Add gzip compression support.

Any paths ending in ".gz" will atomatically be compressed on write, and decompressed on read.

Author: LexManos

build.gradle

@@ -31,7 +31,8 @@ dependencies {
     //endregion
 
     //region Testing
-    testImplementation libs.bundles.junit
+    testImplementation libs.junit.api
+    testRuntimeOnly libs.bundles.junit.runtime
     testImplementation libs.powermock
     //endregion
 }

settings.gradle

@@ -22,10 +22,11 @@ dependencyResolutionManagement {
         //endregion
 
         //region Testing
-        version 'junit', '5.10.1'
-        library 'junit',        'org.junit.jupiter', 'junit-jupiter'        versionRef 'junit'
-        library 'junit-engine', 'org.junit.jupiter', 'junit-jupiter-engine' versionRef 'junit'
-        bundle 'junit', ['junit', 'junit-engine']
+        version 'junit', '5.10.2'
+        library 'junit-api',               'org.junit.jupiter',  'junit-jupiter-api'       versionRef 'junit'
+        library 'junit-engine',            'org.junit.jupiter',  'junit-jupiter-engine'    versionRef 'junit'
+        library 'junit-platform-launcher', 'org.junit.platform', 'junit-platform-launcher' version    '1.10.2'
+        bundle 'junit-runtime', ['junit-engine', 'junit-platform-launcher']
 
         library 'powermock', 'org.powermock', 'powermock-core' version '2.0.9'
         //endregion

src/main/java/net/minecraftforge/srgutils/IMappingFile.java

@@ -14,10 +14,13 @@
 import java.util.Collection;
 import java.util.Locale;
 import java.util.Map;
+import java.util.zip.GZIPInputStream;
 
 public interface IMappingFile {
     public static IMappingFile load(File path) throws IOException {
         try (InputStream in = new FileInputStream(path)) {
+            if (path.getName().endsWith(".gz"))
+                return load(new GZIPInputStream(in));
             return load(in);
         }
     }

src/main/java/net/minecraftforge/srgutils/INamedMappingFile.java

@@ -9,13 +9,16 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Path;
-import java.util.List;
+import java.util.List;
+import java.util.zip.GZIPInputStream;
 
 import net.minecraftforge.srgutils.IMappingFile.Format;
 
 public interface INamedMappingFile {
     public static INamedMappingFile load(File path) throws IOException {
-        try (InputStream in = new FileInputStream(path)) {
+        try (InputStream in = new FileInputStream(path)) {
+            if (path.getName().endsWith(".gz"))
+                return load(new GZIPInputStream(in));
             return load(in);
         }
     }

src/main/java/net/minecraftforge/srgutils/MappingFile.java

@@ -6,6 +6,9 @@
 
 import java.io.BufferedWriter;
 import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -19,6 +22,7 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.zip.GZIPOutputStream;
 
 import net.minecraftforge.srgutils.InternalUtils.Element;
 import org.jetbrains.annotations.Nullable;
@@ -159,10 +163,15 @@ public void write(Path path, Format format, boolean reversed) throws IOException
         }
 
         Files.createDirectories(path.getParent());
-        try (BufferedWriter writer = Files.newBufferedWriter(path)) {
-            for (String line : lines) {
-                writer.write(line);
-                writer.write('\n');
+        try (OutputStream fos = Files.newOutputStream(path)) {
+            OutputStream out = fos;
+            if (path.getFileName().toString().endsWith(".gz"))
+                out = new GZIPOutputStream(out);
+            try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8))) {
+                for (String line : lines) {
+                    writer.write(line);
+                    writer.write('\n');
+                }
             }
         }
     }

src/main/java/net/minecraftforge/srgutils/NamedMappingFile.java

@@ -6,6 +6,9 @@
 
 import java.io.BufferedWriter;
 import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -20,6 +23,7 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Matcher;
 import java.util.stream.Stream;
+import java.util.zip.GZIPOutputStream;
 
 import net.minecraftforge.srgutils.IMappingFile.Format;
 import org.jetbrains.annotations.Nullable;
@@ -123,10 +127,15 @@ public void write(Path path, Format format, String... order) throws IOException
         }
 
         Files.createDirectories(path.getParent());
-        try (BufferedWriter writer = Files.newBufferedWriter(path)) {
-            for (String line : lines) {
-                writer.write(line);
-                writer.write('\n');
+        try (OutputStream fos = Files.newOutputStream(path)) {
+            OutputStream out = fos;
+            if (path.getFileName().toString().endsWith(".gz"))
+                out = new GZIPOutputStream(out);
+            try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8))) {
+                for (String line : lines) {
+                    writer.write(line);
+                    writer.write('\n');
+                }
             }
         }
     }

src/test/java/net/minecraftforge/srgutils/test/MappingTest.java

@@ -3,7 +3,8 @@
  * SPDX-License-Identifier: LGPL-2.1-only
  */
 package net.minecraftforge.srgutils.test;
-
+
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
@@ -169,7 +170,6 @@ void tinyV2NamedTest(INamedMappingFile named, String left, String right) {
     void tinyV2OptionalAndLVs() throws IOException {
         INamedMappingFile named = INamedMappingFile.load(getStream("./tiny_v2_09_2024_edition.tiny"));
         assertIterableEquals(Arrays.asList("source", "same", "rename"), named.getNames());
-
     }
     */
 
@@ -191,5 +191,46 @@ void tsrg2NamedWriteReordered() throws IOException {
             lines,
             "Invalid ordering"
         );
+    }
+
+    @Test
+    void testCompression() throws IOException {
+        final String compressable = "easilyCompressableAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        byte[] stringData = ("cls " + compressable).getBytes(StandardCharsets.UTF_8);
+
+        IMappingFile map = IMappingFile.load(new ByteArrayInputStream(stringData));
+
+        Path path = temp.resolve("map.tsrg.gz");
+        map.write(path, Format.TSRG2, false);
+
+        byte[] fileData = Files.readAllBytes(path);
+        assertTrue(fileData.length < stringData.length, "Expected the file data to be compressed, was not");
+
+        IMappingFile read = IMappingFile.load(path.toFile());
+        IMappingFile.IClass cls = read.getClass("cls");
+        assertNotNull(cls, "Expected to find \"cls\" mapping");
+
+        assertEquals(compressable, cls.getMapped());
+    }
+
+    @Test
+    void testNamedCompression() throws IOException {
+        final String compressable = "easilyCompressableAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        byte[] stringData = ("cls " + compressable).getBytes(StandardCharsets.UTF_8);
+
+        INamedMappingFile map = INamedMappingFile.load(new ByteArrayInputStream(stringData));
+
+        Path path = temp.resolve("map.tsrg.gz");
+        map.write(path, Format.TSRG2, "left", "right");
+
+        byte[] fileData = Files.readAllBytes(path);
+        assertTrue(fileData.length < stringData.length, "Expected the file data to be compressed, was not");
+
+        INamedMappingFile named = INamedMappingFile.load(path.toFile());
+        IMappingFile read = named.getMap("left", "right");
+        IMappingFile.IClass cls = read.getClass("cls");
+        assertNotNull(cls, "Expected to find \"cls\" mapping");
+
+        assertEquals(compressable, cls.getMapped());
     }
 }