Java 8: computeIfAbsent()

jenkinsci · Feb 21, 2019 · 1eaeae9 · 1eaeae9
1 parent 9213e6f
commit 1eaeae9
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Showing 6 changed files with 7 additions and 25 deletions.
diff --git a/core/src/main/java/hudson/model/DependencyGraph.java b/core/src/main/java/hudson/model/DependencyGraph.java
@@ -334,11 +334,7 @@ private Set<AbstractProject> getTransitive(Map<AbstractProject, List<DependencyG
     }
 
     private void add(Map<AbstractProject, List<DependencyGroup>> map, AbstractProject key, Dependency dep) {
-        List<DependencyGroup> set = map.get(key);
-        if(set==null) {
-            set = new ArrayList<>();
-            map.put(key,set);
-        }
+        List<DependencyGroup> set = map.computeIfAbsent(key, k -> new ArrayList<>());
         for (DependencyGroup d : set) {
             // Check for existing edge that connects the same two projects:
             if (d.getUpstreamProject() == dep.getUpstreamProject() && d.getDownstreamProject() == dep.getDownstreamProject()) {

diff --git a/core/src/main/java/hudson/model/RunnerStack.java b/core/src/main/java/hudson/model/RunnerStack.java
@@ -42,8 +42,7 @@ final class RunnerStack {
 
     synchronized void push(RunExecution r) {
         Executor e = Executor.currentExecutor();
-        Stack<RunExecution> s = stack.get(e);
-        if(s==null) stack.put(e,s= new Stack<>());
+        Stack<RunExecution> s = stack.computeIfAbsent(e, k -> new Stack<>());
         s.push(r);
     }
 

diff --git a/core/src/main/java/hudson/model/queue/MappingWorksheet.java b/core/src/main/java/hudson/model/queue/MappingWorksheet.java
@@ -325,9 +325,7 @@ public MappingWorksheet(BuildableItem item, List<? extends ExecutorSlot> offers,
         Map<Computer,List<ExecutorSlot>> j = new HashMap<>();
         for (ExecutorSlot o : offers) {
             Computer c = o.getExecutor().getOwner();
-            List<ExecutorSlot> l = j.get(c);
-            if (l==null)
-                j.put(c,l= new ArrayList<>());
+            List<ExecutorSlot> l = j.computeIfAbsent(c, k -> new ArrayList<>());
             l.add(o);
         }
 
@@ -378,9 +376,7 @@ public MappingWorksheet(BuildableItem item, List<? extends ExecutorSlot> offers,
             Object c = meu.getSameNodeConstraint();
             if (c==null)    c = new Object();
 
-            List<SubTask> l = m.get(c);
-            if (l==null)
-                m.put(c,l= new ArrayList<>());
+            List<SubTask> l = m.computeIfAbsent(c, k -> new ArrayList<>());
             l.add(meu);
         }
 

diff --git a/core/src/main/java/hudson/tools/InstallerTranslator.java b/core/src/main/java/hudson/tools/InstallerTranslator.java
@@ -58,10 +58,7 @@ public String getToolHome(Node node, ToolInstallation tool, TaskListener log) th
             if (installer.appliesTo(node)) {
                 Semaphore semaphore;
                 synchronized (mutexByNode) {
-                    Map<ToolInstallation, Semaphore> mutexByTool = mutexByNode.get(node);
-                    if (mutexByTool == null) {
-                        mutexByNode.put(node, mutexByTool = new WeakHashMap<>());
-                    }
+                    Map<ToolInstallation, Semaphore> mutexByTool = mutexByNode.computeIfAbsent(node, k -> new WeakHashMap<>());
                     semaphore = mutexByTool.get(tool);
                     if (semaphore == null) {
                         mutexByTool.put(tool, semaphore = new Semaphore(1));

diff --git a/core/src/main/java/hudson/util/QueryParameterMap.java b/core/src/main/java/hudson/util/QueryParameterMap.java
@@ -61,9 +61,7 @@ public QueryParameterMap(String queryString) {
                 String[] kv = param.split("=");
                 String key = URLDecoder.decode(kv[0], "UTF-8");
                 String value = URLDecoder.decode(kv[1], "UTF-8");
-                List<String> values = store.get(key);
-                if (values == null)
-                    store.put(key, values = new ArrayList<>());
+                List<String> values = store.computeIfAbsent(key, k -> new ArrayList<>());
                 values.add(value);
             }
         } catch (UnsupportedEncodingException e) {

diff --git a/core/src/main/java/jenkins/triggers/ReverseBuildTrigger.java b/core/src/main/java/jenkins/triggers/ReverseBuildTrigger.java
@@ -266,11 +266,7 @@ private Map<Job,Collection<ReverseBuildTrigger>> calculateCache() {
                         if (upstream instanceof AbstractProject && downstream instanceof AbstractProject) {
                             continue; // handled specially
                         }
-                        Collection<ReverseBuildTrigger> triggers = result.get(upstream);
-                        if (triggers == null) {
-                            triggers = new LinkedList<>();
-                            result.put(upstream, triggers);
-                        }
+                        Collection<ReverseBuildTrigger> triggers = result.computeIfAbsent(upstream, k -> new LinkedList<>());
                         triggers.remove(trigger);
                         triggers.add(trigger);
                     }