libutil: return a source from readFile

don't consume a sink, return a source instead. the only reason to not do
this is a very slight reduction in dynamic allocations, but since we are
going to *at least* do disk io that will not be a lot of overhead anyway

Change-Id: Iae2f879ec64c3c3ac1d5310eeb6a85e696d4614a

5 files changed, 7 insertions, 7 deletions

diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index 07c722016..d6ded0a24 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -385,7 +385,7 @@ StorePath BinaryCacheStore::addToStore(
     if (method == FileIngestionMethod::Recursive) {
         dumpPath(srcPath, sink, filter);
     } else {
-        readFile(srcPath, sink);
+        readFileSource(srcPath)->drainInto(sink);
     }
     auto h = sink.finish().first;
 
diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc
index 7066f5c93..bae821266 100644
--- a/src/libstore/build/local-derivation-goal.cc
+++ b/src/libstore/build/local-derivation-goal.cc
@@ -2486,7 +2486,7 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
             HashModuloSink caSink { outputHash.hashType, oldHashPart };
             std::visit(overloaded {
                 [&](const TextIngestionMethod &) {
-                    readFile(actualPath, caSink);
+                    readFileSource(actualPath)->drainInto(caSink);
                 },
                 [&](const FileIngestionMethod & m2) {
                     switch (m2) {
@@ -2494,7 +2494,7 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
                         dumpPath(actualPath, caSink);
                         break;
                     case FileIngestionMethod::Flat:
-                        readFile(actualPath, caSink);
+                        readFileSource(actualPath)->drainInto(caSink);
                         break;
                     }
                 },
diff --git a/src/libstore/local-binary-cache-store.cc b/src/libstore/local-binary-cache-store.cc
index 5684dcd80..5f6730476 100644
--- a/src/libstore/local-binary-cache-store.cc
+++ b/src/libstore/local-binary-cache-store.cc
@@ -71,7 +71,7 @@ protected:
     void getFile(const std::string & path, Sink & sink) override
     {
         try {
-            readFile(binaryCacheDir + "/" + path, sink);
+            readFileSource(binaryCacheDir + "/" + path)->drainInto(sink);
         } catch (SysError & e) {
             if (e.errNo == ENOENT)
                 throw NoSuchBinaryCacheFile("file '%s' does not exist in binary cache", path);
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 5e79630c6..6f441a0a1 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1890,7 +1890,7 @@ ContentAddress LocalStore::hashCAPath(
     HashModuloSink caSink ( hashType, std::string(pathHash) );
     std::visit(overloaded {
         [&](const TextIngestionMethod &) {
-            readFile(path, caSink);
+            readFileSource(path)->drainInto(caSink);
         },
         [&](const FileIngestionMethod & m2) {
             switch (m2) {
@@ -1898,7 +1898,7 @@ ContentAddress LocalStore::hashCAPath(
                 dumpPath(path, caSink);
                 break;
             case FileIngestionMethod::Flat:
-                readFile(path, caSink);
+                readFileSource(path)->drainInto(caSink);
                 break;
             }
         },
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 55083e834..e954acff3 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -279,7 +279,7 @@ StorePath Store::addToStore(
         if (method == FileIngestionMethod::Recursive)
             dumpPath(srcPath, sink, filter);
         else
-            readFile(srcPath, sink);
+            readFileSource(srcPath)->drainInto(sink);
     });
     return addToStoreFromDump(*source, name, method, hashAlgo, repair, references);
 }