PHP 26 Apr 2012 05:00 pm
While there is no doubt PHP is broken beyond repair, it does have a few virtues that keeps it as one of my first choices when writing certain kind of web frontends and minor tools.
There is a huge laundry list of how PHP is broken at “PHP a fractal of bad design“, which I almost entirely agree with. What I will do here is point out the few things on that list that I do not agree with, and why.
C++ 25 Feb 2012 01:19 pm
A comparison of how many reallocations a worse case poorly coded use of realloc() does, compared to just using std::vector. 10000000 integers are added to the containers one-by-one. Clearly you would never abuse realloc() like this in real code, but it’s interesting nonetheless. Idea from sacrebleu at Freenode’s ##C++.
|Allocs / OS||std::vector||realloc()|
|Linux: Fedora 10||24||438|
|Mac OS X||24||31|
- Mac OS X: OS X 10.7.3, 2.3 GHz Core i5, 8 GiB RAM. XCode 4.3, clang++ 3.1 -std=c++0x -stdlib=libc++ -O3.
- Windows 7: 64 bit, 1.60GHz Core i7 Q720, 8 GiB RAM. MSVC++ 2010 _SECURE_SCL=0
- Linux: Arch: VirtualBox on the Windows machine, VT-x, Arch Linux, kernel 3.2.7-1-ARCH x86_64, 1 GiB RAM. GNU g++ 4.6.2 -std=c++0x -O3
- Linux: Fedora 10: Fedora 10, kernel 2.6.27 x86_64, 2.66GHz Xeon, 8 GiB RAM. GNU g++ 4.4.1 -O3
C++ 20 Feb 2012 04:12 pm
(Old version from 2010-04-02)
A performance comparison of the speed of operations on the various set implementations used in C++. There are 16383 unique elements across which 1000000 insert, lookup, iterate, and erase operations are performed.
The raw tick numbers are shown and table sorting is enabled so you can compare for yourself. Just be aware that the Mac OS X, Linux, and Windows numbers cannot be compared against each other.
- std::set, std::unordered_set, boost::unordered_set – the usual general purpose suspects.
- CG3::sorted_vector, std::vector based replacement for std::set. Suitable for small amounts of cheap objects, such as integers.
- CG3::sorted_deque, rubbish version of sorted_vector.
- CG3::interval_vector, specialized for storing integers that form intervals.
- sti::sset, skip-list based std::set replacement. Wouldn’t compile with g++ or clang++.
- Ticks counted via cycle.h (local mirror)
- Source: CMake Project: benchmarks, primary source set.cpp
C++ 31 Aug 2011 10:27 pm
A performance benchmark of which include guard method is faster. Test times the compilation of a main.cpp that includes 10000 files 3 times each.
The tested methods are:
#pragma oncefollowed by
Sources for the test is at inc.tar.gz, but it’s just 5×10000 files.
C++ 28 May 2011 07:04 pm
(There is also a string-to-int performance test.)
A performance benchmark of which method is faster of converting an std::string to a double. The goal is ending up with a double of the value represented in an std::string.
The tested methods are:
- a hand-written naive loop
- std::stringstream, reusing the object