安卓实现miniLzo压缩算法

LZO官方源码

http://www.oberhumer.com/opensource/lzo

找到miniLZO点击Dowload miniLZO下载源码

http://www.oberhumer.com/opensource/lzo/download/minilzo-2.10.tar.gz

demo源码(包含安卓)

https://github.com/xzw421771880/MiniLzo_Mobile.git

1.代码部分

1.1.测试用例

public void lzo_compress_decompress(){String ss = "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF";System.out.println("原16进制数据"+ss);//原数据字节流格式byte[] bytes = hexStr2ByteArr(ss);//开始压缩bytes = JNITools.lzo_compress(bytes);System.out.println("Lzo压缩后16进制数据"+byteTobyteStr(bytes));//开始解压bytes = JNITools.lzo_decompress(bytes);System.out.println("Lzo解压后16进制数据"+byteTobyteStr(bytes));
}

1.2实现流程

1.2.1.新建工程(参考源码中名为minilzo的moudle)

1.2.2.在src/main目录下新建文件jni

1.2.3.将从lzo官方下载的文件中（lzoconf.h,lzodefs.h,minilzo.h,minilzo.c）放入jni文件

1.2.4.新建jnitools.c文件(或者直接复制)

1.2.5.引入相关文件头

#include <jni.h>
#include <android/log.h>
#include <stdio.h>
#include <stdlib.h>#include "minilzo.h"#define IN_LEN      (128*1024ul)
#define OUT_LEN     (IN_LEN + IN_LEN / 16 + 64 + 3)#define LOG_TAG "MyTag"static unsigned char __LZO_MMODEL in1  [ IN_LEN ];
static unsigned char __LZO_MMODEL out1 [ OUT_LEN ];#define HEAP_ALLOC(var,size) \lzo_align_t __LZO_MMODEL var [ ((size) + (sizeof(lzo_align_t) - 1)) / sizeof(lzo_align_t) ]static HEAP_ALLOC(wrkmem, LZO1X_1_MEM_COMPRESS);

1.2.6.实现压缩

jbyteArray compress(JNIEnv *env,jclass clazz,jbyteArray a){//将jbyteArray转成jbyte *格式jsize length = (*env)->GetArrayLength(env,a);jbyte *bytes = (*env)->GetByteArrayElements(env,a, NULL);//将jbyte *格式转成unsigned char *unsigned char *unsignedChars = (unsigned char *)malloc(length * sizeof(unsigned char));memcpy(unsignedChars, bytes, length * sizeof(unsigned char));(*env)->ReleaseByteArrayElements(env,a, bytes, 0);//执行lzo压缩int length1 = lzo_compress1(unsignedChars, (int )length);jbyteArray jArray = (*env)->NewByteArray(env, length1);// 复制数据从cArray到jArray(*env)->SetByteArrayRegion(env, jArray, 0, length1, (jbyte*)out1);//释放内存
//    (*env)->ReleaseByteArrayElements(env,a, bytes, 0);
//    free(unsignedChars);return jArray;
}int  lzo_compress1(unsigned char * data,int datalen)
{
//    __android_log_print(ANDROID_LOG_DEBUG, "JNITag", "datalen-%d",datalen);int r;lzo_uint in_len;lzo_uint out_len;/** Step 1: initialize the LZO library*/if (lzo_init() != LZO_E_OK){printf("internal error - lzo_init() failed !!!\n");printf("(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable '-DLZO_DEBUG' for diagnostics)\n");}in_len = IN_LEN;in_len = datalen;//    lzo_memset(in,0,in_len);
//    in = data;//    unsigned char __LZO_MMODEL newout [ OUT_LEN ];printf("out----%s\n",out1);//__android_log_print(ANDROID_LOG_DEBUG, "JNITag", "out0---%s",out1);r = lzo1x_1_compress(data,datalen,out1,&out_len,wrkmem);//__android_log_print(ANDROID_LOG_DEBUG, "JNITag", "out1---%s",out1);//    printf("out----%s\n",out1);if (r == LZO_E_OK){printf("compressed %lu bytes into %lu bytes\n",(unsigned long) in_len, (unsigned long) out_len);__android_log_print(ANDROID_LOG_DEBUG, "JNITag", "compressed %lu bytes into %lu bytes\n",(unsigned long) in_len, (unsigned long) out_len);}else{/* this should NEVER happen */printf("internal error - compression failed: %d\n", r);__android_log_print(ANDROID_LOG_DEBUG, "JNITag", "internal error - compression failed: %d\n", r);}/* check for an incompressible block */
//    if (out_len >= in_len)
//    {
//        printf("This block contains incompressible data.\n");
//        return 0;
//    }
//    unsigned char *a = lzo_decompress(out,in, out_len);return out_len;
}

1.2.7.实现解压

jbyteArray decompress(JNIEnv *env,jclass clazz,jbyteArray a){//将jbyteArray转成jbyte *格式jsize length = (*env)->GetArrayLength(env,a);jbyte *bytes = (*env)->GetByteArrayElements(env,a, NULL);//将jbyte *格式转成unsigned char *unsigned char *unsignedChars = (unsigned char *)malloc(length * sizeof(unsigned char));memcpy(unsignedChars, bytes, length * sizeof(unsigned char));(*env)->ReleaseByteArrayElements(env,a, bytes, 0);//执行lzo解压int length1 = lzo_decompress1(unsignedChars, (int )length);jbyteArray jArray = (*env)->NewByteArray(env, length1);// 复制数据从cArray到jArray(*env)->SetByteArrayRegion(env, jArray, 0, length1, (jbyte*)in1);//释放内存
//    (*env)->ReleaseByteArrayElements(env,a, bytes, 0);
//    free(unsignedChars);return jArray;
}int lzo_decompress1(unsigned char * data,int datalen)
{int r;lzo_uint out_len;if (lzo_init() != LZO_E_OK){printf("internal error - lzo_init() failed !!!\n");printf("(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable '-DLZO_DEBUG' for diagnostics)\n");}out_len = 0;//    printf("%s",in1);r = lzo1x_decompress(data,datalen,in1,&out_len,NULL);
//    printf("%s",in);
//    printf("%s",in1);if (r == LZO_E_OK)printf("decompressed %lu bytes back into %lu bytes\n",(unsigned long) datalen, (unsigned long) out_len);else{/* this should NEVER happen */printf("internal error - decompression failed: %d\n", r);}return out_len;
}

1.2.8.java部分（新建JNItools）

public class JNITools {static {System.loadLibrary("jnidemo");}//加法public static native byte[] lzo_compress(byte[] a);public static native byte[] lzo_decompress(byte[] a);
}