CMake/Source/cmConnection.h
2017-11-29 16:36:31 -05:00

136 lines
3.4 KiB
C++

/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
file Copyright.txt or https://cmake.org/licensing for details. */
#pragma once
#include "cmConfigure.h" // IWYU pragma: keep
#include "cmUVHandlePtr.h"
#include "cm_uv.h"
#include <cstddef>
#include <memory>
#include <string>
class cmServerBase;
/***
* Given a sequence of bytes with any kind of buffering, instances of this
* class arrange logical chunks according to whatever the use case is for
* the connection.
*/
class cmConnectionBufferStrategy
{
public:
virtual ~cmConnectionBufferStrategy();
/***
* Called whenever with an active raw buffer. If a logical chunk
* becomes available, that chunk is returned and that portion is
* removed from the rawBuffer
*
* @param rawBuffer in/out parameter. Receive buffer; the buffer strategy is
* free to manipulate this buffer anyway it needs to.
*
* @return Next chunk from the stream. Returns the empty string if a chunk
* isn't ready yet. Users of this interface should repeatedly call this
* function until an empty string is returned since its entirely possible
* multiple chunks come in a single raw buffer.
*/
virtual std::string BufferMessage(std::string& rawBuffer) = 0;
/***
* Called to properly buffer an outgoing message.
*
* @param rawBuffer Message to format in the correct way
*
* @return Formatted message
*/
virtual std::string BufferOutMessage(const std::string& rawBuffer) const
{
return rawBuffer;
};
/***
* Resets the internal state of the buffering
*/
virtual void clear();
// TODO: There should be a callback / flag set for errors
};
class cmConnection
{
CM_DISABLE_COPY(cmConnection)
public:
cmConnection() {}
virtual void WriteData(const std::string& data) = 0;
virtual ~cmConnection();
virtual bool OnConnectionShuttingDown();
virtual bool IsOpen() const = 0;
virtual void SetServer(cmServerBase* s);
virtual void ProcessRequest(const std::string& request);
virtual bool OnServeStart(std::string* pString);
protected:
cmServerBase* Server = nullptr;
};
/***
* Abstraction of a connection; ties in event callbacks from libuv and notifies
* the server when appropriate
*/
class cmEventBasedConnection : public cmConnection
{
public:
/***
* @param bufferStrategy If no strategy is given, it will process the raw
* chunks as they come in. The connection
* owns the pointer given.
*/
cmEventBasedConnection(cmConnectionBufferStrategy* bufferStrategy = nullptr);
virtual void Connect(uv_stream_t* server);
virtual void ReadData(const std::string& data);
bool IsOpen() const override;
void WriteData(const std::string& data) override;
bool OnConnectionShuttingDown() override;
virtual void OnDisconnect(int errorCode);
static void on_close(uv_handle_t* handle);
template <typename T>
static void on_close_delete(uv_handle_t* handle)
{
delete reinterpret_cast<T*>(handle);
}
protected:
cm::uv_stream_ptr WriteStream;
std::string RawReadBuffer;
std::unique_ptr<cmConnectionBufferStrategy> BufferStrategy;
static void on_read(uv_stream_t* stream, ssize_t nread, const uv_buf_t* buf);
static void on_write(uv_write_t* req, int status);
static void on_new_connection(uv_stream_t* stream, int status);
static void on_alloc_buffer(uv_handle_t* handle, size_t suggested_size,
uv_buf_t* buf);
};