From b6f2f0f3604c97af00b9d539fd647bafd237abbf Mon Sep 17 00:00:00 2001
From: Guillaume Nodet <gnodet@gmail.com>
Date: Mon, 3 Aug 2026 02:36:30 +0200
Subject: [PATCH] =?UTF-8?q?Cache=20projectsWithDeployExecution=20list=20to?=
 =?UTF-8?q?=20avoid=20O(N=C2=B2)=20reactor=20scan?=
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DeployMojo.allProjectsMarked() calls hasDeployExecution() for every
reactor project on every module invocation. hasDeployExecution() calls
getPluginsAsMap() for each project, producing O(N²) evaluations in a
large reactor build (e.g., 4383² ≈ 19.2M calls in a 4383-module project).

Fix: cache the filtered list of projects with deploy executions in the
first reactor project's plugin context. The list is invariant during a
build. Also simplify allProjectsMarked() to only check the projects
that actually have deploy executions, rather than iterating the full
reactor and testing the disjunction (hasState || !hasDeployExecution).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 .../maven/plugins/deploy/DeployMojo.java      | 25 ++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/main/java/org/apache/maven/plugins/deploy/DeployMojo.java b/src/main/java/org/apache/maven/plugins/deploy/DeployMojo.java
index 3f0e32d..d95d182 100644
--- a/src/main/java/org/apache/maven/plugins/deploy/DeployMojo.java
+++ b/src/main/java/org/apache/maven/plugins/deploy/DeployMojo.java
@@ -26,6 +26,7 @@
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import org.apache.maven.api.Artifact;
 import org.apache.maven.api.MojoExecution;
@@ -145,6 +146,8 @@ private enum State {
         TO_BE_DEPLOYED
     }
 
+    private static final String PROJECTS_WITH_DEPLOY_KEY = DeployMojo.class.getName() + ".projectsWithDeploy";
+
     public DeployMojo() {}
 
     private void putState(State state) {
@@ -195,7 +198,27 @@ public void execute() {
     }
 
     private boolean allProjectsMarked() {
-        return session.getProjects().stream().allMatch(p -> hasState(p) || !hasDeployExecution(p));
+        return getProjectsWithDeployExecution().stream().allMatch(this::hasState);
+    }
+
+    /**
+     * Returns the list of reactor projects that have a deploy execution, cached on first call.
+     * The list is invariant during a build and is stored in the first reactor project's plugin
+     * context to avoid recomputing it on every module invocation (O(N) total instead of O(N²)).
+     */
+    @SuppressWarnings("unchecked")
+    private List<Project> getProjectsWithDeployExecution() {
+        List<Project> allProjects = session.getProjects();
+        if (allProjects.isEmpty()) {
+            return List.of();
+        }
+        Map<String, Object> ctx = session.getPluginContext(allProjects.get(0));
+        List<Project> cached = (List<Project>) ctx.get(PROJECTS_WITH_DEPLOY_KEY);
+        if (cached == null) {
+            cached = allProjects.stream().filter(this::hasDeployExecution).collect(Collectors.toList());
+            ctx.put(PROJECTS_WITH_DEPLOY_KEY, cached);
+        }
+        return cached;
     }
 
     private boolean hasDeployExecution(Project p) {