From f041812939db26215861af0364ea402dffbcda82 Mon Sep 17 00:00:00 2001
From: Andrew Gaul <andrew@gaul.org>
Date: Mon, 27 Nov 2023 00:51:17 +0900
Subject: [PATCH] Revert "Call C++11 get_time and put_time (#2375)" (#2381)

This reverts commit 10a72bfd0f52bc70ad7f1dd6fbb92dbea376614c.  These
commit is incompatible with older CentOS 7 libstdc++.
---
 src/metaheader.cpp  | 10 ++++------
 src/s3fs_logger.cpp |  5 +++--
 src/string_util.cpp | 42 ++++++++++++++++++++++++++++++------------
 src/string_util.h   |  6 ++++++
 4 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/src/metaheader.cpp b/src/metaheader.cpp
index 90a4895..69e97e8 100644
--- a/src/metaheader.cpp
+++ b/src/metaheader.cpp
@@ -19,8 +19,6 @@
  */
 
 #include <ctime>
-#include <iomanip>
-#include <sstream>
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -256,8 +254,8 @@ time_t cvtIAMExpireStringToTime(const char* s)
     if(!s){
         return 0L;
     }
-    std::istringstream ss(s);
-    ss >> std::get_time(&tm, "%Y-%m-%dT%H:%M:%S");
+    memset(&tm, 0, sizeof(struct tm));
+    strptime(s, "%Y-%m-%dT%H:%M:%S", &tm);
     return timegm(&tm); // GMT
 }
 
@@ -267,8 +265,8 @@ time_t get_lastmodified(const char* s)
     if(!s){
         return -1;
     }
-    std::istringstream ss(s);
-    ss >> std::get_time(&tm, "%a, %d %b %Y %H:%M:%S %Z");
+    memset(&tm, 0, sizeof(struct tm));
+    strptime(s, "%a, %d %b %Y %H:%M:%S %Z", &tm);
     return timegm(&tm); // GMT
 }
 
diff --git a/src/s3fs_logger.cpp b/src/s3fs_logger.cpp
index ddee301..12b93cb 100644
--- a/src/s3fs_logger.cpp
+++ b/src/s3fs_logger.cpp
@@ -54,14 +54,15 @@ std::string S3fsLog::GetCurrentTime()
         struct timeval  now;
         struct timespec tsnow;
         struct tm res;
+        char   tmp[32];
         if(-1 == clock_gettime(S3FS_CLOCK_MONOTONIC, &tsnow)){
             now.tv_sec  = tsnow.tv_sec;
             now.tv_usec = (tsnow.tv_nsec / 1000);
         }else{
             gettimeofday(&now, nullptr);
         }
-        current_time << std::put_time(gmtime_r(&now.tv_sec, &res), "%Y-%m-%dT%H:%M:%S")
-                     << "." << std::setfill('0') << std::setw(3) << (now.tv_usec / 1000) << "Z ";
+        strftime(tmp, sizeof(tmp), "%Y-%m-%dT%H:%M:%S", gmtime_r(&now.tv_sec, &res));
+        current_time << tmp << "." << std::setfill('0') << std::setw(3) << (now.tv_usec / 1000) << "Z ";
     }
     return current_time.str();
 }
diff --git a/src/string_util.cpp b/src/string_util.cpp
index 235f912..a1ab4cd 100644
--- a/src/string_util.cpp
+++ b/src/string_util.cpp
@@ -23,6 +23,7 @@
 #include <cerrno>
 #include <climits>
 #include <iomanip>
+
 #include <sstream>
 
 #include "s3fs_logger.h"
@@ -46,6 +47,24 @@ std::string str(const struct timespec value)
     return s.str();
 }
 
+#ifdef __MSYS__
+/*
+ * Polyfill for strptime function
+ *
+ * This source code is from https://gist.github.com/jeremyfromearth/5694aa3a66714254752179ecf3c95582 .
+ */
+char* strptime(const char* s, const char* f, struct tm* tm)
+{
+    std::istringstream input(s);
+    input.imbue(std::locale(setlocale(LC_ALL, nullptr)));
+    input >> std::get_time(tm, f);
+    if (input.fail()) {
+        return nullptr;
+    }
+    return (char*)(s + input.tellg());
+}
+#endif
+
 bool s3fs_strtoofft(off_t* value, const char* str, int base)
 {
     if(value == nullptr || str == nullptr){
@@ -240,11 +259,11 @@ bool get_keyword_value(const std::string& target, const char* keyword, std::stri
 //
 std::string get_date_rfc850()
 {
-    std::ostringstream ss;
+    char buf[100];
     time_t t = time(nullptr);
     struct tm res;
-    ss << std::put_time(gmtime_r(&t, &res), "%a, %d %b %Y %H:%M:%S GMT");
-    return ss.str();
+    strftime(buf, sizeof(buf), "%a, %d %b %Y %H:%M:%S GMT", gmtime_r(&t, &res));
+    return buf;
 }
 
 void get_date_sigv3(std::string& date, std::string& date8601)
@@ -256,18 +275,18 @@ void get_date_sigv3(std::string& date, std::string& date8601)
 
 std::string get_date_string(time_t tm)
 {
-    std::ostringstream ss;
+    char buf[100];
     struct tm res;
-    ss << std::put_time(gmtime_r(&tm, &res), "%Y%m%d");
-    return ss.str();
+    strftime(buf, sizeof(buf), "%Y%m%d", gmtime_r(&tm, &res));
+    return buf;
 }
 
 std::string get_date_iso8601(time_t tm)
 {
-    std::ostringstream s;
+    char buf[100];
     struct tm res;
-    s << std::put_time(gmtime_r(&tm, &res), "%Y%m%dT%H%M%SZ");
-    return s.str();
+    strftime(buf, sizeof(buf), "%Y%m%dT%H%M%SZ", gmtime_r(&tm, &res));
+    return buf;
 }
 
 bool get_unixtime_from_iso8601(const char* pdate, time_t& unixtime)
@@ -277,9 +296,8 @@ bool get_unixtime_from_iso8601(const char* pdate, time_t& unixtime)
     }
 
     struct tm tm;
-    std::istringstream ss(pdate);
-    ss >> std::get_time(&tm, "%Y-%m-%dT%T");
-    if(ss.fail()){
+    const char* prest = strptime(pdate, "%Y-%m-%dT%T", &tm);
+    if(prest == pdate){
         // wrong format
         return false;
     }
diff --git a/src/string_util.h b/src/string_util.h
index e2eeaf6..2577d49 100644
--- a/src/string_util.h
+++ b/src/string_util.h
@@ -55,6 +55,12 @@ static inline const char* SAFESTRPTR(const char *strptr) { return strptr ? strpt
 // TODO: rename to to_string?
 std::string str(const struct timespec value);
 
+#ifdef __MSYS__
+//
+// Polyfill for strptime function.
+//
+char* strptime(const char* s, const char* f, struct tm* tm);
+#endif
 //
 // Convert string to off_t.  Returns false on bad input.
 // Replacement for C++11 std::stoll.