cc/gapic/stream_reader.h

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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.
 */

#ifndef GAPIC_STREAM_READER_H
#define GAPIC_STREAM_READER_H

#include <stdint.h>

namespace gapic {

// StreamReader is a pure-virtual interface used to read from data streams.
class StreamReader {
public:
    // read attempts to read max_size bytes to the pointer data, blocking until
    // the data is available. Returns the number of bytes successfully read,
    // which may be less than size if the stream was closed or there was an
    // error.
    virtual uint64_t read(void* data, uint64_t max_size) = 0;

    // read attempts to read the s from the stream, returning true on success or
    // false if the read was partial or a complete failure.
    // Note: T must be a plain-old-data type.
    template <typename T> inline bool read(T& s);

protected:
    virtual ~StreamReader() {}
};

template <typename T>
inline bool StreamReader::read(T& s) {
    return read(&s, sizeof(s)) == sizeof(s);
}

} // namespace gapic

#endif // GAPIC_STREAM_READER_H