symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_largefile.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_largefile.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,177 @@
+"""Test largefile support on system where this makes sense.
+"""
+
+import os
+import stat
+import sys
+import unittest
+from test.test_support import run_unittest, TESTFN, verbose, requires, \
+                              TestSkipped, unlink
+
+try:
+    import signal
+    # The default handler for SIGXFSZ is to abort the process.
+    # By ignoring it, system calls exceeding the file size resource
+    # limit will raise IOError instead of crashing the interpreter.
+    oldhandler = signal.signal(signal.SIGXFSZ, signal.SIG_IGN)
+except (ImportError, AttributeError):
+    pass
+
+# create >2GB file (2GB = 2147483648 bytes)
+size = 2500000000L
+
+
+class TestCase(unittest.TestCase):
+    """Test that each file function works as expected for a large
+    (i.e. > 2GB, do  we have to check > 4GB) files.
+
+    NOTE: the order of execution of the test methods is important! test_seek
+    must run first to create the test file. File cleanup must also be handled
+    outside the test instances because of this.
+
+    """
+
+    def test_seek(self):
+        if verbose:
+            print 'create large file via seek (may be sparse file) ...'
+        with open(TESTFN, 'wb') as f:
+            f.write('z')
+            f.seek(0)
+            f.seek(size)
+            f.write('a')
+            f.flush()
+            if verbose:
+                print 'check file size with os.fstat'
+            self.assertEqual(os.fstat(f.fileno())[stat.ST_SIZE], size+1)
+
+    def test_osstat(self):
+        if verbose:
+            print 'check file size with os.stat'
+        self.assertEqual(os.stat(TESTFN)[stat.ST_SIZE], size+1)
+
+    def test_seek_read(self):
+        if verbose:
+            print 'play around with seek() and read() with the built largefile'
+        with open(TESTFN, 'rb') as f:
+            self.assertEqual(f.tell(), 0)
+            self.assertEqual(f.read(1), 'z')
+            self.assertEqual(f.tell(), 1)
+            f.seek(0)
+            self.assertEqual(f.tell(), 0)
+            f.seek(0, 0)
+            self.assertEqual(f.tell(), 0)
+            f.seek(42)
+            self.assertEqual(f.tell(), 42)
+            f.seek(42, 0)
+            self.assertEqual(f.tell(), 42)
+            f.seek(42, 1)
+            self.assertEqual(f.tell(), 84)
+            f.seek(0, 1)
+            self.assertEqual(f.tell(), 84)
+            f.seek(0, 2)  # seek from the end
+            self.assertEqual(f.tell(), size + 1 + 0)
+            f.seek(-10, 2)
+            self.assertEqual(f.tell(), size + 1 - 10)
+            f.seek(-size-1, 2)
+            self.assertEqual(f.tell(), 0)
+            f.seek(size)
+            self.assertEqual(f.tell(), size)
+            # the 'a' that was written at the end of file above
+            self.assertEqual(f.read(1), 'a')
+            f.seek(-size-1, 1)
+            self.assertEqual(f.read(1), 'z')
+            self.assertEqual(f.tell(), 1)
+
+    def test_lseek(self):
+        if verbose:
+            print 'play around with os.lseek() with the built largefile'
+        with open(TESTFN, 'rb') as f:
+            self.assertEqual(os.lseek(f.fileno(), 0, 0), 0)
+            self.assertEqual(os.lseek(f.fileno(), 42, 0), 42)
+            self.assertEqual(os.lseek(f.fileno(), 42, 1), 84)
+            self.assertEqual(os.lseek(f.fileno(), 0, 1), 84)
+            self.assertEqual(os.lseek(f.fileno(), 0, 2), size+1+0)
+            self.assertEqual(os.lseek(f.fileno(), -10, 2), size+1-10)
+            self.assertEqual(os.lseek(f.fileno(), -size-1, 2), 0)
+            self.assertEqual(os.lseek(f.fileno(), size, 0), size)
+            # the 'a' that was written at the end of file above
+            self.assertEqual(f.read(1), 'a')
+
+    def test_truncate(self):
+        if verbose:
+            print 'try truncate'
+        with open(TESTFN, 'r+b') as f:
+            # this is already decided before start running the test suite
+            # but we do it anyway for extra protection
+            if not hasattr(f, 'truncate'):
+                raise TestSkipped, "open().truncate() not available on this system"
+            f.seek(0, 2)
+            # else we've lost track of the true size
+            self.assertEqual(f.tell(), size+1)
+            # Cut it back via seek + truncate with no argument.
+            newsize = size - 10
+            f.seek(newsize)
+            f.truncate()
+            self.assertEqual(f.tell(), newsize)  # else pointer moved
+            f.seek(0, 2)
+            self.assertEqual(f.tell(), newsize)  # else wasn't truncated
+            # Ensure that truncate(smaller than true size) shrinks
+            # the file.
+            newsize -= 1
+            f.seek(42)
+            f.truncate(newsize)
+            self.assertEqual(f.tell(), 42)       # else pointer moved
+            f.seek(0, 2)
+            self.assertEqual(f.tell(), newsize)  # else wasn't truncated
+
+            # XXX truncate(larger than true size) is ill-defined
+            # across platform; cut it waaaaay back
+            f.seek(0)
+            f.truncate(1)
+            self.assertEqual(f.tell(), 0)       # else pointer moved
+            self.assertEqual(len(f.read()), 1)  # else wasn't truncated
+
+
+def test_main():
+    # On Windows and Mac OSX this test comsumes large resources; It
+    # takes a long time to build the >2GB file and takes >2GB of disk
+    # space therefore the resource must be enabled to run this test.
+    # If not, nothing after this line stanza will be executed.
+    if sys.platform[:3] == 'win' or sys.platform == 'darwin':
+        requires('largefile',
+                 'test requires %s bytes and a long time to run' % str(size))
+    else:
+        # Only run if the current filesystem supports large files.
+        # (Skip this test on Windows, since we now always support
+        # large files.)
+        f = open(TESTFN, 'wb')
+        try:
+            # 2**31 == 2147483648
+            f.seek(2147483649L)
+            # Seeking is not enough of a test: you must write and
+            # flush, too!
+            f.write("x")
+            f.flush()
+        except (IOError, OverflowError):
+            f.close()
+            unlink(TESTFN)
+            raise TestSkipped, "filesystem does not have largefile support"
+        else:
+            f.close()
+    suite = unittest.TestSuite()
+    suite.addTest(TestCase('test_seek'))
+    suite.addTest(TestCase('test_osstat'))
+    suite.addTest(TestCase('test_seek_read'))
+    suite.addTest(TestCase('test_lseek'))
+    with open(TESTFN, 'w') as f:
+        if hasattr(f, 'truncate'):
+            suite.addTest(TestCase('test_truncate'))
+    unlink(TESTFN)
+    try:
+        run_unittest(suite)
+    finally:
+        unlink(TESTFN)
+
+
+if __name__ == '__main__':
+    test_main()