Class: DL::CPtr

Inherits:
Object
  • Object
show all
Defined in:
cptr.c,
cptr.c

Overview

CPtr is a class to handle C pointers

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#DL::CPtr.new(address) ⇒ Object #DL::CPtr.new(address, size) ⇒ Object #DL::CPtr.new(address, size, freefunc) ⇒ Object

Create a new pointer to address with an optional size and freefunc. freefunc will be called when the instance is garbage collected.



140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
# File 'cptr.c', line 140

static VALUE
rb_dlptr_initialize(int argc, VALUE argv[], VALUE self)
{
    VALUE ptr, sym, size, wrap = 0, funcwrap = 0;
    struct ptr_data *data;
    void *p = NULL;
    freefunc_t f = NULL;
    long s = 0;

    if (rb_scan_args(argc, argv, "12", &ptr, &size, &sym) >= 1) {
	VALUE addrnum = rb_Integer(ptr);
	if (addrnum != ptr) wrap = ptr;
	p = NUM2PTR(addrnum);
    }
    if (argc >= 2) {
	s = NUM2LONG(size);
    }
    if (argc >= 3) {
	f = get_freefunc(sym, &funcwrap);
    }

    if (p) {
	TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
	if (data->ptr && data->free) {
	    /* Free previous memory. Use of inappropriate initialize may cause SEGV. */
	    (*(data->free))(data->ptr);
	}
	data->wrap[0] = wrap;
	data->wrap[1] = funcwrap;
	data->ptr  = p;
	data->size = s;
	data->free = f;
    }

    return Qnil;
}

Class Method Details

.DL::CPtr.to_ptr(val) ⇒ Object .DL::CPtrObject

Get the underlying pointer for ruby object val and return it as a DL::CPtr object.



591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
# File 'cptr.c', line 591

static VALUE
rb_dlptr_s_to_ptr(VALUE self, VALUE val)
{
    VALUE ptr, wrap = val, vptr;

    if (RTEST(rb_obj_is_kind_of(val, rb_cIO))){
	rb_io_t *fptr;
	FILE *fp;
	GetOpenFile(val, fptr);
	fp = rb_io_stdio_file(fptr);
	ptr = rb_dlptr_new(fp, 0, NULL);
    }
    else if (RTEST(rb_obj_is_kind_of(val, rb_cString))){
	char *str = StringValuePtr(val);
	ptr = rb_dlptr_new(str, RSTRING_LEN(val), NULL);
    }
    else if ((vptr = rb_check_funcall(val, id_to_ptr, 0, 0)) != Qundef){
	if (rb_obj_is_kind_of(vptr, rb_cDLCPtr)){
	    ptr = vptr;
	    wrap = 0;
	}
	else{
	    rb_raise(rb_eDLError, "to_ptr should return a CPtr object");
	}
    }
    else{
	VALUE num = rb_Integer(val);
	if (num == val) wrap = 0;
	ptr = rb_dlptr_new(NUM2PTR(num), 0, NULL);
    }
    OBJ_INFECT(ptr, val);
    if (wrap) RPTR_DATA(ptr)->wrap[0] = wrap;
    return ptr;
}

.DL::CPtr.malloc(size, freefunc = nil) ⇒ Object

Allocate size bytes of memory and associate it with an optional freefunc that will be called when the pointer is garbage collected. freefunc must be an address pointing to a function or an instance of DL::CFunc



187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
# File 'cptr.c', line 187

static VALUE
rb_dlptr_s_malloc(int argc, VALUE argv[], VALUE klass)
{
    VALUE size, sym, obj, wrap = 0;
    long s;
    freefunc_t f;

    switch (rb_scan_args(argc, argv, "11", &size, &sym)) {
      case 1:
	s = NUM2LONG(size);
	f = NULL;
	break;
      case 2:
	s = NUM2LONG(size);
	f = get_freefunc(sym, &wrap);
	break;
      default:
	rb_bug("rb_dlptr_s_malloc");
    }

    obj = rb_dlptr_malloc(s,f);
    if (wrap) RPTR_DATA(obj)->wrap[1] = wrap;

    return obj;
}

.DL::CPtr.to_ptr(val) ⇒ Object .DL::CPtrObject

Get the underlying pointer for ruby object val and return it as a DL::CPtr object.



591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
# File 'cptr.c', line 591

static VALUE
rb_dlptr_s_to_ptr(VALUE self, VALUE val)
{
    VALUE ptr, wrap = val, vptr;

    if (RTEST(rb_obj_is_kind_of(val, rb_cIO))){
	rb_io_t *fptr;
	FILE *fp;
	GetOpenFile(val, fptr);
	fp = rb_io_stdio_file(fptr);
	ptr = rb_dlptr_new(fp, 0, NULL);
    }
    else if (RTEST(rb_obj_is_kind_of(val, rb_cString))){
	char *str = StringValuePtr(val);
	ptr = rb_dlptr_new(str, RSTRING_LEN(val), NULL);
    }
    else if ((vptr = rb_check_funcall(val, id_to_ptr, 0, 0)) != Qundef){
	if (rb_obj_is_kind_of(vptr, rb_cDLCPtr)){
	    ptr = vptr;
	    wrap = 0;
	}
	else{
	    rb_raise(rb_eDLError, "to_ptr should return a CPtr object");
	}
    }
    else{
	VALUE num = rb_Integer(val);
	if (num == val) wrap = 0;
	ptr = rb_dlptr_new(NUM2PTR(num), 0, NULL);
    }
    OBJ_INFECT(ptr, val);
    if (wrap) RPTR_DATA(ptr)->wrap[0] = wrap;
    return ptr;
}

Instance Method Details

#+(n) ⇒ Object

Returns a new DL::CPtr that has been advanced n bytes.



448
449
450
451
452
453
454
455
456
457
458
# File 'cptr.c', line 448

static VALUE
rb_dlptr_plus(VALUE self, VALUE other)
{
    void *ptr;
    long num, size;

    ptr = rb_dlptr2cptr(self);
    size = RPTR_DATA(self)->size;
    num = NUM2LONG(other);
    return rb_dlptr_new((char *)ptr + num, size - num, 0);
}

#ptrObject

Returns a DL::CPtr that is a dereferenced pointer for this DL::CPtr. Analogous to the star operator in C.



246
247
248
249
250
251
252
253
# File 'cptr.c', line 246

VALUE
rb_dlptr_ptr(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return rb_dlptr_new(*((void**)(data->ptr)),0,0);
}

#-(n) ⇒ Object

Returns a new DL::CPtr that has been moved back n bytes.



466
467
468
469
470
471
472
473
474
475
476
# File 'cptr.c', line 466

static VALUE
rb_dlptr_minus(VALUE self, VALUE other)
{
    void *ptr;
    long num, size;

    ptr = rb_dlptr2cptr(self);
    size = RPTR_DATA(self)->size;
    num = NUM2LONG(other);
    return rb_dlptr_new((char *)ptr - num, size + num, 0);
}

#refObject

Returns a DL::CPtr that is a reference pointer for this DL::CPtr. Analogous to the ampersand operator in C.



261
262
263
264
265
266
267
268
# File 'cptr.c', line 261

VALUE
rb_dlptr_ref(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return rb_dlptr_new(&(data->ptr),0,0);
}

#<=>(other) ⇒ -1, ...

Returns -1 if less than, 0 if equal to, 1 if greater than other. Returns nil if ptr cannot be compared to other.

Returns:

  • (-1, 0, 1, nil)


427
428
429
430
431
432
433
434
435
436
437
438
439
440
# File 'cptr.c', line 427

static VALUE
rb_dlptr_cmp(VALUE self, VALUE other)
{
    void *ptr1, *ptr2;
    SIGNED_VALUE diff;

    if(!rb_obj_is_kind_of(other, rb_cDLCPtr)) return Qnil;

    ptr1 = rb_dlptr2cptr(self);
    ptr2 = rb_dlptr2cptr(other);
    diff = (SIGNED_VALUE)ptr1 - (SIGNED_VALUE)ptr2;
    if (!diff) return INT2FIX(0);
    return diff > 0 ? INT2NUM(1) : INT2NUM(-1);
}

#==(other) ⇒ Boolean #eql?(other) ⇒ Boolean

Returns true if other wraps the same pointer, otherwise returns false.

Overloads:

  • #==(other) ⇒ Boolean

    Returns:

    • (Boolean)
  • #eql?(other) ⇒ Boolean

    Returns:

    • (Boolean)


407
408
409
410
411
412
413
414
415
416
417
418
# File 'cptr.c', line 407

VALUE
rb_dlptr_eql(VALUE self, VALUE other)
{
    void *ptr1, *ptr2;

    if(!rb_obj_is_kind_of(other, rb_cDLCPtr)) return Qfalse;

    ptr1 = rb_dlptr2cptr(self);
    ptr2 = rb_dlptr2cptr(other);

    return ptr1 == ptr2 ? Qtrue : Qfalse;
}

#[](index) ⇒ Integer #[](start, length) ⇒ String

Returns integer stored at index. If start and length are given, a string containing the bytes from start of length length will be returned.

Overloads:

  • #[](index) ⇒ Integer

    Returns:

    • (Integer)
  • #[](start, length) ⇒ String

    Returns:

    • (String)


487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
# File 'cptr.c', line 487

VALUE
rb_dlptr_aref(int argc, VALUE argv[], VALUE self)
{
    VALUE arg0, arg1;
    VALUE retval = Qnil;
    size_t offset, len;
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    if (!data->ptr) rb_raise(rb_eDLError, "NULL pointer dereference");
    switch( rb_scan_args(argc, argv, "11", &arg0, &arg1) ){
      case 1:
	offset = NUM2ULONG(arg0);
	retval = INT2NUM(*((char *)data->ptr + offset));
	break;
      case 2:
	offset = NUM2ULONG(arg0);
	len    = NUM2ULONG(arg1);
	retval = rb_tainted_str_new((char *)data->ptr + offset, len);
	break;
      default:
	rb_bug("rb_dlptr_aref()");
    }
    return retval;
}

#[]=(index) ⇒ Integer #[]=(start, length) ⇒ String

Set the value at index to int. Or, set the memory at start until length with the contents of string, the memory from dl_cptr, or the memory pointed at by the memory address addr.

Overloads:

  • #[]=(index) ⇒ Integer

    Returns:

    • (Integer)
  • #[]=(start, length) ⇒ String

    Returns:

    • (String)


522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
# File 'cptr.c', line 522

VALUE
rb_dlptr_aset(int argc, VALUE argv[], VALUE self)
{
    VALUE arg0, arg1, arg2;
    VALUE retval = Qnil;
    size_t offset, len;
    void *mem;
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    if (!data->ptr) rb_raise(rb_eDLError, "NULL pointer dereference");
    switch( rb_scan_args(argc, argv, "21", &arg0, &arg1, &arg2) ){
      case 2:
	offset = NUM2ULONG(arg0);
	((char*)data->ptr)[offset] = NUM2UINT(arg1);
	retval = arg1;
	break;
      case 3:
	offset = NUM2ULONG(arg0);
	len    = NUM2ULONG(arg1);
	if (RB_TYPE_P(arg2, T_STRING)) {
	    mem = StringValuePtr(arg2);
	}
	else if( rb_obj_is_kind_of(arg2, rb_cDLCPtr) ){
	    mem = rb_dlptr2cptr(arg2);
	}
	else{
	    mem    = NUM2PTR(arg2);
	}
	memcpy((char *)data->ptr + offset, mem, len);
	retval = arg2;
	break;
      default:
	rb_bug("rb_dlptr_aset()");
    }
    return retval;
}

#==(other) ⇒ Boolean #eql?(other) ⇒ Boolean

Returns true if other wraps the same pointer, otherwise returns false.

Overloads:

  • #==(other) ⇒ Boolean

    Returns:

    • (Boolean)
  • #eql?(other) ⇒ Boolean

    Returns:

    • (Boolean)

Returns:

  • (Boolean)


407
408
409
410
411
412
413
414
415
416
417
418
# File 'cptr.c', line 407

VALUE
rb_dlptr_eql(VALUE self, VALUE other)
{
    void *ptr1, *ptr2;

    if(!rb_obj_is_kind_of(other, rb_cDLCPtr)) return Qfalse;

    ptr1 = rb_dlptr2cptr(self);
    ptr2 = rb_dlptr2cptr(other);

    return ptr1 == ptr2 ? Qtrue : Qfalse;
}

#freeObject

Get the free function for this pointer. Returns DL::CFunc or nil.



305
306
307
308
309
310
311
312
313
# File 'cptr.c', line 305

static VALUE
rb_dlptr_free_get(VALUE self)
{
    struct ptr_data *pdata;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, pdata);

    return rb_dlcfunc_new(pdata->free, DLTYPE_VOID, "free<anonymous>", CFUNC_CDECL);
}

#free=(function) ⇒ Object

Set the free function for this pointer to the DL::CFunc in function.



289
290
291
292
293
294
295
296
297
298
# File 'cptr.c', line 289

static VALUE
rb_dlptr_free_set(VALUE self, VALUE val)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    data->free = get_freefunc(val, &data->wrap[1]);

    return Qnil;
}

#inspectObject

Returns a string formatted with an easily readable representation of the internal state of the DL::CPtr



387
388
389
390
391
392
393
394
395
396
397
# File 'cptr.c', line 387

static VALUE
rb_dlptr_inspect(VALUE self)
{
    struct ptr_data *data;
    char str[1024];

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    snprintf(str, 1023, "#<%s:%p ptr=%p size=%ld free=%p>",
	     rb_class2name(CLASS_OF(self)), data, data->ptr, data->size, data->free);
    return rb_str_new2(str);
}

#null?Boolean

Returns true if this is a null pointer.

Returns:

  • (Boolean)


275
276
277
278
279
280
281
282
# File 'cptr.c', line 275

VALUE
rb_dlptr_null_p(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return data->ptr ? Qfalse : Qtrue;
}

#ptrObject

Returns a DL::CPtr that is a dereferenced pointer for this DL::CPtr. Analogous to the star operator in C.



246
247
248
249
250
251
252
253
# File 'cptr.c', line 246

VALUE
rb_dlptr_ptr(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return rb_dlptr_new(*((void**)(data->ptr)),0,0);
}

#refObject

Returns a DL::CPtr that is a reference pointer for this DL::CPtr. Analogous to the ampersand operator in C.



261
262
263
264
265
266
267
268
# File 'cptr.c', line 261

VALUE
rb_dlptr_ref(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return rb_dlptr_new(&(data->ptr),0,0);
}

#sizeObject

Get the size of this pointer.



577
578
579
580
581
# File 'cptr.c', line 577

static VALUE
rb_dlptr_size_get(VALUE self)
{
    return LONG2NUM(RPTR_DATA(self)->size);
}

#size=(size) ⇒ Object

Set the size of this pointer to size



565
566
567
568
569
570
# File 'cptr.c', line 565

static VALUE
rb_dlptr_size_set(VALUE self, VALUE size)
{
    RPTR_DATA(self)->size = NUM2LONG(size);
    return size;
}

#to_iObject

Returns the integer memory location of this DL::CPtr.



218
219
220
221
222
223
224
225
# File 'cptr.c', line 218

static VALUE
rb_dlptr_to_i(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return PTR2NUM(data->ptr);
}

#to_iObject

Returns the integer memory location of this DL::CPtr.



218
219
220
221
222
223
224
225
# File 'cptr.c', line 218

static VALUE
rb_dlptr_to_i(VALUE self)
{
    struct ptr_data *data;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return PTR2NUM(data->ptr);
}

#to_sString #to_s(len) ⇒ String

Returns the pointer contents as a string. When called with no arguments, this method will return the contents until the first NULL byte. When called with len, a string of len bytes will be returned.

Overloads:

  • #to_sString

    Returns:

    • (String)
  • #to_s(len) ⇒ String

    Returns:

    • (String)


325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
# File 'cptr.c', line 325

static VALUE
rb_dlptr_to_s(int argc, VALUE argv[], VALUE self)
{
    struct ptr_data *data;
    VALUE arg1, val;
    int len;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    switch (rb_scan_args(argc, argv, "01", &arg1)) {
      case 0:
	val = rb_tainted_str_new2((char*)(data->ptr));
	break;
      case 1:
	len = NUM2INT(arg1);
	val = rb_tainted_str_new((char*)(data->ptr), len);
	break;
      default:
	rb_bug("rb_dlptr_to_s");
    }

    return val;
}

#to_strString #to_str(len) ⇒ String

Returns the pointer contents as a string. When called with no arguments, this method will return the contents with the length of this pointer’s size. When called with len, a string of len bytes will be returned.

Overloads:

  • #to_strString

    Returns:

    • (String)
  • #to_str(len) ⇒ String

    Returns:

    • (String)


358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
# File 'cptr.c', line 358

static VALUE
rb_dlptr_to_str(int argc, VALUE argv[], VALUE self)
{
    struct ptr_data *data;
    VALUE arg1, val;
    int len;

    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    switch (rb_scan_args(argc, argv, "01", &arg1)) {
      case 0:
	val = rb_tainted_str_new((char*)(data->ptr),data->size);
	break;
      case 1:
	len = NUM2INT(arg1);
	val = rb_tainted_str_new((char*)(data->ptr), len);
	break;
      default:
	rb_bug("rb_dlptr_to_str");
    }

    return val;
}

#to_valueObject

Cast this CPtr to a ruby object.



232
233
234
235
236
237
238
# File 'cptr.c', line 232

static VALUE
rb_dlptr_to_value(VALUE self)
{
    struct ptr_data *data;
    TypedData_Get_Struct(self, struct ptr_data, &dlptr_data_type, data);
    return (VALUE)(data->ptr);
}