Perf: triggers a Maven model build for every dependency artifact

[elharo]

Summary

Referencing $projects (or $projectsSortedByOrganization) in a template triggers getProjects(), which performs a full projectBuilder.build(...) for every dependency artifact — not just the reactor projects.

src/main/java/org/apache/maven/plugin/resources/remote/AbstractProcessRemoteResourcesMojo.java:770-783, 533-556

public Object internalGet(String key) {
    Object result = super.internalGet(key);
    if (result == null && key != null && key.startsWith(KEY_PROJECTS) && containsKey(key)) {
        List<MavenProject> projects = getProjects();
        put(KEY_PROJECTS, projects);
        put(KEY_PROJECTS_ORGS, getProjectsSortedByOrganization(projects));
        return super.internalGet(key);
    }
    return result;
}

getProjects() builds a ProjectBuildingRequest and calls projectBuilder.build(artifact, req) for each artifact in the (filtered) dependency set (:541-556), then sorts the results.

Impact

• For projects with hundreds of dependencies, $projects costs hundreds of expensive model builds (POM fetch + parent chain + property resolution each).
• The computation is eager for both projects and projectsSortedByOrganization even when a template references only one of them.
• It is recomputed whenever a new projects* key is accessed before caching settles, though the first computation is the dominant cost.

The lazy mechanism is intentional, but the cost per use is high and worth documenting or optimizing (e.g. only build models for artifacts not already in the reactor, or cache across executions).

Suggested fix

Consider reusing reactor projects from mavenSession.getProjects() when the artifact matches, building only genuinely external artifacts, and computing the org-sorted map only when actually referenced.