config rewrite bug

[iushas]

Search before asking

• I had searched in the issues and found no similar issues.

Version

2.3.0

Minimal reproduce step

namespace add xxx
config rewrite

What did you expect to see?

no extra blank lines in kvrocks.conf

What did you see instead?

First create 1w namespace, then config rewrite.
There are 1w extra blank lines after config rewrite

Anything Else?

No response

Are you willing to submit a PR?

• I'm willing to submit a PR!

[iushas]

[enjoy-binbin]

It seems that in addition to this problem, every time we perform a config rewrite, an additional newline is appended

[enjoy-binbin]

so it look like file.eof() problem. see https://stackoverflow.com/questions/21647/reading-from-text-file-until-eof-repeats-last-line

change it to this seems work

diff --git a/src/config/config.cc b/src/config/config.cc
index 3e3c286..77825ae 100644
--- a/src/config/config.cc
+++ b/src/config/config.cc
@@ -829,8 +829,8 @@ Status Config::Rewrite() {
   std::ifstream file(path_);
   if (file.is_open()) {
     std::string raw_line;
-    while (!file.eof()) {
-      std::getline(file, raw_line);
+    while (std::getline(file, raw_line)) {
+      if (file.eof()) break;
       auto parsed = ParseConfigLine(raw_line);
       if (!parsed || parsed->first.empty()) {
         lines.emplace_back(raw_line);

[git-hulk]

It seems that in addition to this problem, every time we perform a config rewrite, an additional newline is appended

yes

[enjoy-binbin]

I tested the changes above locally, it will work (and it also can fix this issue)
should we need to change all while (!file.eof()), I see we still have a few places where we use this

[git-hulk]

Yes, I think so. cc @PragmaTwice