IoHandle interface

include/envoy/network/io_handle.h

@@ -1,33 +1,176 @@
 #pragma once
 
+#include <bitset>
 #include <memory>
 
 #include "envoy/common/pure.h"
 
 namespace Envoy {
+
+namespace Buffer {
+struct RawSlice;
+} // namespace Buffer
+
 namespace Network {
 
+namespace Address {
+class Instance;
+} // namespace Address
+
+class IoError;
+
+// IoErrorCode::Again is used frequently. Define it to be a distinguishable address to avoid
+// frequent memory allocation of IoError instance.
+// If this is used, IoHandleCallResult has to be instantiated with a deleter that does not
+// deallocate memory for this error.
+#define ENVOY_ERROR_AGAIN reinterpret_cast<IoError*>(0x01)
+
+class IoError {
+public:
+  enum class IoErrorCode {
+    // No data available right now, try again later.
+    Again,
+    // Not supported.
+    NoSupport,
+    // Address family not supported.
+    AddressFamilyNoSupport,
+    // During non-blocking connect, the connection cannot be completed immediately.
+    InProgress,
+    // Permission denied.
+    Permission,
+    // Other error codes cannot be mapped to any one above in getErrorCode().
+    UnknownError
+  };
+  virtual ~IoError() {}
+
+  // Map platform specific error into IoErrorCode.
+  // Needed to hide errorCode() in case of ENVOY_ERROR_AGAIN.
+  static IoErrorCode getErrorCode(const IoError& err) {
+    if (&err == ENVOY_ERROR_AGAIN) {
+      return IoErrorCode::Again;
+    }
+    return err.errorCode();
+  }
+
+  static std::string getErrorDetails(const IoError& err) {
+    if (&err == ENVOY_ERROR_AGAIN) {
+      return "Try again later";
+    }
+    return err.errorDetails();
+  }
+
+protected:
+  // Map platform specific error into IoErrorCode.
+  virtual IoErrorCode getErrorCode() const PURE;
+
+  virtual std::string getErrorDetails() const PURE;
+};
+
+using IoErrorDeleterType = void (*)(IoError*);
+using IoErrorPtr = std::unique_ptr<IoError, IoErrorDeleterType>;
+
+/**
+ * Basic type for return result which has a return code and error code defined
+ * according to different implementations.
+ * If the call succeeds, |err_| is nullptr and |rc_| is valid. Otherwise |err_|
+ * can be passed into IoError::getErrorCode() to extract the error. In this
+ * case, |rc_| is invalid.
+ */
+template <typename T> struct IoHandleCallResult {
+  IoHandleCallResult(T rc, IoErrorPtr err) : rc_(rc), err_(std::move(err)) {}
+  virtual ~IoHandleCallResult() {}
+
+  T rc_;
+  IoErrorPtr err_;
+};
+
+using IoHandleCallIntResult = IoHandleCallResult<int>;
+using IoHandleCallSizeResult = IoHandleCallResult<ssize_t>;
+
 /**
  * IoHandle: an abstract interface for all I/O operations
  */
 class IoHandle {
 public:
-  IoHandle() {}
+  enum class ShutdownType { Read = 0, Write, Both };
+
+  enum class IoHandleFlag {
+    // Each of these maps to a unique bit.
+    NonBlock = 0b01,
+    Append = 0b10
+  };
 
   virtual ~IoHandle() {}
 
   /**
    * Return data associated with IoHandle.
    *
-   * TODO(sbelair2) remove fd() method
+   * TODO(danzh) move it to IoSocketHandle after replacing the calls to it with
+   * calls to IoHandle API's everywhere.
    */
   virtual int fd() const PURE;
 
   /**
    * Clean up IoHandle resources
    */
-  virtual void close() PURE;
+  virtual IoHandleCallIntResult close() PURE;
+
+  virtual bool isClosed() PURE;
+
+  virtual IoHandleCallSizeResult readv(Buffer::RawSlice* iovecs, int num_iovec) PURE;
+
+  virtual IoHandleCallIntResult recvmmsg(struct mmsghdr* msgvec, unsigned int vlen, int flags,
+                                         struct timespec* timeout) PURE;
+
+  virtual IoHandleCallSizeResult writev(const Buffer::RawSlice* iovec, int num_iovec) PURE;
+
+  virtual IoHandleCallIntResult sendmmsg(struct mmsghdr* msgvec, unsigned int vlen, int flags) PURE;
+
+  virtual IoHandleCallIntResult bind(const Network::Address::Instance& address) PURE;
+
+  virtual IoHandleCallIntResult connect(const Network::Address::Instance& server_address) PURE;
+
+  /**
+   * Wrap setsockopt()
+   */
+  virtual IoHandleCallIntResult setIoHandleOption(int level, int optname, const void* optval,
+                                                  socklen_t optlen) PURE;
+  /**
+   * Wrap getsockopt()
+   */
+  virtual IoHandleCallIntResult getIoHandleOption(int level, int optname, void* optval,
+                                                  socklen_t* optlen) PURE;
+
+  /**
+   * Wrap Address::addressFromFd()
+   */
+  virtual IoHandleCallIntResult getBindToAddress(Network::Address::Instance** address) PURE;
+
+  /**
+   * Wrap Address::peerAddressFromFd()
+   */
+  virtual IoHandleCallIntResult getPeerAddress(Network::Address::Instance** address) PURE;
+
+  /**
+   * Wrap fcntl(fd_, F_SETFL...)
+   * @param flag each bit stands for a flag in enum IoHandleFlag.
+   */
+  virtual IoHandleCallIntResult setIoHandleFlag(std::bitset<2> flag) PURE;
+  /**
+   * Wrap fcntl(fd_, F_GETFL...)
+   */
+  virtual IoHandleCallResult<std::bitset<2>> getIoHandleFlags() PURE;
+
+  virtual IoHandleCallIntResult listen(int backlog) PURE;
+
+  /**
+   * Wrap dup()
+   */
+  virtual std::unique_ptr<IoHandle> dup() PURE;
+
+  virtual IoHandleCallIntResult shutdown(ShutdownType how) PURE;
 };
+
 typedef std::unique_ptr<IoHandle> IoHandlePtr;
 
 } // namespace Network