PHP Extension for Bencode Encoding and Decoding

This PHP extension is a pure C implementation for mapping PHP variable to Bencode string vice versa.

It is inspired from this by unknown original author.

The original extension name and function names are kept at this moment.

Installation

Requirement

SUPPORT PHP7,8 ONLY, no external libraries are needed.

*NIX

phpize
./configure
make
make test
sudo make install

Windows

Follow this instruction for preparing a complete building environment for PHP. It is worthy to spend some time on.

I have done this with VS2015 community edition.

Then checkout the repo to your php-sdk\phpdev\vc14\x64\pecl\ (you should mkdir pecl manually, in the same level of the php sources like php-7.0.2-src.

Run the VS2015 x64 native prompt (Do not follow the instruction above except that you need just a x86 build) and do the same things till run the batch file bin\phpsdk_setvars.bat.

Change work directory to php-sdk\phpdev\vc14\x64\pecl\php-7.x.y-src during developing and building from now on.

• Run buildconf for a configure.bat with all pecl stuff included
• Run configure --disable-all --disable-zts --enable-cli --enable-cg_bcode=shared for a minimal PHP build to save time. Remove --disable-zts for ZTS build.
• Run nmake to start building
• Run nmake test TESTS=../pecl/php-ext-bencode/tests/*.phpt for testing the extension only (optional)
• Run nmake build-dist for packing everything useful up officially or just copy the built DLL file under x64\Release (it differs according to build arch, debug and ZTS)

Usage

bencode()

Very simple with recognition of PHP variable types. No additional type specifitions are need to create a bencode element.

Dictionary keys are sorted automatically without affecting input array.

Integer-like strings are bencoded to integer even it is bigger than PHP_INT_MAX.

bencode([]); // le
bencode(new StdClass); // de
bencode('10000000000000'); // i10000000000000e
bencode(['b' => 1, 'a' => 2]); // d1:ai2e1:bi1ee

bdecode()

The type information is mapped to PHP type as well.

Note that de and le are both converted to [] at this moment.

bencode('i1e'); // int(1)
bdecode('li2e3:123i0ee'); // [2, '123', 0]
bdecode('d1:a3:1231:bi3e1:cl1:x1:y1:zee'); // ['a' => '123', 'b' => 3, 'c' => ['x', 'y', 'z']]

Bencode syntax standard

The syntax for testing and QA is described here.

It does not support parsing becoded dict with non-string key like di0e3:fooe.

Discuss

• Rewrite the decoder with scanner re2c and parser bison, which PHP officially like ext/json
• Globally last error reporting like ext/json and return null silently on failure

This extension is aimed to boost performance for client codes that make use of everything of the bencoded data, or exporting a structure to bencoded string. It do not provide extra functionality.

It consumes memory to some extent because maps all data to userspace, which is not suit for some tasks like editing resume.dat, when only part of data is needed to be read and written. This extension may be more suitable for such applications.

Todos

• Encode string qualified to be an integer as int
• INI setting to raise error in exception or warning
• INI setting/function parameter to specify decode dict as object

License

MIT