import io
import platform
import queue
import re
import subprocess
import sys
import unittest
from _android_support import TextLogStream
from array import array
from contextlib import ExitStack, contextmanager
from threading import Thread
from test.support import LOOPBACK_TIMEOUT
from time import sleep, time
from unittest.mock import patch
if sys.platform != "android":
raise unittest.SkipTest("Android-specific")
api_level = platform.android_ver().api_level
# (name, level, fileno)
STREAM_INFO = [("stdout", "I", 1), ("stderr", "W", 2)]
# Test redirection of stdout and stderr to the Android log.
@unittest.skipIf(
api_level < 23 and platform.machine() == "aarch64",
"SELinux blocks reading logs on older ARM64 emulators"
)
class TestAndroidOutput(unittest.TestCase):
maxDiff = None
def setUp(self):
self.logcat_process = subprocess.Popen(
["logcat", "-v", "tag"], stdout=subprocess.PIPE,
errors="backslashreplace"
)
self.logcat_queue = queue.Queue()
def logcat_thread():
for line in self.logcat_process.stdout:
self.logcat_queue.put(line.rstrip("\n"))
self.logcat_process.stdout.close()
Thread(target=logcat_thread).start()
from ctypes import CDLL, c_char_p, c_int
android_log_write = getattr(CDLL("liblog.so"), "__android_log_write")
android_log_write.argtypes = (c_int, c_char_p, c_char_p)
ANDROID_LOG_INFO = 4
# Separate tests using a marker line with a different tag.
tag, message = "python.test", f"{self.id()} {time()}"
android_log_write(
ANDROID_LOG_INFO, tag.encode("UTF-8"), message.encode("UTF-8"))
self.assert_log("I", tag, message, skip=True, timeout=5)
def assert_logs(self, level, tag, expected, **kwargs):
for line in expected:
self.assert_log(level, tag, line, **kwargs)
def assert_log(self, level, tag, expected, *, skip=False, timeout=0.5):
deadline = time() + timeout
while True:
try:
line = self.logcat_queue.get(timeout=(deadline - time()))
except queue.Empty:
self.fail(f"line not found: {expected!r}")
if match := re.fullmatch(fr"(.)/{tag}: (.*)", line):
try:
self.assertEqual(level, match[1])
self.assertEqual(expected, match[2])
break
except AssertionError:
if not skip:
raise
def tearDown(self):
self.logcat_process.terminate()
self.logcat_process.wait(LOOPBACK_TIMEOUT)
@contextmanager
def unbuffered(self, stream):
stream.reconfigure(write_through=True)
try:
yield
finally:
stream.reconfigure(write_through=False)
# In --verbose3 mode, sys.stdout and sys.stderr are captured, so we can't
# test them directly. Detect this mode and use some temporary streams with
# the same properties.
def stream_context(self, stream_name, level):
# https://developer.android.com/ndk/reference/group/logging
prio = {"I": 4, "W": 5}[level]
stack = ExitStack()
stack.enter_context(self.subTest(stream_name))
stream = getattr(sys, stream_name)
native_stream = getattr(sys, f"__{stream_name}__")
if isinstance(stream, io.StringIO):
stack.enter_context(
patch(
f"sys.{stream_name}",
TextLogStream(
prio, f"python.{stream_name}", native_stream.fileno(),
errors="backslashreplace"
),
)
)
return stack
def test_str(self):
for stream_name, level, fileno in STREAM_INFO:
with self.stream_context(stream_name, level):
stream = getattr(sys, stream_name)
tag = f"python.{stream_name}"
self.assertEqual(f"<TextLogStream '{tag}'>", repr(stream))
self.assertIs(stream.writable(), True)
self.assertIs(stream.readable(), False)
self.assertEqual(stream.fileno(), fileno)
self.assertEqual("UTF-8", stream.encoding)
self.assertIs(stream.line_buffering, True)
self.assertIs(stream.write_through, False)
# stderr is backslashreplace by default; stdout is configured
# that way by libregrtest.main.
self.assertEqual("backslashreplace", stream.errors)
def write(s, lines=None, *, write_len=None):
if write_len is None:
write_len = len(s)
self.assertEqual(write_len, stream.write(s))
if lines is None:
lines = [s]
self.assert_logs(level, tag, lines)
# Single-line messages,
with self.unbuffered(stream):
write("", [])
write("a")
write("Hello")
write("Hello world")
write(" ")
write(" ")
# Non-ASCII text
write("ol\u00e9") # Spanish
write("\u4e2d\u6587") # Chinese
# Non-BMP emoji
write("\U0001f600")
# Non-encodable surrogates
write("\ud800\udc00", [r"\ud800\udc00"])
# Code used by surrogateescape (which isn't enabled here)
write("\udc80", [r"\udc80"])
# Null characters are logged using "modified UTF-8".
write("\u0000", [r"\xc0\x80"])
write("a\u0000", [r"a\xc0\x80"])
write("\u0000b", [r"\xc0\x80b"])
write("a\u0000b", [r"a\xc0\x80b"])
# Multi-line messages. Avoid identical consecutive lines, as
# they may activate "chatty" filtering and break the tests.
write("\nx", [""])
write("\na\n", ["x", "a"])
write("\n", [""])
write("b\n", ["b"])
write("c\n\n", ["c", ""])
write("d\ne", ["d"])
write("xx", [])
write("f\n\ng", ["exxf", ""])
write("\n", ["g"])
# Since this is a line-based logging system, line buffering
# cannot be turned off, i.e. a newline always causes a flush.
stream.reconfigure(line_buffering=False)
self.assertIs(stream.line_buffering, True)
# However, buffering can be turned off completely if you want a
# flush after every write.
with self.unbuffered(stream):
write("\nx", ["", "x"])
write("\na\n", ["", "a"])
write("\n", [""])
write("b\n", ["b"])
write("c\n\n", ["c", ""])
write("d\ne", ["d", "e"])
write("xx", ["xx"])
write("f\n\ng", ["f", "", "g"])
write("\n", [""])
# "\r\n" should be translated into "\n".
write("hello\r\n", ["hello"])
write("hello\r\nworld\r\n", ["hello", "world"])
write("\r\n", [""])
# Non-standard line separators should be preserved.
write("before form feed\x0cafter form feed\n",
["before form feed\x0cafter form feed"])
write("before line separator\u2028after line separator\n",
["before line separator\u2028after line separator"])
# String subclasses are accepted, but they should be converted
# to a standard str without calling any of their methods.
class CustomStr(str):
def splitlines(self, *args, **kwargs):
raise AssertionError()
def __len__(self):
raise AssertionError()
def __str__(self):
raise AssertionError()
write(CustomStr("custom\n"), ["custom"], write_len=7)
# Non-string classes are not accepted.
for obj in [b"", b"hello", None, 42]:
with self.subTest(obj=obj):
with self.assertRaisesRegex(
TypeError,
fr"write\(\) argument must be str, not "
fr"{type(obj).__name__}"
):
stream.write(obj)
# Manual flushing is supported.
write("hello", [])
stream.flush()
self.assert_log(level, tag, "hello")
write("hello", [])
write("world", [])
stream.flush()
self.assert_log(level, tag, "helloworld")
# Long lines are split into blocks of 1000 characters
# (MAX_CHARS_PER_WRITE in _android_support.py), but
# TextIOWrapper should then join them back together as much as
# possible without exceeding 4000 UTF-8 bytes
# (MAX_BYTES_PER_WRITE).
#
# ASCII (1 byte per character)
write(("foobar" * 700) + "\n", # 4200 bytes in
[("foobar" * 666) + "foob", # 4000 bytes out
"ar" + ("foobar" * 33)]) # 200 bytes out
# "Full-width" digits 0-9 (3 bytes per character)
s = "\uff10\uff11\uff12\uff13\uff14\uff15\uff16\uff17\uff18\uff19"
write((s * 150) + "\n", # 4500 bytes in
[s * 100, # 3000 bytes out
s * 50]) # 1500 bytes out
s = "0123456789"
write(s * 200, []) # 2000 bytes in
write(s * 150, []) # 1500 bytes in
write(s * 51, [s * 350]) # 510 bytes in, 3500 bytes out
write("\n", [s * 51]) # 0 bytes in, 510 bytes out
def test_bytes(self):
for stream_name, level, fileno in STREAM_INFO:
with self.stream_context(stream_name, level):
stream = getattr(sys, stream_name).buffer
tag = f"python.{stream_name}"
self.assertEqual(f"<BinaryLogStream '{tag}'>", repr(stream))
self.assertIs(stream.writable(), True)
self.assertIs(stream.readable(), False)
self.assertEqual(stream.fileno(), fileno)
def write(b, lines=None, *, write_len=None):
if write_len is None:
write_len = len(b)
self.assertEqual(write_len, stream.write(b))
if lines is None:
lines = [b.decode()]
self.assert_logs(level, tag, lines)
# Single-line messages,
write(b"", [])
write(b"a")
write(b"Hello")
write(b"Hello world")
write(b" ")
write(b" ")
# Non-ASCII text
write(b"ol\xc3\xa9") # Spanish
write(b"\xe4\xb8\xad\xe6\x96\x87") # Chinese
# Non-BMP emoji
write(b"\xf0\x9f\x98\x80")
# Null bytes are logged using "modified UTF-8".
write(b"\x00", [r"\xc0\x80"])
write(b"a\x00", [r"a\xc0\x80"])
write(b"\x00b", [r"\xc0\x80b"])
write(b"a\x00b", [r"a\xc0\x80b"])
# Invalid UTF-8
write(b"\xff", [r"\xff"])
write(b"a\xff", [r"a\xff"])
write(b"\xffb", [r"\xffb"])
write(b"a\xffb", [r"a\xffb"])
# Log entries containing newlines are shown differently by
# `logcat -v tag`, `logcat -v long`, and Android Studio. We
# currently use `logcat -v tag`, which shows each line as if it
# was a separate log entry, but strips a single trailing
# newline.
#
# On newer versions of Android, all three of the above tools (or
# maybe Logcat itself) will also strip any number of leading
# newlines.
write(b"\nx", ["", "x"] if api_level < 30 else ["x"])
write(b"\na\n", ["", "a"] if api_level < 30 else ["a"])
write(b"\n", [""])
write(b"b\n", ["b"])
write(b"c\n\n", ["c", ""])
write(b"d\ne", ["d", "e"])
write(b"xx", ["xx"])
write(b"f\n\ng", ["f", "", "g"])
write(b"\n", [""])
# "\r\n" should be translated into "\n".
write(b"hello\r\n", ["hello"])
write(b"hello\r\nworld\r\n", ["hello", "world"])
write(b"\r\n", [""])
# Other bytes-like objects are accepted.
write(bytearray(b"bytearray"))
mv = memoryview(b"memoryview")
write(mv, ["memoryview"]) # Continuous
write(mv[::2], ["mmrve"]) # Discontinuous
write(
# Android only supports little-endian architectures, so the
# bytes representation is as follows:
array("H", [
0, # 00 00
1, # 01 00
65534, # FE FF
65535, # FF FF
]),
# After encoding null bytes with modified UTF-8, the only
# valid UTF-8 sequence is \x01. All other bytes are handled
# by backslashreplace.
["\\xc0\\x80\\xc0\\x80"
"\x01\\xc0\\x80"
"\\xfe\\xff"
"\\xff\\xff"],
write_len=8,
)
# Non-bytes-like classes are not accepted.
for obj in ["", "hello", None, 42]:
with self.subTest(obj=obj):
with self.assertRaisesRegex(
TypeError,
fr"write\(\) argument must be bytes-like, not "
fr"{type(obj).__name__}"
):
stream.write(obj)
def test_rate_limit(self):
# https://cs.android.com/android/platform/superproject/+/android-14.0.0_r1:system/logging/liblog/include/log/log_read.h;l=39
PER_MESSAGE_OVERHEAD = 28
# https://developer.android.com/ndk/reference/group/logging
ANDROID_LOG_DEBUG = 3
# To avoid flooding the test script output, use a different tag rather
# than stdout or stderr.
tag = "python.rate_limit"
stream = TextLogStream(ANDROID_LOG_DEBUG, tag)
# Make a test message which consumes 1 KB of the logcat buffer.
message = "Line {:03d} "
message += "." * (
1024 - PER_MESSAGE_OVERHEAD - len(tag) - len(message.format(0))
) + "\n"
# See _android_support.py. The default values of these parameters work
# well across a wide range of devices, but we'll use smaller values to
# ensure a quick and reliable test that doesn't flood the log too much.
MAX_KB_PER_SECOND = 100
BUCKET_KB = 10
with (
patch("_android_support.MAX_BYTES_PER_SECOND", MAX_KB_PER_SECOND * 1024),
patch("_android_support.BUCKET_SIZE", BUCKET_KB * 1024),
):
# Make sure the token bucket is full.
sleep(BUCKET_KB / MAX_KB_PER_SECOND)
line_num = 0
# Write BUCKET_KB messages, and return the rate at which they were
# accepted in KB per second.
def write_bucketful():
nonlocal line_num
start = time()
max_line_num = line_num + BUCKET_KB
while line_num < max_line_num:
stream.write(message.format(line_num))
line_num += 1
return BUCKET_KB / (time() - start)
# The first bucketful should be written with minimal delay. The
# factor of 2 here is not arbitrary: it verifies that the system can
# write fast enough to empty the bucket within two bucketfuls, which
# the next part of the test depends on.
self.assertGreater(write_bucketful(), MAX_KB_PER_SECOND * 2)
# Write another bucketful to empty the token bucket completely.
write_bucketful()
# The next bucketful should be written at the rate limit.
self.assertAlmostEqual(
write_bucketful(), MAX_KB_PER_SECOND,
delta=MAX_KB_PER_SECOND * 0.1
)
# Once the token bucket refills, we should go back to full speed.
sleep(BUCKET_KB / MAX_KB_PER_SECOND)
self.assertGreater(write_bucketful(), MAX_KB_PER_SECOND * 2)
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