start = base::TimeTicks::Now();
     RunAsynchronousCallback();
     if (need_to_wait) {
       // We want to see if we block the message loop for too long.
       UMA_HISTOGRAM_TIMES("AsyncIO.FileStreamClose",
                           base::TimeTicks::Now() - start);
     }
   }
 }
 
 void FileStream::AsyncContext::InitiateAsyncRead(
     base::PlatformFile file, char* buf, int buf_len,
     CompletionCallback* callback) {
   DCHECK(!callback_);
   callback_ = callback;
 
   base::WorkerPool::PostTask(FROM_HERE,
                              NewRunnableFunction(
                                  &ReadFileTask,
                                  file, buf, buf_len,
+                                 record_uma_,
                                  &background_io_completed_callback_),
                              true /* task_is_slow */);
 }
 
 void FileStream::AsyncContext::InitiateAsyncWrite(
     base::PlatformFile file, const char* buf, int buf_len,
     CompletionCallback* callback) {
   DCHECK(!callback_);
   callback_ = callback;
 
   base::WorkerPool::PostTask(FROM_HERE,
                              NewRunnableFunction(
                                  &WriteFileTask,
                                  file, buf, buf_len,
+                                 record_uma_,
                                  &background_io_completed_callback_),
                              true /* task_is_slow */);
 }
 
 void FileStream::AsyncContext::OnBackgroundIOCompleted(int result) {
   result_ = result;
   message_loop_task_ = new CancelableCallbackTask(
       NewCallback(this, &AsyncContext::RunAsynchronousCallback));
   message_loop_->PostTask(FROM_HERE, message_loop_task_);
   background_io_completed_.Signal();
@@ skipping 20 matching lines @@
   std::swap(temp, callback_);
   background_io_completed_.Reset();
   temp->Run(result_);
 }
 
 // FileStream ------------------------------------------------------------
 
 FileStream::FileStream()
     : file_(base::kInvalidPlatformFileValue),
       open_flags_(0),
-      auto_closed_(true) {
+      auto_closed_(false),
+      record_uma_(false) {
   DCHECK(!IsOpen());
 }
 
 FileStream::FileStream(base::PlatformFile file, int flags)
     : file_(file),
       open_flags_(flags),
-      auto_closed_(false) {
+      auto_closed_(false),
+      record_uma_(false) {
   // If the file handle is opened with base::PLATFORM_FILE_ASYNC, we need to
   // make sure we will perform asynchronous File IO to it.
   if (flags & base::PLATFORM_FILE_ASYNC) {
     async_context_.reset(new AsyncContext());
   }
 }
 
 FileStream::~FileStream() {
   if (auto_closed_)
     Close();
@@ skipping 12 matching lines @@
 }
 
 int FileStream::Open(const FilePath& path, int open_flags) {
   if (IsOpen()) {
     DLOG(FATAL) << "File is already open!";
     return ERR_UNEXPECTED;
   }
 
   open_flags_ = open_flags;
   file_ = base::CreatePlatformFile(path, open_flags_, NULL, NULL);
-  if (file_ == base::kInvalidPlatformFileValue) {
-    return MapErrorCode(errno);
-  }
+  if (file_ == base::kInvalidPlatformFileValue)
+    return RecordAndMapError(errno, FILE_ERROR_SOURCE_OPEN);
 
-  if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
+  if (open_flags_ & base::PLATFORM_FILE_ASYNC)
     async_context_.reset(new AsyncContext());
-  }
 
   return OK;
 }
 
 bool FileStream::IsOpen() const {
   return file_ != base::kInvalidPlatformFileValue;
 }
 
 int64 FileStream::Seek(Whence whence, int64 offset) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   if (!IsOpen())
     return ERR_UNEXPECTED;
 
   // If we're in async, make sure we don't have a request in flight.
   DCHECK(!async_context_.get() || !async_context_->callback());
 
   off_t res = lseek(file_, static_cast<off_t>(offset),
                     static_cast<int>(whence));
   if (res == static_cast<off_t>(-1))
-    return MapErrorCode(errno);
+    return RecordAndMapError(errno, FILE_ERROR_SOURCE_SEEK);
 
   return res;
 }
 
 int64 FileStream::Available() {
   base::ThreadRestrictions::AssertIOAllowed();
 
   if (!IsOpen())
     return ERR_UNEXPECTED;
 
   int64 cur_pos = Seek(FROM_CURRENT, 0);
   if (cur_pos < 0)
     return cur_pos;
 
   struct stat info;
   if (fstat(file_, &info) != 0)
-    return MapErrorCode(errno);
+    return RecordAndMapError(errno, FILE_ERROR_SOURCE_GET_SIZE);
 
   int64 size = static_cast<int64>(info.st_size);
   DCHECK_GT(size, cur_pos);
 
   return size - cur_pos;
 }
 
 int FileStream::Read(
     char* buf, int buf_len, CompletionCallback* callback) {
   if (!IsOpen())
     return ERR_UNEXPECTED;
 
   // read(..., 0) will return 0, which indicates end-of-file.
   DCHECK(buf_len > 0);
   DCHECK(open_flags_ & base::PLATFORM_FILE_READ);
 
   if (async_context_.get()) {
     DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
     // If we're in async, make sure we don't have a request in flight.
     DCHECK(!async_context_->callback());
+    if (record_uma_)
+      async_context_->EnableErrorStatistics();
     async_context_->InitiateAsyncRead(file_, buf, buf_len, callback);
     return ERR_IO_PENDING;
   } else {
-    return ReadFile(file_, buf, buf_len);
+    return ReadFile(file_, buf, buf_len, record_uma_);
   }
 }
 
 int FileStream::ReadUntilComplete(char *buf, int buf_len) {
   int to_read = buf_len;
   int bytes_total = 0;
 
   do {
     int bytes_read = Read(buf, to_read, NULL);
     if (bytes_read <= 0) {
@@ skipping 16 matching lines @@
   // write(..., 0) will return 0, which indicates end-of-file.
   DCHECK_GT(buf_len, 0);
 
   if (!IsOpen())
     return ERR_UNEXPECTED;
 
   if (async_context_.get()) {
     DCHECK(open_flags_ & base::PLATFORM_FILE_ASYNC);
     // If we're in async, make sure we don't have a request in flight.
     DCHECK(!async_context_->callback());
+    if (record_uma_)
+      async_context_->EnableErrorStatistics();
     async_context_->InitiateAsyncWrite(file_, buf, buf_len, callback);
     return ERR_IO_PENDING;
   } else {
-    return WriteFile(file_, buf, buf_len);
+    return WriteFile(file_, buf, buf_len, record_uma_);
   }
 }
 
 int64 FileStream::Truncate(int64 bytes) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   if (!IsOpen())
     return ERR_UNEXPECTED;
 
   // We better be open for reading.
   DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
 
   // Seek to the position to truncate from.
   int64 seek_position = Seek(FROM_BEGIN, bytes);
   if (seek_position != bytes)
     return ERR_UNEXPECTED;
 
   // And truncate the file.
-  int result = ftruncate(file_, bytes);
-  return result == 0 ? seek_position : MapErrorCode(errno);
+  int result = HANDLE_EINTR(ftruncate(file_, bytes));
+  if (result == 0)
+    return seek_position;
+
+  return RecordAndMapError(errno, FILE_ERROR_SOURCE_SET_EOF);
 }
 
 int FileStream::Flush() {
   if (!IsOpen())
     return ERR_UNEXPECTED;
 
-  return FlushFile(file_);
+  return FlushFile(file_, record_uma_);
+}
+
+void FileStream::EnableErrorStatistics() {
+  record_uma_ = true;
+}
+
+int FileStream::RecordAndMapError(int error, FileErrorSource source) {
+  RecordFileError(error, source, record_uma_);
+  return MapErrorCode(error);
 }
 
 }  // namespace net