Switch to zlib-ng

zlib-ng boasts higher throughput than regular zlib, by combining patches
from Cloudflare, zlib, and ARM's improvements to zlib along with a more
modern codebase.

Profiling consistently shows that compression is the largest CPU expense
by far, so even a minor speed-up here is significant.

.gitignore

@@ -84,4 +84,8 @@ logs/
 server-icon.png
 /bin/
 run/
-plugins/
+plugins/
+
+### Natives stuff ###
+natives/mbedtls
+natives/zlib-ng

native/compile-linux.sh

@@ -1,10 +1,21 @@
 #!/bin/bash
 
+if [ ! -d zlib-ng ]; then
+  echo "Cloning zlib-ng..."
+  git clone https://github.com/zlib-ng/zlib-ng.git
+fi
+
+echo "Compiling zlib-ng..."
+cd zlib-ng
+CFLAGS="-fPIC -O3" ./configure --zlib-compat --static
+make clean && make
+cd ..
+
 # Modify as you need.
 MBEDTLS_ROOT=mbedtls
 CFLAGS="-O3 -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/ -fPIC -shared"
-gcc $CFLAGS -lz src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
-    src/main/c/jni_zlib_common.c -o src/main/resources/linux_x64/velocity-compress.so
+gcc $CFLAGS -Izlib-ng src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
+    src/main/c/jni_zlib_common.c zlib-ng/libz.a  -o src/main/resources/linux_x64/velocity-compress.so
 gcc $CFLAGS  -I $MBEDTLS_ROOT/include -shared $MBEDTLS_ROOT/library/aes.c $MBEDTLS_ROOT/library/aesni.c \
     $MBEDTLS_ROOT/library/platform.c $MBEDTLS_ROOT/library/platform_util.c src/main/c/jni_util.c src/main/c/jni_cipher.c \
     -o src/main/resources/linux_x64/velocity-cipher.so

native/compile-osx.sh

@@ -1,12 +1,23 @@
 #!/bin/bash
 
+if [ ! -d zlib-ng ]; then
+  echo "Cloning zlib-ng..."
+  git clone https://github.com/zlib-ng/zlib-ng.git
+fi
+
+echo "Compiling zlib-ng..."
+cd zlib-ng
+CFLAGS="-fPIC -O3" ./configure --zlib-compat --static
+make clean && make
+cd ..
+
 # Modify as you need.
 MBEDTLS_ROOT=mbedtls
 export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home
 CFLAGS="-O3 -I$JAVA_HOME/include/ -I$JAVA_HOME/include/darwin/ -fPIC -shared"
 
-clang $CFLAGS -lz src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
-    src/main/c/jni_zlib_common.c -o src/main/resources/macosx/velocity-compress.dylib
+clang $CFLAGS -Izlib-ng src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
+    src/main/c/jni_zlib_common.c zlib-ng/libz.a -o src/main/resources/macosx/velocity-compress.dylib
 clang $CFLAGS -I $MBEDTLS_ROOT/include -shared $MBEDTLS_ROOT/library/aes.c $MBEDTLS_ROOT/library/aesni.c \
     $MBEDTLS_ROOT/library/platform.c $MBEDTLS_ROOT/library/platform_util.c src/main/c/jni_util.c src/main/c/jni_cipher.c \
     -o src/main/resources/macosx/velocity-cipher.dylib

native/src/main/c/jni_zlib_common.c

@@ -8,7 +8,7 @@ void JNICALL
 check_zlib_free(JNIEnv *env, z_stream *stream, bool deflate)
 {
     int ret = deflate ? deflateEnd(stream) : inflateEnd(stream);
-    char *msg = stream->msg;
+    const char *msg = stream->msg;
     free((void*) stream);
 
     switch (ret) {

native/src/main/c/jni_zlib_deflate.c

@@ -33,7 +33,7 @@ Java_com_velocitypowered_natives_compression_NativeZlibDeflate_init(JNIEnv *env,
     if (ret == Z_OK) {
         return (jlong) stream;
     } else {
-        char *zlib_msg = stream->msg;
+        const char *zlib_msg = stream->msg;
         free(stream);
         switch (ret) {
             case Z_MEM_ERROR:

native/src/main/c/jni_zlib_inflate.c

@@ -32,7 +32,7 @@ Java_com_velocitypowered_natives_compression_NativeZlibInflate_init(JNIEnv *env,
     if (ret == Z_OK) {
         return (jlong) stream;
     } else {
-        char *zlib_msg = stream->msg;
+        const char *zlib_msg = stream->msg;
         free(stream);
         switch (ret) {
             case Z_MEM_ERROR: