source: source/ariba/utility/transport/messages/buffer.hpp@ 12755

//-----------------------------------------------------------------------------
// Part of reboost (http://reboost.org).  Released under the
// BSD 2-clause license (http://www.opensource.org/licenses/bsd-license.php).
// Copyright 2012, Sebastian Mies <mies@reboost.org> --- All rights reserved.
//-----------------------------------------------------------------------------

#ifndef BUFFER_HPP_
#define BUFFER_HPP_

#include<cassert>
#include<iostream>

namespace reboost {

/// buffer size and octet
typedef size_t bsize_t;
typedef unsigned char boctet_t;

/**
 * A simple buffer.
 *
 * @author Sebastian Mies <mies@cpptools.org>
 */
class buffer_t {
        typedef buffer_t self;
protected:
        bsize_t size_;
        boctet_t * data_;

public:
        /// a buffer of zero size, pointing to NULL
        inline buffer_t() :
                size_(0), data_((boctet_t*) 0) {
        }

        /// copy constructor
        inline buffer_t(const self& rhs) :
                size_(rhs.size_), data_(rhs.data_){
        }

        /// allocate a buffer of a certain size
        inline buffer_t(bsize_t size) :
                size_(size), data_(new boctet_t[size]) {
        }

        /// convenience constructor
        inline buffer_t(bsize_t size, boctet_t* data) :
                size_(size), data_(data) {
        }

        /// interpret string as buffer (maximal size 64K)
        inline explicit buffer_t(const char* string) :
                size_(0), data_((boctet_t*) string) {
                while (string[size_] != 0 && size_ < 64000)
                        size_++;
        }

        /// clone a buffer
        inline self clone() const {
                buffer_t n(this->size_);
                for (bsize_t i = 0; i < size_; i++)
                        n.data_[i] = this->data_[i];
                return n;
        }

        /// copy a buffer pointer and size.
        inline self& operator=(const self& rhs) {
                this->size_ = rhs.size_;
                this->data_ = rhs.data_;
                return *this;
        }

        /// return sub-buffer.
        inline self operator()(bsize_t index, bsize_t size = 0) const {
                self n(*this);
                n.data_ += index;
                if (size == 0) n.size_ -= index;
                else n.size_ = size;
                return n;
        }

        /// returns a data element at given index
        inline boctet_t operator[](bsize_t index) const {
                return data_[index];
        }

        /// returns a data element at given index
        inline boctet_t& operator[](bsize_t index) {
                return data_[index];
        }

        /// assigns contents to another buffer
        inline const self& copy_to( self& buf, bsize_t index = 0 ) const {
                assert(index + size_ <= buf.size_);
                const boctet_t *src=data_;
                boctet_t* dst=buf.data_+index;
                for (bsize_t i=0; i<size_; i++, src++, dst++ ) *dst = *src;
                return *this;
        }

        /// convert to pointer of an immutable type
        template<class T> inline const T* cast_to() {
                return (T*)data_;
        }

        /// set buffer size
        inline void size( bsize_t size ) {
                size_ = size;
        }


        /// returns the size in octets
        inline bsize_t size() const {
                return size_;
        }

        /// sets the data pointer
        inline void data( boctet_t* data ) {
                data_ = data;
        }

        /// returns a pointer to immutable data
        inline const boctet_t * data() const {
                return data_;
        }

        /// returns a pointer to mutable data
        inline boctet_t * mutable_data() {
                return data_;
        }

        /// returns a hash value of this buffer using the ELF hash
        inline size_t hash() const {
                unsigned h = 0, g;
                for (size_t i = 0; i < size_; i++) {
                        h = (h << 4) + data_[i];
                        g = h & 0xf0000000L;
                        if (g != 0) h ^= g >> 24;
                        h &= ~g;
                }
                return (size_t) h;
        }

        /// returns true if data_ is null
        inline bool is_null() const {
                return data_ == NULL;
        }

        /// returns true if size is zero
        inline bool is_empty() const {
                return size_ == 0;
        }

        /// compare two buffers
        inline int compare_to(const self& rhs) const {
                if (rhs.data_ == data_ && rhs.size_ == size_) return 0;
                if (size_ < rhs.size_) return -1;
                if (size_ > rhs.size_) return 1;
                for (bsize_t i = 0; i < size_; i++) {
                        if (data_[i] > rhs.data_[i]) return 1;
                        if (data_[i] < rhs.data_[i]) return -1;
                }
                return 0;
        }

        /// convenience
        inline bool operator==(const self& rhs) const {
                return (compare_to(rhs) == 0);
        }
        inline bool operator!=(const self& rhs) const {
                return (compare_to(rhs) != 0);
        }
        inline bool operator<(const self& rhs) const {
                return (compare_to(rhs) < 0);
        }
        inline bool operator<=(const self& rhs) const {
                return (compare_to(rhs) <= 0);
        }
        inline bool operator>(const self& rhs) const {
                return (compare_to(rhs) > 0);
        }
        inline bool operator>=(const self& rhs) const {
                return (compare_to(rhs) >= 0);
        }
};

/// stream operator
std::ostream& operator<<( std::ostream& os, const buffer_t& buf );

}

/// boost hash
namespace boost {
inline size_t hash_value(const reboost::buffer_t& buf) {
        return buf.hash();
}}

#endif /* BUFFER_HPP_ */