source: trunk/FACT++/src/Converter.cc@ 10216

// **************************************************************************
/** @class Converter

@brief An interpreter to convert a command line into a command plus data memory

The Converter class interprets arguments in a string accoring to the
given format definition and produces a corresponding memory block from it
which can be attached to an event later.

The format is given according to the Dim format description:

  The format parameter specifies the contents of the structure in the
  form T:N[;T:N]*[;T] where T is the item type: (I)nteger, (C)haracter,
  (L)ong, (S)hort, (F)loat, (D)ouble, X(tra long==long long) and N is the
  number of such items. The type alone at the end means all following items
  are of the same type. Example: "I:3;F:2;C" means 3 Integers, 2 Floats and
  Characters until the end. The format parameter is used for
  communicating between different platforms.

For example:

  Converter c(cout, "I:1;F:2;I:2", "COMMAND 1 2.5 4.2 3 4");

would produce a 20 byte data block with the integers 1, the floats
2.5 and 4.2, and the intergers 3 and 4, in this order.

The opposite direction is also possible

  Converter c(cout, "I:1;F:2;I:2", pointer, size);

@remark
    Most probably we support more formats than dim does...

*/
// **************************************************************************
#include "Converter.h"

#include <iomanip>
#include <sstream>

#include <boost/regex.hpp>

#include "Readline.h"
#include "WindowLog.h"

using namespace std;

// --------------------------------------------------------------------------
//
//! Gets a value of the template type T from the stringstream and adds the
//! value as binary data to the end of the vector. If a value couldn't be
//! obtained it is set to 0.
//!
//! @param i
//!     The number of the processed argument (currently used for some debug
//!     output when an argument is not available and artificially set to 0)
//!
//! @param line
//!     The stringstream from which the data should be read
//!
//! @param vec
//!     The vector of bytes at which end the data is added in binary format
//!
template <class T>
    void Converter::Eval(int i, std::stringstream &line, std::vector<char> &vec) const
{
    T val = 0;
    line >> val;
    if (!line)
        wout << " arg[" << i << "]";
    else
        wout << " (" << val << ")";

    vec.insert(vec.end(),
               reinterpret_cast<char*>(&val),
               reinterpret_cast<char*>(&val+1));
}

// --------------------------------------------------------------------------
//
//! Constructs a data block from the given string according to the given
//! format. (See also the class reference for more details).
//!
//! The data block is stored in a vector<char>. It's content can be
//! retrieved using the member functions Ptr() and Size(). Whether parsing
//! was successfull or not can be checked with GetRc().
//! If parsing was not successfull, either the format contained something
//! odd, the conversion failed (e.g. 5.5 for an int) or the string contained
//! a wrong number of arguments.
//!
//! @param out
//!    The ostream to which errors and debug messages should be printed.
//!
//! @param fmt
//!    The format descriptor according to the dim definition
//!
//! @param str
//!    The string which should be interpreted, e.g. "1 2 5.5 abcdef"
//!
Converter::Converter(std::ostream &out, const std::string &fmt, const std::string &str)
: rc(false), wout(out)
{
    // If the format is empty we are already done
    if (fmt.empty())
    {
        if (!str.empty())
        {
            wout << endl;
            wout << kRed << "Data string not empty as it ought to be!" << endl;
            return;
        }

        wout << endl;
        rc = true;
        return;
    }

    // Access both, the data and the format through a stringstream
    stringstream line(str);
    stringstream stream(fmt);

    // For better performance we could use sregex
    static const boost::regex expr("^[ ]*([CSILFDX])[ ]*(:[ ]*([1-9]+[0-9]*))?[ ]*$");

    // Tokenize the format
    int arg = 0;
    string buffer;
    while (getline(stream, buffer, ';'))
    {
        boost::smatch what;
        if (!boost::regex_match(buffer, what, expr))
        {
            wout << endl;
            wout << kRed << "Wrong format string '" << buffer << "'!" << endl;
            return;
        }

        const string t = what[1]; // type id
        const string n = what[3]; // counter

        int cnt = atoi(n.c_str());

        // Check if the format is just C (without a number)
        // That would mean that it is a \0 terminated string
        if (t[0]=='C' && cnt==0)
        {
            // Remove leading whitespaces
            while (line.peek()==' ')
                line.get();

            // Copy the string into the buffer
            getline(line, buffer, '\0');

            wout << " (" << buffer << ")";
            data.insert(data.end(), buffer.begin(), buffer.end());
            data.push_back(0);
            continue;
        }

        // if the :N part was not given assume 1
        if (cnt==0)
            cnt=1;

        // Get as many items from the input line as requested
        for (int j=0; j<cnt; j++)
            switch (t[0])
            {
            case 'C': // Skip whitespaces when checking for characters
                if (j>0)
                    line >> noskipws;
                Eval<char>(arg++, line, data);
                line >> skipws;
                break;
            case 'S': Eval<short>    (arg++, line, data); break;
            case 'I': Eval<int>      (arg++, line, data); break;
            case 'L': Eval<long>     (arg++, line, data); break;
            case 'F': Eval<float>    (arg++, line, data); break;
            case 'D': Eval<double>   (arg++, line, data); break;
            case 'X': Eval<long long>(arg++, line, data); break;
            default:
                // This should never happen!
                wout << endl << kRed << "Format '" << t[0] << " not known!" << endl;
                break;
            }
    }

    wout << " [" << fmt << "]=" << data.size() << endl;

    // Something wrong with the conversion (e.g. 5.5 for an int)
    if (line.fail() && !line.eof())
    {
        line.clear(); // This is necesasary to get a proper response from tellg()
        wout << kRed << "Error converting argument at " << arg << " [fmt=" << fmt << "]!" << endl;
        wout << kRed << str << endl;
        wout << kRed << setw(int(line.tellg())) << " " << "^" << endl;
        return;
    }

    // Not enough arguments, we have not reached the end
    if (line.fail() && line.eof())
    {
        line.clear();
        wout << kRed << "Not enough arguments [fmt=" << fmt << "]!" << endl;
        wout << kRed << str << endl;
        wout << kRed << setw(int(line.tellg())+1) << " " << "^" << endl;
        return;
    }

    // Too many arguments, we have not reached the end
    // Unfortunately, this can also mean that there is something
    // wrong with the last argument
    if (line.good() && !line.eof())
    {
        wout << kRed << "More arguments available than expected [" << fmt << "]!" << endl;
        wout << kRed << str << endl;
        wout << kRed << setw(int(line.tellg())+1) << " " << "^" << endl;
        return;
    }

    // Set return code to true (successfull)
    rc = true;
}

// --------------------------------------------------------------------------
//
//! Gets the value as a binary from the ptr and return it as a string.
//! The pointer is increased accordingly.
//!
//! @param ptr
//!    A reference to a pointer to the data which should be converted.
//!    The pointer is increased according to the size of the data.
//!
//! @returns
//!    The data converted into a string
//!
template<class T>
string Converter::Get(const char* &ptr) const
{
    ostringstream stream;
    stream << *reinterpret_cast<const T*>(ptr);
    ptr += sizeof(T);

    return stream.str();
}

// --------------------------------------------------------------------------
//
//! Constructs a string from the given data block according to the specified
//! format. (See also the class reference for more details).
//!
//! The resulting string is stored in vector<char>  and 0-terminated.
//! It can be accessed through Ptr().
//!
//! If the conversion faild GetRc will return false. In this case the data
//! contents might not be well defined.
//!
//! If no format is given (size == 0) but the data size is finite (>0)
//! then the data is converted into a hex representation.
//!
//! @remark
//!    In cases of failures the stored data might be inexisting and
//!    Ptr() might return NULL. If you output NULL to our streams
//!    they might not show any further output anymore.
//!
//! @param fmt
//!    The format descriptor according to the dim definition
//!
//! @param out
//!    The ostream to which errors and debug messages should be printed.
//!
//! @param dat
//!    Pointer to the start of the binary data
//!
//! @param size
//!    Size of the binary data region
//!
Converter::Converter(ostream &out, const string &fmt, const void *dat, int size)
: rc(false), wout(out)
{
    const char *ptr = reinterpret_cast<const char *>(dat);

    ostringstream text;

    // Structure: print hex representation
    if (fmt.size()==0)
    {
        if (size==0)
        {
            data.push_back(0);
            rc = true;
            return;
        }

        text << hex;

        for (int i=0; i<size; i++)
            text << setw(2) << ptr[i] << " ";

        const string &ref = text.str();
        data.insert(data.begin(), ref.begin(), ref.end());
        data.push_back(0);
        return;
    }

    // Access both, the data and the format through a stringstream
    stringstream stream(fmt);

    // For better performance we could use sregex
    static const boost::regex expr("^[ ]*([CSILFDX])[ ]*(:[ ]*([1-9]+[0-9]*))?[ ]*$");

    // Tokenize the format
    string buffer;
    while (getline(stream, buffer, ';'))
    {
        if (ptr-size>=dat)
        {
            wout << kRed << "Format description '" << fmt << "' exceeds available data size (" << size << ")" << endl;
            return;
        }

        boost::smatch what;
        if (!boost::regex_match(buffer, what, expr))
        {
            wout << kRed << "Wrong format string '" << buffer << "'!" << endl;
            return;
        }

        const string t = what[1]; // type id
        const string n = what[3]; // counter

        int cnt = atoi(n.c_str());

        // Check if the format is just C (without a number)
        // That would mean that it is a \0 terminated string
        if (t[0]=='C' && cnt==0)
        {
            const string str(ptr);
            text << ' ' << str;
            ptr += str.length()+1;
            break;
        }

        // if the :N part was not given assume 1
        if (cnt==0)
            cnt=1;

        // Get as many items from the input line as requested
        for (int j=0; j<cnt; j++)
        {
            text << ' ';

            switch (t[0])
            {
            case 'C': text << Get<char>     (ptr); break;
            case 'S': text << Get<short>    (ptr); break;
            case 'I': text << Get<int>      (ptr); break;
            case 'L': text << Get<long>     (ptr); break;
            case 'F': text << Get<float>    (ptr); break;
            case 'D': text << Get<double>   (ptr); break;
            case 'X': text << Get<long long>(ptr); break;
            default:
                // This should never happen!
                wout << kRed << "Format '" << t[0] << " not known!" << endl;
                return;
            }
        }
    }

    if (ptr-size!=dat)
    {
        wout << kRed << "Data block size (" << size << ") doesn't fit format description '" << fmt << "'" << endl;
        return;
    }

    rc = true;

    const string &ref = text.str();
    data.insert(data.begin(), ref.begin()+1, ref.end());
    data.push_back(0);
}