Re: [Haskell-cafe] Data.Judy and StablePtr

Thanks Gregory! Probably the solution would be recreating the FFI in a way that doesn't need the StablePtr. Not sure how to do this though. I'm going to test other things, like HashTable, before trying this. And let's see how it goes. ~dsouza On Mon, Dec 20, 2010 at 2:40 PM, Gregory Collins wrote:

Pointers are mapped to StablePtrs using.... *drumroll* a hash table, so you can give up on getting acceptable performance out of this combination IMO.

G

On Mon, Dec 20, 2010 at 5:06 PM, Diego Souza wrote:

...

Hello Haskellers, I'm playing a bit with Data.Judy. However, I noticed that using StablePtr incurs in some performance problems, I don't have any numbers but as a example use Int and ByteString as values and you can notice the difference without any benchmarking tool with the example that comes in the documentation. The question that I have is: is there any way to make it faster for types other than those that fits in word size? I understand that the way the binding to the C code has been done, stableptr is required. Am I wrong assuming this? I would be happy to submit a patch but I failed to find a way to improve the performance. The second question is what is a common practice to avoid memory leaks with StablePtr? I have zero experience programming with the Haskell FFI interface, so probably the most basic stuff would help me a lot in this case.

Thanks in advance, -- ~dsouza yahoo!im: paravinicius gpg key fingerprint: 71B8 CE21 3A6E F894 5B1B 9ECE F88E 067F E891 651E gpg pub key: http://bitforest.org/~dsouza/pub/gpg-pubkey.txt authorized_keys: http://bitforest.org/~dsouza/pub/authorized_keys.txt

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-- Gregory Collins

-- ~dsouza yahoo!im: paravinicius gpg key fingerprint: 71B8 CE21 3A6E F894 5B1B 9ECE F88E 067F E891 651E gpg pub key: http://bitforest.org/~dsouza/pub/gpg-pubkey.txt authorized_keys: http://bitforest.org/~dsouza/pub/authorized_keys.txt