JIndex

Java class file indexing library, implemented in Rust with JNI bindings. The implementation was made in Rust to greatly reduce memory consumption and increase indexing speed.

Features

The current implementation supports indexing of the following data:

• Packages
  • Package name
  • Parent package
  • Contained classes
  • Sub-packages
• Classes
  • Package
  • Name and Source Name (for inner classes)
  • Super class
  • Implemented interfaces
  • Modifiers
  • Inner class type (member, anonymous, local)
  • Generic signature
  • Enclosing class (and method)
  • Inner classes with the member type
  • Methods
    • Name
    • Modifiers
    • Generic signature and descriptor
    • Exceptions
    • Parameter types
    • Return type
  • Fields
    • Name
    • Generic signature and descriptor

The following global operations are supported:

• Find a class
• Find classes by name matching a query
• Find a package
• Find packages by prefix
• Find implementations of a class
• Find implementations of a method
• Find base methods of a method

After the indexing operation is complete, no further modifications to the class index are possible. The whole library only works with ASCII strings. Supplying a non ASCII string will result in an error, or it will be ignored.

NOTE: The Java bindings are incomplete and don't expose all data as usable objects (e.g. generic signatures are only available as strings).

Performance

JIndex was made with TotalDebugCompanion in mind with the goal to be fast and also be able to fit the indexed data nicely into memory.

It has been tested with a set of around 330 jars containing 175k classes, 1.2 million methods and 500k fields. These take roughly 3 seconds to index on modern CPU, a third of this time is spent on file reading. The resulting index amounts to 256MB of memory. When serialized, the index becomes a 13MB file (54MB uncompressed) with a deserialization time of 500ms.

Usage

If anyone wants to use this (not recommended), the java bindings are available on packagecloud. Check the tags for the newest version.

repositories {
    maven { url "https://packagecloud.io/tth05/repo/maven2" }
}

dependencies {
    implementation("com.github.tth05:jindex:VERSION")
}

Development

• Clone the repo
• Run cargo build or cargo test for the rust side
• Run the copyNativeLibrary task and then any test for the java side