Simplify the callback mechanism

1 files changed, 7 insertions, 10 deletions

diff --git a/src/libstore/local-binary-cache-store.cc b/src/libstore/local-binary-cache-store.cc
index 2577e90aef..ae0ffa6a56 100644
--- a/src/libstore/local-binary-cache-store.cc
+++ b/src/libstore/local-binary-cache-store.cc
@@ -35,17 +35,14 @@ protected:
         const std::string & mimeType) override;
 
     void getFile(const std::string & path,
-        std::function<void(std::shared_ptr<std::string>)> success,
-        std::function<void(std::exception_ptr exc)> failure) override
+        Callback<std::shared_ptr<std::string>> callback) override
     {
-        sync2async<std::shared_ptr<std::string>>(success, failure, [&]() {
-            try {
-                return std::make_shared<std::string>(readFile(binaryCacheDir + "/" + path));
-            } catch (SysError & e) {
-                if (e.errNo == ENOENT) return std::shared_ptr<std::string>();
-                throw;
-            }
-        });
+        try {
+            // FIXME: O(n) space
+            callback(std::make_shared<std::string>(readFile(binaryCacheDir + "/" + path)));
+        } catch (SysError & e) {
+            if (e.errNo == ENOENT) callback(nullptr); else callback.rethrow();
+        } catch (...) { callback.rethrow(); }
     }
 
     PathSet queryAllValidPaths() override