diff options
Diffstat (limited to 'libio')
| -rw-r--r-- | libio/Makefile | 2 | ||||
| -rw-r--r-- | libio/Versions | 4 | ||||
| -rw-r--r-- | libio/fmemopen.c | 140 | ||||
| -rw-r--r-- | libio/oldfmemopen.c | 265 |
4 files changed, 317 insertions, 94 deletions
diff --git a/libio/Makefile b/libio/Makefile index 097cfaedda..7b3bcf90fe 100644 --- a/libio/Makefile +++ b/libio/Makefile @@ -46,7 +46,7 @@ routines := \ __fbufsize __freading __fwriting __freadable __fwritable __flbf \ __fpurge __fpending __fsetlocking \ \ - libc_fatal fmemopen + libc_fatal fmemopen oldfmemopen tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \ tst_wprintf2 tst-widetext test-fmemopen tst-ext tst-ext2 \ diff --git a/libio/Versions b/libio/Versions index 8df89d2150..2a1d6e6c85 100644 --- a/libio/Versions +++ b/libio/Versions @@ -148,6 +148,10 @@ libc { GLIBC_2.4 { open_wmemstream; } + GLIBC_2.22 { + # f* + fmemopen; + } GLIBC_PRIVATE { # Used by NPTL and librt __libc_fatal; diff --git a/libio/fmemopen.c b/libio/fmemopen.c index 06e5ab8002..e6e6a49f76 100644 --- a/libio/fmemopen.c +++ b/libio/fmemopen.c @@ -1,7 +1,6 @@ -/* Fmemopen implementation. - Copyright (C) 2000-2015 Free Software Foundation, Inc. +/* fmemopen implementation. + Copyright (C) 2015 Free Software Foundation, Inc. This file is part of the GNU C Library. - Contributed by Hanno Mueller, kontakt@hanno.de, 2000. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public @@ -17,54 +16,10 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ -/* - * fmemopen() - "my" version of a string stream - * Hanno Mueller, kontakt@hanno.de - * - * - * I needed fmemopen() for an application that I currently work on, - * but couldn't find it in libio. The following snippet of code is an - * attempt to implement what glibc's documentation describes. - * - * - * - * I already see some potential problems: - * - * - I never used the "original" fmemopen(). I am sure that "my" - * fmemopen() behaves differently than the original version. - * - * - The documentation doesn't say wether a string stream allows - * seeks. I checked the old fmemopen implementation in glibc's stdio - * directory, wasn't quite able to see what is going on in that - * source, but as far as I understand there was no seek there. For - * my application, I needed fseek() and ftell(), so it's here. - * - * - "append" mode and fseek(p, SEEK_END) have two different ideas - * about the "end" of the stream. - * - * As described in the documentation, when opening the file in - * "append" mode, the position pointer will be set to the first null - * character of the string buffer (yet the buffer may already - * contain more data). For fseek(), the last byte of the buffer is - * used as the end of the stream. - * - * - It is unclear to me what the documentation tries to say when it - * explains what happens when you use fmemopen with a NULL - * buffer. - * - * Quote: "fmemopen [then] allocates an array SIZE bytes long. This - * is really only useful if you are going to write things to the - * buffer and then read them back in again." - * - * What does that mean if the original fmemopen() did not allow - * seeking? How do you read what you just wrote without seeking back - * to the beginning of the stream? - * - * - I think there should be a second version of fmemopen() that does - * not add null characters for each write. (At least in my - * application, I am not actually using strings but binary data and - * so I don't need the stream to add null characters on its own.) - */ +/* 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> @@ -79,25 +34,23 @@ typedef struct fmemopen_cookie_struct fmemopen_cookie_t; struct fmemopen_cookie_struct { - char *buffer; - int mybuffer; - int binmode; - size_t size; - _IO_off64_t pos; - size_t maxpos; + 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; - - c = (fmemopen_cookie_t *) cookie; + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie; - if (c->pos + s > c->size) + if (c->pos + s > c->maxpos) { - if ((size_t) c->pos == c->size) + if ((size_t) c->pos == c->maxpos) return 0; s = c->size - c->pos; } @@ -115,29 +68,28 @@ fmemopen_read (void *cookie, char *b, size_t s) static ssize_t fmemopen_write (void *cookie, const char *b, size_t s) { - fmemopen_cookie_t *c; + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;; + _IO_off64_t pos = c->append ? c->maxpos : c->pos; int addnullc; - c = (fmemopen_cookie_t *) cookie; - - addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0'); + addnullc = (s == 0 || b[s - 1] != '\0'); - if (c->pos + s + addnullc > c->size) + if (pos + s + addnullc > c->size) { if ((size_t) (c->pos + addnullc) >= c->size) { __set_errno (ENOSPC); return 0; } - s = c->size - c->pos - addnullc; + s = c->size - pos - addnullc; } - memcpy (&(c->buffer[c->pos]), b, s); + memcpy (&(c->buffer[pos]), b, s); - c->pos += s; - if ((size_t) c->pos > c->maxpos) + pos += s; + if ((size_t) pos > c->maxpos) { - c->maxpos = c->pos; + c->maxpos = pos; if (addnullc) c->buffer[c->maxpos] = '\0'; } @@ -150,9 +102,7 @@ static int fmemopen_seek (void *cookie, _IO_off64_t *p, int w) { _IO_off64_t np; - fmemopen_cookie_t *c; - - c = (fmemopen_cookie_t *) cookie; + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie; switch (w) { @@ -165,7 +115,7 @@ fmemopen_seek (void *cookie, _IO_off64_t *p, int w) break; case SEEK_END: - np = (c->binmode ? c->size : c->maxpos) - *p; + np = c->maxpos + *p; break; default: @@ -184,9 +134,7 @@ fmemopen_seek (void *cookie, _IO_off64_t *p, int w) static int fmemopen_close (void *cookie) { - fmemopen_cookie_t *c; - - c = (fmemopen_cookie_t *) cookie; + fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie; if (c->mybuffer) free (c->buffer); @@ -197,18 +145,11 @@ fmemopen_close (void *cookie) FILE * -fmemopen (void *buf, size_t len, const char *mode) +__fmemopen (void *buf, size_t len, const char *mode) { cookie_io_functions_t iof; fmemopen_cookie_t *c; - if (__glibc_unlikely (len == 0)) - { - einval: - __set_errno (EINVAL); - return NULL; - } - c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t)); if (c == NULL) return NULL; @@ -231,26 +172,38 @@ fmemopen (void *buf, size_t len, const char *mode) if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf)) { free (c); - goto einval; + __set_errno (EINVAL); + return NULL; } c->buffer = buf; - if (mode[0] == 'w') + /* POSIX states that w+ mode should truncate the buffer. */ + if (mode[0] == 'w' && mode[1] == '+') c->buffer[0] = '\0'; 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] == 'a') + if (mode[0] == 'r') + c->maxpos = len; + + c->append = mode[0] == 'a'; + if (c->append) c->pos = c->maxpos; else c->pos = 0; - c->binmode = mode[0] != '\0' && mode[1] == 'b'; - iof.read = fmemopen_read; iof.write = fmemopen_write; iof.seek = fmemopen_seek; @@ -258,4 +211,5 @@ fmemopen (void *buf, size_t len, const char *mode) return _IO_fopencookie (c, mode, iof); } -libc_hidden_def (fmemopen) +libc_hidden_def (__fmemopen) +versioned_symbol (libc, __fmemopen, fmemopen, GLIBC_2_22); diff --git a/libio/oldfmemopen.c b/libio/oldfmemopen.c new file mode 100644 index 0000000000..8e35672327 --- /dev/null +++ b/libio/oldfmemopen.c @@ -0,0 +1,265 @@ +/* Fmemopen implementation. + Copyright (C) 2000-2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Hanno Mueller, kontakt@hanno.de, 2000. + + 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() - "my" version of a string stream + * Hanno Mueller, kontakt@hanno.de + * + * + * I needed fmemopen() for an application that I currently work on, + * but couldn't find it in libio. The following snippet of code is an + * attempt to implement what glibc's documentation describes. + * + * + * + * I already see some potential problems: + * + * - I never used the "original" fmemopen(). I am sure that "my" + * fmemopen() behaves differently than the original version. + * + * - The documentation doesn't say wether a string stream allows + * seeks. I checked the old fmemopen implementation in glibc's stdio + * directory, wasn't quite able to see what is going on in that + * source, but as far as I understand there was no seek there. For + * my application, I needed fseek() and ftell(), so it's here. + * + * - "append" mode and fseek(p, SEEK_END) have two different ideas + * about the "end" of the stream. + * + * As described in the documentation, when opening the file in + * "append" mode, the position pointer will be set to the first null + * character of the string buffer (yet the buffer may already + * contain more data). For fseek(), the last byte of the buffer is + * used as the end of the stream. + * + * - It is unclear to me what the documentation tries to say when it + * explains what happens when you use fmemopen with a NULL + * buffer. + * + * Quote: "fmemopen [then] allocates an array SIZE bytes long. This + * is really only useful if you are going to write things to the + * buffer and then read them back in again." + * + * What does that mean if the original fmemopen() did not allow + * seeking? How do you read what you just wrote without seeking back + * to the beginning of the stream? + * + * - I think there should be a second version of fmemopen() that does + * not add null characters for each write. (At least in my + * application, I am not actually using strings but binary data and + * so I don't need the stream to add null characters on its own.) + */ + +#include "libioP.h" + +#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_22) + +#include <errno.h> +#include <libio.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <sys/types.h> + + +typedef struct fmemopen_cookie_struct fmemopen_cookie_t; +struct fmemopen_cookie_struct +{ + char *buffer; + int mybuffer; + int binmode; + size_t size; + _IO_off64_t pos; + size_t maxpos; +}; + + +static ssize_t +fmemopen_read (void *cookie, char *b, size_t s) +{ + fmemopen_cookie_t *c; + + c = (fmemopen_cookie_t *) cookie; + + if (c->pos + s > c->size) + { + if ((size_t) c->pos == c->size) + return 0; + s = c->size - c->pos; + } + + memcpy (b, &(c->buffer[c->pos]), s); + + c->pos += s; + if ((size_t) c->pos > c->maxpos) + c->maxpos = c->pos; + + return s; +} + + +static ssize_t +fmemopen_write (void *cookie, const char *b, size_t s) +{ + fmemopen_cookie_t *c; + int addnullc; + + c = (fmemopen_cookie_t *) cookie; + + addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0'); + + if (c->pos + s + addnullc > c->size) + { + if ((size_t) (c->pos + addnullc) >= c->size) + { + __set_errno (ENOSPC); + return 0; + } + s = c->size - c->pos - addnullc; + } + + memcpy (&(c->buffer[c->pos]), b, s); + + c->pos += s; + if ((size_t) c->pos > c->maxpos) + { + c->maxpos = c->pos; + if (addnullc) + c->buffer[c->maxpos] = '\0'; + } + + return s; +} + + +static int +fmemopen_seek (void *cookie, _IO_off64_t *p, int w) +{ + _IO_off64_t np; + fmemopen_cookie_t *c; + + 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->binmode ? c->size : c->maxpos) - *p; + break; + + default: + return -1; + } + + if (np < 0 || (size_t) np > c->size) + return -1; + + *p = c->pos = np; + + return 0; +} + + +static int +fmemopen_close (void *cookie) +{ + fmemopen_cookie_t *c; + + c = (fmemopen_cookie_t *) cookie; + + if (c->mybuffer) + free (c->buffer); + free (c); + + return 0; +} + + +FILE * +__old_fmemopen (void *buf, size_t len, const char *mode) +{ + cookie_io_functions_t iof; + fmemopen_cookie_t *c; + + if (__glibc_unlikely (len == 0)) + { + einval: + __set_errno (EINVAL); + return NULL; + } + + c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t)); + 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'; + c->maxpos = 0; + } + else + { + if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf)) + { + free (c); + goto einval; + } + + c->buffer = buf; + + if (mode[0] == 'w') + c->buffer[0] = '\0'; + + c->maxpos = strnlen (c->buffer, len); + } + + c->size = len; + + if (mode[0] == 'a') + c->pos = c->maxpos; + else + c->pos = 0; + + c->binmode = mode[0] != '\0' && mode[1] == 'b'; + + iof.read = fmemopen_read; + iof.write = fmemopen_write; + iof.seek = fmemopen_seek; + iof.close = fmemopen_close; + + return _IO_fopencookie (c, mode, iof); +} +compat_symbol (libc, __old_fmemopen, fmemopen, GLIBC_2_2); +#endif |