Fixes #1721/#1763. Cached resolution: summarize callers in graph.json

- On some of the builds graph.json is reaching 250MB+
- JSON parsing alone takes hours
- 97% of the content are caller info
- This change summarizes all callers into one (zero caller would have
correctness issues)

ivy/src/main/scala/sbt/JsonUtil.scala

@@ -25,8 +25,34 @@ private[sbt] object JsonUtil {
     }
   def toLite(ur: UpdateReport): UpdateReportLite =
     UpdateReportLite(ur.configurations map { cr =>
-      ConfigurationReportLite(cr.configuration, cr.details)
+      ConfigurationReportLite(cr.configuration, cr.details map { oar =>
+        new OrganizationArtifactReport(oar.organization, oar.name, oar.modules map { mr =>
+          new ModuleReport(
+            mr.module, mr.artifacts, mr.missingArtifacts, mr.status,
+            mr.publicationDate, mr.resolver, mr.artifactResolver,
+            mr.evicted, mr.evictedData, mr.evictedReason,
+            mr.problem, mr.homepage, mr.extraAttributes,
+            mr.isDefault, mr.branch, mr.configurations, mr.licenses,
+            summarizeCallers(mr.callers))
+        })
+      })
     })
+  // #1763/#2030. Caller takes up 97% of space, so we need to shrink it down,
+  // but there are semantics associated with some of them.
+  def summarizeCallers(callers: Seq[Caller]): Seq[Caller] =
+    if (callers.isEmpty) callers
+    else {
+      // Use the first element to represent all callers
+      val head = callers.head
+      val caller = new Caller(
+        head.caller, head.callerConfigurations, head.callerExtraAttributes,
+        callers exists { _.isForceDependency },
+        callers exists { _.isChangingDependency },
+        callers exists { _.isTransitiveDependency },
+        callers exists { _.isDirectlyForceDependency })
+      Seq(caller)
+    }
+
   def fromLite(lite: UpdateReportLite, cachedDescriptor: File): UpdateReport =
     {
       val stats = new UpdateStats(0L, 0L, 0L, false)

ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala

@@ -25,7 +25,7 @@ private[sbt] object CachedResolutionResolveCache {
   def createID(organization: String, name: String, revision: String) =
     ModuleRevisionId.newInstance(organization, name, revision)
   def sbtOrgTemp = "org.scala-sbt.temp"
-  def graphVersion = "0.13.8"
+  def graphVersion = "0.13.9"
 }
 
 private[sbt] class CachedResolutionResolveCache() {