1 files changed, 67 insertions, 22 deletions

diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 6a6f028aa652..892ec4aa36de 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -1,16 +1,23 @@
 #pragma once
 
 #include "types.hh"
+#include "util.hh"
 
 
 namespace nix {
 
 
 /* Abstract destination of binary data. */
-struct Sink 
+struct Sink
 {
     virtual ~Sink() { }
     virtual void operator () (const unsigned char * data, size_t len) = 0;
+    virtual bool good() { return true; }
+
+    void operator () (const std::string & s)
+    {
+        (*this)((const unsigned char *) s.data(), s.size());
+    }
 };
 
 
@@ -24,10 +31,15 @@ struct BufferedSink : Sink
         : bufSize(bufSize), bufPos(0), buffer(0) { }
     ~BufferedSink();
 
-    void operator () (const unsigned char * data, size_t len);
-    
+    void operator () (const unsigned char * data, size_t len) override;
+
+    void operator () (const std::string & s)
+    {
+        Sink::operator()(s);
+    }
+
     void flush();
-    
+
     virtual void write(const unsigned char * data, size_t len) = 0;
 };
 
@@ -36,7 +48,7 @@ struct BufferedSink : Sink
 struct Source
 {
     virtual ~Source() { }
-    
+
     /* Store exactly ‘len’ bytes in the buffer pointed to by ‘data’.
        It blocks until all the requested data is available, or throws
        an error if it is not going to be available.   */
@@ -46,6 +58,8 @@ struct Source
        return the number of bytes stored.  If blocks until at least
        one byte is available. */
     virtual size_t read(unsigned char * data, size_t len) = 0;
+
+    virtual bool good() { return true; }
 };
 
 
@@ -58,9 +72,9 @@ struct BufferedSource : Source
     BufferedSource(size_t bufSize = 32 * 1024)
         : bufSize(bufSize), bufPosIn(0), bufPosOut(0), buffer(0) { }
     ~BufferedSource();
-    
-    size_t read(unsigned char * data, size_t len);
-    
+
+    size_t read(unsigned char * data, size_t len) override;
+
     /* Underlying read call, to be overridden. */
     virtual size_t readUnbuffered(unsigned char * data, size_t len) = 0;
 
@@ -72,14 +86,19 @@ struct BufferedSource : Source
 struct FdSink : BufferedSink
 {
     int fd;
-    bool warn;
-    size_t written;
+    bool warn = false;
+    size_t written = 0;
 
-    FdSink() : fd(-1), warn(false), written(0) { }
-    FdSink(int fd) : fd(fd), warn(false), written(0) { }
+    FdSink() : fd(-1) { }
+    FdSink(int fd) : fd(fd) { }
     ~FdSink();
-    
-    void write(const unsigned char * data, size_t len);
+
+    void write(const unsigned char * data, size_t len) override;
+
+    bool good() override;
+
+private:
+    bool _good = true;
 };
 
 
@@ -87,17 +106,24 @@ struct FdSink : BufferedSink
 struct FdSource : BufferedSource
 {
     int fd;
+    size_t read = 0;
+
     FdSource() : fd(-1) { }
     FdSource(int fd) : fd(fd) { }
-    size_t readUnbuffered(unsigned char * data, size_t len);
+    size_t readUnbuffered(unsigned char * data, size_t len) override;
+    bool good() override;
+private:
+    bool _good = true;
 };
 
 
 /* A sink that writes data to a string. */
 struct StringSink : Sink
 {
-    string s;
-    void operator () (const unsigned char * data, size_t len);
+    ref<std::string> s;
+    StringSink() : s(make_ref<std::string>()) { };
+    StringSink(ref<std::string> s) : s(s) { };
+    void operator () (const unsigned char * data, size_t len) override;
 };
 
 
@@ -107,16 +133,32 @@ struct StringSource : Source
     const string & s;
     size_t pos;
     StringSource(const string & _s) : s(_s), pos(0) { }
-    size_t read(unsigned char * data, size_t len);    
+    size_t read(unsigned char * data, size_t len) override;
 };
 
 
 void writePadding(size_t len, Sink & sink);
-void writeInt(unsigned int n, Sink & sink);
-void writeLongLong(unsigned long long n, Sink & sink);
 void writeString(const unsigned char * buf, size_t len, Sink & sink);
-void writeString(const string & s, Sink & sink);
-template<class T> void writeStrings(const T & ss, Sink & sink);
+
+inline Sink & operator << (Sink & sink, uint64_t n)
+{
+    unsigned char buf[8];
+    buf[0] = n & 0xff;
+    buf[1] = (n >> 8) & 0xff;
+    buf[2] = (n >> 16) & 0xff;
+    buf[3] = (n >> 24) & 0xff;
+    buf[4] = (n >> 32) & 0xff;
+    buf[5] = (n >> 40) & 0xff;
+    buf[6] = (n >> 48) & 0xff;
+    buf[7] = (n >> 56) & 0xff;
+    sink(buf, sizeof(buf));
+    return sink;
+}
+
+Sink & operator << (Sink & sink, const string & s);
+Sink & operator << (Sink & sink, const Strings & s);
+Sink & operator << (Sink & sink, const StringSet & s);
+
 
 void readPadding(size_t len, Source & source);
 unsigned int readInt(Source & source);
@@ -125,6 +167,9 @@ size_t readString(unsigned char * buf, size_t max, Source & source);
 string readString(Source & source);
 template<class T> T readStrings(Source & source);
 
+Source & operator >> (Source & in, string & s);
+Source & operator >> (Source & in, unsigned int & n);
+
 
 MakeError(SerialisationError, Error)