fully automated reproducible space deterministic builds

build.gradle

@@ -1,7 +1,3 @@
-import java.util.jar.JarEntry
-import java.util.jar.JarFile
-import java.util.jar.JarOutputStream
-
 /*
  * This file is part of Baritone.
  *
@@ -103,33 +99,3 @@ jar {
     preserveFileTimestamps = false
     reproducibleFileOrder = true
 }
-
-build {
-    // while "jar" supports preserveFileTimestamps false
-    // reobfJar doesn't, it just sets all the last modified times to that instant where it runs the reobfuscator
-    // so we have to set all those last modified times back to zero
-    doLast {
-        File jarFile = new File("build/libs/baritone-" + version + ".jar")
-        JarFile jf = new JarFile(jarFile)
-        JarOutputStream jos = new JarOutputStream(new FileOutputStream(new File("temp.jar")))
-        jf.entries().unique { it.name }.sort { it.name }.each {
-            if (it.name != "META-INF/fml_cache_annotation.json" && it.name != "META-INF/fml_cache_class_versions.json") {
-                JarEntry clone = new JarEntry(it)
-                clone.time = 0
-                jos.putNextEntry(clone)
-                copy(jf.getInputStream(it), jos)
-            }
-        }
-        jos.finish()
-        jf.close()
-        file("temp.jar").renameTo(jarFile)
-    }
-}
-
-void copy(InputStream is, OutputStream os) {
-    byte[] buffer = new byte[1024]
-    int len = 0
-    while ((len = is.read(buffer)) != -1) {
-        os.write(buffer, 0, len)
-    }
-}

scripts/Determinizer.java

@@ -0,0 +1,49 @@
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.jar.JarOutputStream;
+import java.util.stream.Collectors;
+
+/**
+ * Make a .jar file deterministic by sorting all entries by name, and setting all the last modified times to 0.
+ * This makes the build 100% reproducible since the timestamp when you built it no longer affects the final file.
+ * @author leijurv
+ */
+public class Determinizer {
+
+    public static void main(String[] args) throws IOException {
+        System.out.println("Input path: " + args[0] + " Output path: " + args[1]);
+        JarFile jarFile = new JarFile(new File(args[0]));
+        JarOutputStream jos = new JarOutputStream(new FileOutputStream(new File(args[1])));
+        ArrayList<JarEntry> entries = jarFile.stream().collect(Collectors.toCollection(ArrayList::new));
+        entries.sort(Comparator.comparing(JarEntry::getName));
+        for (JarEntry entry : entries) {
+            if (entry.getName().equals("META-INF/fml_cache_annotation.json")) {
+                continue;
+            }
+            if (entry.getName().equals("META-INF/fml_cache_class_versions.json")) {
+                continue;
+            }
+            JarEntry clone = new JarEntry(entry.getName());
+            clone.setTime(0);
+            jos.putNextEntry(clone);
+            copy(jarFile.getInputStream(entry), jos);
+        }
+        jos.finish();
+        jarFile.close();
+    }
+
+    public static void copy(InputStream is, OutputStream os) throws IOException {
+        byte[] buffer = new byte[1024];
+        int len;
+        while ((len = is.read(buffer)) != -1) {
+            os.write(buffer, 0, len);
+        }
+    }
+}

scripts/build.sh

@@ -3,9 +3,17 @@ set -e # this makes the whole script fail immediately if any one of these comman
 ./gradlew build
 export VERSION=$(cat build.gradle | grep "version '" | cut -d "'" -f 2-2)
 
+cd scripts
+javac Determinizer.java
+java Determinizer ../build/libs/baritone-$VERSION.jar temp.jar
+mv temp.jar ../build/libs/baritone-$VERSION.jar
+cd ..
+
+
 wget -nv https://downloads.sourceforge.net/project/proguard/proguard/6.0/proguard6.0.3.zip
 unzip proguard6.0.3.zip 2>&1 > /dev/null
 cd build/libs
+rm -rf api.pro
 echo "-injars 'baritone-$VERSION.jar'" >> api.pro # insert current version
 cat ../../scripts/proguard.pro | grep -v "this is the rt jar" | grep -v "\-injars" >> api.pro # remove default rt jar and injar lines
 echo "-libraryjars '$(java -verbose 2>/dev/null | sed -ne '1 s/\[Opened \(.*\)\]/\1/p')'" >> api.pro # insert correct rt.jar location
@@ -16,11 +24,17 @@ cat api.pro | grep -v "this is the keep api" > standalone.pro # standalone doesn
 mkdir -p tempLibraries
 cat ../../scripts/proguard.pro | grep tempLibraries | grep .jar | cut -d "/" -f 2- | cut -d "'" -f -1 | xargs -n1 -I{} bash -c "find ~/.gradle -name {}" | tee /dev/stderr | xargs -n1 -I{} cp {} tempLibraries
 
+rm -rf ../../dist
 mkdir ../../dist
 java -jar ../../proguard6.0.3/lib/proguard.jar @api.pro
-mv Obfuscated/baritone-$VERSION.jar ../../dist/baritone-api-$VERSION.jar
+cd ../../scripts
+java Determinizer ../build/libs/Obfuscated/baritone-$VERSION.jar ../dist/baritone-api-$VERSION.jar
+cd ../build/libs
+rm -rf Obfuscated/*
 java -jar ../../proguard6.0.3/lib/proguard.jar @standalone.pro
-mv Obfuscated/baritone-$VERSION.jar ../../dist/baritone-standalone-$VERSION.jar
+cd ../../scripts
+java Determinizer ../build/libs/Obfuscated/baritone-$VERSION.jar ../dist/baritone-standalone-$VERSION.jar
+cd ../build/libs
 mv baritone-$VERSION.jar ../../dist/baritone-unoptimized-$VERSION.jar
 cd ../../dist
 shasum * | tee checksums.txt