From f055a122305cf306b022bd17de35ab999ba002d1 Mon Sep 17 00:00:00 2001
From: Jiakun Yan <jiakunyan1998@gmail.com>
Date: Wed, 20 Dec 2023 11:23:06 -0600
Subject: [PATCH] Let LCT Logger also report hostname

---
 lct/api/lct.h      |  5 +++++
 lct/lct.cpp        | 11 +++++++----
 lct/log/logger.cpp |  8 ++++----
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/lct/api/lct.h b/lct/api/lct.h
index ea6b95bb..d62712b0 100644
--- a/lct/api/lct.h
+++ b/lct/api/lct.h
@@ -19,9 +19,14 @@ LCT_API void LCT_init();
 LCT_API void LCT_fina();
 
 // rank
+extern int LCT_rank;
 LCT_API void LCT_set_rank(int rank);
 LCT_API int LCT_get_rank();
 
+// hostname
+#define LCT_HOSTNAME_MAX_LENGTH 128
+extern char LCT_hostname[LCT_HOSTNAME_MAX_LENGTH];
+
 // time
 typedef uint64_t LCT_time_t;
 LCT_API LCT_time_t LCT_now();
diff --git a/lct/lct.cpp b/lct/lct.cpp
index f470398e..e19a091b 100644
--- a/lct/lct.cpp
+++ b/lct/lct.cpp
@@ -3,6 +3,8 @@
 #include <unistd.h>
 
 LCT_API LCT_log_ctx_t LCT_log_ctx_default = nullptr;
+LCT_API int LCT_rank = -1;
+LCT_API char LCT_hostname[LCT_HOSTNAME_MAX_LENGTH] = "uninitialized";
 
 namespace lct
 {
@@ -14,6 +16,9 @@ void init()
     // init has been called
     return;
 
+  // initialize hostname
+  gethostname(LCT_hostname, LCT_HOSTNAME_MAX_LENGTH);
+
   // initialize LCT_log_ctx_default
   const char* const log_levels[] = {
       "error", "warn", "diag", "info", "debug", "trace",
@@ -49,8 +54,6 @@ void LCT_init() { lct::init(); }
 
 void LCT_fina() { lct::fina(); }
 
-int LCTI_rank = -1;
-
-void LCT_set_rank(int rank) { LCTI_rank = rank; }
+void LCT_set_rank(int rank) { LCT_rank = rank; }
 
-int LCT_get_rank() { return LCTI_rank; }
\ No newline at end of file
+int LCT_get_rank() { return LCT_rank; }
\ No newline at end of file
diff --git a/lct/log/logger.cpp b/lct/log/logger.cpp
index 71ca702f..dea10360 100644
--- a/lct/log/logger.cpp
+++ b/lct/log/logger.cpp
@@ -91,10 +91,10 @@ struct ctx_t {
     // do nothing.
     if (blacklist != nullptr && strstr(blacklist, log_tag) != nullptr) return;
     // print the log
-    size = snprintf(buf, sizeof(buf), "%d:%d:%d:%s:%s:%d<%s:%s:%s> ",
-                    LCT_get_rank(), getpid(), LCT_get_thread_id(), file, func,
-                    line, ctx_name.c_str(), log_levels[log_level].c_str(),
-                    log_tag);
+    size = snprintf(buf, sizeof(buf), "%d:%s:%d:%d:%s:%s:%d<%s:%s:%s> ",
+                    LCT_get_rank(), LCT_hostname, getpid(), LCT_get_thread_id(),
+                    file, func, line, ctx_name.c_str(),
+                    log_levels[log_level].c_str(), log_tag);
 
     vsnprintf(buf + size, sizeof(buf) - size, format, vargs);