Zend: Preallocate error buffer with capacity tracking #20565
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It's often a good idea to choose a factor of 1.5, there's a mathematical reason behind it (https://github.com/facebook/folly/blob/main/folly/docs/FBVector.md#memory-handling). |
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yes will try ; even though usage and growth might not be that as critical as your (nice) link contexts. |
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Interesting, we currently extend arrays by a factor of 2, I wonder what would happen if we do 1.5 instead. |
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Won't work because the hash masking depends on it being a power of 2. |
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Can we get a clearer PR title? |
devnexen
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ndossche
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Jan 4, 2026
Zend/zend.c
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| * Use pow2 realloc if it becomes a problem. */ | ||
| EG(num_errors)++; | ||
| EG(errors) = erealloc(EG(errors), sizeof(zend_error_info*) * EG(num_errors)); | ||
| // pondering if uint32_t is more appropriate but would need to align the allocation size then |
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Storing the size like this is very ugly in my opinion. What you could do is make a struct with a size field and a flexible array member at the end.
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Replace separate num_errors/errors fields with a single struct containing size, capacity, and a flexible array. The buffer grows by 50% when needed instead of reallocating on every recorded error. - Add ZEND_ERR_BUF_SIZE macro and zend_init_errors_buf() helper - Allocate error buffer in zend_startup for NTS builds - Remove redundant NULL checks since buffer is always allocated
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Replace separate num_errors/errors fields with a single struct containing size, capacity, and a flexible array. The buffer grows by 50% when needed instead of reallocating on every recorded error.