modp_bjavascript.h

/**
 * \file modp_bjavascript.h
 * \brief "C-string" to "javascript-string" encoder
 *
 * Used in emitting dynamically-generated javascript.  Given a regular
 * C-string which might contain binary, the encoder will emit a string
 * that can be used inside a javascript string.  For example:
 *
 * \code
 *  printf("var foo = '%s';", modp_bjavascript_encode(mystring, len));
 * \endcode
 *
 * The "b" in "modp_bjavascript" is due to legacy reasons.  It doesn't
 * mean anything
 *
 * There is no decoder.
 */

/*
 * <PRE>
 * High Performance c-string to javascript-string encoder
 *
 * Copyright &copy; 2006-2016  Nick Galbreath
 * All rights reserved.
 *
 * https://github.com/client9/stringencoders
 *
 * Released under MIT license.  See LICENSE for details.
 * </PRE>
 */

#ifndef COM_MODP_STRINGENCODERS_BJAVASCRIPT
#define COM_MODP_STRINGENCODERS_BJAVASCRIPT

#include "modp_stdint.h"

#include "extern_c_begin.h"

/**
 * "javascript" encode a stirng
 * This takes a c-string and does character escaping
 * so it can be put into a var js_string = '...';
 *
 * \param[out] dest output string.  Must
 * \param[in] str The input string
 * \param[in] len  The length of the input string, excluding any
 *   final null byte.
 */
size_t modp_bjavascript_encode(char* dest, const char* str, size_t len);

#define modp_bjavascript_encode_len(A) (4 * A + 1)

/**
 * Given the exact size of output string.
 *
 * Can be used to allocate the right amount of memory for
 * modp_burl_encode.  Be sure to add 1 byte for final null.
 *
 * This is somewhat expensive since it examines every character
 *  in the input string
 *
 * \param[in] str  The input string
 * \param[in] len  THe length of the input string, excluding any
 *   final null byte (i.e. strlen(str))
 * \return the size of the output string, excluding the final
 *   null byte.
 */
size_t modp_bjavascript_encode_strlen(const char* str, size_t len);

#include "extern_c_end.h"

#ifdef __cplusplus
#include <cstring>
#include <string>
namespace modp {

inline std::string javascript_encode(const char* s, size_t len)
{
    std::string x(modp_bjavascript_encode_len(len), '\0');
    size_t d = modp_bjavascript_encode(const_cast<char*>(x.data()), s, len);
    x.erase(d, std::string::npos);
    return x;
}

inline std::string javascript_encode(const char* s)
{
    return javascript_encode(s, strlen(s));
}

inline std::string& javascript_encode(std::string& s)
{
    std::string x(javascript_encode(s.data(), s.size()));
    s.swap(x);
    return s;
}

inline std::string javascript_encode(const std::string& s)
{
    return javascript_encode(s.data(), s.size());
}

} /* namespace modp */
#endif /* __cplusplus */

#endif /* modp_bjavascript */