TTransport.h

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.
 */

#ifndef _SANDESH_TRANSPORT_TTRANSPORT_H_
#define _SANDESH_TRANSPORT_TTRANSPORT_H_ 1

#include <stdint.h>
#include <string>
#include <boost/shared_ptr.hpp>

#include <base/logging.h>

namespace contrail { namespace sandesh { namespace transport {

template <class Transport_>
int32_t readAll(Transport_ &trans, uint8_t* buf, uint32_t len) {
  uint32_t have = 0;
  uint32_t get = 0;

  while (have < len) {
    get = trans.read(buf+have, len-have);
    if (get <= 0) {
      LOG(ERROR, __func__ << ": No more data to read");
      return -1;
    }
    have += get;
  }

  return have;
}


class TTransport {
 public:
  virtual ~TTransport() {}

  virtual bool isOpen() {
    return false;
  }

  virtual bool peek() {
    return isOpen();
  }

  virtual void open() {
    LOG(ERROR, __func__ << ": Cannot open base TTransport.");
    assert(false);
  }

  virtual void close() {
    LOG(ERROR, __func__ << ": Cannot close base TTransport.");
    assert(false);
  }

  int32_t read(uint8_t* buf, uint32_t len) {

    return read_virt(buf, len);
  }
  virtual int32_t read_virt(uint8_t* /* buf */, uint32_t /* len */) {
    LOG(ERROR, __func__ << ": Base TTransport cannot read.");
    assert(false);
    return -1;
  }

  int32_t readAll(uint8_t* buf, uint32_t len) {

    return readAll_virt(buf, len);
  }
  virtual int32_t readAll_virt(uint8_t* buf, uint32_t len) {
    return contrail::sandesh::transport::readAll(*this, buf, len);
  }

  virtual uint32_t readEnd() {
    // default behaviour is to do nothing
    return 0;
  }

  int write(const uint8_t* buf, uint32_t len) {

    return write_virt(buf, len);
  }
  virtual int write_virt(const uint8_t* /* buf */, uint32_t /* len */) {
    LOG(ERROR, __func__ << ": Base TTransport cannot write.");
    assert(false);
    return -1;
  }

  virtual uint32_t writeEnd() {
    // default behaviour is to do nothing
    return 0;
  }

  virtual void flush() {
    // default behaviour is to do nothing
  }

  const uint8_t* borrow(uint8_t* buf, uint32_t* len) {

    return borrow_virt(buf, len);
  }
  virtual const uint8_t* borrow_virt(uint8_t* /* buf */, uint32_t* /* len */) {
    return NULL;
  }

  void consume(uint32_t len) {

    consume_virt(len);
  }
  virtual void consume_virt(uint32_t /* len */) {
    LOG(ERROR, __func__ << ": Base TTransport cannot consume.");
    assert(false);
  }

 protected:
  TTransport() {}
};

class TTransportFactory {
 public:
  TTransportFactory() {}

  virtual ~TTransportFactory() {}

  virtual boost::shared_ptr<TTransport> getTransport(boost::shared_ptr<TTransport> trans) {
    return trans;
  }

};

}}} // contrail::sandesh::transport

#endif // #ifndef _SANDESH_TRANSPORT_TTRANSPORT_H_