ImageRepository

A thread safe, memory cache image repository built to hold images to a certain capacity and includes autocomplete search query.

This implementation uses a least recently used removal policy

How to Use

ImageRepository

ImageRepository class provides four methods as shown below:

• getImage(String name) - Gets image data including image name, size and url location from repository for specified name.
• uploadImage(String name, int size, String url) - Uploads image to repository for specified data.
• deleteImage(String name) - Removes the image for specified name.
• getAllImages() - Get all image names from image repository.
• autoCompleteSearch(String prefix) - Gets list of autocomplete image suggestions from given prefix

Simple implementation

ImageRepository imageRepo = new ImageRepository(500);
imageRepo.uploadImage("hotwheelscar", 100, "https://hotwheelscars.com/images/1");

Create compilation subfolder named target

$ mkdir target

Compiles all files to a specified target folder

$ javac ./src/main/java/com/image/repo/*.java -d ./target/classes

Run the main method with the image repository

$ java -Dfile.encoding=UTF-8 -cp ./target/classes com.image.repo.ImageRepository 

Expected Output

[aushvin at, aushvin at school, aushvin at work, aushvin at yosemite]

Architecture

ImageList

ImageList is a fixed size cache implementation that remembers the order in which images are accessed and uploaded. Once the user-defined capacity has been reached, it replaces the least recently used image with a newly inserted one. This is ideal for fast lookup, insertion and deletion time.

AutoComplete

Autocomplete suggestions retrieval using trie data structure from given prefix. Each node stores a HashMap and boolean terminal value, where the key represents the current character and the value represents the next node.

• Each path down the trie represents an entire word.
• Each node down the trie will hold a boolean value representing the end of the word. Leaf nodes will hold a boolean value of true.

Test

$ mvn clean test

Support

Java 1.7 or greater.