moving core bsdiff logic out of main and into a new function bsdiff

diff --git a/bsdiff.c b/bsdiff.c
index 150a7f7..35aa742 100644 (file)
--- a/bsdiff.c
+++ b/bsdiff.c
@@ -193,11 +193,8 @@ static void offtout(off_t x,u_char *buf)
        if(x<0) buf[7]|=0x80;
 }
 
-int main(int argc,char *argv[])
+int bsdiff(u_char* old, off_t oldsize, u_char* new, off_t newsize, FILE* pf)
 {
-       int fd;
-       u_char *old,*new;
-       off_t oldsize,newsize;
        off_t *I,*V;
        off_t scan,pos,len;
        off_t lastscan,lastpos,lastoffset;
@@ -209,20 +206,9 @@ int main(int argc,char *argv[])
        u_char *db,*eb;
        u_char buf[8];
        u_char header[32];
-       FILE * pf;
        BZFILE * pfbz2;
        int bz2err;
 
-       if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
-
-       /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
-               that we never try to malloc(0) and get a NULL pointer */
-       if(((fd=open(argv[1],O_RDONLY,0))<0) ||
-               ((oldsize=lseek(fd,0,SEEK_END))==-1) ||
-               ((old=malloc(oldsize+1))==NULL) ||
-               (lseek(fd,0,SEEK_SET)!=0) ||
-               (read(fd,old,oldsize)!=oldsize) ||
-               (close(fd)==-1)) err(1,"%s",argv[1]);
 
        if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) ||
                ((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL);
@@ -230,25 +216,11 @@ int main(int argc,char *argv[])
        qsufsort(I,V,old,oldsize);
 
        free(V);
-
-       /* Allocate newsize+1 bytes instead of newsize bytes to ensure
-               that we never try to malloc(0) and get a NULL pointer */
-       if(((fd=open(argv[2],O_RDONLY,0))<0) ||
-               ((newsize=lseek(fd,0,SEEK_END))==-1) ||
-               ((new=malloc(newsize+1))==NULL) ||
-               (lseek(fd,0,SEEK_SET)!=0) ||
-               (read(fd,new,newsize)!=newsize) ||
-               (close(fd)==-1)) err(1,"%s",argv[2]);
-
        if(((db=malloc(newsize+1))==NULL) ||
                ((eb=malloc(newsize+1))==NULL)) err(1,NULL);
        dblen=0;
        eblen=0;
 
-       /* Create the patch file */
-       if ((pf = fopen(argv[3], "w")) == NULL)
-               err(1, "%s", argv[3]);
-
        /* Header is
                0       8        "BSDIFF40"
                8       8       length of bzip2ed ctrl block
@@ -264,7 +236,7 @@ int main(int argc,char *argv[])
        offtout(0, header + 16);
        offtout(newsize, header + 24);
        if (fwrite(header, 32, 1, pf) != 1)
-               err(1, "fwrite(%s)", argv[3]);
+               err(1, "fwrite(%s)", "patch");
 
        /* Compute the differences, writing ctrl as we go */
        if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
@@ -389,14 +361,55 @@ int main(int argc,char *argv[])
        if (fseeko(pf, 0, SEEK_SET))
                err(1, "fseeko");
        if (fwrite(header, 32, 1, pf) != 1)
-               err(1, "fwrite(%s)", argv[3]);
-       if (fclose(pf))
-               err(1, "fclose");
+               err(1, "fwrite(%s)", "patch");
 
        /* Free the memory we used */
        free(db);
        free(eb);
        free(I);
+
+       return 0;
+}
+
+int main(int argc,char *argv[])
+{
+       int fd;
+       u_char *old,*new;
+       off_t oldsize,newsize;
+       FILE * pf;
+
+       if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
+
+       /* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
+               that we never try to malloc(0) and get a NULL pointer */
+       if(((fd=open(argv[1],O_RDONLY,0))<0) ||
+               ((oldsize=lseek(fd,0,SEEK_END))==-1) ||
+               ((old=malloc(oldsize+1))==NULL) ||
+               (lseek(fd,0,SEEK_SET)!=0) ||
+               (read(fd,old,oldsize)!=oldsize) ||
+               (close(fd)==-1)) err(1,"%s",argv[1]);
+
+
+       /* Allocate newsize+1 bytes instead of newsize bytes to ensure
+               that we never try to malloc(0) and get a NULL pointer */
+       if(((fd=open(argv[2],O_RDONLY,0))<0) ||
+               ((newsize=lseek(fd,0,SEEK_END))==-1) ||
+               ((new=malloc(newsize+1))==NULL) ||
+               (lseek(fd,0,SEEK_SET)!=0) ||
+               (read(fd,new,newsize)!=newsize) ||
+               (close(fd)==-1)) err(1,"%s",argv[2]);
+
+       /* Create the patch file */
+       if ((pf = fopen(argv[3], "w")) == NULL)
+               err(1, "%s", argv[3]);
+
+       if (bsdiff(old, oldsize, new, newsize, pf))
+               err(1, "bsdiff");
+
+       if (fclose(pf))
+               err(1, "fclose");
+
+       /* Free the memory we used */
        free(old);
        free(new);