feat: support strptime_ns mixed epoch formats and nanosecond bounds

core/common/Strptime.cpp

@@ -82,7 +82,7 @@ static const unsigned char* find_string(const unsigned char*, int*, const char*
 // Modify from https://github.com/tnodir/luasys/blob/master/src/win32/strptime.c
 const char* strptime_ns(const char* buf, const char* fmt, struct tm* tm, long* nanosecond, int* nanosecondLength) {
     // Replenish %s support.
-    if (0 == strcmp("%s", fmt)) {
+    if (0 == strcmp("%s", fmt) || 0 == strcmp("%s%f", fmt)) {
         char* cp;
         long long n;
         n = strtoll(buf, &cp, 10);
@@ -107,15 +107,20 @@ const char* strptime_ns(const char* buf, const char* fmt, struct tm* tm, long* n
 
         *nanosecond = 0;
         *nanosecondLength = 0;
-        conv_nanosecond((const unsigned char*)(buf + secondTimestampLength), nanosecond, nanosecondLength);
+        const unsigned char* fractionStart = (const unsigned char*)(buf + secondTimestampLength);
+        conv_nanosecond(fractionStart, nanosecond, nanosecondLength);
         return ((const char*)cp);
     }
 
     unsigned char c;
     const unsigned char *bp, *ep;
     int alt_format, i, split_year = 0, neg = 0, offs;
+    char* cp = nullptr;
+    long long n;
+    time_t t;
     const char* new_fmt;
     *nanosecond = 0;
+    *nanosecondLength = 0;
 
     bp = (const unsigned char*)buf;
 
@@ -291,6 +296,22 @@ const char* strptime_ns(const char* buf, const char* fmt, struct tm* tm, long* n
                 LEGAL_ALT(ALT_O);
                 continue;
 
+            case 's': /* Seconds since epoch. */
+                n = strtoll((const char*)bp, &cp, 10);
+                if (n == 0 || (long long)(t = n) != n) {
+                    return NULL;
+                }
+#ifdef _MSC_VER
+                if (localtime_s(tm, &t) != 0)
+                    return NULL;
+#else
+                if (NULL == localtime_r(&t, tm))
+                    return NULL;
+#endif
+                bp = (const unsigned char*)cp;
+                LEGAL_ALT(0);
+                continue;
+
             case 'U': /* The week of year, beginning on sunday. */
             case 'W': /* The week of year, beginning on monday. */
                 /*
@@ -561,20 +582,22 @@ static const unsigned char* conv_num(const unsigned char* buf, int* dest, unsign
 static const unsigned char* conv_nanosecond(const unsigned char* buf, long* dest, int* nanosecondLength) {
     unsigned int result = 0;
     unsigned char ch;
-    int digitNum = 0;
+    int precisionDigitNum = 0;
     const unsigned char* start = buf;
 
     ch = *buf;
     if (ch < '0' || ch > '9')
         return NULL;
 
     do {
-        result *= 10;
-        result += ch - '0';
-        ++digitNum;
+        if (precisionDigitNum < 9) {
+            result *= 10;
+            result += ch - '0';
+            ++precisionDigitNum;
+        }
         ch = *++buf;
     } while (ch >= '0' && ch <= '9');
-    for (int i = 0; i < 9 - digitNum; i++) {
+    for (int i = 0; i < 9 - precisionDigitNum; i++) {
         result *= 10;
     }
     *dest = result;

core/unittest/common/TimeUtilUnittest.h

@@ -193,8 +193,13 @@ void TimeUtilUnittest::TestStrptimeNanosecond() {
          123456000},
         {"1325430307", "%s", "1325430307", "%s", 0},
         {"325430307", "%s", "325430307", "%s", 0},
+        {"1325430307123456", "%s%f", "1325430307", "%s", 123456000},
+        {"1325430307123456789", "%s%f", "1325430307", "%s", 123456789},
+        {"1776235692.2729697", "%s.%f", "1776235692", "%s", 272969700},
+        {"1776235692.2729697123", "%s.%f", "1776235692", "%s", 272969712},
+        {"1776235692.2729697123Z", "%s.%fZ", "1776235692Z", "%sZ", 272969712},
         // the behavior of `strptime_ns` is different with C++ `strptime` in this case
-        // {"1325430307123456", "%s", "1325430307123456", "%s", 123456000},
+        {"1325430307123456", "%s", "1325430307", "%s", 123456000},
         {"15:05:07.123456 2012-01-01", "%H:%M:%S.%f %Y-%m-%d", "15:05:07 2012-01-01", "%H:%M:%S %Y-%m-%d", 123456000},
     };