From 905aefd6b94de705bb269e164c36eadd0d4ee816 Mon Sep 17 00:00:00 2001
From: Inada Naoki <songofacandy@gmail.com>
Date: Thu, 29 Feb 2024 15:26:26 +0900
Subject: [PATCH] use time.time_ns() for better precision (#202)

Signed-off-by: Inada Naoki <songofacandy@gmail.com>
---
 fluent/event.py  |  9 +++++----
 fluent/sender.py | 14 ++++++++++----
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/fluent/event.py b/fluent/event.py
index c69e537..a8c4d7b 100644
--- a/fluent/event.py
+++ b/fluent/event.py
@@ -1,5 +1,3 @@
-import time
-
 from fluent import sender
 
 
@@ -7,5 +5,8 @@ class Event:
     def __init__(self, label, data, **kwargs):
         assert isinstance(data, dict), "data must be a dict"
         sender_ = kwargs.get("sender", sender.get_global_sender())
-        timestamp = kwargs.get("time", int(time.time()))
-        sender_.emit_with_time(label, timestamp, data)
+        timestamp = kwargs.get("time", None)
+        if timestamp is not None:
+            sender_.emit_with_time(label, timestamp, data)
+        else:
+            sender_.emit(label, data)
diff --git a/fluent/sender.py b/fluent/sender.py
index 320ce78..fe5fd35 100644
--- a/fluent/sender.py
+++ b/fluent/sender.py
@@ -30,15 +30,21 @@ def close():  # pragma: no cover
 
 
 class EventTime(msgpack.ExtType):
-    def __new__(cls, timestamp):
+    def __new__(cls, timestamp, nanoseconds=None):
         seconds = int(timestamp)
-        nanoseconds = int(timestamp % 1 * 10**9)
+        if nanoseconds is None:
+            nanoseconds = int(timestamp % 1 * 10**9)
         return super().__new__(
             cls,
             code=0,
             data=struct.pack(">II", seconds, nanoseconds),
         )
 
+    @classmethod
+    def from_unix_nano(cls, unix_nano):
+        seconds, nanos = divmod(unix_nano, 10**9)
+        return cls(seconds, nanos)
+
 
 class FluentSender:
     def __init__(
@@ -78,7 +84,7 @@ def __init__(
 
     def emit(self, label, data):
         if self.nanosecond_precision:
-            cur_time = EventTime(time.time())
+            cur_time = EventTime.from_unix_nano(time.time_ns())
         else:
             cur_time = int(time.time())
         return self.emit_with_time(label, cur_time, data)
@@ -129,7 +135,7 @@ def close(self):
 
     def _make_packet(self, label, timestamp, data):
         if label:
-            tag = ".".join((self.tag, label)) if self.tag else label
+            tag = f"{self.tag}.{label}" if self.tag else label
         else:
             tag = self.tag
         if self.nanosecond_precision and isinstance(timestamp, float):