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author | Damien George <damien.p.george@gmail.com> | 2015-08-14 12:24:11 +0100 |
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committer | Damien George <damien.p.george@gmail.com> | 2015-08-17 12:51:26 +0100 |
commit | 65dc960e3b22a8426e369607e47c19b380ce30ea (patch) | |
tree | 5e55ec2861df54e14fdb0eac1d030b34f684743b /tests/bytecode/pylib-tests/chunk.py | |
parent | 0e978349a5e7696aa44a0faf5d046081a0616ca5 (diff) | |
download | micropython-65dc960e3b22a8426e369607e47c19b380ce30ea.tar.gz micropython-65dc960e3b22a8426e369607e47c19b380ce30ea.zip |
unix-cpy: Remove unix-cpy. It's no longer needed.
unix-cpy was originally written to get semantic equivalent with CPython
without writing functional tests. When writing the initial
implementation of uPy it was a long way between lexer and functional
tests, so the half-way test was to make sure that the bytecode was
correct. The idea was that if the uPy bytecode matched CPython 1-1 then
uPy would be proper Python if the bytecodes acted correctly. And having
matching bytecode meant that it was less likely to miss some deep
subtlety in the Python semantics that would require an architectural
change later on.
But that is all history and it no longer makes sense to retain the
ability to output CPython bytecode, because:
1. It outputs CPython 3.3 compatible bytecode. CPython's bytecode
changes from version to version, and seems to have changed quite a bit
in 3.5. There's no point in changing the bytecode output to match
CPython anymore.
2. uPy and CPy do different optimisations to the bytecode which makes it
harder to match.
3. The bytecode tests are not run. They were never part of Travis and
are not run locally anymore.
4. The EMIT_CPYTHON option needs a lot of extra source code which adds
heaps of noise, especially in compile.c.
5. Now that there is an extensive test suite (which tests functionality)
there is no need to match the bytecode. Some very subtle behaviour is
tested with the test suite and passing these tests is a much better
way to stay Python-language compliant, rather than trying to match
CPy bytecode.
Diffstat (limited to 'tests/bytecode/pylib-tests/chunk.py')
-rw-r--r-- | tests/bytecode/pylib-tests/chunk.py | 167 |
1 files changed, 0 insertions, 167 deletions
diff --git a/tests/bytecode/pylib-tests/chunk.py b/tests/bytecode/pylib-tests/chunk.py deleted file mode 100644 index 5863ed0846..0000000000 --- a/tests/bytecode/pylib-tests/chunk.py +++ /dev/null @@ -1,167 +0,0 @@ -"""Simple class to read IFF chunks. - -An IFF chunk (used in formats such as AIFF, TIFF, RMFF (RealMedia File -Format)) has the following structure: - -+----------------+ -| ID (4 bytes) | -+----------------+ -| size (4 bytes) | -+----------------+ -| data | -| ... | -+----------------+ - -The ID is a 4-byte string which identifies the type of chunk. - -The size field (a 32-bit value, encoded using big-endian byte order) -gives the size of the whole chunk, including the 8-byte header. - -Usually an IFF-type file consists of one or more chunks. The proposed -usage of the Chunk class defined here is to instantiate an instance at -the start of each chunk and read from the instance until it reaches -the end, after which a new instance can be instantiated. At the end -of the file, creating a new instance will fail with a EOFError -exception. - -Usage: -while True: - try: - chunk = Chunk(file) - except EOFError: - break - chunktype = chunk.getname() - while True: - data = chunk.read(nbytes) - if not data: - pass - # do something with data - -The interface is file-like. The implemented methods are: -read, close, seek, tell, isatty. -Extra methods are: skip() (called by close, skips to the end of the chunk), -getname() (returns the name (ID) of the chunk) - -The __init__ method has one required argument, a file-like object -(including a chunk instance), and one optional argument, a flag which -specifies whether or not chunks are aligned on 2-byte boundaries. The -default is 1, i.e. aligned. -""" - -class Chunk: - def __init__(self, file, align=True, bigendian=True, inclheader=False): - import struct - self.closed = False - self.align = align # whether to align to word (2-byte) boundaries - if bigendian: - strflag = '>' - else: - strflag = '<' - self.file = file - self.chunkname = file.read(4) - if len(self.chunkname) < 4: - raise EOFError - try: - self.chunksize = struct.unpack_from(strflag+'L', file.read(4))[0] - except struct.error: - raise EOFError - if inclheader: - self.chunksize = self.chunksize - 8 # subtract header - self.size_read = 0 - try: - self.offset = self.file.tell() - except (AttributeError, IOError): - self.seekable = False - else: - self.seekable = True - - def getname(self): - """Return the name (ID) of the current chunk.""" - return self.chunkname - - def getsize(self): - """Return the size of the current chunk.""" - return self.chunksize - - def close(self): - if not self.closed: - self.skip() - self.closed = True - - def isatty(self): - if self.closed: - raise ValueError("I/O operation on closed file") - return False - - def seek(self, pos, whence=0): - """Seek to specified position into the chunk. - Default position is 0 (start of chunk). - If the file is not seekable, this will result in an error. - """ - - if self.closed: - raise ValueError("I/O operation on closed file") - if not self.seekable: - raise IOError("cannot seek") - if whence == 1: - pos = pos + self.size_read - elif whence == 2: - pos = pos + self.chunksize - if pos < 0 or pos > self.chunksize: - raise RuntimeError - self.file.seek(self.offset + pos, 0) - self.size_read = pos - - def tell(self): - if self.closed: - raise ValueError("I/O operation on closed file") - return self.size_read - - def read(self, size=-1): - """Read at most size bytes from the chunk. - If size is omitted or negative, read until the end - of the chunk. - """ - - if self.closed: - raise ValueError("I/O operation on closed file") - if self.size_read >= self.chunksize: - return '' - if size < 0: - size = self.chunksize - self.size_read - if size > self.chunksize - self.size_read: - size = self.chunksize - self.size_read - data = self.file.read(size) - self.size_read = self.size_read + len(data) - if self.size_read == self.chunksize and \ - self.align and \ - (self.chunksize & 1): - dummy = self.file.read(1) - self.size_read = self.size_read + len(dummy) - return data - - def skip(self): - """Skip the rest of the chunk. - If you are not interested in the contents of the chunk, - this method should be called so that the file points to - the start of the next chunk. - """ - - if self.closed: - raise ValueError("I/O operation on closed file") - if self.seekable: - try: - n = self.chunksize - self.size_read - # maybe fix alignment - if self.align and (self.chunksize & 1): - n = n + 1 - self.file.seek(n, 1) - self.size_read = self.size_read + n - return - except IOError: - pass - while self.size_read < self.chunksize: - n = min(8192, self.chunksize - self.size_read) - dummy = self.read(n) - if not dummy: - raise EOFError |