dplayx: Cache the results of DirectPlayEnumerateAW()

[Bruno Jesus]

On Mon, Jan 5, 2015 at 7:19 AM, Stefan Dösinger
<stefandoesinger at gmail.com> wrote:
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> Hi Bruno,

Hi, Stefan. Thanks for the review.

> Some tests for this behavior would be useful. Also consider adding tests that check if DirectPlayEnumerate always enumerates the same pointers.

I'll try.

> Am 2015-01-04 um 23:05 schrieb Bruno Jesus:
>> +    static struct _data
>> +    {
>> +        GUID guid;
>> +        WCHAR descriptionW[256];
>> +        char descriptionA[256];
>> +    } *providers_cache;
> You don't have to give this structure a name. (i.e., remove "_data").

OK.

>> +    /* Some applications require that the data returned through the callback persist after the callbacks
>> +     * are called, so we buffer the information first and do the callbacks later. We will always rewrite
>> +     * the buffer as some applications may change it (on purpose or due to bugs).
>> +     */
> Please name the application. 2 years from now nobody will remember it, and a search through wine-patches might not be successful.

Makes sense.

>> +    HeapFree(GetProcessHeap(), 0, providers_cache);
>> +    providers_cache = HeapAlloc(GetProcessHeap(), 0, sizeof(*providers_cache) * dwIndex);
>> +    if (!providers_cache)
>> +    {
>> +        ERR(": failed to alloc required memory.\n");
>> +        return DPERR_EXCEPTION;
>> +    }
> Does the registry data change during runtime? I think it is created during prefix creation and then never touched again.

I don't know, I'm just worried that the application may destroy the
data, that's why I Always re-read it.

>> +     if (sizeOfDescription > max_sizeOfDescriptionW)
>> +     {
>> +         HeapFree(GetProcessHeap(), 0, descriptionW);
>> +         max_sizeOfDescriptionW = sizeOfDescription;
>> +     }
>> +     descriptionW = HeapAlloc(GetProcessHeap(), 0, sizeOfDescription);
> This can leak descriptionW. You're also hard-coding a size limit of 256 in providers_cache. One of the two isn't right, most likely the hard-coded limit.

This is the current code, I didn't change it. The patch may seem large
but it's an indentation difference.

>> +     RegQueryValueExW(hkServiceProvider, descW,
>> +                      NULL, NULL, (LPBYTE) descriptionW, &sizeOfDescription);
>> +
>> +     lstrcpynW(providers_cache[dwIndex].descriptionW, descriptionW, sizeof(providers_cache[0].descriptionW));
>> +     WideCharToMultiByte(CP_ACP, 0, providers_cache[dwIndex].descriptionW, -1, providers_cache[dwIndex].descriptionA,
>> +                         sizeof(providers_cache[0].descriptionA), NULL, NULL);
> The old code queries two different values, "DescriptionA" and "DescriptionW". Your code queries "DescriptionW" and converts the content to ASCII. Do DescriptionA and DescriptionW always contain the same content?

I assumed it could be the same because in English and Portuguese
systems it is, but thinking more properly it may make a difference for
non-roman writing languages, I will cache both.

Best Regards,
Bruno