1 files changed, 62 insertions, 13 deletions

diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index a04118512..c29c6b29b 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -166,17 +166,30 @@ struct StringSource : Source
 };
 
 
-/* Adapter class of a Source that saves all data read to `s'. */
+/* A sink that writes all incoming data to two other sinks. */
+struct TeeSink : Sink
+{
+    Sink & sink1, & sink2;
+    TeeSink(Sink & sink1, Sink & sink2) : sink1(sink1), sink2(sink2) { }
+    virtual void operator () (const unsigned char * data, size_t len)
+    {
+        sink1(data, len);
+        sink2(data, len);
+    }
+};
+
+
+/* Adapter class of a Source that saves all data read to a sink. */
 struct TeeSource : Source
 {
     Source & orig;
-    ref<std::string> data;
-    TeeSource(Source & orig)
-        : orig(orig), data(make_ref<std::string>()) { }
+    Sink & sink;
+    TeeSource(Source & orig, Sink & sink)
+        : orig(orig), sink(sink) { }
     size_t read(unsigned char * data, size_t len)
     {
         size_t n = orig.read(data, len);
-        this->data->append((const char *) data, n);
+        sink(data, n);
         return n;
     }
 };
@@ -243,6 +256,19 @@ struct LambdaSource : Source
     }
 };
 
+/* Chain two sources together so after the first is exhausted, the second is
+   used */
+struct ChainSource : Source
+{
+    Source & source1, & source2;
+    bool useSecond = false;
+    ChainSource(Source & s1, Source & s2)
+        : source1(s1), source2(s2)
+    { }
+
+    size_t read(unsigned char * data, size_t len) override;
+};
+
 
 /* Convert a function that feeds data into a Sink into a Source. The
    Source executes the function as a coroutine. */
@@ -286,14 +312,14 @@ T readNum(Source & source)
     source(buf, sizeof(buf));
 
     uint64_t n =
-        ((unsigned long long) buf[0]) |
-        ((unsigned long long) buf[1] << 8) |
-        ((unsigned long long) buf[2] << 16) |
-        ((unsigned long long) buf[3] << 24) |
-        ((unsigned long long) buf[4] << 32) |
-        ((unsigned long long) buf[5] << 40) |
-        ((unsigned long long) buf[6] << 48) |
-        ((unsigned long long) buf[7] << 56);
+        ((uint64_t) buf[0]) |
+        ((uint64_t) buf[1] << 8) |
+        ((uint64_t) buf[2] << 16) |
+        ((uint64_t) buf[3] << 24) |
+        ((uint64_t) buf[4] << 32) |
+        ((uint64_t) buf[5] << 40) |
+        ((uint64_t) buf[6] << 48) |
+        ((uint64_t) buf[7] << 56);
 
     if (n > std::numeric_limits<T>::max())
         throw SerialisationError("serialised integer %d is too large for type '%s'", n, typeid(T).name());
@@ -336,4 +362,27 @@ Source & operator >> (Source & in, bool & b)
 }
 
 
+/* An adapter that converts a std::basic_istream into a source. */
+struct StreamToSourceAdapter : Source
+{
+    std::shared_ptr<std::basic_istream<char>> istream;
+
+    StreamToSourceAdapter(std::shared_ptr<std::basic_istream<char>> istream)
+        : istream(istream)
+    { }
+
+    size_t read(unsigned char * data, size_t len) override
+    {
+        if (!istream->read((char *) data, len)) {
+            if (istream->eof()) {
+                if (istream->gcount() == 0)
+                    throw EndOfFile("end of file");
+            } else
+                throw Error("I/O error in StreamToSourceAdapter");
+        }
+        return istream->gcount();
+    }
+};
+
+
 }