@@ -172,42 +172,51 @@ class TestCounts:
class LineStream:
"""
A class to represent the lines of kernel output.
- Provides a peek()/pop() interface over an iterator of
+ Provides a lazy peek()/pop() interface over an iterator of
(line#, text).
"""
_lines: Iterator[Tuple[int, str]]
_next: Tuple[int, str]
+ _need_next: bool
_done: bool
def __init__(self, lines: Iterator[Tuple[int, str]]):
"""Creates a new LineStream that wraps the given iterator."""
self._lines = lines
self._done = False
+ self._need_next = True
self._next = (0, '')
- self._get_next()
def _get_next(self) -> None:
- """Advances the LineSteam to the next line."""
+ """Advances the LineSteam to the next line, if necessary."""
+ if not self._need_next:
+ return
try:
self._next = next(self._lines)
except StopIteration:
self._done = True
+ finally:
+ self._need_next = False
def peek(self) -> str:
"""Returns the current line, without advancing the LineStream.
"""
+ self._get_next()
return self._next[1]
def pop(self) -> str:
"""Returns the current line and advances the LineStream to
the next line.
"""
- n = self._next
- self._get_next()
- return n[1]
+ s = self.peek()
+ if self._done:
+ raise ValueError(f'LineStream: going past EOF, last line was {s}')
+ self._need_next = True
+ return s
def __bool__(self) -> bool:
"""Returns True if stream has more lines."""
+ self._get_next()
return not self._done
# Only used by kunit_tool_test.py.
@@ -220,6 +229,7 @@ class LineStream:
def line_number(self) -> int:
"""Returns the line number of the current line."""
+ self._get_next()
return self._next[0]
# Parsing helper methods:
@@ -13,9 +13,10 @@ import tempfile, shutil # Handling test_tmpdir
import itertools
import json
+import os
import signal
import subprocess
-import os
+from typing import Iterable
import kunit_config
import kunit_parser
@@ -319,6 +320,45 @@ class KUnitParserTest(unittest.TestCase):
result.status)
self.assertEqual('kunit-resource-test', result.test.subtests[0].name)
+def line_stream_from_strs(strs: Iterable[str]) -> kunit_parser.LineStream:
+ return kunit_parser.LineStream(enumerate(strs, start=1))
+
+class LineStreamTest(unittest.TestCase):
+
+ def test_basic(self):
+ stream = line_stream_from_strs(['hello', 'world'])
+
+ self.assertTrue(stream, msg='Should be more input')
+ self.assertEqual(stream.line_number(), 1)
+ self.assertEqual(stream.peek(), 'hello')
+ self.assertEqual(stream.pop(), 'hello')
+
+ self.assertTrue(stream, msg='Should be more input')
+ self.assertEqual(stream.line_number(), 2)
+ self.assertEqual(stream.peek(), 'world')
+ self.assertEqual(stream.pop(), 'world')
+
+ self.assertFalse(stream, msg='Should be no more input')
+ with self.assertRaisesRegex(ValueError, 'LineStream: going past EOF'):
+ stream.pop()
+
+ def test_is_lazy(self):
+ called_times = 0
+ def generator():
+ nonlocal called_times
+ for i in range(1,5):
+ called_times += 1
+ yield called_times, str(called_times)
+
+ stream = kunit_parser.LineStream(generator())
+ self.assertEqual(called_times, 0)
+
+ self.assertEqual(stream.pop(), '1')
+ self.assertEqual(called_times, 1)
+
+ self.assertEqual(stream.pop(), '2')
+ self.assertEqual(called_times, 2)
+
class LinuxSourceTreeTest(unittest.TestCase):
def setUp(self):