diff --git a/src/main/kotlin/app/extractors/ExtractorInterface.kt b/src/main/kotlin/app/extractors/ExtractorInterface.kt
index 1ff4d2c9..d2572990 100644
--- a/src/main/kotlin/app/extractors/ExtractorInterface.kt
+++ b/src/main/kotlin/app/extractors/ExtractorInterface.kt
@@ -12,20 +12,36 @@ import org.jpmml.evaluator.FieldValue
 import org.jpmml.evaluator.ModelEvaluatorFactory
 import org.jpmml.evaluator.ProbabilityDistribution
 import org.jpmml.model.PMMLUtil
+import java.io.InputStream
 
 interface ExtractorInterface {
     companion object {
-        fun getLibraries(name: String): Set<String> {
+        private val librariesCache = hashMapOf<String, Set<String>>()
+        private val evaluatorsCache = hashMapOf<String, Evaluator>()
+
+        private fun getResource(path: String): InputStream {
             return ExtractorInterface::class.java.classLoader
-                .getResourceAsStream("data/libraries/${name}_libraries.txt")
+                .getResourceAsStream(path)
+        }
+
+        fun getLibraries(name: String): Set<String> {
+            if (librariesCache.containsKey(name)) {
+                return librariesCache[name]!!
+            }
+            val libraries = getResource("data/libraries/${name}_libraries.txt")
                 .bufferedReader().readLines().toSet()
+            librariesCache.put(name, libraries)
+            return libraries
         }
+
         fun getLibrariesModelEvaluator(name: String): Evaluator {
-            val pmml = PMMLUtil.unmarshal(
-                           ExtractorInterface::class.java.classLoader
-                           .getResourceAsStream("data/models/$name.pmml"))
+            if (evaluatorsCache.containsKey(name)) {
+                return evaluatorsCache[name]!!
+            }
+            val pmml = PMMLUtil.unmarshal(getResource("data/models/$name.pmml"))
             val evaluator = ModelEvaluatorFactory.newInstance()
                                                  .newModelEvaluator(pmml)
+            evaluatorsCache.put(name, evaluator)
             return evaluator
         }
     }
diff --git a/src/main/kotlin/app/hashers/RepoHasher.kt b/src/main/kotlin/app/hashers/RepoHasher.kt
index 93da5055..2ce98828 100644
--- a/src/main/kotlin/app/hashers/RepoHasher.kt
+++ b/src/main/kotlin/app/hashers/RepoHasher.kt
@@ -116,10 +116,12 @@ class RepoHasher(private val localRepo: LocalRepo, private val api: Api,
         serverRepo = api.getRepo(serverRepo.rehash)
         Logger.debug("Received repo from server with " +
             serverRepo.commits.size + " commits")
+        Logger.debug(serverRepo.toString())
     }
 
     private fun postRepoToServer() {
         api.postRepo(serverRepo)
+        Logger.debug(serverRepo.toString())
     }
 
     private fun initServerRepo(initCommitRehash: String) {