Update std.tools() and std.toolchain() to sync as a single tarball (

#147)

packages/std/toolchain/native/index.bri

@@ -161,7 +161,9 @@ export const tools = std.memo(async (): Promise<std.Recipe<std.Directory>> => {
     MAGIC: { append: [{ path: "share/misc/magic.mgc" }] },
   });
 
-  return std.sync(tools);
+  tools = syncTarball(tools);
+
+  return tools;
 });
 
 /**
@@ -312,7 +314,7 @@ export const toolchain = std.memo(
 
     toolchain = makePkgConfigPathsRelative(toolchain);
 
-    toolchain = std.sync(toolchain);
+    toolchain = syncTarball(toolchain);
 
     return toolchain;
   },
@@ -428,3 +430,36 @@ function makePkgConfigPathsRelative(
     })
     .toDirectory();
 }
+
+/**
+ * Sync a recipe by creating an archive of it, then unarchiving it. When
+ * fetched from the registry, the recipe will be downloaded as a single
+ * compressed tarball, which may be faster than syncing lots of individual
+ * files.
+ */
+function syncTarball(
+  recipe: std.AsyncRecipe<std.Directory>,
+): std.Recipe<std.Directory> {
+  recipe = std.collectReferences(std.directory({ recipe }));
+
+  const tarredRecipe = std
+    .process({
+      command: "tar",
+      args: [
+        "--zstd",
+        "-cf",
+        std.outputPath,
+        "--hard-dereference",
+        "-C",
+        recipe,
+        ".",
+      ],
+      dependencies: [tar(), zstd()],
+    })
+    .toFile();
+
+  let untarredRecipe = tarredRecipe.unarchive("tar", "zstd");
+  untarredRecipe = std.attachResources(untarredRecipe);
+
+  return std.castToDirectory(untarredRecipe.get("recipe"));
+}