Separate JNI glue from actual C code, move CMakeLists file

app/CMakeLists.txt

@@ -1,5 +0,0 @@
-cmake_minimum_required(VERSION 3.6)
-add_library(zipadjust SHARED src/main/jni/zipadjust.c)
-find_library(libz z)
-find_library(liblog log)
-target_link_libraries(zipadjust ${libz} ${liblog})

app/build.gradle

@@ -38,7 +38,7 @@ android {
     }
     externalNativeBuild {
         cmake {
-            path 'CMakeLists.txt'
+            path 'src/main/jni/CMakeLists.txt'
         }
     }
 }

app/src/main/jni/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.6)
+add_library(zipadjust SHARED
+                jni_glue.c
+                zipadjust.c)
+find_library(libz z)
+find_library(liblog log)
+target_link_libraries(zipadjust ${libz} ${liblog})

app/src/main/jni/jni_glue.c

@@ -0,0 +1,23 @@
+//
+// Java entry point
+//
+
+#include <jni.h>
+#include <stdlib.h>
+#include "zipadjust.h"
+
+JNIEXPORT jbyteArray JNICALL
+Java_com_topjohnwu_magisk_utils_ZipUtils_zipAdjust(JNIEnv *env, jclass type, jbyteArray jbytes, jint size) {
+    fin = (*env)->GetPrimitiveArrayCritical(env, jbytes, NULL);
+    insize = (size_t) size;
+
+    zipadjust(0);
+
+    (*env)->ReleasePrimitiveArrayCritical(env, jbytes, fin, 0);
+
+    jbyteArray ret = (*env)->NewByteArray(env, outsize);
+    (*env)->SetByteArrayRegion(env, ret, 0, outsize, (const jbyte*) fout);
+    free(fout);
+
+    return ret;
+}

app/src/main/jni/zipadjust.c

@@ -1,35 +1,16 @@
-#include <jni.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <zlib.h>
 #include <android/log.h>
+#include "zipadjust.h"
 
 #define  LOG_TAG    "zipadjust"
 
 #define  LOGD(...)  __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)
 #define  LOGE(...)  __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
 
-size_t insize, outsize = 0, alloc = 0;
+size_t insize = 0, outsize = 0, alloc = 0;
-unsigned char *fin, *fout;
+unsigned char *fin = NULL, *fout = NULL;
-
-int zipadjust(int decompress) ;
-
-JNIEXPORT jbyteArray JNICALL
-Java_com_topjohnwu_magisk_utils_ZipUtils_zipAdjust(JNIEnv *env, jclass type, jbyteArray jbytes,
-                                                   jint size) {
-    fin = (*env)->GetPrimitiveArrayCritical(env, jbytes, NULL);
-    insize = (size_t) size;
-
-    zipadjust(0);
-
-    (*env)->ReleasePrimitiveArrayCritical(env, jbytes, fin, 0);
-
-    jbyteArray ret = (*env)->NewByteArray(env, outsize);
-    (*env)->SetByteArrayRegion(env, ret, 0, outsize, (const jbyte*) fout);
-    free(fout);
-
-    return ret;
-}
 
 #pragma pack(1)
 struct local_header_struct {

app/src/main/jni/zipadjust.h

@@ -0,0 +1,9 @@
+#ifndef MAGISKMANAGER_ZIPADJUST_H_H
+#define MAGISKMANAGER_ZIPADJUST_H_H
+
+int zipadjust(int decompress);
+
+extern size_t insize, outsize, alloc;
+extern unsigned char *fin, *fout;
+
+#endif //MAGISKMANAGER_ZIPADJUST_H_H