Don't lock threads when user has specified COURSIER_PROGRESS=disable or otherwise disabled progress bars (#273)

modules/lm-coursier/src/main/scala/lmcoursier/internal/ArtifactsRun.scala

@@ -24,11 +24,6 @@ object ArtifactsRun {
       else
         ""
 
-    // Ensuring only one resolution / artifact fetching runs at a time when the logger
-    // may rely on progress bars, as two progress bar loggers can't display stuff at the
-    // same time.
-    val needsLock = params.loggerOpt.nonEmpty || !RefreshLogger.defaultFallbackMode
-
     val coursierLogger = params.loggerOpt.getOrElse {
       RefreshLogger.create(
         if (RefreshLogger.defaultFallbackMode)
@@ -45,12 +40,9 @@ object ArtifactsRun {
       )
     }
 
-    if (needsLock)
-      Lock.lock.synchronized {
-        result(params, coursierLogger)
-      }
-    else
+    Lock.maybeSynchronized(needsLock = params.loggerOpt.nonEmpty || !RefreshLogger.defaultFallbackMode){
       result(params, coursierLogger)
+    }
   }
 
   private def result(

modules/lm-coursier/src/main/scala/lmcoursier/internal/Lock.scala

@@ -1,10 +1,10 @@
 package lmcoursier.internal
 
 private[lmcoursier] object Lock {
+  private val lock = new Object
 
-  // Wrap blocks downloading stuff (resolution / artifact downloads) in lock.synchronized.
-  // Downloads are already parallel, no need to parallelize further, and this results in
-  // a clearer output.
-  val lock = new Object
-
+  /* Progress bars require us to only work on one module at the time. Without those we can go faster */
+  def maybeSynchronized[T](needsLock: Boolean)(f: => T): T =
+    if (needsLock) lock.synchronized(f)
+    else f
 }

modules/lm-coursier/src/main/scala/lmcoursier/internal/ResolutionRun.scala

@@ -137,10 +137,8 @@ object ResolutionRun {
     }
 
     SbtCoursierCache.default.resolutionOpt(params.resolutionKey).map(Right(_)).getOrElse {
-      // Let's update only one module at once, for a better output.
-      // Downloads are already parallel, no need to parallelize further, anyway.
       val resOrError =
-        Lock.lock.synchronized {
+        Lock.maybeSynchronized(needsLock = params.loggerOpt.nonEmpty || !RefreshLogger.defaultFallbackMode) {
           var map = new mutable.HashMap[Configuration, Resolution]
           val either = params.orderedConfigs.foldLeft[Either[coursier.error.ResolutionError, Unit]](Right(())) {
             case (acc, (config, extends0)) =>

modules/lm-coursier/src/main/scala/lmcoursier/internal/UpdateRun.scala

@@ -1,5 +1,6 @@
 package lmcoursier.internal
 
+import coursier.cache.loggers.RefreshLogger
 import coursier.core.Resolution.ModuleVersion
 import coursier.core._
 import coursier.util.Print
@@ -55,8 +56,7 @@ object UpdateRun {
     params: UpdateParams,
     verbosityLevel: Int,
     log: Logger
-  ): UpdateReport = Lock.lock.synchronized {
-
+  ): UpdateReport = Lock.maybeSynchronized(needsLock = !RefreshLogger.defaultFallbackMode) {
     val depsByConfig = grouped(params.dependencies)
 
     if (verbosityLevel >= 2) {