net: Implement canceling of all async operations in FileStream.

net/base/file_stream_context_win.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 "net/base/file_stream_context.h"
+
+#include <windows.h>
+
+#include "base/file_path.h"
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+#include "base/task_runner_util.h"
+#include "base/threading/worker_pool.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+
+namespace net {
+
+// Ensure that we can just use our Whence values directly.
+COMPILE_ASSERT(FROM_BEGIN == FILE_BEGIN, bad_whence_begin);
+COMPILE_ASSERT(FROM_CURRENT == FILE_CURRENT, bad_whence_current);
+COMPILE_ASSERT(FROM_END == FILE_END, bad_whence_end);
+
+namespace {
+
+void SetOffset(OVERLAPPED* overlapped, const LARGE_INTEGER& offset) {
+  overlapped->Offset = offset.LowPart;
+  overlapped->OffsetHigh = offset.HighPart;
+}
+
+void IncrementOffset(OVERLAPPED* overlapped, DWORD count) {
+  LARGE_INTEGER offset;
+  offset.LowPart = overlapped->Offset;
+  offset.HighPart = overlapped->OffsetHigh;
+  offset.QuadPart += static_cast<LONGLONG>(count);
+  SetOffset(overlapped, offset);
+}
+
+}  // namespace
+
+FileStream::Context::Context(const BoundNetLog& bound_net_log)
+    : io_context_(),
+      file_(base::kInvalidPlatformFileValue),
+      record_uma_(false),
+      async_in_progress_(false),
+      orphaned_(false),
+      bound_net_log_(bound_net_log),
+      error_source_(FILE_ERROR_SOURCE_COUNT) {
+  io_context_.handler = this;
+}
+
+FileStream::Context::Context(base::PlatformFile file,
+                             const BoundNetLog& bound_net_log,
+                             int open_flags)
+    : io_context_(),
+      file_(file),
+      record_uma_(false),
+      async_in_progress_(false),
+      orphaned_(false),
+      bound_net_log_(bound_net_log),
+      error_source_(FILE_ERROR_SOURCE_COUNT) {
+  io_context_.handler = this;
+  if (file_ != base::kInvalidPlatformFileValue &&
+      (open_flags & base::PLATFORM_FILE_ASYNC)) {
+    OnAsyncFileOpened();
+  }
+}
+
+FileStream::Context::~Context() {
+}
+
+int64 FileStream::Context::GetFileSize() const {
+  LARGE_INTEGER file_size;
+  if (!GetFileSizeEx(file_, &file_size)) {
+    DWORD error = GetLastError();
+    LOG(WARNING) << "GetFileSizeEx failed: " << error;
+    return RecordAndMapError(error, FILE_ERROR_SOURCE_GET_SIZE);
+  }
+
+  return file_size.QuadPart;
+}
+
+int FileStream::Context::ReadAsync(IOBuffer* buf,
+                                   int buf_len,
+                                   const CompletionCallback& callback) {
+  DCHECK(!async_in_progress_);
+  error_source_ = FILE_ERROR_SOURCE_READ;
+
+  int rv = 0;
+
+  DWORD bytes_read;
+  if (!ReadFile(file_, buf->data(), buf_len,
+                &bytes_read, &io_context_.overlapped)) {
+    DWORD error = GetLastError();
+    if (error == ERROR_IO_PENDING) {
+      IOCompletionIsPending(callback, buf);
+      rv = ERR_IO_PENDING;
+    } else if (error == ERROR_HANDLE_EOF) {
+      rv = 0;  // Report EOF by returning 0 bytes read.
+    } else {
+      LOG(WARNING) << "ReadFile failed: " << error;
+      rv = RecordAndMapError(error, FILE_ERROR_SOURCE_READ);
+    }
+  } else {
+    IOCompletionIsPending(callback, buf);
+    rv = ERR_IO_PENDING;
+  }
+  return rv;
+}
+
+int FileStream::Context::ReadSync(char* buf, int buf_len) {
+  int rv = 0;
+
+  DWORD bytes_read;
+  if (!ReadFile(file_, buf, buf_len, &bytes_read, NULL)) {
+    DWORD error = GetLastError();
+    if (error == ERROR_HANDLE_EOF) {
+      rv = 0;  // Report EOF by returning 0 bytes read.
+    } else {
+      LOG(WARNING) << "ReadFile failed: " << error;
+      rv = RecordAndMapError(error, FILE_ERROR_SOURCE_READ);
+    }
+  } else {
+    rv = static_cast<int>(bytes_read);
+  }
+  return rv;
+}
+
+int FileStream::Context::WriteAsync(IOBuffer* buf,
+                                    int buf_len,
+                                    const CompletionCallback& callback) {
+  error_source_ = FILE_ERROR_SOURCE_WRITE;
+
+  int rv = 0;
+  DWORD bytes_written = 0;
+  if (!WriteFile(file_, buf->data(), buf_len,
+                 &bytes_written, &io_context_.overlapped)) {
+    DWORD error = GetLastError();
+    if (error == ERROR_IO_PENDING) {
+      IOCompletionIsPending(callback, buf);
+      rv = ERR_IO_PENDING;
+    } else {
+      LOG(WARNING) << "WriteFile failed: " << error;
+      rv = RecordAndMapError(error, FILE_ERROR_SOURCE_WRITE);
+    }
+  } else {
+    IOCompletionIsPending(callback, buf);
+    rv = ERR_IO_PENDING;
+  }
+  return rv;
+}
+
+int FileStream::Context::WriteSync(const char* buf, int buf_len) {
+  int rv = 0;
+  DWORD bytes_written = 0;
+  if (!WriteFile(file_, buf, buf_len, &bytes_written, NULL)) {
+    DWORD error = GetLastError();
+    LOG(WARNING) << "WriteFile failed: " << error;
+    rv = RecordAndMapError(error, FILE_ERROR_SOURCE_WRITE);
+  } else {
+    rv = static_cast<int>(bytes_written);
+  }
+  return rv;
+}
+
+int FileStream::Context::Truncate(int64 bytes) {
+  BOOL result = SetEndOfFile(file_);
+  if (result)
+    return bytes;
+
+  DWORD error = GetLastError();
+  LOG(WARNING) << "SetEndOfFile failed: " << error;
+  return RecordAndMapError(error, FILE_ERROR_SOURCE_SET_EOF);
+}
+
+void FileStream::Context::OnAsyncFileOpened() {
+  MessageLoopForIO::current()->RegisterIOHandler(file_, this);
+}
+
+int64 FileStream::Context::SeekFileImpl(Whence whence, int64 offset) {
+  LARGE_INTEGER distance, res;
+  distance.QuadPart = offset;
+  DWORD move_method = static_cast<DWORD>(whence);
+  if (SetFilePointerEx(file_, distance, &res, move_method)) {
+    SetOffset(&io_context_.overlapped, res);
+    return res.QuadPart;
+  }
+
+  return -static_cast<int>(GetLastError());
+}
+
+int64 FileStream::Context::FlushFileImpl() {
+  if (FlushFileBuffers(file_))
+    return OK;
+
+  return -static_cast<int>(GetLastError());
+}
+
+void FileStream::Context::IOCompletionIsPending(
+    const CompletionCallback& callback,
+    IOBuffer* buf) {
+  DCHECK(callback_.is_null());
+  callback_ = callback;
+  in_flight_buf_ = buf;  // Hold until the async operation ends.
+  async_in_progress_ = true;
+}
+
+void FileStream::Context::OnIOCompleted(MessageLoopForIO::IOContext* context,
+                                        DWORD bytes_read,
+                                        DWORD error) {
+  DCHECK_EQ(&io_context_, context);
+  DCHECK(!callback_.is_null());
+  DCHECK(async_in_progress_);
+
+  async_in_progress_ = false;
+  if (orphaned_) {
+    callback_.Reset();
+    in_flight_buf_ = NULL;
+    CloseAndDelete();
+    return;
+  }
+
+  int result = static_cast<int>(bytes_read);
+  if (error && error != ERROR_HANDLE_EOF)
+    result = RecordAndMapError(error, error_source_);
+
+  if (bytes_read)
+    IncrementOffset(&io_context_.overlapped, bytes_read);
+
+  CompletionCallback temp_callback = callback_;
+  callback_.Reset();
+  scoped_refptr<IOBuffer> temp_buf = in_flight_buf_;
+  in_flight_buf_ = NULL;
+  temp_callback.Run(result);
+}
+
+}  // namespace net