A signature-based search engine
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.



This is an experiment in text search/retrieval. It doesn't work (yet). We're making this available in the spirit of doing development out in the open, but nothing here has been cleaned up for public consumption. The documentation is non-existent and the code is in an incomplete state.

If you really want to try things out, we have some instructions on how to index Wikipedia, and how to play with our query parser. However, the system doesn't do anything useful to an end user -- these instructions are intended to allow contributors to build and run part of a system for the purpose of understand or debugging the system. If you're looking to play with an incomplete and likely buggy system, go ahead! If you want a working search index that you can use in production, check back later.

If you want a description of one of the core ideas, see this StrangeLoop talk transcript. See our engineering diary for descriptions of other parts of the system. We seem to be adding new descriptions at least once a week, and we (sometimes) go back and update old descriptions as things change.

Build status Build status


In order to build BitFunnel you will need CMake (2.8.11+), and a modern C++ compiler (gcc 5+, clang 3.5+, or VC 2015+). You can run CMake directly to generate the appropriate build setup for your platform. Alternately, we have some scripts that have the defaults that we use available.


For *nix platforms (including OS X),

cd build-make
make test

Note that while these instructions are for a make build, it's also possible to build using ninja by changing the cmake command to create ninja files instead of Makefiles. These aren't listed in the instructions because ninja requires installing an extra dependency for some developers, but if you want to use ninja it's available via apt-get, brew, etc., and is susbtantially faster than make.


If you're on Ubuntu 15+, you can install dependencies with:

sudo apt-get install clang cmake

On Ubuntu 14 and below, you'll need to install a newer version of CMake. To install a new-enough CMake, see this link. If you're using gcc, you'll also need to make sure you have gcc-5 (sudo apt-get install g++-5).

To override the default compiler, set the CXX and CC environment variables. For example, if you have clang-3.8 installed as clang-3.8 and are using bash:

export CXX="clang++-3.8"
export CC="clang-3.8"


Install XCode and then run the following command to install required packages using Homebrew (http://brew.sh/):

brew install cmake

BitFunnel can be built on OS X using either standard *nix makefiles or XCode. In order to generate and build makefiles, in the root BitFunnel directory run:

If you want to create an Xcode project instead of using Makefiles, run:


If you use XCode, you'll have to either re-run Configure_XCode or run the ZERO_CHECK target when the CMakeLists changes, e.g., when source files are added or removed.


You will need these tools:

Note: If you install Visual Studio for the first time and select the default install options, you won't get a C++ compiler. To force the install of the C++ compiler, you need to either create a new C++ project or open an existing C++ project.

Clone the BitFunnel repository and then run the following command in BitFunnel's root folder:


Note: You will need to modify the CMake -G option if you use a different version of Visual Studio. Bitfunnel must be built as a 64-bit program, so 'Win64' must be part of the specified G option text.

At this point, you can open the generated solution BitFunnel_CMake.sln from Visual Studio and then build it. Alternatively, you can build from the command line using cmake --build build-MSVC.