GraphContext.kt

TLDR

The GraphContext.kt file contains a class GraphContext which is an in-memory store that can be used to store objects in a HeapGraph instance. It is implemented as a simple MutableMap of String keys to Any values.

Methods

get

The get method allows retrieving a value from the store by providing a key. It returns the value cast to the requested type T, or null if the key does not exist in the store.

getOrPut

The getOrPut method is similar to MutableMap.getOrPut. It retrieves the value associated with the given key if it exists, otherwise it sets a default value in the store by invoking defaultValue and returns that value. It is useful for lazy initialization of values in the store.

set

The set method allows adding or updating a key-value pair in the store. The value must be of type T.

contains

The contains method checks if a key exists in the store. It returns true if the key is present, false otherwise.

minusAssign

The minusAssign method allows removing a key-value pair from the store by providing the key. It performs the same function as the MutableMap.remove method.

END

package shark

/**
 * In memory store that can be used to store objects in a given [HeapGraph] instance.
 * This is a simple [MutableMap] of [String] to [Any], but with unsafe generics access.
 */
class GraphContext {
  private val store = mutableMapOf<String, Any?>()
  operator fun <T> get(key: String): T? {
    @Suppress("UNCHECKED_CAST")
    return store[key] as T?
  }

  /**
   * @see MutableMap.getOrPut
   */
  fun <T> getOrPut(
    key: String,
    defaultValue: () -> T
  ): T {
    @Suppress("UNCHECKED_CAST")
    return store.getOrPut(key) {
      defaultValue()
    } as T
  }

  /**
   * @see MutableMap.set
   */
  operator fun <T> set(
    key: String,
    value: T
  ) {
    store[key] = (value as Any?)
  }

  /**
   * @see MutableMap.containsKey
   */
  operator fun contains(key: String): Boolean {
    return key in store
  }

  /**
   * @see MutableMap.remove
   */
  operator fun minusAssign(key: String) {
    @Suppress("UNCHECKED_CAST")
    store -= key
  }
}