class Fiddle::Pointer
Fiddle::Pointer is a class to handle C pointers
Public Class Methods
static VALUE
rb_fiddle_ptr_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_fiddle_ptr_new(fp, 0, NULL);
}
else if (RTEST(rb_obj_is_kind_of(val, rb_cString))){
char *str = StringValuePtr(val);
ptr = rb_fiddle_ptr_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_cPointer)){
ptr = vptr;
wrap = 0;
}
else{
rb_raise(rb_eFiddleDLError, "to_ptr should return a Fiddle::Pointer object");
}
}
else{
VALUE num = rb_Integer(val);
if (num == val) wrap = 0;
ptr = rb_fiddle_ptr_new(NUM2PTR(num), 0, NULL);
}
if (wrap) RPTR_DATA(ptr)->wrap[0] = wrap;
return ptr;
} Get the underlying pointer for ruby object val and return it as a Fiddle::Pointer object.
static VALUE
rb_fiddle_ptr_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_fiddle_ptr_s_malloc");
}
obj = rb_fiddle_ptr_malloc(klass, s,f);
if (wrap) RPTR_DATA(obj)->wrap[1] = wrap;
if (rb_block_given_p()) {
if (!f) {
rb_raise(rb_eArgError, "a free function must be supplied to Fiddle::Pointer.malloc when it is called with a block");
}
return rb_ensure(rb_yield, obj, rb_fiddle_ptr_call_free, obj);
} else {
return obj;
}
} Examples
# Automatically freeing the pointer when the block is exited - recommended Fiddle::Pointer.malloc(size, Fiddle::RUBY_FREE) do |pointer| ... end # Manually freeing but relying on the garbage collector otherwise pointer = Fiddle::Pointer.malloc(size, Fiddle::RUBY_FREE) ... pointer.call_free # Relying on the garbage collector - may lead to unlimited memory allocated before freeing any, but safe pointer = Fiddle::Pointer.malloc(size, Fiddle::RUBY_FREE) ... # Only manually freeing pointer = Fiddle::Pointer.malloc(size) begin ... ensure Fiddle.free pointer end # No free function and no call to free - the native memory will leak if the pointer is garbage collected pointer = Fiddle::Pointer.malloc(size) ...
Allocate size bytes of memory and associate it with an optional freefunc.
If a block is supplied, the pointer will be yielded to the block instead of being returned, and the return value of the block will be returned. A freefunc must be supplied if a block is.
If a freefunc is supplied it will be called once, when the pointer is garbage collected or when the block is left if a block is supplied or when the user calls call_free, whichever happens first. freefunc must be an address pointing to a function or an instance of Fiddle::Function.
static VALUE
rb_fiddle_ptr_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, &fiddle_ptr_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;
} Create a new pointer to address with an optional size and freefunc.
freefunc will be called when the instance is garbage collected.
static VALUE
rb_fiddle_ptr_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_fiddle_ptr_new(fp, 0, NULL);
}
else if (RTEST(rb_obj_is_kind_of(val, rb_cString))){
char *str = StringValuePtr(val);
ptr = rb_fiddle_ptr_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_cPointer)){
ptr = vptr;
wrap = 0;
}
else{
rb_raise(rb_eFiddleDLError, "to_ptr should return a Fiddle::Pointer object");
}
}
else{
VALUE num = rb_Integer(val);
if (num == val) wrap = 0;
ptr = rb_fiddle_ptr_new(NUM2PTR(num), 0, NULL);
}
if (wrap) RPTR_DATA(ptr)->wrap[0] = wrap;
return ptr;
} Get the underlying pointer for ruby object val and return it as a Fiddle::Pointer object.
Public Instance Methods
static VALUE
rb_fiddle_ptr_plus(VALUE self, VALUE other)
{
void *ptr;
long num, size;
ptr = rb_fiddle_ptr2cptr(self);
size = RPTR_DATA(self)->size;
num = NUM2LONG(other);
return rb_fiddle_ptr_new((char *)ptr + num, size - num, 0);
} Returns a new pointer instance that has been advanced n bytes.
Returns a new Fiddle::Pointer instance that is a dereferenced pointer for this pointer.
Analogous to the star operator in C.
static VALUE
rb_fiddle_ptr_minus(VALUE self, VALUE other)
{
void *ptr;
long num, size;
ptr = rb_fiddle_ptr2cptr(self);
size = RPTR_DATA(self)->size;
num = NUM2LONG(other);
return rb_fiddle_ptr_new((char *)ptr - num, size + num, 0);
} Returns a new pointer instance that has been moved back n bytes.
Returns a new Fiddle::Pointer instance that is a reference pointer for this pointer.
Analogous to the ampersand operator in C.
static VALUE
rb_fiddle_ptr_cmp(VALUE self, VALUE other)
{
void *ptr1, *ptr2;
SIGNED_VALUE diff;
if(!rb_obj_is_kind_of(other, rb_cPointer)) return Qnil;
ptr1 = rb_fiddle_ptr2cptr(self);
ptr2 = rb_fiddle_ptr2cptr(other);
diff = (SIGNED_VALUE)ptr1 - (SIGNED_VALUE)ptr2;
if (!diff) return INT2FIX(0);
return diff > 0 ? INT2NUM(1) : INT2NUM(-1);
} Returns -1 if less than, 0 if equal to, 1 if greater than other.
Returns nil if ptr cannot be compared to other.
static VALUE
rb_fiddle_ptr_eql(VALUE self, VALUE other)
{
void *ptr1, *ptr2;
if(!rb_obj_is_kind_of(other, rb_cPointer)) return Qfalse;
ptr1 = rb_fiddle_ptr2cptr(self);
ptr2 = rb_fiddle_ptr2cptr(other);
return ptr1 == ptr2 ? Qtrue : Qfalse;
} Returns true if other wraps the same pointer, otherwise returns false.
static VALUE
rb_fiddle_ptr_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, &fiddle_ptr_data_type, data);
if (!data->ptr) rb_raise(rb_eFiddleDLError, "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_str_new((char *)data->ptr + offset, len);
break;
default:
rb_bug("rb_fiddle_ptr_aref()");
}
return retval;
} Returns integer stored at index.
If start and length are given, a string containing the bytes from start of length will be returned.
static VALUE
rb_fiddle_ptr_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, &fiddle_ptr_data_type, data);
if (!data->ptr) rb_raise(rb_eFiddleDLError, "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_cPointer) ){
mem = rb_fiddle_ptr2cptr(arg2);
}
else{
mem = NUM2PTR(arg2);
}
memcpy((char *)data->ptr + offset, mem, len);
retval = arg2;
break;
default:
rb_bug("rb_fiddle_ptr_aset()");
}
return retval;
} 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.
static VALUE
rb_fiddle_ptr_call_free(VALUE self)
{
struct ptr_data *pdata;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, pdata);
fiddle_ptr_free_ptr(pdata);
return Qnil;
} Call the free function for this pointer. Calling more than once will do nothing. Does nothing if there is no free function attached.
Returns true if other wraps the same pointer, otherwise returns false.
static VALUE
rb_fiddle_ptr_free_get(VALUE self)
{
struct ptr_data *pdata;
VALUE address;
VALUE arg_types;
VALUE ret_type;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, pdata);
if (!pdata->free)
return Qnil;
address = PTR2NUM(pdata->free);
ret_type = INT2NUM(TYPE_VOID);
arg_types = rb_ary_new();
rb_ary_push(arg_types, INT2NUM(TYPE_VOIDP));
return rb_fiddle_new_function(address, arg_types, ret_type);
} Get the free function for this pointer.
Returns a new instance of Fiddle::Function.
static VALUE
rb_fiddle_ptr_free_set(VALUE self, VALUE val)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
data->free = get_freefunc(val, &data->wrap[1]);
return Qnil;
} Set the free function for this pointer to function in the given Fiddle::Function.
static VALUE
rb_fiddle_ptr_freed_p(VALUE self)
{
struct ptr_data *pdata;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, pdata);
return pdata->freed ? Qtrue : Qfalse;
} Returns if the free function for this pointer has been called.
static VALUE
rb_fiddle_ptr_inspect(VALUE self)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
return rb_sprintf("#<%"PRIsVALUE":%p ptr=%p size=%ld free=%p>",
RB_OBJ_CLASSNAME(self), (void *)data, data->ptr, data->size, (void *)data->free);
} Returns a string formatted with an easily readable representation of the internal state of the pointer.
static VALUE
rb_fiddle_ptr_null_p(VALUE self)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
return data->ptr ? Qfalse : Qtrue;
} Returns true if this is a null pointer.
static VALUE
rb_fiddle_ptr_ptr(VALUE self)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
return rb_fiddle_ptr_new(*((void**)(data->ptr)),0,0);
} Returns a new Fiddle::Pointer instance that is a dereferenced pointer for this pointer.
Analogous to the star operator in C.
static VALUE
rb_fiddle_ptr_ref(VALUE self)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
return rb_fiddle_ptr_new(&(data->ptr),0,0);
} Returns a new Fiddle::Pointer instance that is a reference pointer for this pointer.
Analogous to the ampersand operator in C.
static VALUE
rb_fiddle_ptr_size_get(VALUE self)
{
return LONG2NUM(RPTR_DATA(self)->size);
} Get the size of this pointer.
static VALUE
rb_fiddle_ptr_size_set(VALUE self, VALUE size)
{
RPTR_DATA(self)->size = NUM2LONG(size);
return size;
} Set the size of this pointer to size
static VALUE
rb_fiddle_ptr_to_i(VALUE self)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
return PTR2NUM(data->ptr);
} Returns the integer memory location of this pointer.
Returns the integer memory location of this pointer.
static VALUE
rb_fiddle_ptr_to_s(int argc, VALUE argv[], VALUE self)
{
struct ptr_data *data;
VALUE arg1, val;
int len;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
switch (rb_scan_args(argc, argv, "01", &arg1)) {
case 0:
val = rb_str_new2((char*)(data->ptr));
break;
case 1:
len = NUM2INT(arg1);
val = rb_str_new((char*)(data->ptr), len);
break;
default:
rb_bug("rb_fiddle_ptr_to_s");
}
return val;
} 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.
See to_str
static VALUE
rb_fiddle_ptr_to_str(int argc, VALUE argv[], VALUE self)
{
struct ptr_data *data;
VALUE arg1, val;
int len;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
switch (rb_scan_args(argc, argv, "01", &arg1)) {
case 0:
val = rb_str_new((char*)(data->ptr),data->size);
break;
case 1:
len = NUM2INT(arg1);
val = rb_str_new((char*)(data->ptr), len);
break;
default:
rb_bug("rb_fiddle_ptr_to_str");
}
return val;
} 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.
See to_s
static VALUE
rb_fiddle_ptr_to_value(VALUE self)
{
struct ptr_data *data;
TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, data);
return (VALUE)(data->ptr);
} Cast this pointer to a ruby object.
Ruby Core © 1993–2020 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.