From eecf4ef13cb5138cea62c90b9371183af7c7b733 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Ma=C5=9Blanka?= <piotr.maslanka@henrietta.com.pl>
Date: Mon, 14 Dec 2020 20:08:01 +0100
Subject: [PATCH] add getting current value for VarlenSeries
---
tempsdb/database.pyx | 8 ++++++--
tempsdb/varlen.pxd | 3 ++-
tempsdb/varlen.pyx | 20 ++++++++++++++++++++
tests/test_database.py | 2 ++
4 files changed, 30 insertions(+), 3 deletions(-)
diff --git a/tempsdb/database.pyx b/tempsdb/database.pyx
index 5ddaaf4..1689a24 100644
--- a/tempsdb/database.pyx
+++ b/tempsdb/database.pyx
@@ -56,7 +56,9 @@ cdef class Database:
cpdef int delete_series(self, str name) except -1:
"""
- Deletes a constant-length time series
+ Deletes a constant-length time series.
+
+ Note that the series must either not be open, or closed.
:param name: name of series to delete
:raises ValueError: tried to delete "varlen" series
@@ -77,7 +79,9 @@ cdef class Database:
cpdef int delete_varlen_series(self, str name) except -1:
"""
- Deletes a variable-length time series
+ Deletes a variable-length time series.
+
+ Note that the series must either not be open, or closed.
:param name: name of series to delete
:raises DoesNotExist: series does not exist
diff --git a/tempsdb/varlen.pxd b/tempsdb/varlen.pxd
index e792533..1657ccc 100644
--- a/tempsdb/varlen.pxd
+++ b/tempsdb/varlen.pxd
@@ -1,4 +1,4 @@
-from .series cimport TimeSeries, create_series
+from .series cimport TimeSeries
cdef class VarlenSeries:
@@ -20,6 +20,7 @@ cdef class VarlenSeries:
cpdef int mark_synced_up_to(self, unsigned long long timestamp) except -1
cpdef int close(self) except -1
cpdef int delete(self) except -1
+ cpdef tuple get_current_value(self)
cdef int get_length_for(self, int index)
cpdef int trim(self, unsigned long long timestamp) except -1
cdef int add_series(self) except -1
diff --git a/tempsdb/varlen.pyx b/tempsdb/varlen.pyx
index 3131c53..99d252c 100644
--- a/tempsdb/varlen.pyx
+++ b/tempsdb/varlen.pyx
@@ -435,6 +435,26 @@ cdef class VarlenSeries:
"""
return VarlenIterator(self, start, stop, direct_bytes=direct_bytes)
+ cpdef tuple get_current_value(self):
+ """
+ Return latest value of this series
+
+ :return: tuple of (timestamp, value)
+ :rtype: tp.Tuple[int, bytes]
+ :raises ValueError: series has no data
+ """
+ if self.root_series.last_chunk is None:
+ raise ValueError('No data in series')
+ cdef:
+ VarlenIterator it = self.iterate_range(self.root_series.last_entry_ts,
+ self.root_series.last_entry_ts)
+ VarlenEntry et = it.get_next()
+ try:
+ return et.timestamp(), et.to_bytes()
+ finally:
+ et.close()
+ it.close()
+
def __init__(self, path: str, name: str):
self.closed = False
self.path = path
diff --git a/tests/test_database.py b/tests/test_database.py
index 2d1686d..24ab246 100644
--- a/tests/test_database.py
+++ b/tests/test_database.py
@@ -16,6 +16,7 @@ class TestDatabase(unittest.TestCase):
ser.close()
ser = self.db.get_series('hello-world')
+ self.assertEqual(ser.get_current_value(), (20, b'\x00'))
self.assertEqual(ser.last_entry_ts, 20)
ser.close()
@@ -29,6 +30,7 @@ class TestDatabase(unittest.TestCase):
ser.close()
ser = self.db.get_varlen_series('hello-world')
+ self.assertEqual(ser.get_current_value(), (20, b'\x00\x00\x00'))
self.assertEqual(ser.last_entry_ts, 20)
ser.close()
--
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