ByteToMessageDecoder.h

Go to the documentation of this file.

/*
 * Copyright 2017-present Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <wangle/channel/Handler.h>

namespace wangle {

template <typename M>
class ByteToMessageDecoder : public InboundHandler<folly::IOBufQueue&, M> {
 public:
  typedef typename InboundHandler<folly::IOBufQueue&, M>::Context Context;

  virtual bool decode(Context* ctx, folly::IOBufQueue& buf, M& result, size_t&) = 0;

  void transportActive(Context* ctx) override {
    transportActive_ = true;
    ctx->fireTransportActive();
  }

  void transportInactive(Context* ctx) override {
    transportActive_ = false;
    ctx->fireTransportInactive();
  }

  void read(Context* ctx, folly::IOBufQueue& q) override {
    bool success = true;
    while (success && transportActive_) {
      M result;
      size_t needed = 0;
      success = decode(ctx, q, result, needed);
      if (success) {
        ctx->fireRead(std::move(result));
      }
    }
  }

 private:
  bool transportActive_ = true;
};

typedef ByteToMessageDecoder<std::unique_ptr<folly::IOBuf>> ByteToByteDecoder;

} // namespace wangle