proxy: DRY up some code

src/ioutil.h

@@ -1,13 +1,23 @@
 #ifndef __IOUTIL_H
 #define __IOUTIL_H
 
+#include <sys/types.h>
+struct iobuf {
+	unsigned char *buf;
+	size_t size;
+	size_t needle;
+};
+
+ssize_t iobuf_read( int fd, struct iobuf* iobuf, size_t default_size );
+ssize_t iobuf_write( int fd, struct iobuf* iobuf );
+
 #include "serve.h"
 struct bitset_mapping; /* don't need whole of bitset.h here */
 
 /** Scan the file opened in ''fd'', set bits in ''allocation_map''  that
   * correspond to which blocks are physically allocated on disc (or part-
-  * allocated).  If the OS represents allocated blocks at a finer resolution 
-  * than you've asked for, any block or part block will count as "allocated" 
+  * allocated).  If the OS represents allocated blocks at a finer resolution
+  * than you've asked for, any block or part block will count as "allocated"
   * with the corresponding bit set.  Returns 1 if successful, 0 otherwise.
   */
 int build_allocation_map(struct bitset_mapping* allocation_map, int fd);