From 57d1ab50a8d4093678ff52d82e044fdbf4337231 Mon Sep 17 00:00:00 2001
From: Mathias Laurin <mathias.laurin@checkmk.com>
Date: Thu, 16 Jan 2025 17:24:16 +0100
Subject: [PATCH] Let RRDUDSSocket read bytes

for FETCHBIN

CMK-18929

Change-Id: I40322faa303ccb798f0bb2d00dc202ef8ea52841
---
 .../livestatus/include/livestatus/RRDUDSSocket.h   |  1 +
 packages/livestatus/src/RRDUDSSocket.cc            | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/packages/livestatus/include/livestatus/RRDUDSSocket.h b/packages/livestatus/include/livestatus/RRDUDSSocket.h
index 533c110ac39..6bcaf08178e 100644
--- a/packages/livestatus/include/livestatus/RRDUDSSocket.h
+++ b/packages/livestatus/include/livestatus/RRDUDSSocket.h
@@ -24,6 +24,7 @@ class RRDUDSSocket {
     void connect();
     [[nodiscard]] Logger *logger() const { return logger_; }
     [[nodiscard]] std::string readLine() const;
+    [[nodiscard]] std::string read(std::size_t count) const;
     [[nodiscard]] ssize_t write(std::string_view text,
                                 std::chrono::milliseconds timeout) const;
     [[nodiscard]] bool isConnected() const { return socket_ != -1; }
diff --git a/packages/livestatus/src/RRDUDSSocket.cc b/packages/livestatus/src/RRDUDSSocket.cc
index ca457ee77d1..8f6f702734b 100644
--- a/packages/livestatus/src/RRDUDSSocket.cc
+++ b/packages/livestatus/src/RRDUDSSocket.cc
@@ -8,6 +8,8 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
+#include <algorithm>
+#include <array>
 #include <utility>
 
 #include "livestatus/Logger.h"
@@ -53,6 +55,18 @@ std::string RRDUDSSocket::readLine() const {
     return mk::rstrip(answer);
 }
 
+std::string RRDUDSSocket::read(std::size_t count) const {
+    std::array<char, 512> answer{};
+    // NOLINTBEGIN(cppcoreguidelines-pro-bounds-array-to-pointer-decay,cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    const auto rd = ::fread(answer.data(), sizeof(decltype(answer)::value_type),
+                            std::min(count, answer.size()), file_);
+    if (feof(file_) != 0 || ferror(file_) != 0) {
+        throw generic_error("cannot read reply");
+    }
+    return {answer.begin(), answer.begin() + rd};
+    // NOLINTEND(cppcoreguidelines-pro-bounds-array-to-pointer-decay,cppcoreguidelines-pro-bounds-pointer-arithmetic)
+}
+
 ssize_t RRDUDSSocket::write(std::string_view text,
                             std::chrono::milliseconds timeout) const {
     if (!isConnected()) {