Run benchmarks

X Autoload uses (or, *should* use, argh) an APC cache, with a performance comparable to that of other class loaders (Symfony).

However, it really outperforms those other loaders on systems without APC.
It is designed to scale much better with a high number of namespaces.

Here is a "Preview" benchmark result from a local version of xautoload.
The public version currently has the APC cache disabled, so it behaves mostly equivalent to the "xautoload, no apc".

loadClass() 1 x 300

We register 300 namespaces of test modules (in addition to those already installed), and load one class for each.

classloader + apc: 19 ms
xautoload + apc: 20 ms (*)
xautoload + apc + is_file(): 22 ms
xautoload, no apc: 27 ms
classloader, no apc: 82 ms

Repeated findFile() 10 x 300

We register 300 namespaces of test modules (in addition to those already installed), and call 10x findFile() for a class that is already loaded (one for each of the 300 test modules).

classloader + apc: 10 ms
xautoload + apc: 9 ms (*)
xautoload + apc + is_file(): 14 ms
xautoload, no apc: 62 ms
classloader, no apc: 620 ms

(*) The relevant code is almost identical in the cases where APC is enabled.
We assume the difference is just random, and may be different on other machines.

Note: Again, this is a preview. I am going to upload something to allow others to reproduce, until then it is just my word.

You can have a look at Autoload benchmark in my sandbox, which is what I started with. But it is not the same.

Here is an updated benchmark, finally using publically available code: xautoload-7.x-3.x, and the latest autoload_benchmark.

Benchmark results: 300 namespaces

(avg microseconds per single operation)
We register 300 test namespaces into each loader, and see how well they perform.

171.748

239.519

188.962

292.520

427.918

22.624

83.832

22.730

95.367

35.783

6.239

71.482

6.926

78.984

7.081

3.725

66.670

3.309

68.565

6.799

4.097

62.350

4.093

66.451

7.168

Benchmark results: 100 namespaces

(avg microseconds per single operation)
We register 100 test namespaces into each loader, and see how well they perform.

67.423

129.843

70.244

140.452

140.297

22.366

95.904

24.617

102.150

38.993

6.310

64.445

6.137

66.745

6.604

3.443

60.809

3.304

62.752

6.640

3.604

58.651

3.827

65.148

7.308

Legend

classloader.bare: Symfony\Component\ClassLoader\UniversalClassLoader->loadClass() / ->findFile()
classloader.apc_aggressive: Symfony\Component\ClassLoader\ApcUniversalClassLoader->loadClass() / ->findFile()
xautoload.bare: xautoload_ClassLoader_NoCache->loadClass() / ->findFile()
xautoload.apc: xautoload_ClassLoader_ApcCache->loadClass() / ->findFile()
xautoload.apc_aggressive: xautoload_ClassLoader_NoCache->loadClass() / ->findFile()

The "aggressive" just means that we skip the file_exists() if APC cache has a result, meaning that we potentially crash if that file has moved.

I think the information on the module page is balanced enough now.