da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include "sfdchdr.h"

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define UNSEEKABLE 1

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chintypedef struct _file_s

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{ Sfio_t* f; /* the stream */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin Sfoff_t lower; /* its lowest end */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin} File_t;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chintypedef struct _union_s

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin Sfdisc_t disc; /* discipline structure */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin short type; /* type of streams */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin short c; /* current stream */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin short n; /* number of streams */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin Sfoff_t here; /* current location */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin File_t f[1]; /* array of streams */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin} Union_t;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic ssize_t unwrite(Sfio_t* f, const Void_t* buf, size_t n, Sfdisc_t* disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic ssize_t unwrite(f, buf, n, disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* f; /* stream involved */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinVoid_t* buf; /* buffer to read into */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinsize_t n; /* number of bytes to read */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfdisc_t* disc; /* discipline */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic ssize_t unread(Sfio_t* f, Void_t* buf, size_t n, Sfdisc_t* disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic ssize_t unread(f, buf, n, disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* f; /* stream involved */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinVoid_t* buf; /* buffer to read into */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinsize_t n; /* number of bytes to read */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfdisc_t* disc; /* discipline */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg Union_t* un;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg ssize_t r, m;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un = (Union_t*)disc;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin m = n;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f = un->f[un->c].f;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin while(1)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { if((r = sfread(f,buf,m)) < 0 || (r == 0 && un->c == un->n-1) )

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin m -= r;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->here += r;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(m == 0)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin buf = (char*)buf + r;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfeof(f) && un->c < un->n-1)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin f = un->f[un->c += 1].f;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return n-m;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic Sfoff_t unseek(Sfio_t* f, Sfoff_t addr, int type, Sfdisc_t* disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic Sfoff_t unseek(f, addr, type, disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* f;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfoff_t addr;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint type;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfdisc_t* disc;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg Union_t* un;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg int i;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg Sfoff_t extent, s;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un = (Union_t*)disc;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(un->type&UNSEEKABLE)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1L;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(type == 2)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { extent = 0;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin for(i = 0; i < un->n; ++i)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin extent += (sfsize(un->f[i].f) - un->f[i].lower);

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin addr += extent;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else if(type == 1)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin addr += un->here;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(addr < 0)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin /* find the stream where the addr could be in */

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin extent = 0;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin for(i = 0; i < un->n-1; ++i)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { s = sfsize(un->f[i].f) - un->f[i].lower;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(addr < extent + s)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin extent += s;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin s = (addr-extent) + un->f[i].lower;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfseek(un->f[i].f,s,0) != s)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->c = i;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->here = addr;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin for(i += 1; i < un->n; ++i)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin sfseek(un->f[i].f,un->f[i].lower,0);

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return addr;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int unexcept(Sfio_t* f, int type, Void_t* data, Sfdisc_t* disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int unexcept(f,type,data,disc)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* f;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint type;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinVoid_t* data;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfdisc_t* disc;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(type == SF_FINAL || type == SF_DPOP)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin free(disc);

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return 0;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#if __STD_C

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint sfdcunion(Sfio_t* f, Sfio_t** array, int n)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint sfdcunion(f, array, n)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t* f;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinSfio_t** array;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint n;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg Union_t* un;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin reg int i;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(n <= 0)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(!(un = (Union_t*)malloc(sizeof(Union_t)+(n-1)*sizeof(File_t))) )

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin memset(un, 0, sizeof(*un));

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->disc.readf = unread;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->disc.writef = unwrite;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->disc.seekf = unseek;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->disc.exceptf = unexcept;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->n = n;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin for(i = 0; i < n; ++i)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { un->f[i].f = array[i];

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(!(un->type&UNSEEKABLE))

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { un->f[i].lower = sfseek(array[i],(Sfoff_t)0,1);

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(un->f[i].lower < 0)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin un->type |= UNSEEKABLE;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfdisc(f,(Sfdisc_t*)un) != (Sfdisc_t*)un)

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin { free(un);

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return -1;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return 0;

da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}