Hi Levi Morrison,
> > Hello!
> >
> > Most of PHP's symbols are case insensitive. This means extensions that
> > need to do things with function and method names end up lowercasing
> > and hashing the lowercased names, often having to do more memory
> > allocations too. Since case insensitive symbols is language dictated
> > behavior, it makes sense to expose the correctly cased symbols to
> > extensions. In PHP 8.0 (and possibly older, I did not check), the
> > engine is already interning the lowercased name of user defined
> > functions; it's just not made available to extensions.
> >
> > In my ideal world, we'd actually switch all symbols to be case
> > sensitive. However, that won't be happening for PHP 8 due to BC.
> >
> > So, instead, I propose adding an `.lcname` member (or some other name
> > indicating it's been normalized to the preferred PHP case) to at least
> > zend_op_array and zend_class_entry, but preferably for internal
> > functions too. Note that many internal functions will already be
> > lowercase, so the data can be shared.
> >
> > I could make this change in the main engine, but I strongly suspect it
> > will not play correctly with opcache.
> >
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>
> I just realized I didn't ask any specific questions. Oops:
>
> 1. Can anyone think of issues except increased memory due to
> increasing the size of the struct? Since the strings were previously
> interned, I don't think the strings themselves will have much effect
> on memory usage (but we can measure this).
> 2. Anyone else who thinks this would be useful?
I don't have a personal use case for this and no common operations come to mind
but could be persuaded.
The lack of examples or might be why there's been no response.
I assume the overhead is probably negligible for classes, and larger for
functions.
What fields of zend_op_array did you mean?
What parts of the engine or extensions would use the lowercase string?
I see a few places it's used for compilation in php-src itself but nothing that
seems performance critical.
What are examples of functionality/functions of extensions that you expect
would see a performance improvement?
Why would they need to convert the strings to lowercase rather than use the
casing of the declaration
(e.g. using "memcached" instead of "Memcached" in "class Memcached{...}")
E.g. if something had already looked up the `zend_class_entry *ce` for a class
name, than `ce->name`
would be a string (and a unique pointer) such as "Memcached" that uniquely
identifies that class's name
(unless the code is unexpectedly redeployed later with different casing)
- They're still case sensitive in some ways, e.g. the composer autoloader is
case sensitive
- Changing case should be rare
Regards,
Tyson
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