Add decompile cache rules properties. (#1217)

Closes #1206

src/main/java/net/fabricmc/loom/task/GenerateSourcesTask.java

@@ -93,6 +93,7 @@
 import net.fabricmc.loom.util.FileSystemUtil;
 import net.fabricmc.loom.util.IOStringConsumer;
 import net.fabricmc.loom.util.Platform;
+import net.fabricmc.loom.util.gradle.GradleUtils;
 import net.fabricmc.loom.util.gradle.SyncTaskBuildService;
 import net.fabricmc.loom.util.gradle.ThreadedProgressLoggerConsumer;
 import net.fabricmc.loom.util.gradle.ThreadedSimpleProgressLogger;
@@ -174,6 +175,14 @@ public abstract class GenerateSourcesTask extends AbstractLoomTask {
 	@Internal
 	protected abstract RegularFileProperty getDecompileCacheFile();
 
+	@ApiStatus.Internal
+	@Input
+	protected abstract Property<Integer> getMaxCachedFiles();
+
+	@ApiStatus.Internal
+	@Input
+	protected abstract Property<Integer> getMaxCacheFileAge();
+
 	// Injects
 	@Inject
 	protected abstract WorkerExecutor getWorkerExecutor();
@@ -238,6 +247,9 @@ public GenerateSourcesTask(DecompilerOptions decompilerOptions) {
 
 		getMappings().set(SourceMappingsService.create(getProject()));
 
+		getMaxCachedFiles().set(GradleUtils.getIntegerPropertyProvider(getProject(), Constants.Properties.DECOMPILE_CACHE_MAX_FILES).orElse(50_000));
+		getMaxCacheFileAge().set(GradleUtils.getIntegerPropertyProvider(getProject(), Constants.Properties.DECOMPILE_CACHE_MAX_AGE).orElse(90));
+
 		mustRunAfter(getProject().getTasks().withType(AbstractRemapJarTask.class));
 	}
 
@@ -273,9 +285,17 @@ public void run() throws IOException {
 			}
 
 			// TODO ensure we have a lock on this file to prevent multiple tasks from running at the same time
-			// TODO handle being unable to read the cache file
 			Files.createDirectories(cacheFile.getParent());
 
+			if (Files.exists(cacheFile)) {
+				try (FileSystemUtil.Delegate fs = FileSystemUtil.getJarFileSystem(cacheFile, true)) {
+					// Success, cache exists and can be read
+				} catch (IOException e) {
+					getLogger().warn("Discarding invalid decompile cache file: {}", cacheFile, e);
+					Files.delete(cacheFile);
+				}
+			}
+
 			try (FileSystemUtil.Delegate fs = FileSystemUtil.getJarFileSystem(cacheFile, true)) {
 				runWithCache(fs.getRoot());
 			}
@@ -289,13 +309,14 @@ private void runWithCache(Path cacheRoot) throws IOException {
 		final Path classesInputJar = getClassesInputJar().getSingleFile().toPath();
 		final Path sourcesOutputJar = getSourcesOutputJar().get().getAsFile().toPath();
 		final Path classesOutputJar = getClassesOutputJar().getSingleFile().toPath();
-		final var cacheRules = new CachedFileStoreImpl.CacheRules(50_000, Duration.ofDays(90));
+		final var cacheRules = new CachedFileStoreImpl.CacheRules(getMaxCachedFiles().get(), Duration.ofDays(getMaxCacheFileAge().get()));
 		final var decompileCache = new CachedFileStoreImpl<>(cacheRoot, CachedData.SERIALIZER, cacheRules);
 		final String cacheKey = getCacheKey();
 		final CachedJarProcessor cachedJarProcessor = new CachedJarProcessor(decompileCache, cacheKey);
 		final CachedJarProcessor.WorkRequest workRequest;
 
 		getLogger().info("Decompile cache key: {}", cacheKey);
+		getLogger().debug("Decompile cache rules: {}", cacheRules);
 
 		try (var timer = new Timer("Prepare job")) {
 			workRequest = cachedJarProcessor.prepareJob(classesInputJar);

src/main/java/net/fabricmc/loom/util/Constants.java

@@ -139,6 +139,8 @@ public static final class Properties {
 		 * Only set this when you have a good reason to do so, the default should be fine for almost all cases.
 		 */
 		public static final String RUNTIME_JAVA_COMPATIBILITY_VERSION = "fabric.loom.runtimeJavaCompatibilityVersion";
+		public static final String DECOMPILE_CACHE_MAX_FILES = "fabric.loom.decompileCacheMaxFiles";
+		public static final String DECOMPILE_CACHE_MAX_AGE = "fabric.loom.decompileCacheMaxAge";
 	}
 
 	public static final class Manifest {

src/main/java/net/fabricmc/loom/util/gradle/GradleUtils.java

@@ -86,6 +86,22 @@ public static Provider<Boolean> getBooleanPropertyProvider(Project project, Stri
 		});
 	}
 
+	public static Provider<Integer> getIntegerPropertyProvider(Project project, String key) {
+		return project.provider(() -> {
+			final Object value = project.findProperty(key);
+
+			if (value == null) {
+				return null;
+			}
+
+			try {
+				return Integer.parseInt(value.toString());
+			} catch (final NumberFormatException ex) {
+				throw new IllegalArgumentException("Property " + key + " must be an integer", ex);
+			}
+		});
+	}
+
 	public static boolean getBooleanProperty(Project project, String key) {
 		return getBooleanPropertyProvider(project, key).getOrElse(false);
 	}