lyx_mirror/src/support/docstream.C

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/**
* \file docstream.C
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Georg Baum
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "docstream.h"
#include "unicode.h"
#include <cerrno>
#include <cstdio>
#include <iconv.h>
#include <locale>
using lyx::ucs4_codeset;
using std::string;
namespace {
// We use C IO throughout this file, because the facets might be used with
// lyxerr in the future.
/// codecvt facet for conversion of UCS4 (internal representation) to UTF8
/// (external representation) or vice versa
class iconv_codecvt_facet : public std::codecvt<lyx::char_type, char, std::mbstate_t>
{
typedef std::codecvt<lyx::char_type, char, std::mbstate_t> base;
public:
/// Constructor. You have to specify with \p inout whether you want
/// to use this facet only for input, only for output or for both.
explicit iconv_codecvt_facet(string const & encoding = "UTF-8",
std::ios_base::openmode inout = std::ios_base::in | std::ios_base::out,
size_t refs = 0)
: base(refs), encoding_(encoding)
{
if (inout & std::ios_base::in) {
in_cd_ = iconv_open(ucs4_codeset, encoding.c_str());
if (in_cd_ == (iconv_t)(-1)) {
fprintf(stderr, "Error %d returned from iconv_open(in_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
throw lyx::iconv_codecvt_facet_exception();
}
} else
in_cd_ = (iconv_t)(-1);
if (inout & std::ios_base::out) {
out_cd_ = iconv_open(encoding.c_str(), ucs4_codeset);
if (out_cd_ == (iconv_t)(-1)) {
fprintf(stderr, "Error %d returned from iconv_open(out_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
throw lyx::iconv_codecvt_facet_exception();
}
} else
out_cd_ = (iconv_t)(-1);
}
protected:
virtual ~iconv_codecvt_facet()
{
if (in_cd_ != (iconv_t)(-1))
if (iconv_close(in_cd_) == -1) {
fprintf(stderr, "Error %d returned from iconv_close(in_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
}
if (out_cd_ != (iconv_t)(-1))
if (iconv_close(out_cd_) == -1) {
fprintf(stderr, "Error %d returned from iconv_close(out_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
}
}
virtual result do_out(state_type &, intern_type const * from,
intern_type const * from_end, intern_type const *& from_next,
extern_type * to, extern_type * to_end,
extern_type *& to_next) const
{
size_t inbytesleft = (from_end - from) * sizeof(intern_type);
size_t outbytesleft = (to_end - to) * sizeof(extern_type);
from_next = from;
to_next = to;
result const retval = do_iconv(out_cd_,
reinterpret_cast<char const **>(&from_next),
&inbytesleft, &to_next, &outbytesleft);
if (retval == base::error) {
fprintf(stderr,
"Error %d returned from iconv when converting from %s to %s: %s\n",
errno, ucs4_codeset, encoding_.c_str(),
strerror(errno));
fputs("Converted input:", stderr);
for (intern_type const * i = from; i < from_next; ++i) {
unsigned int const c = *i;
fprintf(stderr, " 0x%04x", c);
}
unsigned int const c = *from_next;
fprintf(stderr, "\nStopped at: 0x%04x\n", c);
fputs("Unconverted input:", stderr);
for (intern_type const * i = from_next + 1; i < from_end; ++i) {
unsigned int const c = *i;
fprintf(stderr, " 0x%04x", c);
}
fputs("\nConverted output:", stderr);
for (extern_type const * i = to; i < to_next; ++i) {
// extern_type may be signed, avoid output of
// something like 0xffffffc2
unsigned int const c =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", c);
}
fputc('\n', stderr);
fflush(stderr);
}
return retval;
}
virtual result do_unshift(state_type &, extern_type * to,
extern_type *, extern_type *& to_next) const
{
// utf8 does not use shifting
to_next = to;
return base::noconv;
}
virtual result do_in(state_type &,
extern_type const * from, extern_type const * from_end,
extern_type const *& from_next,
intern_type * to, intern_type * to_end,
intern_type *& to_next) const
{
size_t inbytesleft = (from_end - from) * sizeof(extern_type);
size_t outbytesleft = (to_end - to) * sizeof(intern_type);
from_next = from;
to_next = to;
result const retval = do_iconv(in_cd_, &from_next, &inbytesleft,
reinterpret_cast<char **>(&to_next),
&outbytesleft);
if (retval == base::error) {
fprintf(stderr,
"Error %d returned from iconv when converting from %s to %s: %s\n",
errno, encoding_.c_str(), ucs4_codeset,
strerror(errno));
fputs("Converted input:", stderr);
for (extern_type const * i = from; i < from_next; ++i) {
// extern_type may be signed, avoid output of
// something like 0xffffffc2
unsigned int const c =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", c);
}
unsigned int const c =
*reinterpret_cast<unsigned char const *>(from_next);
fprintf(stderr, "\nStopped at: 0x%02x\n", c);
fputs("Unconverted input:", stderr);
for (extern_type const * i = from_next + 1; i < from_end; ++i) {
unsigned int const c =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", c);
}
fputs("\nConverted output:", stderr);
for (intern_type const * i = to; i < to_next; ++i) {
unsigned int const c = *i;
fprintf(stderr, " 0x%02x", c);
}
fputc('\n', stderr);
fflush(stderr);
}
return retval;
}
virtual int do_encoding() const throw()
{
return 0;
}
virtual bool do_always_noconv() const throw()
{
return false;
}
virtual int do_length(state_type & /*state*/, extern_type const * from,
extern_type const * end, size_t max) const
{
// The docs are a bit unclear about this method.
// It seems that we should calculate the actual length of the
// converted sequence, but that would not make sense, since
// once could just do the conversion directly.
// Therefore we just return the number of unconverted
// characters, since that is the best guess we can do.
#if 0
intern_type * to = new intern_type[max];
intern_type * to_end = to + max;
intern_type * to_next = to;
extern_type const * from_next = from;
do_in(state, from, end, from_next, to, to_end, to_next);
delete[] to;
return to_next - to;
#else
size_t const length = end - from;
return std::min(length, max);
#endif
}
virtual int do_max_length() const throw()
{
// UTF8 uses at most 4 bytes to represent one UCS4 code point
// (see RFC 3629). RFC 2279 specifies 6 bytes, but that
// information is outdated, and RFC 2279 has been superseded by
// RFC 3629.
// All other encodings encode one UCS4 code point in one byte
// (and can therefore only encode a subset of UCS4)
return encoding_ == "UTF-8" ? 4 : 1;
}
private:
/// Do the actual conversion. The interface is equivalent to that of
/// iconv() (but const correct).
inline base::result do_iconv(iconv_t cd, char const ** from,
size_t * inbytesleft, char ** to, size_t * outbytesleft) const
{
char const * const to_start = *to;
size_t converted = iconv(cd, const_cast<char ICONV_CONST **>(from),
inbytesleft, to, outbytesleft);
if (converted == (size_t)(-1)) {
switch(errno) {
case EINVAL:
case E2BIG:
return base::partial;
case EILSEQ:
default:
return base::error;
}
}
if (*to == to_start)
return base::noconv;
return base::ok;
}
iconv_t in_cd_;
iconv_t out_cd_;
/// The narrow encoding
std::string encoding_;
};
} // namespace anon
namespace lyx {
const char * iconv_codecvt_facet_exception::what() const throw()
{
return "iconv problem in iconv_codecvt_facet initialization";
}
idocfstream::idocfstream(string const & encoding) : base()
{
std::locale global;
std::locale locale(global, new iconv_codecvt_facet(encoding, in));
imbue(locale);
}
idocfstream::idocfstream(const char* s, std::ios_base::openmode mode,
string const & encoding)
: base()
{
// We must imbue the stream before openening the file
std::locale global;
std::locale locale(global, new iconv_codecvt_facet(encoding, in));
imbue(locale);
open(s, mode);
}
odocfstream::odocfstream(string const & encoding) : base()
{
std::locale global;
std::locale locale(global, new iconv_codecvt_facet(encoding, out));
imbue(locale);
}
odocfstream::odocfstream(const char* s, std::ios_base::openmode mode,
string const & encoding)
: base()
{
// We must imbue the stream before openening the file
std::locale global;
std::locale locale(global, new iconv_codecvt_facet(encoding, out));
imbue(locale);
open(s, mode);
}
}
#if (!defined(HAVE_WCHAR_T) || SIZEOF_WCHAR_T != 4) && defined(__GNUC__)
// We get undefined references to these virtual methods. This looks like
// a bug in gcc. The implementation here does not do anything useful, since
// it is overriden in iconv_codecvt_facet.
namespace std {
template<> codecvt<lyx::char_type, char, mbstate_t>::result
codecvt<lyx::char_type, char, mbstate_t>::do_out(mbstate_t &, const lyx::char_type *, const lyx::char_type *, const lyx::char_type *&,
char *, char *, char *&) const { return error; }
template<> codecvt<lyx::char_type, char, mbstate_t>::result
codecvt<lyx::char_type, char, mbstate_t>::do_unshift(mbstate_t &, char *, char *, char *&) const { return error; }
template<> codecvt<lyx::char_type, char, mbstate_t>::result
codecvt<lyx::char_type, char, mbstate_t>::do_in(mbstate_t &, const char *, const char *, const char *&,
lyx::char_type *, lyx::char_type *, lyx::char_type *&) const { return error; }
template<> int codecvt<lyx::char_type, char, mbstate_t>::do_encoding() const throw() { return 0; }
template<> bool codecvt<lyx::char_type, char, mbstate_t>::do_always_noconv() const throw() { return true; }
#if __GNUC__ == 3 && __GNUC_MINOR__ < 4
template<> int codecvt<lyx::char_type, char, mbstate_t>::do_length(mbstate_t const &, const char *, const char *, size_t) const { return 1; }
#else
template<> int codecvt<lyx::char_type, char, mbstate_t>::do_length(mbstate_t &, const char *, const char *, size_t) const { return 1; }
#endif
template<> int codecvt<lyx::char_type, char, mbstate_t>::do_max_length() const throw() { return 4; }
}
#endif