/*
- * Copyright 2014 Facebook, Inc.
+ * Copyright 2015 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#pragma once
+#include <memory>
+#include <sys/uio.h>
+
+#include <folly/io/async/DelayedDestruction.h>
+#include <folly/io/async/EventBase.h>
+#include <folly/io/async/AsyncSocketBase.h>
+
+#include <openssl/ssl.h>
+
+constexpr bool kOpenSslModeMoveBufferOwnership =
+#ifdef SSL_MODE_MOVE_BUFFER_OWNERSHIP
+ true
+#else
+ false
+#endif
+;
+
namespace folly {
+class AsyncSocketException;
+class EventBase;
+class IOBuf;
+class SocketAddress;
+
/*
* flags given by the application for write* calls
*/
* will be acknowledged.
*/
EOR = 0x02,
+ /*
+ * this indicates that only the write side of socket should be shutdown
+ */
+ WRITE_SHUTDOWN = 0x04,
};
/*
* timeout, since most callers want to give up if the remote end stops
* responding and no further progress can be made sending the data.
*/
-class AsyncTransport : public DelayedDestruction {
+class AsyncTransport : public DelayedDestruction, public AsyncSocketBase {
public:
typedef std::unique_ptr<AsyncTransport, Destructor> UniquePtr;
virtual bool isPending() const {
return readable();
}
+
/**
* Determine if transport is connected to the endpoint
*
*/
virtual bool isDetachable() const = 0;
- /**
- * Get the EventBase used by this transport.
- *
- * Returns nullptr if this transport is not currently attached to a
- * EventBase.
- */
- virtual EventBase* getEventBase() const = 0;
-
/**
* Set the send timeout.
*
* @param address The local address will be stored in the specified
* SocketAddress.
*/
- virtual void getLocalAddress(folly::SocketAddress* address) const = 0;
+ virtual void getLocalAddress(SocketAddress* address) const = 0;
+
+ virtual void getAddress(SocketAddress* address) const {
+ getLocalAddress(address);
+ }
/**
* Get the address of the remote endpoint to which this transport is
* @param address The remote endpoint's address will be stored in the
* specified SocketAddress.
*/
- virtual void getPeerAddress(folly::SocketAddress* address) const = 0;
+ virtual void getPeerAddress(SocketAddress* address) const = 0;
/**
* @return True iff end of record tracking is enabled
virtual size_t getRawBytesReceived() const = 0;
protected:
- virtual ~AsyncTransport() {}
+ virtual ~AsyncTransport() = default;
};
+class AsyncReader {
+ public:
+ class ReadCallback {
+ public:
+ virtual ~ReadCallback() = default;
+
+ /**
+ * When data becomes available, getReadBuffer() will be invoked to get the
+ * buffer into which data should be read.
+ *
+ * This method allows the ReadCallback to delay buffer allocation until
+ * data becomes available. This allows applications to manage large
+ * numbers of idle connections, without having to maintain a separate read
+ * buffer for each idle connection.
+ *
+ * It is possible that in some cases, getReadBuffer() may be called
+ * multiple times before readDataAvailable() is invoked. In this case, the
+ * data will be written to the buffer returned from the most recent call to
+ * readDataAvailable(). If the previous calls to readDataAvailable()
+ * returned different buffers, the ReadCallback is responsible for ensuring
+ * that they are not leaked.
+ *
+ * If getReadBuffer() throws an exception, returns a nullptr buffer, or
+ * returns a 0 length, the ReadCallback will be uninstalled and its
+ * readError() method will be invoked.
+ *
+ * getReadBuffer() is not allowed to change the transport state before it
+ * returns. (For example, it should never uninstall the read callback, or
+ * set a different read callback.)
+ *
+ * @param bufReturn getReadBuffer() should update *bufReturn to contain the
+ * address of the read buffer. This parameter will never
+ * be nullptr.
+ * @param lenReturn getReadBuffer() should update *lenReturn to contain the
+ * maximum number of bytes that may be written to the read
+ * buffer. This parameter will never be nullptr.
+ */
+ virtual void getReadBuffer(void** bufReturn, size_t* lenReturn) = 0;
+
+ /**
+ * readDataAvailable() will be invoked when data has been successfully read
+ * into the buffer returned by the last call to getReadBuffer().
+ *
+ * The read callback remains installed after readDataAvailable() returns.
+ * It must be explicitly uninstalled to stop receiving read events.
+ * getReadBuffer() will be called at least once before each call to
+ * readDataAvailable(). getReadBuffer() will also be called before any
+ * call to readEOF().
+ *
+ * @param len The number of bytes placed in the buffer.
+ */
+
+ virtual void readDataAvailable(size_t len) noexcept = 0;
+
+ /**
+ * When data becomes available, isBufferMovable() will be invoked to figure
+ * out which API will be used, readBufferAvailable() or
+ * readDataAvailable(). If isBufferMovable() returns true, that means
+ * ReadCallback supports the IOBuf ownership transfer and
+ * readBufferAvailable() will be used. Otherwise, not.
+
+ * By default, isBufferMovable() always return false. If
+ * readBufferAvailable() is implemented and to be invoked, You should
+ * overwrite isBufferMovable() and return true in the inherited class.
+ *
+ * This method allows the AsyncSocket/AsyncSSLSocket do buffer allocation by
+ * itself until data becomes available. Compared with the pre/post buffer
+ * allocation in getReadBuffer()/readDataAvailabe(), readBufferAvailable()
+ * has two advantages. First, this can avoid memcpy. E.g., in
+ * AsyncSSLSocket, the decrypted data was copied from the openssl internal
+ * buffer to the readbuf buffer. With the buffer ownership transfer, the
+ * internal buffer can be directly "moved" to ReadCallback. Second, the
+ * memory allocation can be more precise. The reason is
+ * AsyncSocket/AsyncSSLSocket can allocate the memory of precise size
+ * because they have more context about the available data than
+ * ReadCallback. Think about the getReadBuffer() pre-allocate 4072 bytes
+ * buffer, but the available data is always 16KB (max OpenSSL record size).
+ */
+
+ virtual bool isBufferMovable() noexcept {
+ return false;
+ }
+
+ /**
+ * readBufferAvailable() will be invoked when data has been successfully
+ * read.
+ *
+ * Note that only either readBufferAvailable() or readDataAvailable() will
+ * be invoked according to the return value of isBufferMovable(). The timing
+ * and aftereffect of readBufferAvailable() are the same as
+ * readDataAvailable()
+ *
+ * @param readBuf The unique pointer of read buffer.
+ */
+
+ virtual void readBufferAvailable(std::unique_ptr<IOBuf> /*readBuf*/)
+ noexcept {};
+
+ /**
+ * readEOF() will be invoked when the transport is closed.
+ *
+ * The read callback will be automatically uninstalled immediately before
+ * readEOF() is invoked.
+ */
+ virtual void readEOF() noexcept = 0;
+
+ /**
+ * readError() will be invoked if an error occurs reading from the
+ * transport.
+ *
+ * The read callback will be automatically uninstalled immediately before
+ * readError() is invoked.
+ *
+ * @param ex An exception describing the error that occurred.
+ */
+ virtual void readErr(const AsyncSocketException& ex) noexcept = 0;
+ };
+
+ // Read methods that aren't part of AsyncTransport.
+ virtual void setReadCB(ReadCallback* callback) = 0;
+ virtual ReadCallback* getReadCallback() const = 0;
+
+ protected:
+ virtual ~AsyncReader() = default;
+};
+
+class AsyncWriter {
+ public:
+ class WriteCallback {
+ public:
+ virtual ~WriteCallback() = default;
+
+ /**
+ * writeSuccess() will be invoked when all of the data has been
+ * successfully written.
+ *
+ * Note that this mainly signals that the buffer containing the data to
+ * write is no longer needed and may be freed or re-used. It does not
+ * guarantee that the data has been fully transmitted to the remote
+ * endpoint. For example, on socket-based transports, writeSuccess() only
+ * indicates that the data has been given to the kernel for eventual
+ * transmission.
+ */
+ virtual void writeSuccess() noexcept = 0;
+
+ /**
+ * writeError() will be invoked if an error occurs writing the data.
+ *
+ * @param bytesWritten The number of bytes that were successfull
+ * @param ex An exception describing the error that occurred.
+ */
+ virtual void writeErr(size_t bytesWritten,
+ const AsyncSocketException& ex) noexcept = 0;
+ };
+
+ // Write methods that aren't part of AsyncTransport
+ virtual void write(WriteCallback* callback, const void* buf, size_t bytes,
+ WriteFlags flags = WriteFlags::NONE) = 0;
+ virtual void writev(WriteCallback* callback, const iovec* vec, size_t count,
+ WriteFlags flags = WriteFlags::NONE) = 0;
+ virtual void writeChain(WriteCallback* callback,
+ std::unique_ptr<IOBuf>&& buf,
+ WriteFlags flags = WriteFlags::NONE) = 0;
+
+ protected:
+ virtual ~AsyncWriter() = default;
+};
+
+// Transitional intermediate interface. This is deprecated.
+// Wrapper around folly::AsyncTransport, that includes read/write callbacks
+class AsyncTransportWrapper : virtual public AsyncTransport,
+ virtual public AsyncReader,
+ virtual public AsyncWriter {
+ public:
+ using UniquePtr = std::unique_ptr<AsyncTransportWrapper, Destructor>;
+
+ // Alias for inherited members from AsyncReader and AsyncWriter
+ // to keep compatibility.
+ using ReadCallback = AsyncReader::ReadCallback;
+ using WriteCallback = AsyncWriter::WriteCallback;
+ virtual void setReadCB(ReadCallback* callback) override = 0;
+ virtual ReadCallback* getReadCallback() const override = 0;
+ virtual void write(WriteCallback* callback, const void* buf, size_t bytes,
+ WriteFlags flags = WriteFlags::NONE) override = 0;
+ virtual void writev(WriteCallback* callback, const iovec* vec, size_t count,
+ WriteFlags flags = WriteFlags::NONE) override = 0;
+ virtual void writeChain(WriteCallback* callback,
+ std::unique_ptr<IOBuf>&& buf,
+ WriteFlags flags = WriteFlags::NONE) override = 0;
+ /**
+ * The transport wrapper may wrap another transport. This returns the
+ * transport that is wrapped. It returns nullptr if there is no wrapped
+ * transport.
+ */
+ virtual AsyncTransportWrapper* getWrappedTransport() {
+ return nullptr;
+ }
+};
} // folly
projects / folly.git / blobdiff