ibrcommon/ibrcommon/ssl/HashStream.cpp

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/*
 * HashStream.cpp
 *
 *  Created on: 12.07.2010
 *      Author: morgenro
 */

#include "HashStream.h"

namespace ibrcommon
{
        HashStream::HashStream(const size_t hash, const size_t buffer)
         : iostream(this), data_buf_(new char[buffer]), data_size_(buffer), hash_buf_(new char[hash]), hash_size_(hash), final_(false)
        {
                // Initialize get pointer.  This should be zero so that underflow is called upon first read.
                setg(0, 0, 0);
                setp(data_buf_, data_buf_ + data_size_ - 1);
        }

        HashStream::~HashStream()
        {
                delete[] data_buf_;
                delete[] hash_buf_;
        }

        int HashStream::sync()
        {
                int ret = std::char_traits<char>::eq_int_type(this->overflow(
                                std::char_traits<char>::eof()), std::char_traits<char>::eof()) ? -1
                                : 0;

                return ret;
        }

        int HashStream::overflow(int c)
        {
                char *ibegin = data_buf_;
                char *iend = pptr();

                // mark the buffer as free
                setp(data_buf_, data_buf_ + data_size_ - 1);

                if (!std::char_traits<char>::eq_int_type(c, std::char_traits<char>::eof()))
                {
                        *iend++ = std::char_traits<char>::to_char_type(c);
                }

                // if there is nothing to send, just return
                if ((iend - ibegin) == 0)
                {
                        return std::char_traits<char>::not_eof(c);
                }

                // hashing
                update(data_buf_, (iend - ibegin));

                return std::char_traits<char>::not_eof(c);
        }

        int HashStream::underflow()
        {
                // TODO: add seek mechanisms to reset the istream

                if (!final_)
                {
                        finalize(hash_buf_, hash_size_);
                        final_ = true;

                        // Since the input buffer content is now valid (or is new)
                        // the get pointer should be initialized (or reset).
                        setg(hash_buf_, hash_buf_, hash_buf_ + hash_size_);

                        return std::char_traits<char>::not_eof(hash_buf_[0]);
                }

                return std::char_traits<char>::eof();
        }
}