third_party/ulib/musl/src/stdio/fread.c

#include "stdio_impl.h"
#include <string.h>

#define MIN(a, b) ((a) < (b) ? (a) : (b))

size_t fread(void* restrict destv, size_t size, size_t nmemb, FILE* restrict f) {
    unsigned char* dest = destv;
    size_t len = size * nmemb, l = len, k;
    if (!size)
        nmemb = 0;

    FLOCK(f);

    f->mode |= f->mode - 1;

    if (f->rend - f->rpos > 0) {
        /* First exhaust the buffer. */
        k = MIN(f->rend - f->rpos, l);
        memcpy(dest, f->rpos, k);
        f->rpos += k;
        dest += k;
        l -= k;
    }

    /* Read the remainder directly */
    for (; l; l -= k, dest += k) {
        k = __toread(f) ? 0 : f->read(f, dest, l);
        if (k + 1 <= 1) {
            FUNLOCK(f);
            return (len - l) / size;
        }
    }

    FUNLOCK(f);
    return nmemb;
}

weak_alias(fread, fread_unlocked);