handle sparse files more efficiently

[rsync/rsync.git] / io.c

diff --git a/io.c b/io.c
index 1b2fb22..95177c4 100644 (file)
--- a/io.c
+++ b/io.c
@@ -237,45 +237,66 @@ static int last_sparse;
 
 int sparse_end(int f)
 {
-  if (last_sparse) {
-    lseek(f,-1,SEEK_CUR);
-    return (write(f,&last_byte,1) == 1 ? 0 : -1);
-  }
-  last_sparse = 0;
-  return 0;
+       if (last_sparse) {
+               lseek(f,-1,SEEK_CUR);
+               return (write(f,&last_byte,1) == 1 ? 0 : -1);
+       }
+       last_sparse = 0;
+       return 0;
 }
 
-int write_sparse(int f,char *buf,int len)
+
+static int write_sparse(int f,char *buf,int len)
 {
-  int l1=0,l2=0;
-  int ret;
+       int l1=0,l2=0;
+       int ret;
 
-  if (!sparse_files) 
-    return write(f,buf,len);
+       for (l1=0;l1<len && buf[l1]==0;l1++) ;
+       for (l2=0;l2<(len-l1) && buf[len-(l2+1)]==0;l2++) ;
 
-  for (l1=0;l1<len && buf[l1]==0;l1++) ;
-  for (l2=0;l2<(len-l1) && buf[len-(l2+1)]==0;l2++) ;
+       last_byte = buf[len-1];
 
-  last_byte = buf[len-1];
+       if (l1 == len || l2 > 0)
+               last_sparse=1;
 
-  if (l1 == len || l2 > 0)
-    last_sparse=1;
+       if (l1 > 0)
+               lseek(f,l1,SEEK_CUR);  
 
-  if (l1 > 0)
-    lseek(f,l1,SEEK_CUR);  
+       if (l1 == len) 
+               return len;
 
-  if (l1 == len) 
-    return len;
+       if ((ret=write(f,buf+l1,len-(l1+l2))) != len-(l1+l2)) {
+               if (ret == -1 || ret == 0) return ret;
+               return (l1+ret);
+       }
 
-  if ((ret=write(f,buf+l1,len-(l1+l2))) != len-(l1+l2)) {
-    if (ret == -1 || ret == 0) return ret;
-    return (l1+ret);
-  }
+       if (l2 > 0)
+               lseek(f,l2,SEEK_CUR);
+       
+       return len;
+}
+
+
+
+int write_file(int f,char *buf,int len)
+{
+       int ret = 0;
 
-  if (l2 > 0)
-    lseek(f,l2,SEEK_CUR);
+       if (!sparse_files) 
+               return write(f,buf,len);
 
-  return len;
+       while (len>0) {
+               int len1 = MIN(len, SPARSE_WRITE_SIZE);
+               int r1 = write_sparse(f, buf, len1);
+               if (r1 <= 0) {
+                       if (ret > 0) return ret;
+                       return r1;
+               }
+               len -= r1;
+               buf += r1;
+               ret += r1;
+       }
+       return ret;
 }