[M] Change in osmocom-bb[master]: trx_toolkit/*: Represent bursts as arrays instead of lists

fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmocom-bb/+/39536?usp=email ) Change subject: trx_toolkit/*: Represent bursts as arrays instead of lists ...................................................................... trx_toolkit/*: Represent bursts as arrays instead of lists Continuing fake_trx profiling story I noticed that on rx path a noticeable time is spent in converting from ubits to sbits via list comprehensions. By changing burst representation from py list, which stores each item as full python object, to an array, which stores each item as just byte, and by leveraging bytearray.translate, we can speed up that conversion by ~ 10x: before: In [1]: from data_msg import Msg In [2]: burst = [0, 1] * (142//2) In [3]: burst Out[3]: [0, 1, 0, 1, 0, ... 0, 1] In [4]: Msg.ubit2sbit(burst) Out[4]: [127, -127, 127, -127, ... 127, -127] In [5]: %timeit Msg.ubit2sbit(burst) 3.01 µs ± 43.3 ns per loop (mean ± std. dev. of 7 runs, 100,000 loops each) after: In [2]: burst = bytearray([0, 1] * (142//2)) In [3]: burst Out[3]: bytearray(b'\x00\x01\x00\x01...\x00\x01') In [4]: Msg.ubit2sbit(burst) Out[4]: array('b', [127, -127, 127, -127, ... 127, -127]) In [5]: %timeit Msg.ubit2sbit(burst) 325 ns ± 12.1 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each) Change-Id: I7314e9e79752e06fa86b9e346a9beacc5e59579e --- M src/target/trx_toolkit/data_msg.py M src/target/trx_toolkit/gsm_shared.py M src/target/trx_toolkit/rand_burst_gen.py M src/target/trx_toolkit/test_data_msg.py 4 files changed, 36 insertions(+), 25 deletions(-) Approvals: fixeria: Looks good to me, approved Jenkins Builder: Verified pespin: Looks good to me, but someone else must approve diff --git a/src/target/trx_toolkit/data_msg.py b/src/target/trx_toolkit/data_msg.py index 898a4ae..b5993d2 100644 --- a/src/target/trx_toolkit/data_msg.py +++ b/src/target/trx_toolkit/data_msg.py @@ -23,8 +23,13 @@ from typing import List from enum import Enum +from array import array from gsm_shared import * +# _bu2s converts unsigned byte to signed. +def _bu2s(x): + return struct.unpack('b', struct.pack('B', x))[0] + class Modulation(Enum): """ Modulation types defined in 3GPP TS 45.002 """ ModGMSK = (0b0000, 1 * GMSK_BURST_LEN) @@ -63,7 +68,7 @@ KNOWN_VERSIONS = (0, 1) def __init__(self, fn = None, tn = None, burst = None, ver = 0): - self.burst = burst + self.burst = burst # bytes|bytearray for ubit, array[b] for sbit, array[B] for usbit self.ver = ver self.fn = fn self.tn = tn @@ -126,24 +131,29 @@ return result @staticmethod - def usbit2sbit(bits: List[int]) -> List[int]: + def usbit2sbit(bits): # array[B] -> array[b] ''' Convert unsigned soft-bits {254..0} to soft-bits {-127..127}. ''' - return [-127 if (b == 0xff) else 127 - b for b in bits] + return array('b', bits.tobytes().translate(Msg._tab_usbit2sbit)) + _tab_usbit2sbit = array('b', [-127 if (b == 0xff) else 127 - b for b in range(0x100)]) @staticmethod - def sbit2usbit(bits: List[int]) -> List[int]: + def sbit2usbit(bits): # array[b] -> array[B] ''' Convert soft-bits {-127..127} to unsigned soft-bits {254..0}. ''' - return [127 - b for b in bits] + return array('B', bits.tobytes().translate(Msg._tab_sbit2usbit)) + _tab_sbit2usbit = array('B', [127 - _bu2s(b) for b in range(0x100)]) @staticmethod - def sbit2ubit(bits: List[int]) -> List[int]: + def sbit2ubit(bits): # array[b] -> bytearray ''' Convert soft-bits {-127..127} to bits {1..0}. ''' - return [int(b < 0) for b in bits] + return bytearray(bits).translate(Msg._tab_sbit2ubit) + _tab_sbit2ubit = array('B', [int(_bu2s(b) < 0) for b in range(0x100)]) @staticmethod - def ubit2sbit(bits: List[int]) -> List[int]: + def ubit2sbit(bits: bytearray): # -> array[b] ''' Convert bits {1..0} to soft-bits {-127..127}. ''' - return [-127 if b else 127 for b in bits] + return array('b', bits.translate(Msg._tab_ubit2sbit)) + _tab_ubit2sbit = array('b', [-127 if b else 127 for b in range(0x100)]) + def validate(self): ''' Validate the message fields (throws ValueError). ''' @@ -328,13 +338,13 @@ # Distinguish between GSM and EDGE if length >= EDGE_BURST_LEN: - self.burst = list(burst[:EDGE_BURST_LEN]) + self.burst = bytearray(burst[:EDGE_BURST_LEN]) else: - self.burst = list(burst[:GMSK_BURST_LEN]) + self.burst = bytearray(burst[:GMSK_BURST_LEN]) def rand_burst(self, length = GMSK_BURST_LEN): ''' Generate a random message specific burst. ''' - self.burst = [random.randint(0, 1) for _ in range(length)] + self.burst = bytearray([random.randint(0, 1) for _ in range(length)]) def trans(self, ver = None): ''' Transform this message into RxMsg. ''' @@ -659,7 +669,7 @@ def parse_burst(self, burst): ''' Parse message specific burst. ''' - burst = list(burst) + burst = array('B', burst) if self.ver == 0x00: burst = self._parse_burst_v0(burst) @@ -673,7 +683,7 @@ if length is None: length = self.mod_type.bl - self.burst = [random.randint(-127, 127) for _ in range(length)] + self.burst = array('b', [random.randint(-127, 127) for _ in range(length)]) def trans(self, ver = None): ''' Transform this message to TxMsg. ''' diff --git a/src/target/trx_toolkit/gsm_shared.py b/src/target/trx_toolkit/gsm_shared.py index 5f59ba6..977d2aa 100644 --- a/src/target/trx_toolkit/gsm_shared.py +++ b/src/target/trx_toolkit/gsm_shared.py @@ -81,7 +81,7 @@ self.tsc_set = tsc_set # Generate Training Sequence bits - self.seq = [int(x) for x in seq_str] + self.seq = bytearray(int(x) for x in seq_str) @classmethod def pick(self, burst): diff --git a/src/target/trx_toolkit/rand_burst_gen.py b/src/target/trx_toolkit/rand_burst_gen.py index c474c75..6cdab30 100644 --- a/src/target/trx_toolkit/rand_burst_gen.py +++ b/src/target/trx_toolkit/rand_burst_gen.py @@ -25,7 +25,7 @@ class RandBurstGen: # GSM 05.02 Chapter 5.2.6 Dummy Burst - db_bits = [ + db_bits = bytearray([ 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, @@ -37,7 +37,7 @@ 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, - ] + ]) # Pick a random TSC for a given burst type def get_rand_tsc(self, bt): @@ -72,11 +72,11 @@ # Tailing bits buf += [0] * 3 - return buf + return bytearray(buf) # Generate a frequency correction burst def gen_fb(self): - return [0] * GMSK_BURST_LEN + return bytearray([0] * GMSK_BURST_LEN) # Generate a synchronization burst def gen_sb(self, tsc = None): @@ -99,7 +99,7 @@ # Tailing bits buf += [0] * 3 - return buf + return bytearray(buf) # Generate a dummy burst def gen_db(self): @@ -126,4 +126,4 @@ # Guard period buf += [0] * 60 - return buf + return bytearray(buf) diff --git a/src/target/trx_toolkit/test_data_msg.py b/src/target/trx_toolkit/test_data_msg.py index ec6c2ec..13a64a6 100644 --- a/src/target/trx_toolkit/test_data_msg.py +++ b/src/target/trx_toolkit/test_data_msg.py @@ -19,6 +19,7 @@ # GNU General Public License for more details. import unittest +from array import array from data_msg import Msg, TxMsg, RxMsg @@ -136,8 +137,8 @@ # Validate bit conversations def test_bit_conv(self): - usbits_ref = list(range(0, 256)) - sbits_ref = list(range(-127, 128)) + usbits_ref = array('B', range(0, 256)) + sbits_ref = array('b', range(-127, 128)) # Test both usbit2sbit() and sbit2usbit() sbits = Msg.usbit2sbit(usbits_ref) @@ -147,10 +148,10 @@ # Test both sbit2ubit() and ubit2sbit() ubits = Msg.sbit2ubit(sbits_ref) - self.assertEqual(ubits, ([1] * 127 + [0] * 128)) + self.assertEqual(ubits, bytearray([1] * 127 + [0] * 128)) sbits = Msg.ubit2sbit(ubits) - self.assertEqual(sbits, ([-127] * 127 + [127] * 128)) + self.assertEqual(sbits, array('b', [-127] * 127 + [127] * 128)) def _test_transform(self, msg): # Prepare given messages -- To view, visit https://gerrit.osmocom.org/c/osmocom-bb/+/39536?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings?usp=email Gerrit-MessageType: merged Gerrit-Project: osmocom-bb Gerrit-Branch: master Gerrit-Change-Id: I7314e9e79752e06fa86b9e346a9beacc5e59579e Gerrit-Change-Number: 39536 Gerrit-PatchSet: 2 Gerrit-Owner: kirr &lt;kirr(a)nexedi.com&gt; Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-Reviewer: pespin &lt;pespin(a)sysmocom.de&gt; Gerrit-CC: osmith &lt;osmith(a)sysmocom.de&gt;