From: René Scharfe <l.s.r@web.de>
Date: Sun, 18 Jan 2026 14:55:23 GMT
Subject: Re: [PATCH 01/10] ivec: introduce the C side of ivec
Message-ID: <5c7e853d-f368-4d8a-a5f0-f4d485c1c3d6@web.de>
In-Reply-To: <CAH=ZcbB=Yf=wn2O273adrvpUpE0bJGKwrAjOAjmB8AgJrjz5Bg@mail.gmail.com>

On 1/17/26 4:58 PM, Ezekiel Newren wrote:
> On Fri, Jan 16, 2026 at 1:19 PM René Scharfe <l.s.r@web.de> wrote:
>>
>>> +void ivec_reserve(void *self_, size_t additional)
>>> +{
>>> +     struct IVec_c_void *self = self_;
>>> +
>>> +     size_t growby = 128;
>>> +     if (self->capacity > growby)
>>> +             growby = self->capacity;
>>> +     if (additional > growby)
>>> +             growby = additional;
>>> +
>>> +     _set_capacity(self, self->capacity + growby);
>>> +}
>>
>> Constant growth steps like these cause linear growth and quadratic
>> complexity.  ALLOC_GROW does exponential growth with factor 1.5 to
>> get linear complexity.  Here's an old plea to do the same:
>> https://blog.mozilla.org/nnethercote/2014/11/04/please-grow-your-buffers-exponentially/
>>
>> René
> 
> It _is_ exponential. ivec_reserve(&vec, 1) means grow by _at least_ 1.
D'oh!  Right, it grows with factor 2, as growby is at least as big as
->capacity.  I can't read.

René