Improves Zstd and Zip handling

build.gradle.kts

@@ -20,7 +20,7 @@ plugins {
 
 allprojects {
     group = "in.dragonbra"
-    version = "1.8.0"
+    version = "1.8.1-SNAPSHOT"
 }
 
 repositories {

src/main/java/in/dragonbra/javasteam/util/VZipUtil.kt

@@ -6,7 +6,7 @@ import `in`.dragonbra.javasteam.util.stream.BinaryReader
 import `in`.dragonbra.javasteam.util.stream.MemoryStream
 import `in`.dragonbra.javasteam.util.stream.SeekOrigin
 import org.tukaani.xz.LZMAInputStream
-import java.util.zip.*
+import java.util.zip.DataFormatException
 import kotlin.math.max
 
 @Suppress("SpellCheckingInspection", "unused")
@@ -21,11 +21,6 @@ object VZipUtil {
 
     private const val VERSION: Byte = 'a'.code.toByte()
 
-    // Thread-local window buffer pool to avoid repeated allocations
-    private val windowBufferPool = ThreadLocal.withInitial {
-        ByteArray(1 shl 23) // 8MB max size
-    }
-
     @JvmStatic
     fun decompress(ms: MemoryStream, destination: ByteArray, verifyChecksum: Boolean = true): Int {
         try {
@@ -67,12 +62,7 @@ object VZipUtil {
 
                 // If the value of dictionary size in properties is smaller than (1 << 12),
                 // the LZMA decoder must set the dictionary size variable to (1 << 12).
-                val windowSize = max(1 shl 12, dictionarySize)
-                val windowBuffer = if (windowSize <= (1 shl 23)) {
-                    windowBufferPool.get() // Reuse thread-local buffer
-                } else {
-                    ByteArray(windowSize) // Fallback for unusually large windows
-                }
+                val windowBuffer = ByteArray(max(1 shl 12, dictionarySize))
                 val bytesRead = LZMAInputStream(
                     ms,
                     sizeDecompressed.toLong(),

src/main/java/in/dragonbra/javasteam/util/VZstdUtil.kt

@@ -1,14 +1,16 @@
 package `in`.dragonbra.javasteam.util
 
-import com.github.luben.zstd.Zstd
+import com.github.luben.zstd.ZstdInputStream
 import `in`.dragonbra.javasteam.util.log.LogManager
+import java.io.ByteArrayInputStream
 import java.io.IOException
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 
 object VZstdUtil {
 
     private const val VZSTD_HEADER: Int = 0x615A5356
+    private const val STREAM_CHUNK_SIZE = 64 * 1024 // 64KB chunks
     private const val HEADER_SIZE = 8
     private const val FOOTER_SIZE = 15
 
@@ -53,13 +55,31 @@ object VZstdUtil {
             throw IllegalArgumentException("The destination buffer is smaller than the decompressed data size.")
         }
 
-        val compressedData = buffer.copyOfRange(HEADER_SIZE, buffer.size - FOOTER_SIZE) // :( allocations
-
         try {
-            val bytesDecompressed = Zstd.decompress(destination, compressedData)
+            // Use streaming decompression to avoid long JNI critical locks
+            var totalDecompressed = 0
+
+            // Use direct ByteArrayInputStream with offset to avoid copying compressed data
+            ByteArrayInputStream(buffer, HEADER_SIZE, buffer.size - FOOTER_SIZE).use { byteStream ->
+                ZstdInputStream(byteStream).use { zstdStream ->
+                    var bytesRead: Int
+                    var offset = 0
+
+                    // Read in chunks to break up JNI locks
+                    while (offset < sizeDecompressed) {
+                        val toRead = minOf(STREAM_CHUNK_SIZE, sizeDecompressed - offset)
+                        bytesRead = zstdStream.read(destination, offset, toRead)
+
+                        if (bytesRead == -1) break
+
+                        offset += bytesRead
+                        totalDecompressed += bytesRead
+                    }
+                }
+            }
 
-            if (bytesDecompressed != sizeDecompressed.toLong()) {
-                throw IOException("Failed to decompress Zstd (expected $sizeDecompressed bytes, got $bytesDecompressed).")
+            if (totalDecompressed != sizeDecompressed) {
+                throw IOException("Failed to decompress Zstd (expected $sizeDecompressed bytes, got $totalDecompressed).")
             }
 
             if (verifyChecksum) {