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/* Skeleton for a conversion module.

   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

   02111-1307 USA.  */

/* This file can be included to provide definitions of several things

   many modules have in common.  It can be customized using the following

   macros:

     DEFINE_INIT        define the default initializer.  This requires the

                        following symbol to be defined.

     CHARSET_NAME       string with official name of the coded character

                        set (in all-caps)

     DEFINE_FINI        define the default destructor function.

     MIN_NEEDED_FROM    minimal number of bytes needed for the from-charset.

     MIN_NEEDED_TO      likewise for the to-charset.

     MAX_NEEDED_FROM    maximal number of bytes needed for the from-charset.

                        This macro is optional, it defaults to MIN_NEEDED_FROM.

     MAX_NEEDED_TO      likewise for the to-charset.

     DEFINE_DIRECTION_OBJECTS

                        two objects will be defined to be used when the

                        `gconv' function must only distinguish two

                        directions.  This is implied by DEFINE_INIT.

                        If this macro is not defined the following

                        macro must be available.

     FROM_DIRECTION     this macro is supposed to return a value != 0

                        if we convert from the current character set,

                        otherwise it return 0.

     EMIT_SHIFT_TO_INIT this symbol is optional.  If it is defined it

                        defines some code which writes out a sequence

                        of characters which bring the current state into

                        the initial state.

     FROM_LOOP          name of the function implementing the conversion

                        from the current characters.

     TO_LOOP            likewise for the other direction

     ONE_DIRECTION      optional.  If defined to 1, only one conversion

                        direction is defined instead of two.  In this

                        case, FROM_DIRECTION should be defined to 1, and

                        FROM_LOOP and TO_LOOP should have the same value.

     SAVE_RESET_STATE   in case of an error we must reset the state for

                        the rerun so this macro must be defined for

                        stateful encodings.  It takes an argument which

                        is nonzero when saving.

     RESET_INPUT_BUFFER If the input character sets allow this the macro

                        can be defined to reset the input buffer pointers

                        to cover only those characters up to the error.

     FUNCTION_NAME      if not set the conversion function is named `gconv'.

     PREPARE_LOOP       optional code preparing the conversion loop.  Can

                        contain variable definitions.

     END_LOOP           also optional, may be used to store information

     EXTRA_LOOP_ARGS    optional macro specifying extra arguments passed

                        to loop function.

 */

#include <assert.h>

#include <gconv.h>

#include <string.h>

#define __need_size_t

#define __need_NULL

#include <stddef.h>

#include <wchar.h>

#ifndef STATIC_GCONV

# include <dlfcn.h>

#endif

# define DL_CALL_FCT(fct, args) fct args

/* The direction objects.  */

#if DEFINE_DIRECTION_OBJECTS || DEFINE_INIT

static int from_object;

static int to_object;

# ifndef FROM_DIRECTION

#  define FROM_DIRECTION (step->__data == &from_object)

# endif

#else

# ifndef FROM_DIRECTION

#  error "FROM_DIRECTION must be provided if direction objects are not used"

# endif

#endif

/* How many bytes are needed at most for the from-charset.  */

#ifndef MAX_NEEDED_FROM

# define MAX_NEEDED_FROM        MIN_NEEDED_FROM

#endif

/* Same for the to-charset.  */

#ifndef MAX_NEEDED_TO

# define MAX_NEEDED_TO          MIN_NEEDED_TO

#endif

/* Define macros which can access unaligned buffers.  These macros are

   supposed to be used only in code outside the inner loops.  For the inner

   loops we have other definitions which allow optimized access.  */

#ifdef _STRING_ARCH_unaligned

/* We can handle unaligned memory access.  */

# define get16u(addr) *((__const uint16_t *) (addr))

# define get32u(addr) *((__const uint32_t *) (addr))

/* We need no special support for writing values either.  */

# define put16u(addr, val) *((uint16_t *) (addr)) = (val)

# define put32u(addr, val) *((uint32_t *) (addr)) = (val)

#else

/* Distinguish between big endian and little endian.  */

# if __BYTE_ORDER == __LITTLE_ENDIAN

#  define get16u(addr) \

     (((__const unsigned char *) (addr))[1] << 8                              \

      | ((__const unsigned char *) (addr))[0])

#  define get32u(addr) \

     (((((__const unsigned char *) (addr))[3] << 8                            \

        | ((__const unsigned char *) (addr))[2]) << 8                         \

       | ((__const unsigned char *) (addr))[1]) << 8                          \

      | ((__const unsigned char *) (addr))[0])

#  define put16u(addr, val) \

     ({ uint16_t __val = (val);                                               \

        ((unsigned char *) (addr))[0] = __val;                                 \

        ((unsigned char *) (addr))[1] = __val >> 8;                           \

        (void) 0; })

#  define put32u(addr, val) \

     ({ uint32_t __val = (val);                                               \

        ((unsigned char *) (addr))[0] = __val;                                 \

        __val >>= 8;                                                          \

        ((unsigned char *) (addr))[1] = __val;                                \

        __val >>= 8;                                                          \

        ((unsigned char *) (addr))[2] = __val;                                \

        __val >>= 8;                                                          \

        ((unsigned char *) (addr))[3] = __val;                                \

        (void) 0; })

# else

#  define get16u(addr) \

     (((__const unsigned char *) (addr))[0] << 8                       \

      | ((__const unsigned char *) (addr))[1])

#  define get32u(addr) \

     (((((__const unsigned char *) (addr))[0] << 8                             \

        | ((__const unsigned char *) (addr))[1]) << 8                         \

       | ((__const unsigned char *) (addr))[2]) << 8                          \

      | ((__const unsigned char *) (addr))[3])

#  define put16u(addr, val) \

     ({ uint16_t __val = (val);                                               \

        ((unsigned char *) (addr))[1] = __val;                                \

        ((unsigned char *) (addr))[0] = __val >> 8;                            \

        (void) 0; })

#  define put32u(addr, val) \

     ({ uint32_t __val = (val);                                               \

        ((unsigned char *) (addr))[3] = __val;                                \

        __val >>= 8;                                                          \

        ((unsigned char *) (addr))[2] = __val;                                \

        __val >>= 8;                                                          \

        ((unsigned char *) (addr))[1] = __val;                                \

        __val >>= 8;                                                          \

        ((unsigned char *) (addr))[0] = __val;                                 \

        (void) 0; })

# endif

#endif

/* For conversions from a fixed width character set to another fixed width

   character set we can define RESET_INPUT_BUFFER in a very fast way.  */

#if !defined RESET_INPUT_BUFFER && !defined SAVE_RESET_STATE

# if MIN_NEEDED_FROM == MAX_NEEDED_FROM && MIN_NEEDED_TO == MAX_NEEDED_TO

/* We have to use these `if's here since the compiler cannot know that

   (outbuf - outerr) is always divisible by MIN_NEEDED_TO.  */

#  define RESET_INPUT_BUFFER \

  if (MIN_NEEDED_FROM % MIN_NEEDED_TO == 0)                                    \

    *inptrp -= (outbuf - outerr) * (MIN_NEEDED_FROM / MIN_NEEDED_TO);         \

  else if (MIN_NEEDED_TO % MIN_NEEDED_FROM == 0)                       \

    *inptrp -= (outbuf - outerr) / (MIN_NEEDED_TO / MIN_NEEDED_FROM);         \

  else                                                                        \

    *inptrp -= ((outbuf - outerr) / MIN_NEEDED_TO) * MIN_NEEDED_FROM

# endif

#endif

/* The default init function.  It simply matches the name and initializes

   the step data to point to one of the objects above.  */

#if DEFINE_INIT

# ifndef CHARSET_NAME

#  error "CHARSET_NAME not defined"

# endif

extern int gconv_init (struct __gconv_step *step);

int

gconv_init (struct __gconv_step *step)

{

  /* Determine which direction.  */

  if (strcmp (step->__from_name, CHARSET_NAME) == 0)

    {

      step->__data = &from_object;

      step->__min_needed_from = MIN_NEEDED_FROM;

      step->__max_needed_from = MAX_NEEDED_FROM;

      step->__min_needed_to = MIN_NEEDED_TO;

      step->__max_needed_to = MAX_NEEDED_TO;

    }

  else if (__builtin_expect (strcmp (step->__to_name, CHARSET_NAME), 0) == 0)

    {

      step->__data = &to_object;

      step->__min_needed_from = MIN_NEEDED_TO;

      step->__max_needed_from = MAX_NEEDED_TO;

      step->__min_needed_to = MIN_NEEDED_FROM;

      step->__max_needed_to = MAX_NEEDED_FROM;

    }

  else

    return __GCONV_NOCONV;

#ifdef SAVE_RESET_STATE

  step->__stateful = 1;

#else

  step->__stateful = 0;

#endif

  return __GCONV_OK;

}

#endif

/* The default destructor function does nothing in the moment and so

   we don't define it at all.  But we still provide the macro just in

   case we need it some day.  */

#if DEFINE_FINI

#endif

/* If no arguments have to passed to the loop function define the macro

   as empty.  */

#ifndef EXTRA_LOOP_ARGS

# define EXTRA_LOOP_ARGS

#endif

/* This is the actual conversion function.  */

#ifndef FUNCTION_NAME

# define FUNCTION_NAME  gconv

#endif

/* The macros are used to access the function to convert single characters.  */

#define SINGLE(fct) SINGLE2 (fct)

#define SINGLE2(fct) fct##_single

extern int FUNCTION_NAME (struct __gconv_step *step,

                          struct __gconv_step_data *data,

                          const unsigned char **inptrp,

                          const unsigned char *inend,

                          unsigned char **outbufstart, size_t *irreversible,

                          int do_flush, int consume_incomplete);

int

FUNCTION_NAME (struct __gconv_step *step, struct __gconv_step_data *data,

               const unsigned char **inptrp, const unsigned char *inend,

               unsigned char **outbufstart, size_t *irreversible, int do_flush,

               int consume_incomplete)

{

  struct __gconv_step *next_step = step + 1;

  struct __gconv_step_data *next_data = data + 1;

  __gconv_fct fct;

  int status;

  fct = (data->__flags & __GCONV_IS_LAST) ? NULL : next_step->__fct;

  /* If the function is called with no input this means we have to reset

     to the initial state.  The possibly partly converted input is

     dropped.  */

  if (__builtin_expect (do_flush, 0))

    {

      /* This should never happen during error handling.  */

      assert (outbufstart == NULL);

      status = __GCONV_OK;

#ifdef EMIT_SHIFT_TO_INIT

      if (do_flush == 1)

        {

          /* We preserve the initial values of the pointer variables.  */

          unsigned char *outbuf = data->__outbuf;

          unsigned char *outstart = outbuf;

          unsigned char *outend = data->__outbufend;

# ifdef PREPARE_LOOP

          PREPARE_LOOP

# endif

# ifdef SAVE_RESET_STATE

          SAVE_RESET_STATE (1);

# endif

          /* Emit the escape sequence to reset the state.  */

          EMIT_SHIFT_TO_INIT;

          /* Call the steps down the chain if there are any but only if we

             successfully emitted the escape sequence.  This should only

             fail if the output buffer is full.  If the input is invalid

             it should be discarded since the user wants to start from a

             clean state.  */

          if (status == __GCONV_OK)

            {

              if (data->__flags & __GCONV_IS_LAST)

                /* Store information about how many bytes are available.  */

                data->__outbuf = outbuf;

              else

                {

                  /* Write out all output which was produced.  */

                  if (outbuf > outstart)

                    {

                      const unsigned char *outerr = outstart;

                      int result;

                      result = DL_CALL_FCT (fct, (next_step, next_data,

                                                  &outerr, outbuf, NULL,

                                                  irreversible, 0,

                                                  consume_incomplete));

                      if (result != __GCONV_EMPTY_INPUT)

                        {

                          if (__builtin_expect (outerr != outbuf, 0))

                            {

                              /* We have a problem.  Undo the conversion.  */

                              outbuf = outstart;

                              /* Restore the state.  */

# ifdef SAVE_RESET_STATE

                              SAVE_RESET_STATE (0);

# endif

                            }

                          /* Change the status.  */

                          status = result;

                        }

                    }

                  if (status == __GCONV_OK)

                    /* Now flush the remaining steps.  */

                    status = DL_CALL_FCT (fct, (next_step, next_data, NULL,

                                                NULL, NULL, irreversible, 1,

                                                consume_incomplete));

                }

            }

        }

      else

#endif

        {

          /* Clear the state object.  There might be bytes in there from

             previous calls with CONSUME_INCOMPLETE == 1.  But don't emit

             escape sequences.  */

          memset (data->__statep, '\0', sizeof (*data->__statep));

          if (! (data->__flags & __GCONV_IS_LAST))

            /* Now flush the remaining steps.  */

            status = DL_CALL_FCT (fct, (next_step, next_data, NULL, NULL,

                                        NULL, irreversible, do_flush,

                                        consume_incomplete));

        }

    }

  else

    {

      /* We preserve the initial values of the pointer variables.  */

      const unsigned char *inptr = *inptrp;

      unsigned char *outbuf = (__builtin_expect (outbufstart == NULL, 1)

                               ? data->__outbuf : *outbufstart);

      unsigned char *outend = data->__outbufend;

      unsigned char *outstart;

      /* This variable is used to count the number of characters we

         actually converted.  */

      size_t lirreversible = 0;

      size_t *lirreversiblep = irreversible ? &lirreversible : NULL;

#if defined _STRING_ARCH_unaligned \

    || MIN_NEEDED_FROM == 1 || MAX_NEEDED_FROM % MIN_NEEDED_FROM != 0 \

    || MIN_NEEDED_TO == 1 || MAX_NEEDED_TO % MIN_NEEDED_TO != 0

# define unaligned 0

#else

      int unaligned;

# define GEN_unaligned(name) GEN_unaligned2 (name)

# define GEN_unaligned2(name) name##_unaligned

#endif

#ifdef PREPARE_LOOP

      PREPARE_LOOP

#endif

#if MAX_NEEDED_FROM > 1 || MAX_NEEDED_TO > 1

      /* If the function is used to implement the mb*towc*() or wc*tomb*()

         functions we must test whether any bytes from the last call are

         stored in the `state' object.  */

      if (((MAX_NEEDED_FROM > 1 && MAX_NEEDED_TO > 1)

           || (MAX_NEEDED_FROM > 1 && FROM_DIRECTION)

           || (MAX_NEEDED_TO > 1 && !FROM_DIRECTION))

          && consume_incomplete && (data->__statep->__count & 7) != 0)

        {

          /* Yep, we have some bytes left over.  Process them now.

             But this must not happen while we are called from an

             error handler.  */

          assert (outbufstart == NULL);

# if MAX_NEEDED_FROM > 1

          if (MAX_NEEDED_TO == 1 || FROM_DIRECTION)

            status = SINGLE(FROM_LOOP) (step, data, inptrp, inend, &outbuf,

                                        outend, lirreversiblep

                                        EXTRA_LOOP_ARGS);

# endif

# if MAX_NEEDED_FROM > 1 && MAX_NEEDED_TO > 1 && !ONE_DIRECTION

          else

# endif

# if MAX_NEEDED_TO > 1 && !ONE_DIRECTION

            status = SINGLE(TO_LOOP) (step, data, inptrp, inend, &outbuf,

                                      outend, lirreversiblep EXTRA_LOOP_ARGS);

# endif

          if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK)

            return status;

        }

#endif

#if !defined _STRING_ARCH_unaligned \

    && MIN_NEEDED_FROM != 1 && MAX_NEEDED_FROM % MIN_NEEDED_FROM == 0 \

    && MIN_NEEDED_TO != 1 && MAX_NEEDED_TO % MIN_NEEDED_TO == 0

      /* The following assumes that encodings, which have a variable length

         what might unalign a buffer even though it is a aligned in the

         beginning, either don't have the minimal number of bytes as a divisor

         of the maximum length or have a minimum length of 1.  This is true

         for all known and supported encodings.  */

      unaligned = ((FROM_DIRECTION

                    && ((uintptr_t) inptr % MIN_NEEDED_FROM != 0

                        || ((data->__flags & __GCONV_IS_LAST)

                            && (uintptr_t) outbuf % MIN_NEEDED_TO != 0)))

                   || (!FROM_DIRECTION

                       && (((data->__flags & __GCONV_IS_LAST)

                            && (uintptr_t) outbuf % MIN_NEEDED_FROM != 0)

                           || (uintptr_t) inptr % MIN_NEEDED_TO != 0)));

#endif

      while (1)

        {

          struct __gconv_trans_data *trans;

          /* Remember the start value for this round.  */

          inptr = *inptrp;

          /* The outbuf buffer is empty.  */

          outstart = outbuf;

#ifdef SAVE_RESET_STATE

          SAVE_RESET_STATE (1);

#endif

          if (__builtin_expect (!unaligned, 1))

            {

              if (FROM_DIRECTION)

                /* Run the conversion loop.  */

                status = FROM_LOOP (step, data, inptrp, inend, &outbuf, outend,

                                    lirreversiblep EXTRA_LOOP_ARGS);

              else

                /* Run the conversion loop.  */

                status = TO_LOOP (step, data, inptrp, inend, &outbuf, outend,

                                  lirreversiblep EXTRA_LOOP_ARGS);

            }

#if !defined _STRING_ARCH_unaligned \

    && MIN_NEEDED_FROM != 1 && MAX_NEEDED_FROM % MIN_NEEDED_FROM == 0 \

    && MIN_NEEDED_TO != 1 && MAX_NEEDED_TO % MIN_NEEDED_TO == 0

          else

            {

              if (FROM_DIRECTION)

                /* Run the conversion loop.  */

                status = GEN_unaligned (FROM_LOOP) (step, data, inptrp, inend,

                                                    &outbuf, outend,

                                                    lirreversiblep

                                                    EXTRA_LOOP_ARGS);

              else

                /* Run the conversion loop.  */

                status = GEN_unaligned (TO_LOOP) (step, data, inptrp, inend,

                                                  &outbuf, outend,

                                                  lirreversiblep

                                                  EXTRA_LOOP_ARGS);

            }

#endif

          /* If we were called as part of an error handling module we

             don't do anything else here.  */

          if (__builtin_expect (outbufstart != NULL, 0))

            {

              *outbufstart = outbuf;

              return status;

            }

          /* Give the transliteration module the chance to store the

             original text and the result in case it needs a context.  */

          for (trans = data->__trans; trans != NULL; trans = trans->__next)

            if (trans->__trans_context_fct != NULL)

              DL_CALL_FCT (trans->__trans_context_fct,

                           (trans->__data, inptr, *inptrp, outstart, outbuf));

          /* We finished one use of the loops.  */

          ++data->__invocation_counter;

          /* If this is the last step leave the loop, there is nothing

             we can do.  */

          if (__builtin_expect (data->__flags & __GCONV_IS_LAST, 0))

            {

              /* Store information about how many bytes are available.  */

              data->__outbuf = outbuf;

              /* Remember how many non-identical characters we

                 converted in a irreversible way.  */

              *irreversible += lirreversible;

              break;

            }

          /* Write out all output which was produced.  */

          if (__builtin_expect (outbuf > outstart, 1))

            {

              const unsigned char *outerr = data->__outbuf;

              int result;

              result = DL_CALL_FCT (fct, (next_step, next_data, &outerr,

                                          outbuf, NULL, irreversible, 0,

                                          consume_incomplete));

              if (result != __GCONV_EMPTY_INPUT)

                {

                  if (__builtin_expect (outerr != outbuf, 0))

                    {

#ifdef RESET_INPUT_BUFFER

                      RESET_INPUT_BUFFER;

#else

                      /* We have a problem with the in on of the functions

                         below.  Undo the conversion upto the error point.  */

                      size_t nstatus;

                      /* Reload the pointers.  */

                      *inptrp = inptr;

                      outbuf = outstart;

                      /* Restore the state.  */

# ifdef SAVE_RESET_STATE

                      SAVE_RESET_STATE (0);

# endif

                      if (__builtin_expect (!unaligned, 1))

                        {

                          if (FROM_DIRECTION)

                            /* Run the conversion loop.  */

                            nstatus = FROM_LOOP (step, data, inptrp, inend,

                                                 &outbuf, outerr,

                                                 lirreversiblep

                                                 EXTRA_LOOP_ARGS);

                          else

                            /* Run the conversion loop.  */

                            nstatus = TO_LOOP (step, data, inptrp, inend,

                                               &outbuf, outerr,

                                               lirreversiblep

                                               EXTRA_LOOP_ARGS);

                        }

# if !defined _STRING_ARCH_unaligned \

     && MIN_NEEDED_FROM != 1 && MAX_NEEDED_FROM % MIN_NEEDED_FROM == 0 \

     && MIN_NEEDED_TO != 1 && MAX_NEEDED_TO % MIN_NEEDED_TO == 0

                      else

                        {

                          if (FROM_DIRECTION)

                            /* Run the conversion loop.  */

                            nstatus = GEN_unaligned (FROM_LOOP) (step, data,

                                                                 inptrp, inend,

                                                                 &outbuf,

                                                                 outerr,

                                                                 lirreversiblep

                                                                 EXTRA_LOOP_ARGS);

                          else

                            /* Run the conversion loop.  */

                            nstatus = GEN_unaligned (TO_LOOP) (step, data,

                                                               inptrp, inend,

                                                               &outbuf, outerr,

                                                               lirreversiblep

                                                               EXTRA_LOOP_ARGS);

                        }

# endif

                      /* We must run out of output buffer space in this

                         rerun.  */

                      assert (outbuf == outerr);

                      assert (nstatus == __GCONV_FULL_OUTPUT);

                      /* If we haven't consumed a single byte decrement

                         the invocation counter.  */

                      if (__builtin_expect (outbuf == outstart, 0))

                        --data->__invocation_counter;

#endif  /* reset input buffer */

                    }

                  /* Change the status.  */

                  status = result;

                }

              else

                /* All the output is consumed, we can make another run

                   if everything was ok.  */

                if (status == __GCONV_FULL_OUTPUT)

                  {

                    status = __GCONV_OK;

                    outbuf = data->__outbuf;

                  }

            }

          if (status != __GCONV_OK)

            break;

          /* Reset the output buffer pointer for the next round.  */

          outbuf = data->__outbuf;

        }

#ifdef END_LOOP

      END_LOOP

#endif

      /* If we are supposed to consume all character store now all of the

         remaining characters in the `state' object.  */

#if MAX_NEEDED_FROM > 1 || MAX_NEEDED_TO > 1

      if (((MAX_NEEDED_FROM > 1 && MAX_NEEDED_TO > 1)

           || (MAX_NEEDED_FROM > 1 && FROM_DIRECTION)

           || (MAX_NEEDED_TO > 1 && !FROM_DIRECTION))

          && __builtin_expect (consume_incomplete, 0)

          && status == __GCONV_INCOMPLETE_INPUT)

        {

# ifdef STORE_REST

          mbstate_t *state = data->__statep;

          STORE_REST

# else

          size_t cnt;

          /* Make sure the remaining bytes fit into the state objects

             buffer.  */

          assert (inend - *inptrp < 4);

          for (cnt = 0; *inptrp < inend; ++cnt)

            data->__statep->__value.__wchb[cnt] = *(*inptrp)++;

          data->__statep->__count &= ~7;

          data->__statep->__count |= cnt;

# endif

        }

#endif

    }

  return status;

}

#undef DEFINE_INIT

#undef CHARSET_NAME

#undef DEFINE_FINI

#undef MIN_NEEDED_FROM

#undef MIN_NEEDED_TO

#undef MAX_NEEDED_FROM

#undef MAX_NEEDED_TO

#undef DEFINE_DIRECTION_OBJECTS

#undef FROM_DIRECTION

#undef EMIT_SHIFT_TO_INIT

#undef FROM_LOOP

#undef TO_LOOP

#undef SAVE_RESET_STATE

#undef RESET_INPUT_BUFFER

#undef FUNCTION_NAME

#undef PREPARE_LOOP

#undef END_LOOP

#undef ONE_DIRECTION

#undef STORE_REST