Add legacy cache support to DiskStoreZipWriter

Signed-off-by: Graham <gpe@openrs2.org>

cache/src/main/kotlin/org/openrs2/cache/DiskStoreZipWriter.kt

@@ -30,10 +30,12 @@ public class DiskStoreZipWriter(
     private val prefix: String = "cache/",
     level: Int = Deflater.BEST_COMPRESSION,
     timestamp: Instant = Instant.EPOCH,
-    private val alloc: ByteBufAllocator = ByteBufAllocator.DEFAULT
+    private val alloc: ByteBufAllocator = ByteBufAllocator.DEFAULT,
+    legacy: Boolean = false
 ) : Store {
     private data class IndexEntry(val len: Int, val block: Int)
 
+    private val archiveOffset = if (legacy) 1 else 0
     private val timestamp = FileTime.from(timestamp)
     private val indexes = arrayOfNulls<Int2ObjectSortedMap<IndexEntry>>(Store.MAX_ARCHIVE + 1)
     private val zeroBlock = ByteArray(DiskStore.BLOCK_SIZE)
@@ -45,7 +47,13 @@ public class DiskStoreZipWriter(
 
         out.putNextEntry(createZipEntry(""))
 
-        out.putNextEntry(createZipEntry("main_file_cache.dat2"))
+        val dataFile = if (legacy) {
+            "main_file_cache.dat"
+        } else {
+            "main_file_cache.dat2"
+        }
+
+        out.putNextEntry(createZipEntry(dataFile))
         out.write(zeroBlock)
     }
 
@@ -136,7 +144,7 @@ public class DiskStoreZipWriter(
                     tempBuf.writeMedium(0)
                 }
 
-                tempBuf.writeByte(archive)
+                tempBuf.writeByte(archive + archiveOffset)
                 tempBuf.readBytes(out, tempBuf.readableBytes())
 
                 // write data

cache/src/test/kotlin/org/openrs2/cache/DiskStoreZipWriterTest.kt

@@ -89,14 +89,13 @@ class DiskStoreZipWriterTest {
         }
     }
 
-    @Test
-    fun testWrite() {
+    private fun testWrite(expected: String, legacy: Boolean) {
         Jimfs.newFileSystem(Configuration.forCurrentPlatform()).use { fs ->
             val actual = fs.rootDirectories.first().resolve("zip")
             Files.createDirectories(actual)
 
             Files.newOutputStream(actual.resolve("cache.zip")).use { out ->
-                DiskStoreZipWriter(ZipOutputStream(out)).use { store ->
+                DiskStoreZipWriter(ZipOutputStream(out), legacy = legacy).use { store ->
                     store.create(0)
 
                     copiedBuffer("OpenRS2").use { buf ->
@@ -113,10 +112,20 @@ class DiskStoreZipWriterTest {
                 }
             }
 
-            assertTrue(ROOT.recursiveEquals(actual))
+            assertTrue(ROOT.resolve(expected).recursiveEquals(actual))
         }
     }
 
+    @Test
+    fun testWrite() {
+        testWrite("cache", legacy = false)
+    }
+
+    @Test
+    fun testWriteLegacy() {
+        testWrite("cache-legacy", legacy = true)
+    }
+
     private companion object {
         private val ROOT = Path.of(DiskStoreZipWriterTest::class.java.getResource("disk-store-zip").toURI())
     }