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/fmemopen.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/fmemopen.c')
-rw-r--r-- | libc/stdio/fmemopen.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/libc/stdio/fmemopen.c b/libc/stdio/fmemopen.c new file mode 100644 index 000000000..ff03cb426 --- /dev/null +++ b/libc/stdio/fmemopen.c @@ -0,0 +1,176 @@ +/* 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 + +typedef struct { + size_t pos; + size_t len; + size_t eof; + int dynbuf; + unsigned char *buf; + FILE *fp; +} __fmo_cookie; + +#define COOKIE ((__fmo_cookie *) cookie) + +static ssize_t fmo_read(register void *cookie, char *buf, size_t bufsize) +{ + size_t count = COOKIE->len - COOKIE->pos; + + /* Note: 0 < bufsize < SSIZE_MAX because of _stdio_READ. */ + if (!count) { /* EOF! */ + return 0; + } + + if (bufsize > count) { + bufsize = count; + } + + memcpy(buf, COOKIE->buf + COOKIE->pos, bufsize); + COOKIE->pos += bufsize; + + return bufsize; +} + +static ssize_t fmo_write(register void *cookie, const char *buf, size_t bufsize) +{ + size_t count; + + /* Note: bufsize < SSIZE_MAX because of _stdio_WRITE. */ + + /* If appending, need to seek to end of file!!!! */ + if (COOKIE->fp->__modeflags & __FLAG_APPEND) { + COOKIE->pos = COOKIE->eof; + } + + count = COOKIE->len - COOKIE->pos; + + if (bufsize > count) { + bufsize = count; + if (count == 0) { /* We're at the end of the buffer... */ + __set_errno(EFBIG); + return -1; + } + } + + memcpy(COOKIE->buf + COOKIE->pos, buf, bufsize); + COOKIE->pos += bufsize; + + if (COOKIE->pos > COOKIE->eof) { + COOKIE->eof = COOKIE->pos; + if (bufsize < count) { /* New eof and still room in buffer? */ + *(COOKIE->buf + COOKIE->pos) = 0; + } + } + + return bufsize; +} + +/* glibc doesn't allow seeking, but it has in-buffer seeks... we don't. */ +static int fmo_seek(register void *cookie, __offmax_t *pos, int whence) +{ + __offmax_t p = *pos; + + /* 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 > eof, or offset overflow... */ + if (((uintmax_t) p) > COOKIE->eof) { + return -1; + } + + COOKIE->pos = *pos = p; + return 0; +} + +static int fmo_close(register void *cookie) +{ + if (COOKIE->dynbuf) { + free(COOKIE->buf); + } + free(cookie); + return 0; +} + +#undef COOKIE + +static const cookie_io_functions_t _fmo_io_funcs = { + fmo_read, fmo_write, fmo_seek, fmo_close +}; + +/* TODO: If we have buffers enabled, it might be worthwile to add a pointer + * to the FILE in the cookie and have read, write, and seek operate directly + * on the buffer itself (ie replace the FILE buffer with the cookie buffer + * and update FILE bufstart, etc. whenever we seek). */ + +FILE *fmemopen(void *s, size_t len, const char *modes) +{ + FILE *fp; + register __fmo_cookie *cookie; + size_t i; + + if ((cookie = malloc(sizeof(__fmo_cookie))) != NULL) { + cookie->len = len; + cookie->eof = cookie->pos = 0; /* pos and eof adjusted below. */ + cookie->dynbuf = 0; + if (((cookie->buf = s) == NULL) && (len > 0)) { + if ((cookie->buf = malloc(len)) == NULL) { + goto EXIT_cookie; + } + cookie->dynbuf = 1; + *cookie->buf = 0; /* If we're appending, treat as empty file. */ + } + +#ifndef __BCC__ + fp = fopencookie(cookie, modes, _fmo_io_funcs); +#else + fp = fopencookie(cookie, modes, &_fmo_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) { + cookie->fp = fp; + if (fp->__modeflags & __FLAG_READONLY) { + cookie->eof = len; + } + if ((fp->__modeflags & __FLAG_APPEND) && (len > 0)) { + for (i = 0 ; i < len ; i++) { + if (cookie->buf[i] == 0) { + break; + } + } + cookie->eof = cookie->pos = i; /* Adjust eof and pos. */ + } + + __STDIO_STREAM_VALIDATE(fp); + + return fp; + } + } + + if (!s) { + free(cookie->buf); + } + EXIT_cookie: + free(cookie); + + return NULL; +} |