readNBytes impl

src/main/kotlin/ru/dbotthepony/kstarbound/io/StarboundPak.kt

@@ -7,6 +7,7 @@ import java.io.BufferedInputStream
 import java.io.Closeable
 import java.io.DataInputStream
 import java.io.File
+import java.io.IOError
 import java.io.IOException
 import java.io.InputStream
 import java.io.RandomAccessFile
@@ -101,6 +102,25 @@ class StarboundPak(val path: File, callback: (finished: Boolean, status: String)
 					return reader.read()
 				}
 
+				override fun readNBytes(len: Int): ByteArray {
+					require(len >= 0) { "Negative length to read: $len" }
+
+					val readMax = len.coerceAtMost((length - innerOffset).toInt())
+
+					if (readMax == 0)
+						return ByteArray(0)
+
+					val b = ByteArray(readMax)
+					reader.seek(innerOffset + offset)
+					val readBytes = reader.read(b)
+
+					if (readBytes != readMax)
+						throw IOError(RuntimeException("Reading $readMax bytes returned only $readBytes bytes"))
+
+					innerOffset += readBytes
+					return b
+				}
+
 				override fun read(b: ByteArray, off: Int, len: Int): Int {
 					Objects.checkFromIndexSize(off, len, b.size)
 
@@ -116,9 +136,8 @@ class StarboundPak(val path: File, callback: (finished: Boolean, status: String)
 					reader.seek(innerOffset + offset)
 					val readBytes = reader.read(b, off, readMax)
 
-					if (readBytes == -1) {
+					if (readBytes == -1)
 						throw RuntimeException("Unexpected EOF, want to read $readMax bytes from starting $offset in $path")
-					}
 
 					innerOffset += readBytes
 					return readBytes