From f24cdb4b77c2dcccfb8774ea9432d62f58a48468 Mon Sep 17 00:00:00 2001
From: Kefu Chai <kefu.chai@scylladb.com>
Date: Fri, 1 Nov 2024 20:08:45 +0800
Subject: [PATCH] treewide: include core/format.hh when appropriate

before this change, we include core/print.hh for formatting and/or
for printing. but core/print.hh includes `<iostream>` which is a
heavyweight header in the C++ standard library. under most
circumstances, all we need is but `seastar::format()`, which is
provided by a smaller header -- `core/format.hh`.

in this change, we include `core/format.hh` instead of `core/print.hh`
when appropriate. and adapt the translation units where `iostream` is
used to include this header.

this should reduce the header dependency of Seastar library and
speed up the compilation.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
---
 apps/io_tester/ioinfo.cc                             | 1 +
 apps/rpc_tester/rpc_tester.cc                        | 1 +
 demos/rpc_demo.cc                                    | 1 +
 include/seastar/core/internal/estimated_histogram.hh | 2 +-
 include/seastar/rpc/rpc_impl.hh                      | 2 +-
 include/seastar/util/backtrace.hh                    | 2 +-
 include/seastar/util/program-options.hh              | 2 +-
 7 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/apps/io_tester/ioinfo.cc b/apps/io_tester/ioinfo.cc
index 0f0909b4c5b..ec4e840a91d 100644
--- a/apps/io_tester/ioinfo.cc
+++ b/apps/io_tester/ioinfo.cc
@@ -18,6 +18,7 @@
 /*
  * Copyright (C) 2021 ScyllaDB
  */
+#include <iostream>
 #include <seastar/core/app-template.hh>
 #include <seastar/core/thread.hh>
 #include <seastar/core/reactor.hh>
diff --git a/apps/rpc_tester/rpc_tester.cc b/apps/rpc_tester/rpc_tester.cc
index 805c5025ad4..99b6bd8daaf 100644
--- a/apps/rpc_tester/rpc_tester.cc
+++ b/apps/rpc_tester/rpc_tester.cc
@@ -19,6 +19,7 @@
  * Copyright (C) 2022 ScyllaDB
  */
 
+#include <iostream>
 #include <vector>
 #include <chrono>
 #include <random>
diff --git a/demos/rpc_demo.cc b/demos/rpc_demo.cc
index dd7abbfc8a7..9c683813387 100644
--- a/demos/rpc_demo.cc
+++ b/demos/rpc_demo.cc
@@ -19,6 +19,7 @@
  * Copyright 2015 Cloudius Systems
  */
 #include <cmath>
+#include <iostream>
 #include <ranges>
 #include <seastar/core/reactor.hh>
 #include <seastar/core/app-template.hh>
diff --git a/include/seastar/core/internal/estimated_histogram.hh b/include/seastar/core/internal/estimated_histogram.hh
index fff87dc70dc..636a3336d4f 100644
--- a/include/seastar/core/internal/estimated_histogram.hh
+++ b/include/seastar/core/internal/estimated_histogram.hh
@@ -25,8 +25,8 @@
 #include <algorithm>
 #include <vector>
 #include <chrono>
+#include <string>
 #include <seastar/core/metrics_types.hh>
-#include <seastar/core/print.hh>
 #include <seastar/core/bitops.hh>
 #include <limits>
 #include <array>
diff --git a/include/seastar/rpc/rpc_impl.hh b/include/seastar/rpc/rpc_impl.hh
index faf01f199db..6ca03c80c63 100644
--- a/include/seastar/rpc/rpc_impl.hh
+++ b/include/seastar/rpc/rpc_impl.hh
@@ -20,6 +20,7 @@
  */
 #pragma once
 
+#include <seastar/core/format.hh>
 #include <seastar/core/function_traits.hh>
 #include <seastar/core/shared_ptr.hh>
 #include <seastar/core/sstring.hh>
@@ -27,7 +28,6 @@
 #include <seastar/util/is_smart_ptr.hh>
 #include <seastar/core/simple-stream.hh>
 #include <seastar/net/packet-data-source.hh>
-#include <seastar/core/print.hh>
 
 #include <boost/type.hpp> // for compatibility
 
diff --git a/include/seastar/util/backtrace.hh b/include/seastar/util/backtrace.hh
index 675116cb7e0..5a4dbad54e6 100644
--- a/include/seastar/util/backtrace.hh
+++ b/include/seastar/util/backtrace.hh
@@ -21,8 +21,8 @@
 
 #pragma once
 
+#include <seastar/core/format.hh>
 #include <seastar/core/sstring.hh>
-#include <seastar/core/print.hh>
 #include <seastar/core/scheduling.hh>
 #include <seastar/core/shared_ptr.hh>
 #include <seastar/util/modules.hh>
diff --git a/include/seastar/util/program-options.hh b/include/seastar/util/program-options.hh
index 54e52ed7152..fd48c2603fd 100644
--- a/include/seastar/util/program-options.hh
+++ b/include/seastar/util/program-options.hh
@@ -21,8 +21,8 @@
 
 #pragma once
 
+#include <seastar/core/format.hh>
 #include <seastar/core/sstring.hh>
-#include <seastar/core/print.hh>
 #include <seastar/util/modules.hh>
 
 #ifndef SEASTAR_MODULE