idempotent change propagation

using lastModified instead of a non-idempotent needsUpdate flag
this fixes a bug where dependees would not be rebuilt if cbt exited
or was killed after dependencies were already rebuilt.

1 files changed, 75 insertions, 65 deletions

diff --git a/nailgun_launcher/EarlyDependencies.java b/nailgun_launcher/EarlyDependencies.java
index fdb54b5..8709e69 100644
--- a/nailgun_launcher/EarlyDependencies.java
+++ b/nailgun_launcher/EarlyDependencies.java
@@ -4,6 +4,7 @@ import java.io.*;
 import java.nio.file.*;
 import java.net.*;
 import java.security.*;
+import java.util.*;
 import static cbt.Stage0Lib.*;
 import static cbt.NailgunLauncher.*;
 
@@ -28,7 +29,7 @@ class EarlyDependencies{
   String scalaLibrary_2_10_6_File;
 
   public EarlyDependencies(
-    String mavenCache, String mavenUrl, JavaCache<ClassLoader> classLoaderCache, ClassLoader rootClassLoader
+    String mavenCache, String mavenUrl, ClassLoaderCache classLoaderCache, ClassLoader rootClassLoader
   ) throws Throwable {
     scalaReflect_2_11_8_File = mavenCache + "/org/scala-lang/scala-reflect/2.11.8/scala-reflect-2.11.8.jar";
     scalaCompiler_2_11_8_File = mavenCache + "/org/scala-lang/scala-compiler/2.11.8/scala-compiler-2.11.8.jar";
@@ -46,95 +47,104 @@ class EarlyDependencies{
     download(new URL(mavenUrl + "/org/scala-lang/scala-compiler/2.11.8/scala-compiler-2.11.8.jar"), Paths.get(scalaCompiler_2_11_8_File), "fe1285c9f7b58954c5ef6d80b59063569c065e9a");
 
     // org.scala-lang:scala-library:2.10.6
-    download(new URL(mavenUrl + "/org/scala-lang/scala-library/2.10.6/scala-library-2.10.6.jar"), Paths.get(scalaLibrary_2_10_6_File), "421989aa8f95a05a4f894630aad96b8c7b828732");
-
     String[] scalaLibrary_2_10_6_ClasspathArray = new String[]{scalaLibrary_2_10_6_File};
-    String scalaLibrary_2_10_6_Classpath = classpath( scalaLibrary_2_10_6_ClasspathArray );
-    ClassLoader scalaLibrary_2_10_6_ =
-      classLoaderCache.contains( scalaLibrary_2_10_6_Classpath )
-      ? classLoaderCache.get( scalaLibrary_2_10_6_Classpath )
-      : classLoaderCache.put( classLoader( scalaLibrary_2_10_6_File, rootClassLoader ), scalaLibrary_2_10_6_Classpath );
+    ClassLoader scalaLibrary_2_10_6_ = loadDependency(
+      mavenUrl + "/org/scala-lang/scala-library/2.10.6/scala-library-2.10.6.jar",
+      scalaLibrary_2_10_6_File,
+      "421989aa8f95a05a4f894630aad96b8c7b828732",
+      classLoaderCache,
+      rootClassLoader,
+      scalaLibrary_2_10_6_ClasspathArray
+    );
 
     // org.scala-lang:scala-reflect:2.10.6
-    download(new URL(mavenUrl + "/org/scala-lang/scala-reflect/2.10.6/scala-reflect-2.10.6.jar"), Paths.get(scalaReflect_2_10_6_File), "3259f3df0f166f017ef5b2d385445808398c316c");
-
     String[] scalaReflect_2_10_6_ClasspathArray = new String[]{scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    String scalaReflect_2_10_6_Classpath = classpath( scalaReflect_2_10_6_ClasspathArray );
-    ClassLoader scalaReflect_2_10_6_ =
-      classLoaderCache.contains( scalaReflect_2_10_6_Classpath )
-      ? classLoaderCache.get( scalaReflect_2_10_6_Classpath )
-      : classLoaderCache.put( classLoader( scalaReflect_2_10_6_File, scalaLibrary_2_10_6_ ), scalaReflect_2_10_6_Classpath );
+    ClassLoader scalaReflect_2_10_6_ = loadDependency(
+      mavenUrl + "/org/scala-lang/scala-reflect/2.10.6/scala-reflect-2.10.6.jar",
+      scalaReflect_2_10_6_File,
+      "3259f3df0f166f017ef5b2d385445808398c316c",
+      classLoaderCache,
+      scalaLibrary_2_10_6_,
+      scalaReflect_2_10_6_ClasspathArray
+    );
 
     // com.typesafe.sbt:sbt-interface:0.13.12
-    download(new URL(mavenUrl + "/com/typesafe/sbt/sbt-interface/0.13.12/sbt-interface-0.13.12.jar"), Paths.get(sbtInterface_0_13_12_File), "fcc7875c02f0d4641fac0518121bd71475d3909b");
-
     String[] sbtInterface_0_13_12_ClasspathArray = new String[]{sbtInterface_0_13_12_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    String sbtInterface_0_13_12_Classpath = classpath( sbtInterface_0_13_12_ClasspathArray );
-    ClassLoader sbtInterface_0_13_12_ =
-      classLoaderCache.contains( sbtInterface_0_13_12_Classpath )
-      ? classLoaderCache.get( sbtInterface_0_13_12_Classpath )
-      : classLoaderCache.put( classLoader( sbtInterface_0_13_12_File, scalaReflect_2_10_6_ ), sbtInterface_0_13_12_Classpath );
+    ClassLoader sbtInterface_0_13_12_ = loadDependency(
+      mavenUrl + "/com/typesafe/sbt/sbt-interface/0.13.12/sbt-interface-0.13.12.jar",
+      sbtInterface_0_13_12_File,
+      "fcc7875c02f0d4641fac0518121bd71475d3909b",
+      classLoaderCache,
+      scalaReflect_2_10_6_,
+      sbtInterface_0_13_12_ClasspathArray
+    );
 
     // org.scala-lang:scala-compiler:2.10.6
-    download(new URL(mavenUrl + "/org/scala-lang/scala-compiler/2.10.6/scala-compiler-2.10.6.jar"), Paths.get(scalaCompiler_2_10_6_File), "9b15174852f5b6bb1edbf303d5722286a0a54011");
-
     String[] scalaCompiler_2_10_6_ClasspathArray = new String[]{sbtInterface_0_13_12_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    String scalaCompiler_2_10_6_Classpath = classpath( scalaCompiler_2_10_6_ClasspathArray );
-    ClassLoader scalaCompiler_2_10_6_ =
-      classLoaderCache.contains( scalaCompiler_2_10_6_Classpath )
-      ? classLoaderCache.get( scalaCompiler_2_10_6_Classpath )
-      : classLoaderCache.put( classLoader( scalaCompiler_2_10_6_File, sbtInterface_0_13_12_ ), scalaCompiler_2_10_6_Classpath );
+    ClassLoader scalaCompiler_2_10_6_ = loadDependency(
+      mavenUrl + "/org/scala-lang/scala-compiler/2.10.6/scala-compiler-2.10.6.jar",
+      scalaCompiler_2_10_6_File,
+      "9b15174852f5b6bb1edbf303d5722286a0a54011",
+      classLoaderCache,
+      sbtInterface_0_13_12_,
+      scalaCompiler_2_10_6_ClasspathArray
+    );
 
     // com.typesafe.sbt:compiler-interface:0.13.12
-    download(new URL(mavenUrl + "/com/typesafe/sbt/compiler-interface/0.13.12/compiler-interface-0.13.12-sources.jar"), Paths.get(compilerInterface_0_13_12_File), "d9c3270576e162bf017b146af262364c2db87a32");
-
     String[] compilerInterface_0_13_12_ClasspathArray = new String[]{compilerInterface_0_13_12_File, sbtInterface_0_13_12_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    String compilerInterface_0_13_12_Classpath = classpath( compilerInterface_0_13_12_ClasspathArray );
-    ClassLoader compilerInterface_0_13_12_ =
-      classLoaderCache.contains( compilerInterface_0_13_12_Classpath )
-      ? classLoaderCache.get( compilerInterface_0_13_12_Classpath )
-      : classLoaderCache.put( classLoader( compilerInterface_0_13_12_File, scalaCompiler_2_10_6_ ), compilerInterface_0_13_12_Classpath );
+    ClassLoader compilerInterface_0_13_12_ = loadDependency(
+      mavenUrl + "/com/typesafe/sbt/compiler-interface/0.13.12/compiler-interface-0.13.12-sources.jar",
+      compilerInterface_0_13_12_File,
+      "d9c3270576e162bf017b146af262364c2db87a32",
+      classLoaderCache,
+      scalaCompiler_2_10_6_,
+      compilerInterface_0_13_12_ClasspathArray
+    );
 
     // com.typesafe.sbt:incremental-compiler:0.13.12
-    download(new URL(mavenUrl + "/com/typesafe/sbt/incremental-compiler/0.13.12/incremental-compiler-0.13.12.jar"), Paths.get(incrementalCompiler_0_13_12_File), "259f6d24a5a3791bb233787d6a8e639c4ab86fe5");
-
     String[] incrementalCompiler_0_13_12_ClasspathArray = new String[]{compilerInterface_0_13_12_File, incrementalCompiler_0_13_12_File, sbtInterface_0_13_12_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    String incrementalCompiler_0_13_12_Classpath = classpath( incrementalCompiler_0_13_12_ClasspathArray );
-    ClassLoader incrementalCompiler_0_13_12_ =
-      classLoaderCache.contains( incrementalCompiler_0_13_12_Classpath )
-      ? classLoaderCache.get( incrementalCompiler_0_13_12_Classpath )
-      : classLoaderCache.put( classLoader( incrementalCompiler_0_13_12_File, compilerInterface_0_13_12_ ), incrementalCompiler_0_13_12_Classpath );
+    ClassLoader incrementalCompiler_0_13_12_ = loadDependency(
+      mavenUrl + "/com/typesafe/sbt/incremental-compiler/0.13.12/incremental-compiler-0.13.12.jar",
+      incrementalCompiler_0_13_12_File,
+      "259f6d24a5a3791bb233787d6a8e639c4ab86fe5",
+      classLoaderCache,
+      compilerInterface_0_13_12_,
+      incrementalCompiler_0_13_12_ClasspathArray
+    );
 
     // com.typesafe.zinc:zinc:0.3.12
-    download(new URL(mavenUrl + "/com/typesafe/zinc/zinc/0.3.12/zinc-0.3.12.jar"), Paths.get(zinc_0_3_12_File), "c4339e93f5b7273f49ad026248f4fdb1d4d6c7c4");
-
     String[] zinc_0_3_12_ClasspathArray = new String[]{compilerInterface_0_13_12_File, incrementalCompiler_0_13_12_File, sbtInterface_0_13_12_File, zinc_0_3_12_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    String zinc_0_3_12_Classpath = classpath( zinc_0_3_12_ClasspathArray );
-    ClassLoader zinc_0_3_12_ =
-      classLoaderCache.contains( zinc_0_3_12_Classpath )
-      ? classLoaderCache.get( zinc_0_3_12_Classpath )
-      : classLoaderCache.put( classLoader( zinc_0_3_12_File, incrementalCompiler_0_13_12_ ), zinc_0_3_12_Classpath );
+    ClassLoader zinc_0_3_12_ = loadDependency(
+      mavenUrl + "/com/typesafe/zinc/zinc/0.3.12/zinc-0.3.12.jar",
+      zinc_0_3_12_File,
+      "c4339e93f5b7273f49ad026248f4fdb1d4d6c7c4",
+      classLoaderCache,
+      incrementalCompiler_0_13_12_,
+      zinc_0_3_12_ClasspathArray
+    );
 
     // org.scala-lang:scala-library:2.11.8
-    download(new URL(mavenUrl + "/org/scala-lang/scala-library/2.11.8/scala-library-2.11.8.jar"), Paths.get(scalaLibrary_2_11_8_File), "ddd5a8bced249bedd86fb4578a39b9fb71480573");
-
     String[] scalaLibrary_2_11_8_ClasspathArray = new String[]{scalaLibrary_2_11_8_File};
-    String scalaLibrary_2_11_8_Classpath = classpath( scalaLibrary_2_11_8_ClasspathArray );
-    ClassLoader scalaLibrary_2_11_8_ =
-      classLoaderCache.contains( scalaLibrary_2_11_8_Classpath )
-      ? classLoaderCache.get( scalaLibrary_2_11_8_Classpath )
-      : classLoaderCache.put( classLoader( scalaLibrary_2_11_8_File, rootClassLoader ), scalaLibrary_2_11_8_Classpath );
+    ClassLoader scalaLibrary_2_11_8_ = loadDependency(
+      mavenUrl + "/org/scala-lang/scala-library/2.11.8/scala-library-2.11.8.jar",
+      scalaLibrary_2_11_8_File,
+      "ddd5a8bced249bedd86fb4578a39b9fb71480573",
+      classLoaderCache,
+      rootClassLoader,
+      scalaLibrary_2_11_8_ClasspathArray
+    );
 
     // org.scala-lang.modules:scala-xml_2.11:1.0.5
-    download(new URL(mavenUrl + "/org/scala-lang/modules/scala-xml_2.11/1.0.5/scala-xml_2.11-1.0.5.jar"), Paths.get(scalaXml_1_0_5_File), "77ac9be4033768cf03cc04fbd1fc5e5711de2459");
-
     String[] scalaXml_1_0_5_ClasspathArray = new String[]{scalaXml_1_0_5_File, scalaLibrary_2_11_8_File};
-    String scalaXml_1_0_5_Classpath = classpath( scalaXml_1_0_5_ClasspathArray );
-    ClassLoader scalaXml_1_0_5_ =
-      classLoaderCache.contains( scalaXml_1_0_5_Classpath )
-      ? classLoaderCache.get( scalaXml_1_0_5_Classpath )
-      : classLoaderCache.put( classLoader( scalaXml_1_0_5_File, scalaLibrary_2_11_8_ ), scalaXml_1_0_5_Classpath );
-  
+    ClassLoader scalaXml_1_0_5_ = loadDependency(
+      mavenUrl + "/org/scala-lang/modules/scala-xml_2.11/1.0.5/scala-xml_2.11-1.0.5.jar",
+      scalaXml_1_0_5_File,
+      "77ac9be4033768cf03cc04fbd1fc5e5711de2459",
+      classLoaderCache,
+      scalaLibrary_2_11_8_,
+      scalaXml_1_0_5_ClasspathArray
+    );
+
     classLoader = scalaXml_1_0_5_;
     classpathArray = scalaXml_1_0_5_ClasspathArray;