From 29c82ccc77714a74e8948ce8c531de5a8d870176 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 13 Sep 2020 14:39:11 +0200
Subject: [PATCH] Add Source.drainInto(Sink)

---
 src/libutil/serialise.cc | 13 ++++++++++---
 src/libutil/serialise.hh |  2 ++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc
index 00c945113..a469a1e73 100644
--- a/src/libutil/serialise.cc
+++ b/src/libutil/serialise.cc
@@ -93,7 +93,7 @@ void Source::operator () (unsigned char * data, size_t len)
 }
 
 
-std::string Source::drain()
+void Source::drainInto(Sink & sink)
 {
     std::string s;
     std::vector<unsigned char> buf(8192);
@@ -101,12 +101,19 @@ std::string Source::drain()
         size_t n;
         try {
             n = read(buf.data(), buf.size());
-            s.append((char *) buf.data(), n);
+            sink(buf.data(), n);
         } catch (EndOfFile &) {
             break;
         }
     }
-    return s;
+}
+
+
+std::string Source::drain()
+{
+    StringSink s;
+    drainInto(s);
+    return *s.s;
 }
 
 
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 6f4f4c855..2fd06bb4d 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -69,6 +69,8 @@ struct Source
 
     virtual bool good() { return true; }
 
+    void drainInto(Sink & sink);
+
     std::string drain();
 };