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// -*- Mode: C++; indent-tabs-mode: nil; tab-width: 2 -*-
/*
* Copyright 2011 Inalogic® Inc.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License, as
* published by the Free Software Foundation; either version 2.1 or 3.0
* of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranties of
* MERCHANTABILITY, SATISFACTORY QUALITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the applicable version of the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of both the GNU Lesser General Public
* License along with this program. If not, see <http://www.gnu.org/licenses/>
*
* Authored by: Tim Penhey <tim.penhey@canonical.com>
*
*/
#include "NuxCore.h"
#include "AsyncFileWriter.h"
#include <sstream>
#include <gio/gio.h>
#include <iostream>
namespace nux
{
/**
* CAUTION: right now this class is not thread aware. It assumes that all the
* write calls are coming from a single thread. Perhaps we need to fix this?
*/
class AsyncFileWriter::Impl
{
public:
Impl(AsyncFileWriter* owner, std::string const& filename);
~Impl();
void Write(std::string const& data);
void Close();
void ProcessAsync();
static void AppendAsyncCallback(GFile* source, GAsyncResult* res, Impl* impl);
static void WriteAsyncCallback(GOutputStream* source, GAsyncResult* res, Impl* impl);
static void CloseAsyncCallback(GOutputStream* source, GAsyncResult* res, Impl* impl);
AsyncFileWriter* owner_;
GCancellable* cancel_;
GFile* file_;
GFileOutputStream* output_stream_;
bool close_pending_;
bool pending_async_call_;
std::stringstream pending_content_;
std::string data_to_write_;
};
AsyncFileWriter::Impl::Impl(AsyncFileWriter* owner, std::string const& filename)
: owner_(owner)
, cancel_(g_cancellable_new())
, file_(g_file_new_for_path(filename.c_str()))
, output_stream_(0)
, close_pending_(false)
, pending_async_call_(true)
{
g_file_append_to_async(file_,
G_FILE_CREATE_NONE,
G_PRIORITY_DEFAULT,
cancel_,
(GAsyncReadyCallback)&AsyncFileWriter::Impl::AppendAsyncCallback,
this);
}
AsyncFileWriter::Impl::~Impl()
{
if (pending_async_call_)
{
g_cancellable_cancel(cancel_);
}
// make sure the file is closed.
if (output_stream_)
{
// If we had an output stream, sync write any pending content.
if (pending_content_.tellp())
{
std::string data(pending_content_.str());
gsize bytes_written;
g_output_stream_write_all((GOutputStream*)output_stream_,
data.c_str(),
data.size(),
&bytes_written,
NULL, NULL);
}
owner_->closed.emit();
g_object_unref(output_stream_);
}
g_object_unref(file_);
g_object_unref(cancel_);
}
void AsyncFileWriter::Impl::AppendAsyncCallback(GFile* source,
GAsyncResult* res,
Impl* impl)
{
GError* error = NULL;
GFileOutputStream* stream = g_file_append_to_finish(source, res, &error);
if (error) {
// Cancelled callbacks call back, but have a cancelled error code.
if (error->code != G_IO_ERROR_CANCELLED) {
std::cerr << error->message << "\n";
}
g_error_free(error);
return;
}
impl->output_stream_ = stream;
impl->pending_async_call_ = false;
impl->owner_->opened.emit();
impl->ProcessAsync();
}
void AsyncFileWriter::Impl::Write(std::string const& data)
{
if (close_pending_) return;
// TODO: lock the pending_content_ access
pending_content_ << data;
ProcessAsync();
}
void AsyncFileWriter::Impl::ProcessAsync()
{
if (output_stream_ == NULL || pending_async_call_) return;
if (pending_content_.tellp())
{
// TODO: lock the pending_content_ access
data_to_write_ = pending_content_.str();
g_output_stream_write_async((GOutputStream*)output_stream_,
data_to_write_.c_str(),
data_to_write_.size(),
G_PRIORITY_DEFAULT,
cancel_,
(GAsyncReadyCallback)&AsyncFileWriter::Impl::WriteAsyncCallback,
this);
pending_async_call_ = true;
}
else if (close_pending_)
{
g_output_stream_close_async((GOutputStream*)output_stream_,
G_PRIORITY_DEFAULT,
cancel_,
(GAsyncReadyCallback)&AsyncFileWriter::Impl::CloseAsyncCallback,
this);
pending_async_call_ = true;
}
}
void AsyncFileWriter::Impl::WriteAsyncCallback(GOutputStream* source,
GAsyncResult* res,
Impl* impl)
{
GError* error = NULL;
gssize g_bytes_written = g_output_stream_write_finish(source, res, &error);
if (error) {
// Cancelled callbacks call back, but have a cancelled error code.
if (error->code != G_IO_ERROR_CANCELLED) {
std::cerr << error->message << "\n";
}
g_error_free(error);
return;
}
// g_bytes_written is signed from gio, but only negative if there is an error.
// The error should be set too if there was an error, so no negative bytes
// written get past here.
std::size_t bytes_written = g_bytes_written;
impl->pending_async_call_ = false;
// TODO: lock the pending_content_ access
std::string data = impl->pending_content_.str();
if (bytes_written >= data.size()) {
// There should be no reason why bytes_written should be greater than the
// number of bytes in the stream, but this is paranoia.
impl->pending_content_.str("");
} else {
impl->pending_content_.str(data.substr(bytes_written));
}
impl->ProcessAsync();
}
void AsyncFileWriter::Impl::Close()
{
close_pending_ = true;
ProcessAsync();
}
void AsyncFileWriter::Impl::CloseAsyncCallback(GOutputStream* source,
GAsyncResult* res,
Impl* impl)
{
GError* error = NULL;
g_output_stream_close_finish(source, res, &error);
if (error) {
// Cancelled callbacks call back, but have a cancelled error code.
if (error->code != G_IO_ERROR_CANCELLED) {
std::cerr << error->message << "\n";
}
g_error_free(error);
return;
}
g_object_unref(impl->output_stream_);
impl->output_stream_ = 0;
impl->owner_->closed.emit();
}
AsyncFileWriter::AsyncFileWriter(std::string const& filename)
: pimpl(new Impl(this, filename))
{}
AsyncFileWriter::~AsyncFileWriter()
{
delete pimpl;
}
void AsyncFileWriter::Write(std::string const& data)
{
pimpl->Write(data);
}
void AsyncFileWriter::Close()
{
pimpl->Close();
}
bool AsyncFileWriter::IsClosing() const
{
return pimpl->close_pending_;
}
} // namespace nux
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