From 47baa9d43c0339b0a738b9b75c5ddcfb07d7131d Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sat, 1 Jan 2022 19:24:20 +0100
Subject: make Pos smaller

reduces peak hep memory use on eval of our test system from 264.4MB to 242.3MB,
possibly also a slight performance boost.

theoretically memory use could be cut down by another eight bytes per Pos on
average by turning it into a tuple containing an index into a global base
position table with row and column offsets, but that doesn't seem worth the
effort at this point.
---
 src/libutil/error.hh | 1 +
 1 file changed, 1 insertion(+)

(limited to 'src/libutil')

diff --git a/src/libutil/error.hh b/src/libutil/error.hh
index d55e1d701..bb43aa53b 100644
--- a/src/libutil/error.hh
+++ b/src/libutil/error.hh
@@ -53,6 +53,7 @@ typedef enum {
     lvlVomit
 } Verbosity;
 
+/* adjust Pos::origin bit width when adding stuff here */
 typedef enum {
     foFile,
     foStdin,
-- 
cgit v1.2.3


From 8e2eaaaf69d9e216fce3ca6f7913bd0e2048e4b2 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Fri, 31 Dec 2021 00:50:23 +0100
Subject: make Finally more local

no need for function<> with c++17 deduction. this saves allocations and virtual
calls, but has the same semantics otherwise. not going through function has the
side effect of giving compilers more insight into the cleanup code, so we need a
few local warning disables.
---
 src/libutil/finally.hh |  7 +++----
 src/libutil/util.cc    | 15 ++++++++-------
 2 files changed, 11 insertions(+), 11 deletions(-)

(limited to 'src/libutil')

diff --git a/src/libutil/finally.hh b/src/libutil/finally.hh
index 7760cfe9a..dee2e8d2f 100644
--- a/src/libutil/finally.hh
+++ b/src/libutil/finally.hh
@@ -1,14 +1,13 @@
 #pragma once
 
-#include <functional>
-
 /* A trivial class to run a function at the end of a scope. */
+template<typename Fn>
 class Finally
 {
 private:
-    std::function<void()> fun;
+    Fn fun;
 
 public:
-    Finally(std::function<void()> fun) : fun(fun) { }
+    Finally(Fn fun) : fun(std::move(fun)) { }
     ~Finally() { fun(); }
 };
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index b833038a9..9f13d5f02 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -682,7 +682,14 @@ std::string drainFD(int fd, bool block, const size_t reserveSize)
 
 void drainFD(int fd, Sink & sink, bool block)
 {
-    int saved;
+    // silence GCC maybe-uninitialized warning in finally
+    int saved = 0;
+
+    if (!block) {
+        saved = fcntl(fd, F_GETFL);
+        if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1)
+            throw SysError("making file descriptor non-blocking");
+    }
 
     Finally finally([&]() {
         if (!block) {
@@ -691,12 +698,6 @@ void drainFD(int fd, Sink & sink, bool block)
         }
     });
 
-    if (!block) {
-        saved = fcntl(fd, F_GETFL);
-        if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1)
-            throw SysError("making file descriptor non-blocking");
-    }
-
     std::vector<unsigned char> buf(64 * 1024);
     while (1) {
         checkInterrupt();
-- 
cgit v1.2.3