diff options
Diffstat (limited to 'iconv/loop.c')
| -rw-r--r-- | iconv/loop.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/iconv/loop.c b/iconv/loop.c new file mode 100644 index 0000000..b8657d5 --- /dev/null +++ b/iconv/loop.c @@ -0,0 +1,226 @@ +/* Conversion loop frame work. + Copyright (C) 1998 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* This file provides a frame for the reader loop in all conversion modules. + The actual code must (of course) be provided in the actual module source + code but certain actions can be written down generically, with some + customization options which are these: + + MIN_NEEDED_INPUT minimal number of input bytes needed for the next + conversion. + MIN_NEEDED_OUTPUT minimal number of bytes produced by the next round + of conversion. + + MAX_NEEDED_INPUT you guess it, this is the maximal number of input + bytes needed. It defaults to MIN_NEEDED_INPUT + MAX_NEEDED_OUTPUT likewise for output bytes. + + Both values have a default of 1. + + LOOPFCT name of the function created. If not specified + the name is `loop' but this prevents the use + of multiple functions in the same file. + + COUNT_CONVERTED optional macro which is used to count the actual + number of characters converted. For some conversion + it is easy to compute the value afterwards, but for + others explicit counting is cheaper. + + BODY this is supposed to expand to the body of the loop. + The user must provide this. +*/ + +#include <gconv.h> +#include <sys/param.h> /* For MIN. */ +#define __need_size_t +#include <stddef.h> + + +/* We need at least one byte for the next round. */ +#ifndef MIN_NEEDED_INPUT +# define MIN_NEEDED_INPUT 1 +#endif + +/* Let's see how many bytes we produce. */ +#ifndef MAX_NEEDED_INPUT +# define MAX_NEEDED_INPUT MIN_NEEDED_INPUT +#endif + +/* We produce at least one byte in the next round. */ +#ifndef MIN_NEEDED_OUTPUT +# define MIN_NEEDED_OUTPUT 1 +#endif + +/* Let's see how many bytes we produce. */ +#ifndef MAX_NEEDED_OUTPUT +# define MAX_NEEDED_OUTPUT MIN_NEEDED_OUTPUT +#endif + +/* Default name for the function. */ +#ifndef LOOPFCT +# define LOOPFCT loop +#endif + +/* Make sure we have a loop body. */ +#ifndef BODY +# error "Definition of BODY missing for function" LOOPFCT +#endif + +/* We can calculate the number of converted characters easily if one + of the character sets has a fixed width. */ +#ifndef COUNT_CONVERTED +# if MIN_NEEDED_INPUT == MAX_NEEDED_INPUT +# if MIN_NEEDED_OUTPUT == MAX_NEEDED_OUTPUT +/* Decide whether one of the charsets has size 1. */ +# if MIN_NEEDED_INPUT == 1 +# define COUNT_CONVERTED (inptr - *inptrp) +# elif MIN_NEEDED_OUTPUT == 1 +# define COUNT_CONVERTED (outptr - *outptrp) +# else +/* Else we should see whether one of the two numbers is a power of 2. */ +# define COUNT_CONVERTED \ + ((MIN_NEEDED_INPUT & (-MIN_NEEDED_INPUT)) == MIN_NEEDED_INPUT \ + ? (inptr - *inptrp) : (outptr - *outptrp)) +# endif +# else +# define COUNT_CONVERTED (inptr - *inptrp) +# endif +# elif MIN_NEEDED_OUTPUT == MAX_NEEDED_OUTPUT +# define COUNT_CONVERTED (outptr - *outptrp) +# endif +#endif + + +/* The function returns the status, as defined in gconv.h. */ +static inline int +LOOPFCT (const unsigned char **inptrp, const unsigned char *inend, + unsigned char **outptrp, unsigned char *outend, mbstate_t *state, + void *data, size_t *converted) +{ + int result = GCONV_OK; + const unsigned char *inptr = *inptrp; + unsigned char *outptr = *outptrp; +#ifndef COUNT_CONVERTED + size_t done = 0; +#endif + + /* We run one loop where we avoid checks for underflow/overflow of the + buffers to speed up the conversion a bit. */ + size_t min_in_rounds = (inend - inptr) / MAX_NEEDED_INPUT; + size_t min_out_rounds = (outend - outptr) / MAX_NEEDED_OUTPUT; + size_t min_rounds = MIN (min_in_rounds, min_out_rounds); + +#undef NEED_LENGTH_TEST +#define NEED_LENGTH_TEST 0 + while (min_rounds-- > 0) + { + /* Here comes the body the user provides. It can stop with RESULT + set to GCONV_INCOMPLETE_INPUT (if the size of the input characters + vary in size), GCONV_ILLEGAL_INPUT, or GCONV_FULL_OUTPUT (if the + output characters vary in size. */ + BODY + + /* If necessary count the successful conversion. */ +#ifndef COUNT_CONVERTED + ++done; +#endif + } + + if (result == GCONV_OK) + { +#if MIN_NEEDED_INPUT == MAX_NEEDED_INPUT \ + && MIN_NEEDED_OUTPUT == MAX_NEEDED_OUTPUT + /* We don't need to start another loop since we were able to determine + the maximal number of characters to copy in advance. What remains + to be determined is the status. */ + if (inptr == inend) + /* No more input. */ + result = GCONV_EMPTY_INPUT; + else if ((MIN_NEEDED_OUTPUT != 1 && outptr + MIN_NEEDED_OUTPUT > outend) + || (MIN_NEEDED_OUTPUT == 1 && outptr >= outend)) + /* Overflow in the output buffer. */ + result = GCONV_FULL_OUTPUT; + else + /* We have something left in the input buffer. */ + result = GCONV_INCOMPLETE_INPUT; +#else + result = GCONV_EMPTY_INPUT; + +# undef NEED_LENGTH_TEST +# define NEED_LENGTH_TEST 1 + while (inptr != inend) + { + /* `if' cases for MIN_NEEDED_OUTPUT ==/!= 1 is made to help the + compiler generating better code. It will optimized away + since MIN_NEEDED_OUTPUT is always a constant. */ + if ((MIN_NEEDED_OUTPUT != 1 && outptr + MIN_NEEDED_OUTPUT > outend) + || (MIN_NEEDED_OUTPUT == 1 && outptr >= outend)) + { + /* Overflow in the output buffer. */ + result = GCONV_FULL_OUTPUT; + break; + } + if (MIN_NEEDED_INPUT > 1 && inptr + MIN_NEEDED_INPUT > inend) + { + /* We don't have enough input for another complete input + character. */ + result = GCONV_INCOMPLETE_INPUT; + break; + } + + /* Here comes the body the user provides. It can stop with + RESULT set to GCONV_INCOMPLETE_INPUT (if the size of the + input characters vary in size), GCONV_ILLEGAL_INPUT, or + GCONV_FULL_OUTPUT (if the output characters vary in size. */ + BODY + + /* If necessary count the successful conversion. */ +# ifndef COUNT_CONVERTED + ++done; +# endif + } +#endif /* Input and output charset are not both fixed width. */ + } + + /* Add the number of characters we actually converted. */ +#ifdef COUNT_CONVERTED + *converted += COUNT_CONVERTED; +#else + *converted += done; +#endif + + /* Update the pointers pointed to by the parameters. */ + *inptrp = inptr; + *outptrp = outptr; + + return result; +} + + +/* We remove the macro definitions so that we can include this file again + for the definition of another function. */ +#undef MIN_NEEDED_INPUT +#undef MAX_NEEDED_INPUT +#undef MIN_NEEDED_OUTPUT +#undef MAX_NEEDED_OUTPUT +#undef LOOPFCT +#undef COUNT_CONVERTED +#undef BODY +#undef LOOPFCT |