Python mmap.PAGESIZE Examples

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def __init__(self, *args, **kwds):
        ## Create shared memory for rendered image
        #pg.dbg(namespace={'r': self})
        if sys.platform.startswith('win'):
            self.shmtag = "pyqtgraph_shmem_" + ''.join([chr((random.getrandbits(20)%25) + 97) for i in range(20)])
            self.shm = mmap.mmap(-1, mmap.PAGESIZE, self.shmtag) # use anonymous mmap on windows
        else:
            self.shmFile = tempfile.NamedTemporaryFile(prefix='pyqtgraph_shmem_')
            self.shmFile.write(b'\x00' * (mmap.PAGESIZE+1))
            fd = self.shmFile.fileno()
            self.shm = mmap.mmap(fd, mmap.PAGESIZE, mmap.MAP_SHARED, mmap.PROT_WRITE)
        atexit.register(self.close)
        
        GraphicsView.__init__(self, *args, **kwds)
        self.scene().changed.connect(self.update)
        self.img = None
        self.renderTimer = QtCore.QTimer()
        self.renderTimer.timeout.connect(self.renderView)
        self.renderTimer.start(16) 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def __init__(self, *args, **kwds):
        ## Create shared memory for rendered image
        #pg.dbg(namespace={'r': self})
        if sys.platform.startswith('win'):
            self.shmtag = "pyqtgraph_shmem_" + ''.join([chr((random.getrandbits(20)%25) + 97) for i in range(20)])
            self.shm = mmap.mmap(-1, mmap.PAGESIZE, self.shmtag) # use anonymous mmap on windows
        else:
            self.shmFile = tempfile.NamedTemporaryFile(prefix='pyqtgraph_shmem_')
            self.shmFile.write(b'\x00' * (mmap.PAGESIZE+1))
            fd = self.shmFile.fileno()
            self.shm = mmap.mmap(fd, mmap.PAGESIZE, mmap.MAP_SHARED, mmap.PROT_WRITE)
        atexit.register(self.close)
        
        GraphicsView.__init__(self, *args, **kwds)
        self.scene().changed.connect(self.update)
        self.img = None
        self.renderTimer = QtCore.QTimer()
        self.renderTimer.timeout.connect(self.renderView)
        self.renderTimer.start(16) 

def __init__(self, *args, **kwds):
        ## Create shared memory for rendered image
        #pg.dbg(namespace={'r': self})
        if sys.platform.startswith('win'):
            self.shmtag = "pyqtgraph_shmem_" + ''.join([chr((random.getrandbits(20)%25) + 97) for i in range(20)])
            self.shm = mmap.mmap(-1, mmap.PAGESIZE, self.shmtag) # use anonymous mmap on windows
        else:
            self.shmFile = tempfile.NamedTemporaryFile(prefix='pyqtgraph_shmem_')
            self.shmFile.write(b'\x00' * (mmap.PAGESIZE+1))
            fd = self.shmFile.fileno()
            self.shm = mmap.mmap(fd, mmap.PAGESIZE, mmap.MAP_SHARED, mmap.PROT_WRITE)
        atexit.register(self.close)
        
        GraphicsView.__init__(self, *args, **kwds)
        self.scene().changed.connect(self.update)
        self.img = None
        self.renderTimer = QtCore.QTimer()
        self.renderTimer.timeout.connect(self.renderView)
        self.renderTimer.start(16) 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            util.info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            util.info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            util.info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def _malloc(self, size):
        # returns a large enough block -- it might be much larger
        i = bisect.bisect_left(self._lengths, size)
        if i == len(self._lengths):
            length = self._roundup(max(self._size, size), mmap.PAGESIZE)
            self._size *= 2
            util.info('allocating a new mmap of length %d', length)
            arena = Arena(length)
            self._arenas.append(arena)
            return (arena, 0, length)
        else:
            length = self._lengths[i]
            seq = self._len_to_seq[length]
            block = seq.pop()
            if not seq:
                del self._len_to_seq[length], self._lengths[i]

        (arena, start, stop) = block
        del self._start_to_block[(arena, start)]
        del self._stop_to_block[(arena, stop)]
        return block 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def test_mmap_find_large():
        P10 = PAGESIZE * 10
        P11 = PAGESIZE * 11
        f = open(TESTFN, 'w+')
        try:
            f.write((P10 - 1) * '\0')
            f.write('foofoo')
            f.write('\0' * PAGESIZE)
            f.write('foo')
            f.flush()
            m = mmap.mmap(f.fileno(), P11 + 8)
            f.close()

            AreEqual(m.find('foo'), P10 - 1)
            AreEqual(m.find('foo', P10 - 1), P10 - 1)
            AreEqual(m.find('foo', P10), P10 + 2)
            AreEqual(m.find('foo', P10 + 173), P11 + 5)
            AreEqual(m.find('foo', P10 + 173, P11 + 7), -1)

        finally:
            m.close()
            try:
                f.close()
            except OSError:
                pass

        mmap_tearDown() 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def test_anon():
    print "  anonymous mmap.mmap(-1, PAGESIZE)..."
    m = mmap.mmap(-1, PAGESIZE)
    for x in xrange(PAGESIZE):
        verify(m[x] == '\0', "anonymously mmap'ed contents should be zero")

    for x in xrange(PAGESIZE):
        m[x] = ch = chr(x & 255)
        vereq(m[x], ch) 

def align_to_mmap(num, round_up):
    """
    Align the given integer number to the closest page offset, which usually is 4096 bytes.

    :param round_up: if True, the next higher multiple of page size is used, otherwise
        the lower page_size will be used (i.e. if True, 1 becomes 4096, otherwise it becomes 0)
    :return: num rounded to closest page"""
    res = (num // ALLOCATIONGRANULARITY) * ALLOCATIONGRANULARITY
    if round_up and (res != num):
        res += ALLOCATIONGRANULARITY
    # END handle size
    return res 

def _set_cache_too_slow_without_c(self, attr):
        # the direct algorithm is fastest and most direct if there is only one
        # delta. Also, the extra overhead might not be worth it for items smaller
        # than X - definitely the case in python, every function call costs
        # huge amounts of time
        # if len(self._dstreams) * self._bstream.size < self.k_max_memory_move:
        if len(self._dstreams) == 1:
            return self._set_cache_brute_(attr)

        # Aggregate all deltas into one delta in reverse order. Hence we take
        # the last delta, and reverse-merge its ancestor delta, until we receive
        # the final delta data stream.
        dcl = connect_deltas(self._dstreams)

        # call len directly, as the (optional) c version doesn't implement the sequence
        # protocol
        if dcl.rbound() == 0:
            self._size = 0
            self._mm_target = allocate_memory(0)
            return
        # END handle empty list

        self._size = dcl.rbound()
        self._mm_target = allocate_memory(self._size)

        bbuf = allocate_memory(self._bstream.size)
        stream_copy(self._bstream.read, bbuf.write, self._bstream.size, 256 * mmap.PAGESIZE)

        # APPLY CHUNKS
        write = self._mm_target.write
        dcl.apply(bbuf, write)

        self._mm_target.seek(0) 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def read_all_values_from_file(filename):
        with open(filename, 'rb') as infp:
            # Read the first block of data, including the first 4 bytes which tell us
            # how much of the file (which is preallocated to _INITIAL_MMAP_SIZE bytes) is occupied.
            data = infp.read(mmap.PAGESIZE)
            used = _unpack_integer(data, 0)[0]
            if used > len(data):  # Then read in the rest, if needed.
                data += infp.read(used - len(data))
        return _read_all_values(data, used) 

def test_mmap_rfind_large():
        P10 = PAGESIZE * 10
        P11 = PAGESIZE * 11
        f = open(TESTFN, 'w+')
        try:
            f.write((P10 - 1) * '\0')
            f.write('foofoo')
            f.write('\0' * PAGESIZE)
            f.write('foo')
            f.flush()
            m = mmap.mmap(f.fileno(), P11 + 8)
            f.close()

            AreEqual(m.rfind('foo'), P11 + 5)
            AreEqual(m.rfind('foo', 651, P11 - 117), P10 + 2)
            AreEqual(m.rfind('foo', 475, P10 + 5), P10 + 2)
            AreEqual(m.rfind('foo', 475, P10 + 4), P10 - 1)
            AreEqual(m.rfind('foo', P10 + 4, P11 + 7), -1)
            AreEqual(m.rfind('foo', P10 + 4), P11 + 5)

        finally:
            m.close()
            try:
                f.close()
            except OSError:
                pass

        mmap_tearDown()


#--MAIN------------------------------------------------------------------------ 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def _decompress_dwarf_section(section):
        """ Returns the uncompressed contents of the provided DWARF section.
        """
        # TODO: support other compression formats from readelf.c
        assert section.size > 12, 'Unsupported compression format.'

        section.stream.seek(0)
        # According to readelf.c the content should contain "ZLIB"
        # followed by the uncompressed section size - 8 bytes in
        # big-endian order
        compression_type = section.stream.read(4)
        assert compression_type == b'ZLIB', \
            'Invalid compression type: %r' % (compression_type)

        uncompressed_size = struct.unpack('>Q', section.stream.read(8))[0]

        decompressor = zlib.decompressobj()
        uncompressed_stream = BytesIO()
        while True:
            chunk = section.stream.read(PAGESIZE)
            if not chunk:
                break
            uncompressed_stream.write(decompressor.decompress(chunk))
        uncompressed_stream.write(decompressor.flush())

        uncompressed_stream.seek(0, io.SEEK_END)
        size = uncompressed_stream.tell()
        assert uncompressed_size == size, \
                'Wrong uncompressed size: expected %r, but got %r' % (
                    uncompressed_size, size,
                )

        return section._replace(stream=uncompressed_stream, size=size) 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def __init__(self, size=mmap.PAGESIZE):
        self._lastpid = os.getpid()
        self._lock = threading.Lock()
        self._size = size
        self._lengths = []
        self._len_to_seq = {}
        self._start_to_block = {}
        self._stop_to_block = {}
        self._allocated_blocks = set()
        self._arenas = []
        # list of pending blocks to free - see free() comment below
        self._pending_free_blocks = [] 

def test_mmap_rfind_large():
        P10 = PAGESIZE * 10
        P11 = PAGESIZE * 11
        f = open(TESTFN, 'w+')
        try:
            f.write((P10 - 1) * '\0')
            f.write('foofoo')
            f.write('\0' * PAGESIZE)
            f.write('foo')
            f.flush()
            m = mmap.mmap(f.fileno(), P11 + 8)
            f.close()

            AreEqual(m.rfind('foo'), P11 + 5)
            AreEqual(m.rfind('foo', 651, P11 - 117), P10 + 2)
            AreEqual(m.rfind('foo', 475, P10 + 5), P10 + 2)
            AreEqual(m.rfind('foo', 475, P10 + 4), P10 - 1)
            AreEqual(m.rfind('foo', P10 + 4, P11 + 7), -1)
            AreEqual(m.rfind('foo', P10 + 4), P11 + 5)

        finally:
            m.close()
            try:
                f.close()
            except OSError:
                pass

        mmap_tearDown()


#--MAIN------------------------------------------------------------------------