Handle importing NARs containing files greater than 4 GiB

Also templatize readInt() to work for various integer types.

2 files changed, 53 insertions, 44 deletions

diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc
index a68f7a0fa8ee..6064e15f5e67 100644
--- a/src/libutil/serialise.cc
+++ b/src/libutil/serialise.cc
@@ -194,39 +194,9 @@ void readPadding(size_t len, Source & source)
 }
 
 
-unsigned int readInt(Source & source)
-{
-    unsigned char buf[8];
-    source(buf, sizeof(buf));
-    if (buf[4] || buf[5] || buf[6] || buf[7])
-        throw SerialisationError("implementation cannot deal with > 32-bit integers");
-    return
-        buf[0] |
-        (buf[1] << 8) |
-        (buf[2] << 16) |
-        (buf[3] << 24);
-}
-
-
-unsigned long long readLongLong(Source & source)
-{
-    unsigned char buf[8];
-    source(buf, sizeof(buf));
-    return
-        ((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);
-}
-
-
 size_t readString(unsigned char * buf, size_t max, Source & source)
 {
-    size_t len = readInt(source);
+    auto len = readNum<size_t>(source);
     if (len > max) throw Error("string is too long");
     source(buf, len);
     readPadding(len, source);
@@ -236,7 +206,7 @@ size_t readString(unsigned char * buf, size_t max, Source & source)
 
 string readString(Source & source)
 {
-    size_t len = readInt(source);
+    auto len = readNum<size_t>(source);
     auto buf = std::make_unique<unsigned char[]>(len);
     source(buf.get(), len);
     readPadding(len, source);
@@ -250,16 +220,9 @@ Source & operator >> (Source & in, string & s)
 }
 
 
-Source & operator >> (Source & in, unsigned int & n)
-{
-    n = readInt(in);
-    return in;
-}
-
-
 template<class T> T readStrings(Source & source)
 {
-    unsigned int count = readInt(source);
+    auto count = readNum<size_t>(source);
     T ss;
     while (count--)
         ss.insert(ss.end(), readString(source));
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 5646d08c1314..3072f422ea93 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -177,18 +177,64 @@ Sink & operator << (Sink & sink, const Strings & s);
 Sink & operator << (Sink & sink, const StringSet & s);
 
 
+MakeError(SerialisationError, Error)
+
+
+template<typename T>
+T readNum(Source & source)
+{
+    unsigned char buf[8];
+    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);
+
+    if (n > std::numeric_limits<T>::max())
+        throw SerialisationError("serialised integer %d is too large for type ‘%s’", n, typeid(T).name());
+
+    return n;
+}
+
+
+inline unsigned int readInt(Source & source)
+{
+    return readNum<unsigned int>(source);
+}
+
+
+inline uint64_t readLongLong(Source & source)
+{
+    return readNum<uint64_t>(source);
+}
+
+
 void readPadding(size_t len, Source & source);
-unsigned int readInt(Source & source);
-unsigned long long readLongLong(Source & source);
 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);
 
+template<typename T>
+Source & operator >> (Source & in, T & n)
+{
+    n = readNum<T>(in);
+    return in;
+}
 
-MakeError(SerialisationError, Error)
+template<typename T>
+Source & operator >> (Source & in, bool & b)
+{
+    b = readNum<uint64_t>(in);
+    return in;
+}
 
 
 }