Add `gzip` and `ungzip`

mirai-core/src/androidMain/kotlin/net/mamoe/mirai/utils/platformAndroid.kt

@@ -21,6 +21,8 @@ import java.io.InputStream
 import java.net.Inet4Address
 import java.security.MessageDigest
 import java.util.zip.Deflater
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
 import java.util.zip.Inflater
 
 
@@ -63,6 +65,7 @@ actual object MiraiPlatformUtils {
         }
     }
 
+
     actual fun md5(data: ByteArray, offset: Int, length: Int): ByteArray {
         data.checkOffsetAndLength(offset, length)
         return MessageDigest.getInstance("MD5").apply { update(data, offset, length) }.digest()
@@ -99,4 +102,18 @@ actual object MiraiPlatformUtils {
             block(read)
         }
     }
+
+    actual fun gzip(data: ByteArray, offset: Int, length: Int): ByteArray {
+        ByteArrayOutputStream().use { buf ->
+            GZIPOutputStream(buf).use { gzip ->
+                data.inputStream(offset, length).use { t -> t.copyTo(gzip) }
+            }
+            buf.flush()
+            return buf.toByteArray()
+        }
+    }
+
+    actual fun ungzip(data: ByteArray, offset: Int, length: Int): ByteArray {
+        return GZIPInputStream(data.inputStream(offset, length)).use { it.readBytes() }
+    }
 }
\ No newline at end of file

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/platform.kt

@@ -30,6 +30,10 @@ expect object MiraiPlatformUtils {
 
     fun zip(data: ByteArray, offset: Int = 0, length: Int = data.size - offset): ByteArray
 
+    fun gzip(data: ByteArray, offset: Int = 0, length: Int = data.size - offset): ByteArray
+
+    fun ungzip(data: ByteArray, offset: Int = 0, length: Int = data.size - offset): ByteArray
+
 
     fun md5(data: ByteArray, offset: Int = 0, length: Int = data.size - offset): ByteArray
 

mirai-core/src/commonTest/kotlin/net/mamoe/mirai/utils/PlatformUtilsTest.kt

@@ -14,11 +14,16 @@ import net.mamoe.mirai.utils.io.encodeToString
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
+@OptIn(MiraiInternalAPI::class)
 internal class PlatformUtilsTest {
 
-    @OptIn(MiraiInternalAPI::class)
     @Test
     fun testZip() {
         assertEquals("test", MiraiPlatformUtils.unzip(MiraiPlatformUtils.zip("test".toByteArray())).encodeToString())
     }
+
+    @Test
+    fun testGZip() {
+        assertEquals("test", MiraiPlatformUtils.ungzip(MiraiPlatformUtils.gzip("test".toByteArray())).encodeToString())
+    }
 }
\ No newline at end of file

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/utils/PlatformUtilsJvm.kt

@@ -22,6 +22,8 @@ import java.io.OutputStream
 import java.net.Inet4Address
 import java.security.MessageDigest
 import java.util.zip.Deflater
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
 import java.util.zip.Inflater
 
 /**
@@ -64,6 +66,20 @@ actual object MiraiPlatformUtils {
         }
     }
 
+    actual fun gzip(data: ByteArray, offset: Int, length: Int): ByteArray {
+        ByteArrayOutputStream().use { buf ->
+            GZIPOutputStream(buf).use { gzip ->
+                data.inputStream(offset, length).use { t -> t.copyTo(gzip) }
+            }
+            buf.flush()
+            return buf.toByteArray()
+        }
+    }
+
+    actual fun ungzip(data: ByteArray, offset: Int, length: Int): ByteArray {
+        return GZIPInputStream(data.inputStream(offset, length)).use { it.readBytes() }
+    }
+
     actual fun md5(data: ByteArray, offset: Int, length: Int): ByteArray {
         data.checkOffsetAndLength(offset, length)
         return MessageDigest.getInstance("MD5").apply { update(data, offset, length) }.digest()