Calrissian Mango

Mango provides common reusable utilities for the cloud toolkit.

Batchers

The Batcher utilities provide an easy to configure means of generating batches of data triggered based on size and time. These are designed to work in a multi-threaded environment making it easy to integrate anywhere a simple batching solution is needed.

The following is an example for triggering a new batch when it hits 100 elements or 10 seconds have elapsed.

Batcher batcher = BatcherBuilder.create()
    .sizeBound(100)
    .timeBound(10, SECONDS)
    .build(batch -> System.out.println("Do something with batch"));

Collect

The collect module provides many tools for working with Iterators and Iterables. Most of these utilities provide extensions to the capabilities provided by Guava.

The primary capability provided by these tools is the inclusion of the CloseableIterator and the CloseableIterable iterfaces which provide utilities for working with data sets which may be backed by a closeable resource. This is very useful when working with large databases or third party systems where streaming data lazily is a better access pattern. By wrapping, the results in a Closeable resource, the utilities provided in the CloseableIterators and CloseableIterables classes allow easy manipulation of these datasets while still being able to close the underlying resource.

//Close with try-with-resources block to autoclose data
try (CloseableIterables<String> data = CloseableIterable.limit(rawData, 100)) {
    for (String value : data) {
        System.out.println("Do somethting with value");   
    }
}

There is also a FluentCloseableIterable with is designed to be very similar to Guava's FluentIterable. This utilitity is useful to use in conjunction with the autoClose method to close the underlying resource once the data has been exhausted.

//autoClose() will close the resource in 'rawData' if there is an exception or when done building the list.
List<Integer> data = FluentCloseableIterables.from(rawData)
    .filter(Objects::nonNull)
    .limit(100)
    .transform(v -> Integer.parseInt(v))
    .autoClose()
    .toList(); 

IO

There are a few simple utilities for working with IO. The Serializables utilities are helpers for converting Java serialiable objects to and from byte arrays. The abstract buffered streams are utilities for chunking up streams and reconstituting that data later.

Net

The net package provides utilities working with IP addresses and Java's InetAddress classes. The IPv4 and IPv6 classes are lightweight wrappers around Java's Inet4address and Inet6Address classes respectively, with the primary goal of making them Comparable. This makes these classes much easier to use to for things like range checks. For instance, an instance of Guava's Range can be constructed from a CIDR block which can be used to test IP's.

Range<IPv4> cidr = IPv4.cidrRange("10.0.0.0/8");

//Just check the ip within the range.
boolean containsIP = cidr.contains(IPv4.fromString("10.1.1.1"));

The MoreInetAddresses utilities are designed to provide an extension to Guava's InetAddresses. In addition to tools such as CIDR parsing the MoreInetAddresses also provides several utilities to work around the fact that Java will automatically convert "IPv4 Mapped" IPv6 addresses to an Inet4Address. This behavior isinhereted by the InetAddresses utilities in Guava. MoreInetAddresses utilities will always preserve the original ipv6 address as an Inet6Address irregardless of if it represents a "IPv4 Mapped" address.

Types

One of the primary utilities are the type encoders. These are a set of utilities for encoding and decoding data in a number of formats. At its heart is the the TypeEncoder interface and the TypeRegistry class for interacting with each encoder. The TypeRegistry provides a means for interacting with similar groups of TypeEncoders.

By default the following are provided:

• SimpleTypeEncoders - This class contains methods for generating String encoders for all the core java types in a consistent and easy serialize format. It could be used for something such as Json or other string data formats.
• LexiTypeEncoders - This class containts methods for generating lexicographically encoded Strings for all the core java types. It is best suited for situations where the order of the encoded strings needs to match the same natural ordering of the original data. This is useful in situations like sorted key-value databases.