bsdiff的编译与使用

bsdiff是一个差异包比较工具,可以用来实现增量更新.

下载地址:http://www.daemonology.net/bsdiff

编译

Mac环境

版本：macOS 10.12

1.解压下载的bsdiff-4.3.tar.gz

tar -zxvf bsdiff-4.3.tar.gz

2.进入bsdiff-4.3目录，在终端下执行构建

cd bsdiff-4.3

make

此时报错： Makefile:13: *** missing separator.  Stop.

这是makefile文件的内容的格式不对，修改Makefile文件，修改后的文件内容如下：

CFLAGS        +=    -O3 -lbz2

PREFIX        ?=    /usr/local
INSTALL_PROGRAM    ?=    ${INSTALL} -c -s -m
INSTALL_MAN    ?=    ${INSTALL} -c -m 

all:        bsdiff bspatch
bsdiff:        bsdiff.c
bspatch:    bspatch.c

install:
    ${INSTALL_PROGRAM} bsdiff bspatch ${PREFIX}/bin
    .ifndef WITHOUT_MAN
    ${INSTALL_MAN} bsdiff. bspatch. ${PREFIX}/man/man1
    .endif

即.ifndef WITHOUT_MAN，.endi语句f前面加TAB键进行缩进

然后再执行make，此时又报错：

bspatch.c::: error: unknown type name 'u_char'; did you mean 'char'?
static off_t offtin(u_char *buf)
                    ^~~~~~
                    char
bspatch.c::: error: expected ';' after expression
        u_char header[],buf[];
              ^
              ;
bspatch.c::: error: use of undeclared identifier 'u_char'; did you mean 'putchar'?
        u_char header[],buf[];
        ^~~~~~
        putchar
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10..sdk/usr/include/stdio.h::: note:
      'putchar' declared here
int      putchar(int);
         ^
bspatch.c::: error: use of undeclared identifier 'header'
        u_char header[],buf[];
               ^
bspatch.c::: error: use of undeclared identifier 'buf'
        u_char header[],buf[];
                          ^
bspatch.c::: error: use of undeclared identifier 'u_char'; did you mean 'putchar'?
        u_char *old, *new;
        ^~~~~~
        putchar
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10..sdk/usr/include/stdio.h::: note:
      'putchar' declared here
int      putchar(int);
         ^
bspatch.c::: error: use of undeclared identifier 'old'
        u_char *old, *new;
                ^
bspatch.c::: error: use of undeclared identifier 'new'
        u_char *old, *new;
                      ^
bspatch.c::: error: use of undeclared identifier 'header'
        if (fread(header, , , f) < ) {
                  ^
bspatch.c::: error: use of undeclared identifier 'header'
        if (memcmp(header, "BSDIFF40", ) != )
                   ^
bspatch.c::: error: use of undeclared identifier 'header'
        bzctrllen=offtin(header+);
                         ^
bspatch.c::: error: use of undeclared identifier 'header'
        bzdatalen=offtin(header+);
                         ^
bspatch.c::: error: use of undeclared identifier 'header'
        newsize=offtin(header+);
                       ^
bspatch.c::: error: use of undeclared identifier 'old'
                ((old=malloc(oldsize+))==NULL) ||
                  ^
bspatch.c::: error: use of undeclared identifier 'old'
                (read(fd,old,oldsize)!=oldsize) ||
                         ^
bspatch.c::: error: use of undeclared identifier 'new'
        if((new=malloc(newsize+))==NULL) err(,NULL);
            ^
bspatch.c::: error: use of undeclared identifier 'buf'
                        lenread = BZ2_bzRead(&cbz2err, cpfbz2, buf, );
                                                               ^
bspatch.c::: error: use of undeclared identifier 'buf'
                        ctrl[i]=offtin(buf);
                                       ^
bspatch.c::: error: use of undeclared identifier 'new'
                lenread = BZ2_bzRead(&dbz2err, dpfbz2, new + newpos, ctrl[]);
                                                       ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
 errors generated.
make: *** [bspatch] Error 

在bspatch.c文件中加入#include <sys/types.h>

然后再执行make命令，此时命令执行成功，会在当前目录下生成bsdiff,bspatch文件

Ubuntu

版本：15.04

在终端执行sudo apt-get install bsdiff,执行完成后可以在/usr/bin目录下找到bsdiff,bspatch文件

OpenSUSE

版本：SUSE 11 SP4

1.解压下载的bsdiff-4.3.tar.gz

tar -zxvf bsdiff-4.3.tar.gz

2.进入bsdiff-4.3目录，在终端下执行构建

cd bsdiff-4.3

make

此时报错： Makefile:13: *** missing separator.  Stop.

这是makefile文件的内容的格式不对，修改Makefile文件，修改后的文件内容如下：

CFLAGS        +=    -O3 -lbz2

PREFIX        ?=    /usr/local
INSTALL_PROGRAM    ?=    ${INSTALL} -c -s -m 555
INSTALL_MAN    ?=    ${INSTALL} -c -m 444

all:        bsdiff bspatch
bsdiff:        bsdiff.c
bspatch:    bspatch.c

install:
    ${INSTALL_PROGRAM} bsdiff bspatch ${PREFIX}/bin
    .ifndef WITHOUT_MAN
    ${INSTALL_MAN} bsdiff.1 bspatch.1 ${PREFIX}/man/man1
    .endif

接着编译,结果报错,找不到 bzlib.h头文件，这是由于bsdiff,bspatch依赖bzip2,下载bzip2,地址：http://www.bzip.org/downloads.html，然后执行以下命令

tar zxvf bzip2-1.0.6.tar.gz

cd bzip2-1.0.6
make
sudo make install

然后再编译bsdiff,出现以下信息：

修改Makefile, 修改后如下：

CC=gcc
LDFLAGS=
CFLAGS        +=    -O3 -lbz2

PREFIX        ?=    /usr/local
INSTALL_PROGRAM    ?=    cp
INSTALL_MAN    ?=    cp

all:        bsdiff bspatch
bsdiff:        bsdiff.c
    $(CC) bsdiff.c  $(CFLAGS) $(LDFLAGS) -o  bsdiff
bspatch:    bspatch.c
    $(CC) bspatch.c  $(CFLAGS) $(LDFLAGS) -o  bspatch
install:
    ${INSTALL_PROGRAM} bsdiff bspatch ${PREFIX}/bin
    ${INSTALL_MAN} bsdiff. bspatch. ${PREFIX}/man/man1

然后再编译，安装就可以了

使用

生成差异文件，常用于服务端生成差异包

bsdiff oldfile newfile patchfile

oldfile: 旧的文件

newfile:新的文件

patchfile:生成的差异文件

合并文件，常用于客户端根据差异包合并生成新的文件

bspatch oldfile newfile2 patchfile

oldfile:旧的文件

newfile2:生成的新的文件

patchfile:差异文件

举个例子，测试一下使用bsdiff进行增量更新

./bsdiff old.apk new.apk old-new.patch

./bspatch old.apk new2.apk old-new.patch

md5 new.apk

MD5 (new.apk) = fc8bdb15f80abef22eb25f9601063cf0

md5 new2.apk

MD5 (new2.apk) = fc8bdb15f80abef22eb25f9601063cf0

此时new.apk和new2.apk的md5值是一致的