Been trying to learn how to use ruby and Ruby/DL and I'm unsure how to
implement this:
I have a callback function in C which I want to implement in ruby
void my_callback(my_struct resultList, DWORD count)
{
while (count != 0)
{
if (resultList != NULL)
{
printf("field1 - %s , field2 - %f \n", resultList->field1,
resultList->field2);
}
resultList++;
count--;
}
}
I started with this:
MY_CALLBACK = DL.callback('0PL') { |result_list, count|
if result_list
record = MyStruct.new(result_list)
puts record.field1
end
}
My problem is I don't know how to get the other records if result_list
points to 2 or more records. I want to be able to traverse the whole set
or records like in the C callback function. I understand that I will
need to loop "count" times but how do I make my pointer point to the
next record?
Thanks for the help 
···
--
Posted via http://www.ruby-forum.com/.
Result list should always be a pointer to a pointer, right? If that is
the case, you need to create a struct of size count that contains that array.
From the new list struct, you should be able to access each MyStruct.
···
On Thu, Aug 13, 2009 at 07:06:51PM +0900, Gin Mendi wrote:
Been trying to learn how to use ruby and Ruby/DL and I'm unsure how to
implement this:
I have a callback function in C which I want to implement in ruby
void my_callback(my_struct resultList, DWORD count)
{
while (count != 0)
{
if (resultList != NULL)
{
printf("field1 - %s , field2 - %f \n", resultList->field1,
resultList->field2);
}
resultList++;
count--;
}
}
I started with this:
MY_CALLBACK = DL.callback('0PL') { |result_list, count|
if result_list
record = MyStruct.new(result_list)
puts record.field1
end
}
My problem is I don't know how to get the other records if result_list
points to 2 or more records. I want to be able to traverse the whole set
or records like in the C callback function. I understand that I will
need to loop "count" times but how do I make my pointer point to the
next record?
--
Aaron Patterson
http://tenderlovemaking.com/
Aaron Patterson wrote:
{
MY_CALLBACK = DL.callback('0PL') { |result_list, count|
next record?
Result list should always be a pointer to a pointer, right? If that is
the case, you need to create a struct of size count that contains that
array.
From the new list struct, you should be able to access each MyStruct.
I'm not so sure how I should exactly implement this. Been researching
online and trying out stuff with the code but haven't gotten any luck.
I first tried creating a structure that just contains an array:
ResultList = struct [
"PVOID list"
]
and then using this with resultList
rl = ResultList.new(resultList)
but this doesn't seem to work for me.
How should I exactly use resultList to get the array of records (I'm
assuming it's always an array of records). Right now the previous code i
posted just captures the first record and puts it in my structure
properly. Still can't get the other records.
Thanks for reply! 
···
On Thu, Aug 13, 2009 at 07:06:51PM +0900, Gin Mendi wrote:
--
Posted via http://www.ruby-forum.com/\.
Aaron Patterson wrote:
>> {
>> MY_CALLBACK = DL.callback('0PL') { |result_list, count|
>> next record?
> Result list should always be a pointer to a pointer, right? If that is
> the case, you need to create a struct of size count that contains that
> array.
>
> From the new list struct, you should be able to access each MyStruct.
I'm not so sure how I should exactly implement this. Been researching
online and trying out stuff with the code but haven't gotten any luck.
I first tried creating a structure that just contains an array:
ResultList = struct [
"PVOID list"
]
and then using this with resultList
rl = ResultList.new(resultList)
but this doesn't seem to work for me.
How should I exactly use resultList to get the array of records (I'm
assuming it's always an array of records). Right now the previous code i
posted just captures the first record and puts it in my structure
properly. Still can't get the other records.
Hmmm. You wouldn't happen to have some sample C code I could compile
and try accessing with DL?
Thanks for reply!
No problem! I'm happy to help solve this, but I want to make sure we're
on the same page.
···
On Fri, Aug 14, 2009 at 01:43:24PM +0900, Gin Mendi wrote:
> On Thu, Aug 13, 2009 at 07:06:51PM +0900, Gin Mendi wrote:
--
Aaron Patterson
http://tenderlovemaking.com/
Aaron Patterson wrote:
Hmmm. You wouldn't happen to have some sample C code I could compile
and try accessing with DL?
All I have are the compiled DLLs and the callback sample that is called
by the function I use that I first posted:
void my_callback(my_struct resultList, DWORD count)
{
while (count != 0)
{
if (resultList != NULL)
{
printf("field1 - %s , field2 - %f \n", resultList->field1,
resultList->field2);
}
resultList++;
count--;
}
}
which I attempted to translate to:
MY_CALLBACK = DL.callback('0PL') { |result_list, count|
if result_list
record = MyStruct.new(result_list)
puts record.field1
end
}
The C callback works fine. My ruby callback works if count is 1. If it's
more than 1 I only end up showing the first record. MyStruct is just a
structure full of string, longs, int, and float values. my_struct data
type in the C callback is just a pointer for the structure. Is there any
other information I can give?
···
On Fri, Aug 14, 2009 at 01:43:24PM +0900, Gin Mendi wrote:
--
Posted via http://www.ruby-forum.com/\.
I'm assuming the API will return an array when count is greater than
one. So I was thinking I'd just convert the PtrData object I get from
the callback to an array. Been trying to look on how I can go about
doing that but can't seem to get it done. Everything I find just shows
how to convert pointers to structures. I tried making a structure with
an array in it and using that but that doesn't seem to work. How can I
convert this pointer to an array?
···
--
Posted via http://www.ruby-forum.com/.