path: root/externals/build/src/prepend.c

/* Copyright (c) 2002-2003 krzYszcz and others.
 * For information on usage and redistribution, and for a DISCLAIMER OF ALL
 * WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

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

#define PREPEND_INISIZE   32  /* LATER rethink */
#define PREPEND_MAXSIZE  256

typedef struct _prepend
{
    t_object   x_ob;
    t_symbol  *x_selector;
    int        x_size;    /* as allocated */
    int        x_natoms;  /* as used */
    t_atom    *x_message;
    t_atom     x_messini[PREPEND_INISIZE];
    int        x_entered;
    int        x_auxsize;
    t_atom    *x_auxbuf;
} t_prepend;

static t_class *prepend_class;

void *grow_nodata(int *nrequested, int *sizep, void *bufp,
                  int inisize, void *bufini, size_t typesize);

void *grow_withtail(int *nrequested, int *nexisting, char **startp, 
	            int *sizep, void *bufp,
	            int inisize, void *bufini, size_t typesize);

void *grow_withdata(int *nrequested, int *nexisting,
                    int *sizep, void *bufp,
                    int inisize, void *bufini, size_t typesize);

/* Usually a preallocation method is used, except in special cases of:
   1) reentrant output request, or 2) an output request which would cause
   resizing to more than MAXSIZE (no such limit for a 'set' message).
   In both special cases, a temporary output buffer is allocated.
   A separately preallocated output buffer is not used, thus avoiding
   memcpying of the stored message (a small performance gain when the
   preallocation method is chosen).  Instead, self-invoked 'set'
   messages are postponed, using an auxiliary buffer.
*/

static void prepend_dooutput(t_prepend *x, t_symbol *s, int ac, t_atom *av)
{
    if (s == &s_float)
    {
	if (ac > 1)
	    outlet_list(((t_object *)x)->ob_outlet, &s_list, ac, av);
	else
	    outlet_float(((t_object *)x)->ob_outlet, av->a_w.w_float);
    }
    else if (s == &s_list)
	outlet_list(((t_object *)x)->ob_outlet, &s_list, ac, av);
    else if (s)
	/* CHECKED: 'bang' is prepended -- we cannot do so...
	   ('symbol' cannot be compatible too) */
    {
	outlet_anything(((t_object *)x)->ob_outlet, s, ac, av);
    }
}

static void prepend_anything(t_prepend *x, t_symbol *s, int ac, t_atom *av)
{
    int reentered = x->x_entered;
    int prealloc = !reentered;
    int ntotal = x->x_natoms + ac;
    t_atom *buf;
    x->x_entered = 1;
    if (s == &s_) s = 0;
    if (s)
	ntotal++;
    if (prealloc && ntotal > x->x_size)
    {
	if (ntotal > PREPEND_MAXSIZE)
	    prealloc = 0;
	else
	{
	    int nrequested = ntotal;
	    x->x_message = grow_withdata(&nrequested, &x->x_natoms,
					 &x->x_size, x->x_message,
					 PREPEND_INISIZE, x->x_messini,
					 sizeof(*x->x_message));
	    prealloc = (nrequested == ntotal);
	}
    }
    if (prealloc)
    {
	buf = x->x_message + x->x_natoms;
	if (s)
	{
	    SETSYMBOL(buf, s);
	    buf++;
	}
	if (ac)
	    memcpy(buf, av, ac * sizeof(*buf));
	prepend_dooutput(x, x->x_selector, ntotal, x->x_message);
    }
    else
    {
	/* LATER consider using the stack if ntotal <= MAXSTACK */
	if (buf = getbytes(ntotal * sizeof(*buf)))
	{
	    t_atom *bp = buf + x->x_natoms;
	    if (x->x_natoms)
		memcpy(buf, x->x_message, x->x_natoms * sizeof(*buf));
	    if (s)
	    {
		SETSYMBOL(bp, s);
		bp++;
	    }
	    if (ac)
		memcpy(bp, av, ac * sizeof(*bp));
	    prepend_dooutput(x, x->x_selector, ntotal, buf);
	    freebytes(buf, ntotal * sizeof(*buf));
	}
    }
    if (!reentered)
    {
	x->x_entered = 0;
	if (x->x_auxbuf)
	{
	    if (x->x_auxsize <= x->x_size)
	    {
		x->x_natoms = x->x_auxsize / 2;
		memcpy(x->x_message, x->x_auxbuf,
		       x->x_natoms * sizeof(*x->x_message));
		freebytes(x->x_auxbuf, x->x_auxsize * sizeof(*x->x_auxbuf));
	    }
	    else
	    {
		if (x->x_message != x->x_messini)
		    freebytes(x->x_message, x->x_size * sizeof(*x->x_message));
		x->x_size = x->x_auxsize;
		x->x_message = x->x_auxbuf;
		x->x_natoms = x->x_auxsize / 2;
	    }
	    x->x_auxbuf = 0;
	}
    }
}

static void prepend_bang(t_prepend *x)
{
    t_atom at;
    SETSYMBOL(&at, &s_bang);  /* CHECKED */
    prepend_anything(x, 0, 1, &at);
}

static void prepend_float(t_prepend *x, t_float f)
{
    t_atom at;
    SETFLOAT(&at, f);
    prepend_anything(x, 0, 1, &at);
}

static void prepend_symbol(t_prepend *x, t_symbol *s)
{
    t_atom at;
    SETSYMBOL(&at, s);
    prepend_anything(x, 0, 1, &at);
}

/* LATER gpointer */

static void prepend_list(t_prepend *x, t_symbol *s, int ac, t_atom *av)
{
    prepend_anything(x, 0, ac, av);
}

static void prepend_set(t_prepend *x, t_symbol *s, int ac, t_atom *av)
{
    if (ac)
    {
	int newsize;
	if (av->a_type == A_FLOAT)
	{
	    if (ac > 1) x->x_selector = &s_list;
	    else x->x_selector = &s_float;
	}
	else if (av->a_type == A_SYMBOL)
	{
	    x->x_selector = av->a_w.w_symbol;
	    ac--;
	    av++;
	}
	else
	    return;  /* LATER rethink */
	newsize = ac * 2;
	if (x->x_entered)
	{
	    if (x->x_auxbuf)
	    {
		freebytes(x->x_auxbuf, x->x_auxsize * sizeof(*x->x_auxbuf));
		x->x_auxsize = 0;
	    }
	    if (x->x_auxbuf = getbytes(newsize * sizeof(*x->x_auxbuf)))
	    {
		memcpy(x->x_auxbuf, av, ac * sizeof(*x->x_auxbuf));
		x->x_auxsize = newsize;
	    }
	}
	else
	{
	    t_atom *ap;
	    if (newsize > x->x_size)
	    {
		int sz = newsize;
		x->x_message = grow_nodata(&sz, &x->x_size, x->x_message,
					   PREPEND_INISIZE, x->x_messini,
					   sizeof(*x->x_message));
		if (sz != newsize)
		    ac = sz / 2;  /* LATER rethink */
	    }
	    x->x_natoms = ac;
	    ap = x->x_message;
	    while (ac--) *ap++ = *av++;
	}
    }
}

static void prepend_free(t_prepend *x)
{
    if (x->x_message != x->x_messini)
	freebytes(x->x_message, x->x_size * sizeof(*x->x_message));
}

static void *prepend_new(t_symbol *s, int ac, t_atom *av)
{
    t_prepend *x = (t_prepend *)pd_new(prepend_class);
    x->x_selector = 0;
    x->x_size = PREPEND_INISIZE;
    x->x_natoms = 0;
    x->x_message = x->x_messini;
    x->x_auxbuf = 0;
    x->x_entered = 0;
    outlet_new((t_object *)x, &s_anything);
    prepend_set(x, 0, ac, av);
    return (x);
}

void prepend_setup(void)
{
    prepend_class = class_new(gensym("prepend"),
			      (t_newmethod)prepend_new,
			      (t_method)prepend_free,
			      sizeof(t_prepend), 0,
			      A_GIMME, 0);
    class_addbang(prepend_class, prepend_bang);
    class_addfloat(prepend_class, prepend_float);
    class_addsymbol(prepend_class, prepend_symbol);
    class_addlist(prepend_class, prepend_list);
    class_addanything(prepend_class, prepend_anything);
    class_addmethod(prepend_class, (t_method)prepend_set,
		    gensym("set"), A_GIMME, 0);
}


/* Prior to this call a caller is supposed to check for *nrequested > *sizep.
   Returns a reallocated buffer's pointer (success) or a given 'bufini'
   default value (failure).
   Upon return *nrequested contains the actual number of elements:
   requested (success) or a given default value of 'inisize' (failure). */
void *grow_nodata(int *nrequested, int *sizep, void *bufp,
		  int inisize, void *bufini, size_t typesize)
{
    int newsize = *sizep * 2;
    while (newsize < *nrequested) newsize *= 2;
    if (bufp == bufini)
	bufp = getbytes(newsize * typesize);
    else
	bufp = resizebytes(bufp, *sizep * typesize, newsize * typesize);
    if (bufp)
    {
	*sizep = newsize;
	return (bufp);
    }
    else
    {
	*nrequested = *sizep = inisize;
	return (bufini);
    }
}

/* Like grow_nodata(), but preserving first *nexisting elements. */
void *grow_withdata(int *nrequested, int *nexisting,
		    int *sizep, void *bufp,
		    int inisize, void *bufini, size_t typesize)
{
    int newsize = *sizep * 2;
    while (newsize < *nrequested) newsize *= 2;
    if (bufp == bufini)
    {
	if (!(bufp = getbytes(newsize * typesize)))
	{
	    *nrequested = *sizep = inisize;
	    return (bufini);
	}
	*sizep = newsize;
	memcpy(bufp, bufini, *nexisting * typesize);
    }
    else
    {
	int oldsize = *sizep;
	if (!(bufp = resizebytes(bufp, *sizep * typesize, newsize * typesize)))
	{
	    *nrequested = *sizep = inisize;
	    *nexisting = 0;
	    return (bufini);
	}
	*sizep = newsize;
    }
    return (bufp);
}

/* Like grow_nodata(), but preserving a 'tail' of *nexisting elements,
   starting from *startp. */
/* LATER rethink handling of a start pointer (clumsy now) */
void *grow_withtail(int *nrequested, int *nexisting, char **startp,
		    int *sizep, void *bufp,
		    int inisize, void *bufini, size_t typesize)
{
    int newsize = *sizep * 2;
    while (newsize < *nrequested) newsize *= 2;
    if (bufp == bufini)
    {
	char *oldstart = *startp;
	if (!(bufp = getbytes(newsize * typesize)))
	{
	    *nrequested = *sizep = inisize;
	    return (bufini);
	}
	*startp = (char *)bufp + (newsize - *nexisting) * typesize;
	*sizep = newsize;
	memcpy(*startp, oldstart, *nexisting * typesize);
    }
    else
    {
	int oldsize = *sizep;
	if (!(bufp = resizebytes(bufp, *sizep * typesize, newsize * typesize)))
	{
	    *startp = (char *)bufini + inisize * typesize;
	    *nrequested = *sizep = inisize;
	    *nexisting = 0;
	    return (bufini);
	}
	*startp = (char *)bufp + (newsize - *nexisting) * typesize;
	*sizep = newsize;
	memmove(*startp, (char *)bufp + (oldsize - *nexisting) * typesize,
		*nexisting * typesize);
    }
    return (bufp);
}