minilzo使用流程

 /* testmini.c -- very simple test program for the miniLZO library

    This file is part of the LZO real-time data compression library.

    Copyright (C) 1996-2017 Markus Franz Xaver Johannes Oberhumer
    All Rights Reserved.

    The LZO library is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of
    the License, or (at your option) any later version.

    The LZO library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with the LZO library; see the file COPYING.
    If not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

    Markus F.X.J. Oberhumer
    <markus@oberhumer.com>
    http://www.oberhumer.com/opensource/lzo/
  */

 #include <stdio.h>
 #include <stdlib.h>

 /*************************************************************************
 // This program shows the basic usage of the LZO library.
 // We will compress a block of data and decompress again.
 //
 // For more information, documentation, example programs and other support
 // files (like Makefiles and build scripts) please download the full LZO
 // package from
 //    http://www.oberhumer.com/opensource/lzo/
 **************************************************************************/

 /* First let's include "minizo.h". */

 #include "minilzo.h"

 /* We want to compress the data block at 'in' with length 'IN_LEN' to
  * the block at 'out'. Because the input block may be incompressible,
  * we must provide a little more output space in case that compression
  * is not possible.
  */

 #define IN_LEN      (128*1024ul)
 #define OUT_LEN     (IN_LEN + IN_LEN / 16 + 64 + 3)

 static unsigned char __LZO_MMODEL in  [ IN_LEN ];
 static unsigned char __LZO_MMODEL out [ OUT_LEN ];

 /* Work-memory needed for compression. Allocate memory in units
  * of 'lzo_align_t' (instead of 'char') to make sure it is properly aligned.
  */

 #define HEAP_ALLOC(var,size) \
     lzo_align_t __LZO_MMODEL var [ ((size) + (sizeof(lzo_align_t) - )) / sizeof(lzo_align_t) ]

 static HEAP_ALLOC(wrkmem, LZO1X_1_MEM_COMPRESS);

 /*************************************************************************
 //
 **************************************************************************/

 int main(int argc, char *argv[])
 {
     int r;
     lzo_uint in_len;
     lzo_uint out_len;
     lzo_uint new_len;

     if (argc <  && argv == NULL)   /* avoid warning about unused args */
         return ;

     printf("\nLZO real-time data compression library (v%s, %s).\n",
            lzo_version_string(), lzo_version_date());
     printf("Copyright (C) 1996-2017 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n");

 /*
  * 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");
         return ;
     }

 /*
  * Step 2: prepare the input block that will get compressed.
  *         We just fill it with zeros in this example program,
  *         but you would use your real-world data here.
  */
     in_len = IN_LEN;
     lzo_memset(in,,in_len);

 /*
  * Step 3: compress from 'in' to 'out' with LZO1X-1
  */
     r = lzo1x_1_compress(in,in_len,out,&out_len,wrkmem);
     if (r == LZO_E_OK)
         printf("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);
         return ;
     }
     /* check for an incompressible block */
     if (out_len >= in_len)
     {
         printf("This block contains incompressible data.\n");
         return ;
     }

 /*
  * Step 4: decompress again, now going from 'out' to 'in'
  */
     new_len = in_len;
     r = lzo1x_decompress(out,out_len,in,&new_len,NULL);
     if (r == LZO_E_OK && new_len == in_len)
         printf("decompressed %lu bytes back into %lu bytes\n",
             (unsigned long) out_len, (unsigned long) in_len);
     else
     {
         /* this should NEVER happen */
         printf("internal error - decompression failed: %d\n", r);
         return ;
     }

     printf("\nminiLZO simple compression test passed.\n");
     return ;
 }

 /* vim:set ts=4 sw=4 et: */

testmini.c

首先需要准备好数组，然后知道长度。

第一步：初始化LZO库

    if (lzo_init() != LZO_E_OK) {
        ...
    }

lzo_init

第二步：清空数组，准备存放的缓存

    in_len = IN_LEN;
    lzo_memset(in,,in_len);

lzo_memset

第三步：压缩后数据放入缓存中

    r = lzo1x_1_compress(in,in_len,out,&out_len,wrkmem);
    if (r == LZO_E_OK)
        printf("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);
        return ;
    }

    /* check for an incompressible block */
    if (out_len >= in_len) {
        printf("This block contains incompressible data.\n");
        return ;
    }

lzo1x_1_compress