Class AbstractRequestCache

java.lang.Object
org.apache.maven.impl.cache.AbstractRequestCache
All Implemented Interfaces:
org.apache.maven.api.cache.RequestCache
Direct Known Subclasses:
DefaultRequestCache
public abstract class AbstractRequestCache extends Object implements org.apache.maven.api.cache.RequestCache
Abstract implementation of the RequestCache interface, providing common caching mechanisms for executing and caching request results in Maven.

This class implements caching strategies for individual and batch requests, ensuring that results are stored and reused where appropriate to optimize performance.

Since:
4.0.0

  • Constructor Summary

    Constructors
    Constructor
    Description
    AbstractRequestCache()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    protected abstract <REQ extends org.apache.maven.api.services.Request<?>, REP extends org.apache.maven.api.services.Result<REQ>>
    CachingSupplier<REQ,REP>
    doCache(REQ req, Function<REQ,REP> supplier)
    Abstract method to be implemented by subclasses to handle caching logic.
    <REQ extends org.apache.maven.api.services.Request<?>, REP extends org.apache.maven.api.services.Result<REQ>>
    REP
    request(REQ req, Function<REQ,REP> supplier)
    Executes and optionally caches a single request.
    <REQ extends org.apache.maven.api.services.Request<?>, REP extends org.apache.maven.api.services.Result<REQ>>
    List<REP>
    requests(List<REQ> reqs, Function<List<REQ>, List<REP>> supplier)
    Executes and optionally caches a batch of requests.
    protected static <T extends Throwable>
    void
    uncheckedThrow(Throwable t)
     

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • AbstractRequestCache

      public AbstractRequestCache()

  • Method Details

    • request

      public <REQ extends org.apache.maven.api.services.Request<?>, REP extends org.apache.maven.api.services.Result<REQ>> REP request(REQ req, Function<REQ,REP> supplier)
      Executes and optionally caches a single request.

      The caching behavior is determined by the specific implementation of doCache(Request, Function). If caching is enabled, the result is retrieved from the cache or computed using the supplier function.

      Specified by:
      request in interface org.apache.maven.api.cache.RequestCache
      Type Parameters:
      REQ - The request type
      REP - The response type
      Parameters:
      req - The request object used as the cache key
      supplier - The function that provides the response if not cached
      Returns:
      The cached or computed response

    • requests

      public <REQ extends org.apache.maven.api.services.Request<?>, REP extends org.apache.maven.api.services.Result<REQ>> List<REP> requests(List<REQ> reqs, Function<List<REQ>, List<REP>> supplier)
      Executes and optionally caches a batch of requests.

      This method processes a list of requests, utilizing caching where applicable and executing only the non-cached requests using the provided supplier function.

      This implementation uses CachingSupplier.complete(Object) with wait/notifyAll to coordinate batch results, and a ThreadLocal re-entrancy guard to prevent deadlocks when batch resolution triggers nested calls (e.g., parent POM resolution during artifact resolution).

      Concurrent calls for the same request on different threads: the first thread performs the resolution; the second thread's CachingSupplier.apply(REQ) blocks (via Object.wait()) until complete() is called, avoiding duplicate work.

      Re-entrant calls on the same thread: detected via RESOLVING_ON_THREAD. CachingSupplier.apply(REQ) skips the wait and invokes the fallback supplier directly so the inner call can complete without waiting for the outer call's batch result.

      Specified by:
      requests in interface org.apache.maven.api.cache.RequestCache
      Type Parameters:
      REQ - The request type
      REP - The response type
      Parameters:
      reqs - List of requests to process
      supplier - Function to execute the batch of requests
      Returns:
      List of results corresponding to the input requests
      Throws:
      org.apache.maven.api.cache.BatchRequestException - if any request in the batch fails

    • doCache

      protected abstract <REQ extends org.apache.maven.api.services.Request<?>, REP extends org.apache.maven.api.services.Result<REQ>> CachingSupplier<REQ,REP> doCache(REQ req, Function<REQ,REP> supplier)
      Abstract method to be implemented by subclasses to handle caching logic.

      This method is responsible for determining whether a request result should be cached, retrieving it from cache if available, or executing the supplier function if necessary.

      Type Parameters:
      REQ - The request type
      REP - The response type
      Parameters:
      req - The request object
      supplier - The function that provides the response
      Returns:
      A caching supplier that handles caching logic for the request

    • uncheckedThrow

      protected static <T extends Throwable> void uncheckedThrow(Throwable t) throws T
      Throws:
      T