diff options
Diffstat (limited to 'REORG.TODO/libio/fmemopen.c')
| -rw-r--r-- | REORG.TODO/libio/fmemopen.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/REORG.TODO/libio/fmemopen.c b/REORG.TODO/libio/fmemopen.c new file mode 100644 index 0000000000..0b45f9c323 --- /dev/null +++ b/REORG.TODO/libio/fmemopen.c @@ -0,0 +1,227 @@ +/* fmemopen implementation. + Copyright (C) 2015-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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, see + <http://www.gnu.org/licenses/>. */ + +/* fmemopen() from 2.22 and forward works as defined by POSIX. It also + provides an older symbol, version 2.2.5, that behaves different regarding + SEEK_END (libio/oldfmemopen.c). */ + + +#include <errno.h> +#include <libio.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <sys/types.h> +#include "libioP.h" + + +typedef struct fmemopen_cookie_struct fmemopen_cookie_t; +struct fmemopen_cookie_struct +{ + char *buffer; /* memory buffer. */ + int mybuffer; /* allocated my buffer? */ + int append; /* buffer open for append? */ + size_t size; /* buffer length in bytes. */ + _IO_off64_t pos; /* current position at the buffer. */ + size_t maxpos; /* max position in buffer. */ +}; + + +static ssize_t +fmemopen_read (void *cookie, char *b, size_t s) +{ + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie; + + if (c->pos + s > c->maxpos) + { + s = c->maxpos - c->pos; + if ((size_t) c->pos > c->maxpos) + s = 0; + } + + memcpy (b, &(c->buffer[c->pos]), s); + + c->pos += s; + + return s; +} + + +static ssize_t +fmemopen_write (void *cookie, const char *b, size_t s) +{ + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;; + _IO_off64_t pos = c->append ? c->maxpos : c->pos; + int addnullc = (s == 0 || b[s - 1] != '\0'); + + if (pos + s > c->size) + { + if ((size_t) (c->pos + addnullc) >= c->size) + { + __set_errno (ENOSPC); + return 0; + } + s = c->size - pos; + } + + memcpy (&(c->buffer[pos]), b, s); + + c->pos = pos + s; + if ((size_t) c->pos > c->maxpos) + { + c->maxpos = c->pos; + if (c->maxpos < c->size && addnullc) + c->buffer[c->maxpos] = '\0'; + /* A null byte is written in a stream open for update iff it fits. */ + else if (c->append == 0 && addnullc != 0) + c->buffer[c->size-1] = '\0'; + } + + return s; +} + + +static int +fmemopen_seek (void *cookie, _IO_off64_t *p, int w) +{ + _IO_off64_t np; + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie; + + switch (w) + { + case SEEK_SET: + np = *p; + break; + + case SEEK_CUR: + np = c->pos + *p; + break; + + case SEEK_END: + np = c->maxpos + *p; + break; + + default: + return -1; + } + + if (np < 0 || (size_t) np > c->size) + { + __set_errno (EINVAL); + return -1; + } + + *p = c->pos = np; + + return 0; +} + + +static int +fmemopen_close (void *cookie) +{ + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie; + + if (c->mybuffer) + free (c->buffer); + free (c); + + return 0; +} + + +FILE * +__fmemopen (void *buf, size_t len, const char *mode) +{ + cookie_io_functions_t iof; + fmemopen_cookie_t *c; + FILE *result; + + c = (fmemopen_cookie_t *) calloc (sizeof (fmemopen_cookie_t), 1); + if (c == NULL) + return NULL; + + c->mybuffer = (buf == NULL); + + if (c->mybuffer) + { + c->buffer = (char *) malloc (len); + if (c->buffer == NULL) + { + free (c); + return NULL; + } + c->buffer[0] = '\0'; + } + else + { + if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf)) + { + free (c); + __set_errno (EINVAL); + return NULL; + } + + c->buffer = buf; + + /* POSIX states that w+ mode should truncate the buffer. */ + if (mode[0] == 'w' && mode[1] == '+') + c->buffer[0] = '\0'; + + if (mode[0] == 'a') + c->maxpos = strnlen (c->buffer, len); + } + + + /* Mode | starting position (cookie::pos) | size (cookie::size) + ------ |----------------------------------|----------------------------- + read | beginning of the buffer | size argument + write | beginning of the buffer | zero + append | first null or size buffer + 1 | first null or size argument + */ + + c->size = len; + + if (mode[0] == 'r') + c->maxpos = len; + + c->append = mode[0] == 'a'; + if (c->append) + c->pos = c->maxpos; + else + c->pos = 0; + + iof.read = fmemopen_read; + iof.write = fmemopen_write; + iof.seek = fmemopen_seek; + iof.close = fmemopen_close; + + result = _IO_fopencookie (c, mode, iof); + if (__glibc_unlikely (result == NULL)) + { + if (c->mybuffer) + free (c->buffer); + + free (c); + } + + return result; +} +libc_hidden_def (__fmemopen) +versioned_symbol (libc, __fmemopen, fmemopen, GLIBC_2_22); |