readable.cpp

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#include <jwsc++/config.h>

#include <iostream>
#include <sstream>
#include <fstream>
#include <cctype>
#include <cstring>

#include <jwsc++/base/exception.h>
#include <jwsc++/base/readable.h>

#ifdef JWSCXX_HAVE_DMALLOC
#include <dmalloc.h>
#endif


using namespace jwscxx::base;


void Readable::read(const char* fname) throw (jwscxx::base::IO_error,
        jwscxx::base::Arg_error)
{
    std::ifstream in;
    std::ostringstream ost;

    in.open(fname);
    if (in.fail())
    {
        ost << fname << ": Could not open file";
        throw IO_error(ost.str());
    }

    try
    {
        read(in);
    }
    catch (IO_error e)
    {
        ost << fname << ": " << e.get_msg();
        throw IO_error(ost.str());
    }

    in.close();
    if (in.fail())
    {
        ost << fname << ": Could not close file";
        throw IO_error(ost.str());
    }
}


const char* Readable::read_field_value
(
    std::istream& in,
    const char*   field_name, 
    char*         field_buf,
    size_t        buf_len,
    char          separator
) 
throw (jwscxx::base::Arg_error, jwscxx::base::IO_error)
{
    using std::ostringstream;
    using std::isspace;
    using std::strlen;
    using std::strncmp;

    in.getline(field_buf, buf_len);
    if (in.fail()) 
    {
        throw IO_error("Could not read field line");
    }

    const char* field_ptr = field_buf;

    while (isspace(*field_ptr) && *field_ptr != 0)
    {
        field_ptr++;
    }

    if (strncmp(field_ptr, field_name, strlen(field_name)) != 0)
    {
        ostringstream ost;
        ost << "Field name '" << field_name << "' not found in '" 
            << field_buf << "'";
        throw Arg_error(ost.str());
    }

    while (*field_ptr != separator && *field_ptr != 0)
    {
        field_ptr++;
    }

    if (*field_ptr == 0)
    {
        ostringstream ost;
        ost << "Field '" << field_buf << "' improperly formatted";
        throw Arg_error(ost.str());
    }

    field_ptr++;

    while (isspace(*field_ptr) && *field_ptr != 0)
    {
        field_ptr++;
    }

    if (*field_ptr == 0)
        return 0;

    return field_ptr;
}


const char* Readable::read_field_value
(
    std::istream& in,
    const char*   field_name, 
    char          separator
) 
throw (jwscxx::base::Arg_error, jwscxx::base::IO_error)
{
    // TODO This is not thread-safe.
    static char field_buf[256] = {0};

    return read_field_value(in, field_name, field_buf, 256, separator);
}