Revamped README and CONTRIBUTING.

CONTRIBUTING.md

@@ -0,0 +1,165 @@
+# Contributing
+
+This project is work of [many contributors](https://github.com/rcongiu/Hive-JSON-Serde/graphs/contributors).
+
+You're encouraged to submit [pull requests](https://github.com/rcongiu/Hive-JSON-Serde/pulls), [propose features and discuss issues](https://github.com/rcongiu/Hive-JSON-Serde/issues).
+
+In the examples below, substitute your Github username for `contributor` in URLs.
+
+## Fork the Project
+
+Fork the [project on Github](https://github.com/rcongiu/Hive-JSON-Serde) and check out your copy.
+
+```
+git clone https://github.com/contributor/Hive-JSON-Serde.git
+cd Hive-JSON-Serde
+git remote add upstream https://github.com/rcongiu/Hive-JSON-Serde.git
+```
+
+## Build
+
+Ensure that you can build the project and run tests.
+
+```
+git checkout develop
+mvn test
+```
+
+### Architecture
+
+JSON encoding and decoding is using a somewhat modified version of [Douglas Crockfords JSON library](https://github.com/douglascrockford/JSON-java), which is included in the distribution.
+
+The SerDe builds a series of wrappers around `JSONObject`. Since serialization and deserialization are executed for every (and possibly billions) record we want to minimize object creation, so instead of serializing/deserializing to an `ArrayList`, the `JSONObject` is kept and a cached
+`ObjectInspector` is built around it. When deserializing, Hive gets a `JSONObject`, and a `JSONStructObjectInspector` to read from. Hive has `Structs`, `Maps`, `Arrays` and primitives while `JSON` has `Objects`, `Arrays` and primitives. Hive `Maps` and `Structs` are both implemented as `Object`, which are less restrictive than hive maps. A JSON `Object` could be a mix of keys and values of different types, while Hive expects you to declare the
+type of map (eg. `map<string,string>`). The user is responsible for having the JSON data structure match hive table declaration.
+
+See [www.congiu.com](http://www.congiu.com/?s=serde) for details.
+
+### Compiling for Specific Targets
+
+Use maven to compile the SerDe. This project uses maven profiles to support multiple version of Hive/CDH.
+
+#### CDH4
+
+```
+mvn -Pcdh4 clean package
+```
+
+#### CDH5
+
+```
+mvn -Pcdh5 clean package
+```
+
+#### HDP 2.3
+
+```
+mvn -Phdp23 clean package
+```
+
+### Generate a JAR
+
+All output is generated into `json-serde/target/json-serde-VERSION-jar-with-dependencies.jar`.
+
+```
+$ mvn package
+```
+
+#### Specific Versions of Hive
+
+If you want to compile the SerDe against a different version of the cloudera libs, use `-D`.
+
+```
+$ mvn -Dcdh.version=0.9.0-cdh3u4c-SNAPSHOT package
+```
+
+For Hive 0.14.0 and Cloudera 1.0.0.
+
+```
+mvn -Pcdh5 -Dcdh5.hive.version=1.0.0 clean package
+```
+
+## Write Tests
+
+Try to write a test that reproduces the problem you're trying to fix or describes a feature that you want to build.
+
+We definitely appreciate pull requests that highlight or reproduce a problem, even without a fix.
+
+## Write Code
+
+Implement your feature or bug fix.
+
+## Write Documentation
+
+Document any external behavior in the [README](README.md).
+
+## Update Changelog
+
+Add a line to [CHANGELOG](CHANGELOG.md) under *Next* release.
+Make it look like every other line, including your name and link to your Github account.
+
+## Commit Changes
+
+Make sure git knows your name and email address:
+
+```
+git config --global user.name "Your Name"
+git config --global user.email "[email protected]"
+```
+
+Writing good commit logs is important. A commit log should describe what changed and why.
+
+```
+git add ...
+git commit
+```
+
+## Push
+
+```
+git push origin my-feature-branch
+```
+
+## Make a Pull Request
+
+Go to https://github.com/contributor/Hive-JSON-Serde and select your feature branch.
+Click the 'Pull Request' button and fill out the form. Pull requests are usually reviewed within a few days.
+
+## Rebase
+
+If you've been working on a change for a while, rebase with upstream/master.
+
+```
+git fetch upstream
+git rebase upstream/master
+git push origin my-feature-branch -f
+```
+
+## Update CHANGELOG Again
+
+Update the [CHANGELOG](CHANGELOG.md) with the pull request number. A typical entry looks as follows.
+
+```
+* [#123](https://github.com/rcongiu/Hive-JSON-Serde/pull/123): Reticulated splines - [@contributor](https://github.com/contributor).
+```
+
+Amend your previous commit and force push the changes.
+
+```
+git commit --amend
+git push origin my-feature-branch -f
+```
+
+## Check on Your Pull Request
+
+Go back to your pull request after a few minutes and see whether it passed muster with Travis-CI. Everything should look green, otherwise fix issues and amend your commit as described above.
+
+## Be Patient
+
+It's likely that your change will not be merged and that the nitpicky maintainers will ask you to do more, or fix seemingly benign problems. Hang on there!
+
+## Thank You
+
+Please do know that we really appreciate and value your time and work. We love you, really.
+
+