diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/io.py | 36 | ||||
| -rw-r--r-- | Lib/test/test_io.py | 67 |
2 files changed, 59 insertions, 44 deletions
@@ -1,9 +1,15 @@ -"""New I/O library. +"""New I/O library conforming to PEP 3116. This is an early prototype; eventually some of this will be reimplemented in C and the rest may be turned into a package. -See PEP 3116. +Conformance of alternative implementations: all arguments are intended +to be positional-only except the arguments of the open() function. +Argument names except those of the open() function are not part of the +specification. Instance variables and methods whose name starts with +a leading underscore are not part of the specification (except "magic" +names like __iter__). Only the top-level names listed in the __all__ +variable are part of the specification. XXX need to default buffer size to 1 if isatty() XXX need to support 1 meaning line-buffered @@ -142,6 +148,9 @@ class IOBase: This does not define read(), readinto() and write(), nor readline() and friends, since their signatures vary per layer. + + Not that calling any method (even inquiries) on a closed file is + undefined. Implementations may raise IOError in this case. """ ### Internal ### @@ -153,19 +162,20 @@ class IOBase: ### Positioning ### - def seek(self, pos: int, whence: int = 0) -> None: - """seek(pos: int, whence: int = 0) -> None. Change stream position. + def seek(self, pos: int, whence: int = 0) -> int: + """seek(pos: int, whence: int = 0) -> int. Change stream position. Seek to byte offset pos relative to position indicated by whence: 0 Start of stream (the default). pos should be >= 0; 1 Current position - whence may be negative; 2 End of stream - whence usually negative. + Returns the new absolute position. """ self._unsupported("seek") def tell(self) -> int: """tell() -> int. Return current stream position.""" - self._unsupported("tell") + return self.seek(0, 1) def truncate(self, pos: int = None) -> None: """truncate(size: int = None) -> None. Truncate file to size bytes. @@ -432,7 +442,7 @@ class _BufferedIOMixin(BufferedIOBase): ### Positioning ### def seek(self, pos, whence=0): - self.raw.seek(pos, whence) + return self.raw.seek(pos, whence) def tell(self): return self.raw.tell() @@ -515,6 +525,7 @@ class _MemoryIOMixin(BufferedIOBase): self._pos = max(0, len(self._buffer) + pos) else: raise IOError("invalid whence value") + return self._pos def tell(self): return self._pos @@ -620,8 +631,9 @@ class BufferedReader(_BufferedIOMixin): def seek(self, pos, whence=0): if whence == 1: pos -= len(self._read_buf) - self.raw.seek(pos, whence) + pos = self.raw.seek(pos, whence) self._read_buf = b"" + return pos class BufferedWriter(_BufferedIOMixin): @@ -679,7 +691,7 @@ class BufferedWriter(_BufferedIOMixin): def seek(self, pos, whence=0): self.flush() - self.raw.seek(pos, whence) + return self.raw.seek(pos, whence) class BufferedRWPair(BufferedIOBase): @@ -750,13 +762,9 @@ class BufferedRandom(BufferedWriter, BufferedReader): self.flush() # First do the raw seek, then empty the read buffer, so that # if the raw seek fails, we don't lose buffered data forever. - self.raw.seek(pos, whence) + pos = self.raw.seek(pos, whence) self._read_buf = b"" - # XXX I suppose we could implement some magic here to move through the - # existing read buffer in the case of seek(<some small +ve number>, 1) - # XXX OTOH it might be good to *guarantee* that the buffer is - # empty after a seek or flush; for small relative forward - # seeks one might as well use small reads instead. + return pos def tell(self): if (self._write_buf): diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py index 2ca1e70..87d6df6 100644 --- a/Lib/test/test_io.py +++ b/Lib/test/test_io.py @@ -4,10 +4,10 @@ import unittest from itertools import chain from test import test_support -import io +import io # The module under test -class MockIO(io.RawIOBase): +class MockRawIO(io.RawIOBase): def __init__(self, read_stack=()): self._read_stack = list(read_stack) @@ -56,13 +56,13 @@ class MockFileIO(io.BytesIO): class MockNonBlockWriterIO(io.RawIOBase): - def __init__(self, blockingScript): - self.bs = list(blockingScript) + def __init__(self, blocking_script): + self._blocking_script = list(blocking_script) self._write_stack = [] def write(self, b): self._write_stack.append(b[:]) - n = self.bs.pop(0) + n = self._blocking_script.pop(0) if (n < 0): raise io.BlockingIOError(0, "test blocking", -n) else: @@ -90,6 +90,23 @@ class IOTest(unittest.TestCase): f.seek(-2, 2) f.truncate() + def large_file_ops(self, f): + assert f.readable() + assert f.writable() + self.assertEqual(f.seek(2**32), 2**32) + self.assertEqual(f.tell(), 2**32) + self.assertEqual(f.write(b"xxx"), 3) + self.assertEqual(f.tell(), 2**32 + 3) + self.assertEqual(f.seek(-1, 1), 2**32 + 2) + f.truncate() + self.assertEqual(f.tell(), 2**32 + 2) + self.assertEqual(f.seek(0, 2), 2**32 + 2) + f.truncate(2**32 + 1) + self.assertEqual(f.tell(), 2**32 + 1) + self.assertEqual(f.seek(0, 2), 2**32 + 1) + self.assertEqual(f.seek(-1, 2), 2**32) + self.assertEqual(f.read(2), b"x") + def read_ops(self, f): data = f.read(5) self.assertEqual(data, b"hello") @@ -130,19 +147,9 @@ class IOTest(unittest.TestCase): f = io.BytesIO(data) self.read_ops(f) - def test_fileio_FileIO(self): - import _fileio - f = _fileio._FileIO(test_support.TESTFN, "w") - self.assertEqual(f.readable(), False) - self.assertEqual(f.writable(), True) - self.assertEqual(f.seekable(), True) - self.write_ops(f) - f.close() - f = _fileio._FileIO(test_support.TESTFN, "r") - self.assertEqual(f.readable(), True) - self.assertEqual(f.writable(), False) - self.assertEqual(f.seekable(), True) - self.read_ops(f) + def test_large_file_ops(self): + f = io.open(test_support.TESTFN, "w+b", buffering=0) + self.large_file_ops(f) f.close() @@ -205,7 +212,7 @@ class StringIOTest(MemorySeekTestMixin, unittest.TestCase): class BufferedReaderTest(unittest.TestCase): def testRead(self): - rawio = MockIO((b"abc", b"d", b"efg")) + rawio = MockRawIO((b"abc", b"d", b"efg")) bufio = io.BufferedReader(rawio) self.assertEquals(b"abcdef", bufio.read(6)) @@ -231,7 +238,7 @@ class BufferedReaderTest(unittest.TestCase): def testReadNonBlocking(self): # Inject some None's in there to simulate EWOULDBLOCK - rawio = MockIO((b"abc", b"d", None, b"efg", None, None)) + rawio = MockRawIO((b"abc", b"d", None, b"efg", None, None)) bufio = io.BufferedReader(rawio) self.assertEquals(b"abcd", bufio.read(6)) @@ -241,19 +248,19 @@ class BufferedReaderTest(unittest.TestCase): self.assertEquals(b"", bufio.read()) def testReadToEof(self): - rawio = MockIO((b"abc", b"d", b"efg")) + rawio = MockRawIO((b"abc", b"d", b"efg")) bufio = io.BufferedReader(rawio) self.assertEquals(b"abcdefg", bufio.read(9000)) def testReadNoArgs(self): - rawio = MockIO((b"abc", b"d", b"efg")) + rawio = MockRawIO((b"abc", b"d", b"efg")) bufio = io.BufferedReader(rawio) self.assertEquals(b"abcdefg", bufio.read()) def testFileno(self): - rawio = MockIO((b"abc", b"d", b"efg")) + rawio = MockRawIO((b"abc", b"d", b"efg")) bufio = io.BufferedReader(rawio) self.assertEquals(42, bufio.fileno()) @@ -268,7 +275,7 @@ class BufferedWriterTest(unittest.TestCase): def testWrite(self): # Write to the buffered IO but don't overflow the buffer. - writer = MockIO() + writer = MockRawIO() bufio = io.BufferedWriter(writer, 8) bufio.write(b"abc") @@ -276,7 +283,7 @@ class BufferedWriterTest(unittest.TestCase): self.assertFalse(writer._write_stack) def testWriteOverflow(self): - writer = MockIO() + writer = MockRawIO() bufio = io.BufferedWriter(writer, 8) bufio.write(b"abc") @@ -305,13 +312,13 @@ class BufferedWriterTest(unittest.TestCase): # later. def testFileno(self): - rawio = MockIO((b"abc", b"d", b"efg")) + rawio = MockRawIO((b"abc", b"d", b"efg")) bufio = io.BufferedWriter(rawio) self.assertEquals(42, bufio.fileno()) def testFlush(self): - writer = MockIO() + writer = MockRawIO() bufio = io.BufferedWriter(writer, 8) bufio.write(b"abc") @@ -323,8 +330,8 @@ class BufferedWriterTest(unittest.TestCase): class BufferedRWPairTest(unittest.TestCase): def testRWPair(self): - r = MockIO(()) - w = MockIO() + r = MockRawIO(()) + w = MockRawIO() pair = io.BufferedRWPair(r, w) # XXX need implementation @@ -333,7 +340,7 @@ class BufferedRWPairTest(unittest.TestCase): class BufferedRandomTest(unittest.TestCase): def testReadAndWrite(self): - raw = MockIO((b"asdf", b"ghjk")) + raw = MockRawIO((b"asdf", b"ghjk")) rw = io.BufferedRandom(raw, 8, 12) self.assertEqual(b"as", rw.read(2)) |