These were checking whether the instruction set is supported by
the host CPU, however they were only used to condition on whether
this instruction set is targeted at all. It would still use dynamic
dispatch (e.g. based on ifunc resolvers) to select the actual
implementation. Whether the target is guaranteed to support the
instruction set without dispatch is determined based on pre-defined
macros like __SSE2__.
This removes the configure-time builtin cpu checks to remove
confusion. Additionally this allows targeting an architecture that
is newer than the host architecture.
First, the limitation already doesn't trigger if you copy the whole
file (i.e. use copy() or stream_copy_to_stream() and don't specify
a length). This happens because length will be 0 at the time of the
check and only later calculated based on the file size. This means
that we're already completely blowing the length limit for what is
likely the most common case, and it doesn't seem like anyone complained
about that.
Second, the premise of the code comment ("to avoid runaway swapping")
seems incorrect to me. Because this performs a file-backed non-private
mmap, no swap backing is needed for the mapping. Concerns over "memory
usage" are also misplaced, as this is a virtual mapping.
We're currently splitting up large writes into 8K size chunks, which
adversely affects I/O performance in some cases. Splitting up writes
doesn't make a lot of sense, as we already must have a backing buffer,
so there is no memory/performance tradeoff to be made here.
This change disables the write chunking at the stream layer, but
retains the current retry loop for partial writes. In particular
network writes will typically only write part of the data for large
writes, so we need to keep the retry loop to preserve backwards
compatibility.
If issues due to this change turn up, chunking should be reintroduced
at lower levels where it is needed to avoid issues for specific streams,
rather than unnecessarily enforcing it for all streams.
Use the shared empty array from ZVAL_EMPTY_ARRAY
For code that created an 10 arrays of 100000 empty arrays
(has the same result with `$assoc=true` and `{}`)
- This is the worst-case comparison, but I'd expect 0-length arrays to be fairly
common in regular data for json_decode
- The parser implementation was using function pointers so that third party
extension developers could reuse the json parser for their own
data structures, etc. (I think).
This PR is meant to let those third party extensions continue working
without changes.
Before this patch: In 0.126 seconds: added 97.99 MiB
After this patch: In 0.096 seconds: added 41.99 MiB
```php
<?php
$json = '[' . str_repeat('[],', 100000) . "null]";
$start_memory = memory_get_usage();
$start_time = microtime(true);
$result = [];
for ($i = 0; $i < 10; $i++) {
$result[] = json_decode($json);
}
$end_memory = memory_get_usage();
$end_time = microtime(true);
// Before this patch: In 0.126 seconds: added 97.99 MiB
// After this patch: In 0.096 seconds: added 41.99 MiB
printf("In %.3f seconds: added %.2f MiB\n", $end_time - $start_time, ($end_memory - $start_memory)/1000000);
// For objects
$json = '[' . str_repeat('{},', 100000) . "null]";
$start_memory = memory_get_usage();
$start_time = microtime(true);
for ($i = 0; $i < 10; $i++) {
$result[] = json_decode($json, true);
}
$end_memory = memory_get_usage();
$end_time = microtime(true);
// Before this patch: In 0.126 seconds: added 97.99 MiB
// After this patch: In 0.096 seconds: added 41.99 MiB
printf("In %.3f seconds: added %.2f MiB (objects decoded as arrays) \n", $end_time - $start_time, ($end_memory - $start_memory)/1000000);
```
Closes GH-4861.
Previously:
* If only ["" => "x"] was present, the original string was returned
without warning.
* If both ["" => "x"] and at least one more element was present,
false was returned without warning.
New behavior:
* Ignore "" keys in the replacement array (and perform any remaining
replacement).
* Throw a warning indicating that an empty string replacement has
been ignored.
Closes GH-4792.
Fix folding for the new helper method.
Clarify comment in UPGRADING:
The performance on associative arrays would also improve,
as long as no offsets were unset (no gaps).
Packed arrays can have gaps.
Closes GH-4873.
[ci skip]
We are now guaranteed that $this always exists inside methods, as
well as insides closures (if they use $this at all).
This removes checks for $this existence from the individual object
opcodes. Instead ZEND_FETCH_THIS is used in the cases where $this
is not guaranteed to exist, which is mainly the pseudo-main scope.
Closes GH-3822.
The implementation of `XMLReader::open()` and `XMLReader::XML()` still
supports calling the methods statically and non-statically. However,
as of PHP 8.0.0, calling these methods statically is not allowed,
because they are not declared as static methods. Since we consider it
to be cleaner to call these methods statically, but had deprecated to
call them statically, we properly support both variants.
We implement support for static and non-static calls by overloading, so
that non-static calls have access to the `$this` pointer.
