diff options
Diffstat (limited to 'libc/stdio/fread.c')
-rw-r--r-- | libc/stdio/fread.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/libc/stdio/fread.c b/libc/stdio/fread.c new file mode 100644 index 000000000..875c82616 --- /dev/null +++ b/libc/stdio/fread.c @@ -0,0 +1,108 @@ +/* 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" + +#ifdef __DO_UNLOCKED + +weak_alias(__fread_unlocked,fread_unlocked); +#ifndef __UCLIBC_HAS_THREADS__ +weak_alias(__fread_unlocked,fread); +#endif + +size_t __fread_unlocked(void * __restrict ptr, size_t size, size_t nmemb, + FILE * __restrict stream) +{ + __STDIO_STREAM_VALIDATE(stream); + assert(stream->__filedes >= -1); + + /* Note: If nmbem * size > SIZE_MAX then there is an application + * bug since no array can be larger than SIZE_MAX in size. */ + + if ((__STDIO_STREAM_IS_NARROW_READING(stream) + || !__STDIO_STREAM_TRANS_TO_READ(stream, __FLAG_NARROW)) + && size && nmemb + ) { + + if (nmemb <= (SIZE_MAX / size)) { + unsigned char *buffer = (unsigned char *) ptr; + size_t todo, bytes, avail; + + todo = bytes = size * nmemb; + + /* Check for ungots... */ + while (stream->__modeflags & __FLAG_UNGOT) { + *buffer++ = stream->__ungot[(stream->__modeflags--) & 1]; + stream->__ungot[1] = 0; + if (!--todo) { + goto DONE; + } + } + +#ifdef __STDIO_BUFFERS + /* Next check for available buffered... */ + if ((avail = stream->__bufread - stream->__bufpos) > 0) { + if (avail > todo) { + avail = todo; + } + memcpy(buffer, stream->__bufpos, avail); + buffer += avail; + stream->__bufpos += avail; + if (!(todo -= avail)) { + goto DONE; + } + } + + /* We need to read from the host environment, so we must + * flush all line buffered streams if the stream is not + * fully buffered. */ + if (!__STDIO_STREAM_IS_FBF(stream)) { + __STDIO_FLUSH_LBF_STREAMS; + } +#endif + +#ifdef __UCLIBC_MJN3_ONLY__ +#warning CONSIDER: should we refill and read from the buffer sometimes? +#endif + while ((avail = __stdio_READ(stream, buffer, todo)) > 0) { + buffer += avail; + if (!(todo -= avail)) { + break; + } + } + + DONE: + __STDIO_STREAM_VALIDATE(stream); + return (bytes - todo) / size; + } + + __STDIO_STREAM_SET_ERROR(stream); + __set_errno(EINVAL); + } + + __STDIO_STREAM_VALIDATE(stream); + return 0; +} + +#elif defined __UCLIBC_HAS_THREADS__ + +size_t fread(void * __restrict ptr, size_t size, size_t nmemb, + register FILE * __restrict stream) +{ + size_t retval; + __STDIO_AUTO_THREADLOCK_VAR; + + __STDIO_AUTO_THREADLOCK(stream); + + retval = __fread_unlocked(ptr, size, nmemb, stream); + + __STDIO_AUTO_THREADUNLOCK(stream); + + return retval; +} + +#endif |