diff options
author | Manuel Novoa III <mjn3@codepoet.org> | 2004-02-11 23:48:50 +0000 |
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committer | Manuel Novoa III <mjn3@codepoet.org> | 2004-02-11 23:48:50 +0000 |
commit | 082e680bd54e999f2bb4eb77141958938b1e9ee9 (patch) | |
tree | 203c45b85ca608e1550d8ffc459456fc9cf0b30b /libc/stdio/open_memstream.c | |
parent | 17c21765b4a97c6f0b74ba8466073e5a3f97cdee (diff) |
New stdio core. Should be more maintainable. Fixes a couple of bugs.
Codepaths streamlined. Improved performance for nonthreaded apps
when linked with a thread-enabled libc.
Minor iconv bug and some locale/thread related startup issues fixed.
These showed up in getting a gcj-compiled java helloworld app running.
Removed some old extension functions... _stdio_fdout and _stdio_fsfopen.
Diffstat (limited to 'libc/stdio/open_memstream.c')
-rw-r--r-- | libc/stdio/open_memstream.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/libc/stdio/open_memstream.c b/libc/stdio/open_memstream.c new file mode 100644 index 000000000..0e3df43d1 --- /dev/null +++ b/libc/stdio/open_memstream.c @@ -0,0 +1,162 @@ +/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org> + * + * GNU Library General Public License (LGPL) version 2 or later. + * + * Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details. + */ + +#include "_stdio.h" + +#ifndef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__ +#error no custom streams! +#endif + +#define COOKIE ((__oms_cookie *) cookie) + +typedef struct { + char *buf; + size_t len; + size_t pos; + size_t eof; + char **bufloc; + size_t *sizeloc; +} __oms_cookie; + +/* Nothing to do here, as memstreams are write-only. */ +/* static ssize_t oms_read(void *cookie, char *buf, size_t bufsize) */ +/* { */ +/* } */ + +static ssize_t oms_write(register void *cookie, const char *buf, size_t bufsize) +{ + register char *newbuf; + size_t count; + + /* Note: we already know bufsize < SSIZE_MAX... */ + + count = COOKIE->len - COOKIE->pos - 1; + assert(COOKIE->pos < COOKIE->len); /* Always nul-terminate! */ + + if (bufsize > count) { + newbuf = realloc(COOKIE->buf, COOKIE->len + bufsize - count); + if (newbuf) { + *COOKIE->bufloc = COOKIE->buf = newbuf; + COOKIE->len += (bufsize - count); + } else { + bufsize = count; + if (count == 0) { + __set_errno(EFBIG); /* TODO: check glibc errno setting... */ + return -1; + } + } + } + + memcpy(COOKIE->buf + COOKIE->pos, buf, bufsize); + COOKIE->pos += bufsize; + + if (COOKIE->pos > COOKIE->eof) { + *COOKIE->sizeloc = COOKIE->eof = COOKIE->pos; + COOKIE->buf[COOKIE->eof] = 0; /* Need to nul-terminate. */ + } + + return bufsize; +} + +static int oms_seek(register void *cookie, __offmax_t *pos, int whence) +{ + __offmax_t p = *pos; + register char *buf; + size_t leastlen; + + /* Note: fseek already checks that whence is legal, so don't check here + * unless debugging. */ + assert(((unsigned int) whence) <= 2); + + if (whence != SEEK_SET) { + p += (whence == SEEK_CUR) ? COOKIE->pos : /* SEEK_END */ COOKIE->eof; + } + + /* Note: glibc only allows seeking in the buffer. We'll actually restrict + * to the data. */ + /* Check for offset < 0, offset >= too big (need nul), or overflow... */ + if (((uintmax_t) p) >= SIZE_MAX - 1) { + return -1; + } + + leastlen = ((size_t) p) + 1; /* New pos + 1 for nul if necessary. */ + + if (leastlen >= COOKIE->len) { /* Need to grow buffer... */ + buf = realloc(COOKIE->buf, leastlen); + if (buf) { + *COOKIE->bufloc = COOKIE->buf = buf; + COOKIE->len = leastlen; + memset(buf + COOKIE->eof, leastlen - COOKIE->eof, 0); /* 0-fill */ + } else { + /* TODO: check glibc errno setting... */ + return -1; + } + } + + *pos = COOKIE->pos = --leastlen; + + if (leastlen > COOKIE->eof) { + memset(COOKIE->buf + COOKIE->eof, leastlen - COOKIE->eof, 0); + *COOKIE->sizeloc = COOKIE->eof; + } + + return 0; +} + +static int oms_close(void *cookie) +{ + free(cookie); + return 0; +} + +#undef COOKIE + +static const cookie_io_functions_t _oms_io_funcs = { + NULL, oms_write, oms_seek, oms_close +}; + +/* TODO: If we have buffers enabled, it might be worthwile to add a pointer + * to the FILE in the cookie and operate directly on the buffer itself + * (ie replace the FILE buffer with the cookie buffer and update FILE bufstart, + * etc. whenever we seek). */ + +FILE *open_memstream(char **__restrict bufloc, size_t *__restrict sizeloc) +{ + register __oms_cookie *cookie; + register FILE *fp; + + if ((cookie = malloc(sizeof(__oms_cookie))) != NULL) { + if ((cookie->buf = malloc(cookie->len = BUFSIZ)) == NULL) { + goto EXIT_cookie; + } + *cookie->buf = 0; /* Set nul terminator for buffer. */ + *(cookie->bufloc = bufloc) = cookie->buf; + *(cookie->sizeloc = sizeloc) = cookie->eof = cookie->pos = 0; + +#ifndef __BCC__ + fp = fopencookie(cookie, "w", _oms_io_funcs); +#else + fp = fopencookie(cookie, "w", &_oms_io_funcs); +#endif + /* Note: We don't need to worry about locking fp in the thread case + * as the only possible access would be a close or flush with + * nothing currently in the FILE's write buffer. */ + + if (fp != NULL) { + __STDIO_STREAM_VALIDATE(fp); + return fp; + } + } + + if (cookie->buf != NULL) { + free(cookie->buf); + } + EXIT_cookie: + free(cookie); + + return NULL; +} |