* Skeleton of the privileged worker program.

* Some refactoring: put the NAR archive integer/string serialisation
  code in a separate file so it can be reused by the worker protocol
  implementation.

src/libutil/serialise.hh

@@ -0,0 +1,71 @@
+#ifndef __SERIALISE_H
+#define __SERIALISE_H
+
+#include "types.hh"
+
+
+namespace nix {
+
+
+/* Abstract destination of binary data. */
+struct Sink 
+{
+    virtual ~Sink() { }
+    virtual void operator () (const unsigned char * data, unsigned int len) = 0;
+};
+
+
+/* Abstract source of binary data. */
+struct Source
+{
+    virtual ~Source() { }
+    
+    /* The callee should store exactly *len bytes in the buffer
+       pointed to by data.  It should block if that much data is not
+       yet available, or throw an error if it is not going to be
+       available. */
+    virtual void operator () (unsigned char * data, unsigned int len) = 0;
+};
+
+
+/* A sink that writes data to a file descriptor. */
+struct FdSink : Sink
+{
+    int fd;
+
+    FdSink(int fd) 
+    {
+        this->fd = fd;
+    }
+    
+    void operator () (const unsigned char * data, unsigned int len);
+};
+
+
+/* A source that reads data from a file descriptor. */
+struct FdSource : Source
+{
+    int fd;
+
+    FdSource(int fd) 
+    {
+        this->fd = fd;
+    }
+    
+    void operator () (unsigned char * data, unsigned int len);
+};
+
+
+void writePadding(unsigned int len, Sink & sink);
+void writeInt(unsigned int n, Sink & sink);
+void writeString(const string & s, Sink & sink);
+
+void readPadding(unsigned int len, Source & source);
+unsigned int readInt(Source & source);
+string readString(Source & source);
+
+ 
+}
+
+
+#endif /* !__SERIALISE_H */