Use File (if available) when sending data to remote build cache

Author: vlsi

src/main/kotlin/ch/myniva/gradle/caching/s3/internal/AwsS3BuildCacheService.kt

@@ -199,12 +199,18 @@ class AwsS3BuildCacheService internal constructor(
         }
         metadata?.appendTo(meta.userMetadata)
         try {
-            val stream = ByteArrayInputStream(
-                ByteArrayOutputStream()
-                    .also { os -> writer.writeTo(os) }
-                    .toByteArray()
+            val request = writer.file()?.let {
+                // If file is avaliable, use it directly
+                PutObjectRequest(bucketName, bucketPath, it)
+            } ?: PutObjectRequest(
+                bucketName, bucketPath,
+                ByteArrayInputStream(
+                    ByteArrayOutputStream()
+                        .also { os -> writer.writeTo(os) }
+                        .toByteArray()
+                ), meta
             )
-            val request = PutObjectRequest(bucketName, bucketPath, stream, meta)
+            request.metadata = meta
             if (reducedRedundancy) {
                 request.withStorageClass(StorageClass.ReducedRedundancy)
             }

src/main/kotlin/ch/myniva/gradle/caching/s3/internal/BuildCacheEntryWriterExtensions.kt

@@ -0,0 +1,13 @@
+package ch.myniva.gradle.caching.s3.internal
+
+import org.gradle.caching.BuildCacheEntryWriter
+import java.io.File
+
+fun BuildCacheEntryWriter.file(): File? = try {
+    this::class.java.getDeclaredField("file").run {
+        isAccessible = true
+        get(this@file) as? File
+    }
+} catch(ignore: Throwable) {
+    null
+}

src/main/kotlin/ch/myniva/gradle/caching/s3/internal/MetadataReader.kt

@@ -47,14 +47,10 @@ fun CacheEntryMetadata(map: Map<String, String>) = CacheEntryMetadata(
     gradleVersion = map["gradleVersion"]
 )
 
-fun BuildCacheEntryWriter.readBuildMetadata(): CacheEntryMetadata? {
-    try {
-        val file =
-            this::class.java.getDeclaredField("file").get(this) as? File ?: return null
-        return file.readBuildMetadata()
-    } catch (ignore: Throwable) {
-    }
-    return null
+fun BuildCacheEntryWriter.readBuildMetadata(): CacheEntryMetadata? = try {
+    file()?.readBuildMetadata()
+} catch (ignore: Throwable) {
+    null
 }
 
 fun File.readBuildMetadata(): CacheEntryMetadata? {