Re: [aether-users] performance: creation of DependencyNode, DefaultArtif

[Benjamin Bentmann <bentmann@xxxxxxxxxxxx>]

Martin Koci wrote:

> > Can you detail all chains of objects/fields holding the artifact instances?
>
> The holding structure is
> [...]
> org.apache.maven.project.MavenProject ->
> org.sonatype.aether.util.DefaultRepositorySystemSession ->
> org.sonatype.aether.graph.Dependency

Am I right to assume that the omitted part of the chain is

MavenProject.projectBuilderConfiguration
-> DefaultRepositorySystemSession.cache
?

If so, I suggest to have m2e reset/clear the cache once dependency 
resolution is done or otherwise use a size-restricted cache impl.

> Sorry, it's really chaotic. Let's have Dependecy A. Then:
> project B: depends on A
> project C: depends on B and A
>
> As result, Project C has dependency A twice: 1) direct dependency 2)
> transitive dependency from B. When I remove the direct dependency, will
> be resolution faster?

Potentially, it depends on whether the paths leading to A employ the 
same remote repositories, dependency management etc. If all factors that 
could affect the transitive dependencies of A are equal, the sub graph 
rooted at A is shared and not build again.

Note however, that removing a direct dependency when a project actually 
uses its code, is conceptually wrong. The better approach would rather 
be to exclude the transitive dependency if you really want to go down 
that path.

> Theoreticaly, when we minimize dependencyManagement section, will be
> resolution faster?

Theoretically, yes. dependencyManagement translates into some HashMap's 
that get consulted for each dependency to see whether its version or 
scope are managed and the dependency object needs to get updated. 
However, whether this processing has actually significant contribution 
to your case or not is something I can't tell. From what you said 
earlier, it seems conflict resolution is the biggest CPU task.


Benjamin