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From: bart <bc@freeuk.com>
Newsgroups: comp.lang.c
Subject: Re: macro for fir list?
Date: Sat, 30 Mar 2024 11:05:04 +0000
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On 30/03/2024 09:56, fir wrote:

>>
> yet other example
> 
> //bytes container
>    char* bytes = NULL; int bytes_size = 0;
>    void bytes_add(char val) { 
> (bytes=(char*)realloc(bytes,++bytes_size*sizeof(char)))[bytes_size-1]=val;  }
>    void bytes_load(char* name)  {    FILE *f = fopen(name, "rb"); int c; 
> while((c=getc(f))!=EOF) bytes_add(c);   fclose(f);  }

This is pretty inefficient. Loading an 8MB file this way takes 3 
seconds, vs. 50ms to load it in one go.

Loading the same 90KB file 10,000 times took 120 seconds, vs. 0.8 
seconds even using a scripting language.

80% of the inefficiency is growing the buffer one byte at a time. The 
other 20% is reading the file one byte at a time.