From 28a98d152c071ec48b8bf510f87ac9710c56d7fb Mon Sep 17 00:00:00 2001
From: eldritch horrors <pennae@lix.systems>
Date: Sun, 28 Apr 2024 00:56:10 +0200
Subject: [PATCH] libstore: de-callback-ify Store::queryRealisation

Change-Id: I8d74745c519518f163f51dfaa39063836f17599e
---
 src/libstore/store-api.cc | 81 +++++++++++++--------------------------
 src/libstore/store-api.hh |  6 ---
 2 files changed, 26 insertions(+), 61 deletions(-)

diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 7ebab3933..942e3f521 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -716,65 +716,36 @@ ref<const ValidPathInfo> Store::queryPathInfo(const StorePath & storePath)
     return ref<const ValidPathInfo>(info);
 }
 
-void Store::queryRealisation(const DrvOutput & id,
-        Callback<std::shared_ptr<const Realisation>> callback) noexcept
-{
-
-    try {
-        if (diskCache) {
-            auto [cacheOutcome, maybeCachedRealisation]
-                = diskCache->lookupRealisation(getUri(), id);
-            switch (cacheOutcome) {
-            case NarInfoDiskCache::oValid:
-                debug("Returning a cached realisation for %s", id.to_string());
-                callback(maybeCachedRealisation);
-                return;
-            case NarInfoDiskCache::oInvalid:
-                debug(
-                    "Returning a cached missing realisation for %s",
-                    id.to_string());
-                callback(nullptr);
-                return;
-            case NarInfoDiskCache::oUnknown:
-                break;
-            }
-        }
-    } catch (...) {
-        return callback.rethrow();
-    }
-
-    try {
-        auto info = queryRealisationUncached(id);
-
-        if (diskCache) {
-            if (info)
-                diskCache->upsertRealisation(getUri(), *info);
-            else
-                diskCache->upsertAbsentRealisation(getUri(), id);
-        }
-
-        callback(std::shared_ptr<const Realisation>(info));
-
-    } catch (...) {
-        callback.rethrow();
-    }
-}
-
 std::shared_ptr<const Realisation> Store::queryRealisation(const DrvOutput & id)
 {
-    using RealPtr = std::shared_ptr<const Realisation>;
-    std::promise<RealPtr> promise;
 
-    queryRealisation(id,
-        {[&](std::future<RealPtr> result) {
-            try {
-                promise.set_value(result.get());
-            } catch (...) {
-                promise.set_exception(std::current_exception());
-            }
-        }});
+    if (diskCache) {
+        auto [cacheOutcome, maybeCachedRealisation]
+            = diskCache->lookupRealisation(getUri(), id);
+        switch (cacheOutcome) {
+        case NarInfoDiskCache::oValid:
+            debug("Returning a cached realisation for %s", id.to_string());
+            return maybeCachedRealisation;
+        case NarInfoDiskCache::oInvalid:
+            debug(
+                "Returning a cached missing realisation for %s",
+                id.to_string());
+            return nullptr;
+        case NarInfoDiskCache::oUnknown:
+            break;
+        }
+    }
 
-    return promise.get_future().get();
+    auto info = queryRealisationUncached(id);
+
+    if (diskCache) {
+        if (info)
+            diskCache->upsertRealisation(getUri(), *info);
+        else
+            diskCache->upsertAbsentRealisation(getUri(), id);
+    }
+
+    return info;
 }
 
 void Store::substitutePaths(const StorePathSet & paths)
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 1aab3c8a3..47e644fed 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -371,12 +371,6 @@ public:
      */
     std::shared_ptr<const Realisation> queryRealisation(const DrvOutput &);
 
-    /**
-     * Asynchronous version of queryRealisation().
-     */
-    void queryRealisation(const DrvOutput &,
-        Callback<std::shared_ptr<const Realisation>> callback) noexcept;
-
 
     /**
      * Check whether the given valid path info is sufficiently attested, by