Import fatfs R0.15

[z180-stamp.git] / fatfs / documents / res / app5.c

/*----------------------------------------------------------------------/\r
/ Test if the file is contiguous                                        /\r
/----------------------------------------------------------------------*/\r
\r
FRESULT test_contiguous_file (\r
    FIL* fp,    /* [IN]  Open file object to be checked */\r
    int* cont   /* [OUT] 1:Contiguous, 0:Fragmented or zero-length */\r
)\r
{\r
    DWORD clst, clsz, step;\r
    FSIZE_t fsz;\r
    FRESULT fr;\r
\r
\r
    *cont = 0;\r
    fr = f_rewind(fp);              /* Validates and prepares the file */\r
    if (fr != FR_OK) return fr;\r
\r
#if FF_MAX_SS == FF_MIN_SS\r
    clsz = (DWORD)fp->obj.fs->csize * FF_MAX_SS;    /* Cluster size */\r
#else\r
    clsz = (DWORD)fp->obj.fs->csize * fp->obj.fs->ssize;\r
#endif\r
    fsz = f_size(fp);\r
    if (fsz > 0) {\r
        clst = fp->obj.sclust - 1;  /* A cluster leading the first cluster for first test */\r
        while (fsz) {\r
            step = (fsz >= clsz) ? clsz : (DWORD)fsz;\r
            fr = f_lseek(fp, f_tell(fp) + step);    /* Advances file pointer a cluster */\r
            if (fr != FR_OK) return fr;\r
            if (clst + 1 != fp->clust) break;       /* Is not the cluster next to previous one? */\r
            clst = fp->clust; fsz -= step;          /* Get current cluster for next test */\r
        }\r
        if (fsz == 0) *cont = 1;    /* All done without fail? */\r
    }\r
\r
    return FR_OK;\r
}\r