Contributing

This is a guide to help you get started contributing to the DataStax C/C++ Driver.

Forking and Branching

Fork the driver on GitHub and clone your fork locally.

$ git clone https://github.com/username/cassandra-cpp-driver.git
$ cd cassandra-cpp-driver
$ git remote add upstream https://github.com/apache/cassandra-cpp-driver

Features that require breaking API or ABI changes should be reserved for major releases and will probably not be considered for minor or patch releases. For features and big changes consider using a feature branch.

$ git checkout -b awesome-new-feature

Make sure to git rebase to keep your branch up-to-date.

$ git fetch upstream
$ git rebase upstream

To avoid duplication of work it's important to check JIRA to see if a bug or feature has already been fixed or added. JIRA should also be used to report issues and to track new features.

Coding Style

As a rule of thumb, follow the style of the current code. In general, the code follows the conventions and style defined in the Google C++ Style Guide. Differences and other key points are outlined below.

General

  • Code should be cross platform and cross architecture or be explicitly defined for all supported platforms/architectures.
  • Comments shouldn't explain the obvious.
  • Comments should be constructed using proper sentences with punctuation.

Whitespace

  • Use two space indentation and with no tabs.
  • Lines should be wrapped at 80 characters, but this is loose right now. Maybe this can be bumped to 100.
  • Lines should have no trailing whitespace and use unix-style (LF) line endings.

Conventions

  • Exposed names should be prefixed with cass_ or CASS_.
  • Code in cassandra.h should conform to C89 syntax.
  • Use early exits to simplfy code.

Style

  • Use proper case for structs, classes, and enums e.g. SomeClass.
  • Use lower case with underscores for variables and functions e.g. do_something_with_object.
  • Member variables should have a trailing _ character
  • The if, while, switch etc. keywords should have a space between it and the opening parenthesis.
if (some_condition) {
  // Do something
} else if (some_other_condition) {
  // Do something else
}

while (some_condition) {
  // Do something
}
  • Line up constructor initialization list on the colon.
SomeObject()
  : member1_(1)
  , member2_(0.0f)
  // ...
  , memberN_("foo") {}
  • Comments should begin with a space.
// This is comment

Testing

Tests should be included for both bug fixes and features. Tests should be added to test/unit_tests/src or tests/integration_tests/src. Unit tests should be used for testing components or changes that don't require Cassandra.

This testing guide is useful for understanding the structure of the tests and how to run them.

Committing

Make sure that your commit has a proper commit message with a succinct, and descriptive first line followed by a blank line. The message should also contain a description of the change and why it was required.

Pull Requests

Once your changes look good and you've crafted a proper commit message push your branch and create a pull request.

$ git push origin awesome-new-feature

Go to your fork (https://github.com/username/cassandra-cpp-driver), select the branch with your changes and click ‘Pull Request’. Fill out the pull request and submit.

Your changes should usually be reviewed within a few days, otherwise we'll try to give you a timeline. If your pull request requires fixes or changes please submit them in a new commit. These commits will be squashed before your pull request is merged.