A C++ library offering the core functionality of Adblock Plus.
This repo uses pre-commit to maintain agreed conventions in the repo. It should
be installed (tldr; pip install pre-commit then pre-commit install)
before making any new commits to the repo.
Project dependencies are declared as git submodules, ensure you include submodules in your checkout.
Additionally one should provide V8 headers in order to build libadblockplus library and V8 prebuilt libraries in order to link a binary (executable, shared object/DLL), even libadblockplus tests. The last time is was tested against V8 6.7. For more details see below.
Win32, MacOS, Linux and Android are supported target platforms.
The only officially supported development platform is Linux. If you plan to build libadblockplus on any other operating system, we recommend using a Docker container.
General:
- You need a C++14 compatible compiler to build libadblockplus.
Linux:
- We use Clang and libc++ instead of the libstdc++ that gcc uses,
since by default v8 builds with libc++. Make sure you have the right
development package installed for libc++:
libc++-devandlibc++abi-devon Debian/Ubuntu,libcxx-develandlibcxxabi-develon RedHat/Fedora.
Android:
You need V8 prior to building. Two options:
- Use the default prebuild V8 by invoking the make target
get-prebuilt-v8. This will download and extract the prebuilt V8 for your setup. The default environment will be set by the Makefile at build time. If you are cross compiling use the same options as below to invoke make. This option works only on Linux
Pass WGET_QUIET=true to download the files silently.
If you switch the version of V8 using the same source tree, you should
manually remove the third_party/prebuilt-v8 (also,
third_party/v8-include.tar.xz and third_party/v8-prebuilt.tar.xz are not
needed) directory and redownload again with the right options.
Or
- Prepare V8 and set environment variables LIBV8_LIB_DIR and LIBV8_INCLUDE_DIR.
LIBV8_INCLUDE_DIR should point to the include directory of V8, e.g.
.../v8/includeand there should belibv8_monolith.ain the directory LIBV8_LIB_DIR.
To clone:
git clone --recursive https://gitlab.com/eyeo/adblockplus/libadblockplus
To build:
Using Make:
make
The default target architecture is the architecture of a host. In order to build for a different architecture pass ABP_TARGET_ARCH to make, e.g. run:
make ABP_TARGET_ARCH=ia32
supported values are ia32 and x64.
To build and run the tests:
make test
Likewise, use the following with ABP_TARGET_ARCH:
make test ABP_TARGET_ARCH=ia32
To run specific tests, you can specify a filter:
make test FILTER=*.Matches
Configure V8 as for Unix and set ANDROID_NDK_ROOT environment variable to your Android NDK directory.
To build for x86 or x64 arch run:
make TARGET_OS=android ABP_TARGET_ARCH=ia32
or
make TARGET_OS=android ABP_TARGET_ARCH=x64
To build for arm or arm64 arch run:
make TARGET_OS=android ABP_TARGET_ARCH=arm
or
make TARGET_OS=android ABP_TARGET_ARCH=arm64
You can use libadblockplus to build an ad blocker. Or, strictly speaking, a web content filter. Just like Adblock Plus, it can detect resources that should be blocked based on their URL and context information, and generate CSS selectors to hide DOM elements.
The basic usage is explained below, see comments in the header files for more information. See the filter documentation to learn more about Adblock Plus filters.
All the types and functions in libadblockplus are in the AdblockPlus
namespace. For brevity's sake, we'll assume the following using declaration:
using namespace AdblockPlus;
Most of the functionality of libadblockplus is available via the
IFilterEngine
class. First you need to create a
Platform
instance based on information about your application.
AppInfo appInfo;
appInfo.name = "awesomewebfilter";
appInfo.version = "0.1";
appInfo.locale = "en-US";
PlatformFactory::CreationParameters platformParameters;
auto platform = PlatformFactory::CreatePlatform(std::move(platformParameters));
platform->SetUp(appInfo);
Depending on your application and platform, you possibly will need to supply your own
implementations for subsytems dealing with logging, network, files, etc. For this, modify
PlatformFactory::CreationParameters
fields. In this case it is important to remember that if your implementation uses a
multi-threaded model, Platform instance should be destroyed only after all threads
have finished.
In addition, it is expected that other objects returned by the API, such as Filter, Subscription and JsValue, will be released before the Platform.
Next, you can create a IFilterEngine instance:
FilterEngineFactory::CreationParameters engineParamters;
platform->CreateFilterEngineAsync(engineParamters, [](const IFilterEngine&)> { ... });
When initialised, IFilterEngine will automatically select a suitable ad
blocking subscription based on AppInfo::locale and download the filters for
it. To manually configure subscriptions you can modify StringPrefName::FirstRunSubscriptionAutoselect in preconfiguredPrefs for
FilterEngineFactory::CreationParameters.
libadblockplus takes care of storing and updating subscriptions.
You can add more:
Subscription subscription =
filterEngine.GetSubscription("https://example.org/filters.txt");
filterEngine.AddSubscription(subscription);
To retrieve a list of all subscriptions use
FilterEngine::GetListedSubscriptions.
To check if a subscription has been added or not, do the following:
auto subscriptions = GetFilterEngine().GetListedSubscriptions();
auto subscription = std::find_if(subscriptions.begin(), subscriptions.end(), [](const auto& cur) {
return cur.GetUrl() == "https://example.org/filters.txt";
});
if (subscription != subscriptions.end())
....
Removing a subscription is not rocket science either:
Subscription subscription =
filterEngine.GetSubscription("https://example.org/filters.txt");
filterEngine.RemoveSubscription(subscription);
Working with custom filters is very similar to working with subscriptions:
Filter filter = filterEngine.GetFilter("||example.com/ad.png");
filterEngine.AddFilter(filter);
filterEngine.RemoveFilter(filter);
Note that applications should only do this to manage a user's custom filters. In general, filter lists should be hosted somewhere and added as a subscription.
As mentioned above, one of the two main tasks of libadblockplus is to check if a URL matches any of the active blocking filters.
To demonstrate this, we'll add a custom filter:
Filter filter = filterEngine.GetFilter("||example.com/ad.png");
filterEngine.AddFilter(filter);
Now we'll call matches on an URL that should be blocked:
Filter match =
filterEngine.Matches("http://example.com/ad.png", "IMAGE", "");
Since we've added a matching filter, match will point to the same filter
object as filter.
Note that we've ignored the third parameter of
IFilterEngine::Matches
here to keep things simple. Real applications should pass the frame structure
in here - this is necessary because many filters and exception rules are domain
specific.
Some filters should be applied only for sites providing special key. It is
provided in X-Adblock-Key header. Usually it is used to allowlist specific
sites. You can read more about this in
filters documentation.
To find match filter taking into account site key, please use 4th parameter
for IFilterEngine::Matches
It should contain decoded and verified public key extracted from X-Adblock-Key header.
Filter match =
filterEngine.Matches("http://example.com/ad.png", "IMAGE", "",
"DECODED PUBLIC KEY");
You can take a look for the sitekey-related tests for reference.
Aside from blocking requests, ad blockers typically also hide elements. This is done via a second type of filter that is completely ignored when matching URLs: element hiding rules.
You can retrieve a CSS style sheet for elements that should be hidden
using
IFilterEngine::GetElementHidingStyleSheet.
What libadblockplus clients typically do with this is to inject the CSS style sheet into each page.
At any moment you can call IFilterEngine::SetAllowedConnectionType to change the settings indicating what connection types are allowed in your application. However to have it working you should also pass a callback function into factory method of IFilterEngine. This callback is being called before each request and the value of argument is earlier passed string into IFilterEngine::SetAllowedConnectionType, what allows to query the system and check whether the current connection is in accordance with earlier stored value in settings.
For example, you can pass "not_metered" into IFilterEngine::SetAllowedConnectionType and on each request you can check whether the current connection is "not_metered" and return true or false from you implementation of callback AdblockPlus::IFilterEngine::IsConnectionAllowedAsyncCallback.
The shell subdirectory contains an example application using libadblockplus.
It's a simple shell that loads subscriptions into memory and checks whether a specified resource would be blocked or not.
To see the available commands, type help.
The shell is automatically built by make, you can run it as follows:
build/out/abpshell
Just run the project abpshell.
Just in case one can find args files to build V8 in v8-args directory.
You can lint the code using ESLint.
npm run eslint
In order to set up ESLint and
configuration eslint-config-eyeo you need Node.js 7 or higher and once it is installed please run npm install in the repository directory.
In order to learn about the usage of deprecated V8 API please set libv8_show_warnings to "true" on *nix, e.g.
make libv8_show_warnings="true"
or on Windows add it to GYP_DEFINES.