| --- |
| layout: page |
| title: Coding Guidelines |
| --- |
| |
| ## General rules |
| |
| * All files must have an Apache copyright header at the top of the file. |
| * Code should be removed rather than commented out. |
| * All public functions should have javadoc comments. |
| * Always use braces to surround branches. |
| * try-finally should be avoided. |
| |
| ## Formatting |
| |
| * All files must have an 100 character maximum line length. |
| * Indentation should be 2 spaces. |
| * Files should use spaces instead of tabs. |
| * Wrapping lines |
| * Break after a comma. |
| * Break before an operator. |
| * Prefer higher-level breaks to lower-level breaks. |
| * Align the new line with beginning of the expression at the same level |
| on the previous line. |
| * If the above rules lead to confusing code, just indent 8 spaces. |
| * One variable declaration per a line. |
| |
| ## Naming |
| |
| * Packages should be all lowercase. |
| * C++ code should be in `orc::`. |
| * Java code should be in `org.apache.orc`, except for compatibility classes, |
| which should be in `org.apache.hadoop.hive.ql.io.orc`. |
| * Classes should be in mixed case. |
| * Variables should be in camel case. |
| * Constants should be in upper case. |
| |
| ## Static code analysis tool |
| |
| * [CheckStyle-IDEA](https://plugins.jetbrains.com/plugin/1065-checkstyle-idea) |
| |
| You can download this plugin to load `java/checkstyle.xml` to check the java code style. This way you get checkstyle errors/warnings already when you are coding. |
