Cleanup

Author: edolstra

src/libstore/binary-cache-store.cc

@@ -420,19 +420,26 @@ void BinaryCacheStore::narFromPath(const StorePath & storePath, Sink & sink)
         }
     }
 
-    LengthSink narSize;
-    TeeSink tee{narSize, sink};
     std::unique_ptr<Sink> narCacheSink;
-    std::unique_ptr<Sink> tee2;
-    Sink * sink2 = &tee;
-
-    if (narCache) {
+    if (narCache)
         narCacheSink = sourceToSink([&](Source & source) { narCache->upsertNar(info->narHash, source); });
-        tee2 = std::make_unique<TeeSink>(*narCacheSink, tee);
-        sink2 = tee2.get();
-    }
 
-    auto decompressor = makeDecompressionSink(info->compression, *sink2);
+    uint64_t narSize = 0;
+
+    LambdaSink uncompressedSink{
+        [&](std::string_view data) {
+            narSize += data.size();
+            if (narCacheSink)
+                (*narCacheSink)(data);
+            sink(data);
+        },
+        [&]() {
+            stats.narRead++;
+            // stats.narReadCompressedBytes += nar->size(); // FIXME
+            stats.narReadBytes += narSize;
+        }};
+
+    auto decompressor = makeDecompressionSink(info->compression, uncompressedSink);
 
     try {
         getFile(info->url, *decompressor);
@@ -442,10 +449,7 @@ void BinaryCacheStore::narFromPath(const StorePath & storePath, Sink & sink)
 
     decompressor->finish();
 
-    // FIXME: this is never reached
-    stats.narRead++;
-    // stats.narReadCompressedBytes += nar->size(); // FIXME
-    stats.narReadBytes += narSize.length;
+    // Note: don't do anything here because it's never reached if we're called as a coroutine.
 }
 
 void BinaryCacheStore::queryPathInfoUncached(