Split PipeReader off into a separate class

While here, clean up the API to PipeReader a little bit and split
up the class so there can be multiple ways to accept the data
from the pipe.

BUG=358344

Review URL: https://codereview.chromium.org/219333010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@261319 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 90 insertions, 0 deletions

diff --git a/chromeos/dbus/pipe_reader.cc b/chromeos/dbus/pipe_reader.cc
new file mode 100644
index 0000000..8d857ea
--- /dev/null
+++ b/chromeos/dbus/pipe_reader.cc
@@ -0,0 +1,90 @@
+// Copyright 2014 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 "chromeos/dbus/pipe_reader.h"
+
+#include "base/bind.h"
+#include "base/platform_file.h"
+#include "base/posix/eintr_wrapper.h"
+#include "net/base/net_errors.h"
+
+namespace chromeos {
+
+PipeReader::PipeReader(PipeReader::IOCompleteCallback callback)
+    : write_fd_(-1),
+      io_buffer_(new net::IOBufferWithSize(4096)),
+      callback_(callback),
+      weak_ptr_factory_(this) {}
+
+PipeReader::~PipeReader() {
+  CloseWriteFD();
+}
+
+void PipeReader::CloseWriteFD() {
+  if (write_fd_ == -1)
+    return;
+  if (IGNORE_EINTR(close(write_fd_)) < 0)
+    PLOG(ERROR) << "close";
+  write_fd_ = -1;
+}
+
+bool PipeReader::StartIO() {
+  // Use a pipe to collect data
+  int pipe_fds[2];
+  const int status = HANDLE_EINTR(pipe(pipe_fds));
+  if (status < 0) {
+    PLOG(ERROR) << "pipe";
+    return false;
+  }
+  write_fd_ = pipe_fds[1];
+  base::PlatformFile data_file_ = pipe_fds[0];
+  // Pass ownership of pipe_fds[0] to data_stream_, which will will close it.
+  data_stream_.reset(new net::FileStream(
+      data_file_,
+      base::PLATFORM_FILE_READ | base::PLATFORM_FILE_ASYNC,
+      NULL));
+
+  // Post an initial async read to setup data collection
+  int rv = data_stream_->Read(
+      io_buffer_.get(), io_buffer_->size(),
+      base::Bind(&PipeReader::OnDataReady, weak_ptr_factory_.GetWeakPtr()));
+  if (rv != net::ERR_IO_PENDING) {
+    LOG(ERROR) << "Unable to post initial read";
+    return false;
+  }
+  return true;
+}
+
+void PipeReader::OnDataReady(int byte_count) {
+  DVLOG(1) << "OnDataReady byte_count " << byte_count;
+  if (byte_count <= 0) {
+    callback_.Run();  // signal creator to take data and delete us
+    return;
+  }
+
+  AcceptData(io_buffer_->data(), byte_count);
+
+  // Post another read
+  int rv = data_stream_->Read(
+      io_buffer_.get(), io_buffer_->size(),
+      base::Bind(&PipeReader::OnDataReady, weak_ptr_factory_.GetWeakPtr()));
+  if (rv != net::ERR_IO_PENDING) {
+    LOG(ERROR) << "Unable to post another read";
+    // TODO(sleffler) do something more intelligent?
+  }
+}
+
+PipeReaderForString::PipeReaderForString(
+    PipeReader::IOCompleteCallback callback) : PipeReader(callback) {}
+
+void PipeReaderForString::AcceptData(const char *data, int byte_count) {
+  data_.append(data, byte_count);
+}
+
+
+void PipeReaderForString::GetData(std::string* data) {
+  data_.swap(*data);
+}
+
+}  // namespace chromeos