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-rw-r--r--Lib/_pyio.py21
1 files changed, 13 insertions, 8 deletions
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index b684a9f..c06f4b8 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -16,6 +16,11 @@ except ImportError:
import io
from io import (__all__, SEEK_SET, SEEK_CUR, SEEK_END)
+valid_seek_flags = {0, 1, 2} # Hardwired values
+if hasattr(os, 'SEEK_HOLE') :
+ valid_seek_flags.add(os.SEEK_HOLE)
+ valid_seek_flags.add(os.SEEK_DATA)
+
# open() uses st_blksize whenever we can
DEFAULT_BUFFER_SIZE = 8 * 1024 # bytes
@@ -306,6 +311,7 @@ class IOBase(metaclass=abc.ABCMeta):
* 0 -- start of stream (the default); offset should be zero or positive
* 1 -- current stream position; offset may be negative
* 2 -- end of stream; offset is usually negative
+ Some operating systems / file systems could provide additional values.
Return an int indicating the new absolute position.
"""
@@ -866,7 +872,7 @@ class BytesIO(BufferedIOBase):
elif whence == 2:
self._pos = max(0, len(self._buffer) + pos)
else:
- raise ValueError("invalid whence value")
+ raise ValueError("unsupported whence value")
return self._pos
def tell(self):
@@ -1041,7 +1047,7 @@ class BufferedReader(_BufferedIOMixin):
return _BufferedIOMixin.tell(self) - len(self._read_buf) + self._read_pos
def seek(self, pos, whence=0):
- if not (0 <= whence <= 2):
+ if whence not in valid_seek_flags:
raise ValueError("invalid whence value")
with self._read_lock:
if whence == 1:
@@ -1138,8 +1144,8 @@ class BufferedWriter(_BufferedIOMixin):
return _BufferedIOMixin.tell(self) + len(self._write_buf)
def seek(self, pos, whence=0):
- if not (0 <= whence <= 2):
- raise ValueError("invalid whence")
+ if whence not in valid_seek_flags:
+ raise ValueError("invalid whence value")
with self._write_lock:
self._flush_unlocked()
return _BufferedIOMixin.seek(self, pos, whence)
@@ -1235,8 +1241,8 @@ class BufferedRandom(BufferedWriter, BufferedReader):
BufferedWriter.__init__(self, raw, buffer_size, max_buffer_size)
def seek(self, pos, whence=0):
- if not (0 <= whence <= 2):
- raise ValueError("invalid whence")
+ if whence not in valid_seek_flags:
+ raise ValueError("invalid whence value")
self.flush()
if self._read_buf:
# Undo read ahead.
@@ -1852,8 +1858,7 @@ class TextIOWrapper(TextIOBase):
self._decoder.reset()
return position
if whence != 0:
- raise ValueError("invalid whence (%r, should be 0, 1 or 2)" %
- (whence,))
+ raise ValueError("unsupported whence (%r)" % (whence,))
if cookie < 0:
raise ValueError("negative seek position %r" % (cookie,))
self.flush()