3198: Added Collection.rename (needs test). Fixing tests broken on account of
[arvados.git] / sdk / python / arvados / arvfile.py
index e8dac463e5670818e8bf2495a31c9b05640a1e0d..c46019a0d412cd3cc7ec426fd2271634add55d9d 100644 (file)
@@ -1,4 +1,26 @@
 import functools
+import os
+import zlib
+import bz2
+from .ranges import *
+from arvados.retry import retry_method
+import config
+import hashlib
+import hashlib
+import threading
+import Queue
+
+def split(path):
+    """split(path) -> streamname, filename
+
+    Separate the stream name and file name in a /-separated stream path.
+    If no stream name is available, assume '.'.
+    """
+    try:
+        stream_name, file_name = path.rsplit('/', 1)
+    except ValueError:  # No / in string
+        stream_name, file_name = '.', path
+    return stream_name, file_name
 
 class ArvadosFileBase(object):
     def __init__(self, name, mode):
@@ -27,3 +49,473 @@ class ArvadosFileBase(object):
 
     def close(self):
         self.closed = True
+
+
+class ArvadosFileReaderBase(ArvadosFileBase):
+    class _NameAttribute(str):
+        # The Python file API provides a plain .name attribute.
+        # Older SDK provided a name() method.
+        # This class provides both, for maximum compatibility.
+        def __call__(self):
+            return self
+
+    def __init__(self, name, mode, num_retries=None):
+        super(ArvadosFileReaderBase, self).__init__(self._NameAttribute(name), mode)
+        self._filepos = 0L
+        self.num_retries = num_retries
+        self._readline_cache = (None, None)
+
+    def __iter__(self):
+        while True:
+            data = self.readline()
+            if not data:
+                break
+            yield data
+
+    def decompressed_name(self):
+        return re.sub('\.(bz2|gz)$', '', self.name)
+
+    @ArvadosFileBase._before_close
+    def seek(self, pos, whence=os.SEEK_CUR):
+        if whence == os.SEEK_CUR:
+            pos += self._filepos
+        elif whence == os.SEEK_END:
+            pos += self.size()
+        self._filepos = min(max(pos, 0L), self.size())
+
+    def tell(self):
+        return self._filepos
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readall(self, size=2**20, num_retries=None):
+        while True:
+            data = self.read(size, num_retries=num_retries)
+            if data == '':
+                break
+            yield data
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readline(self, size=float('inf'), num_retries=None):
+        cache_pos, cache_data = self._readline_cache
+        if self.tell() == cache_pos:
+            data = [cache_data]
+        else:
+            data = ['']
+        data_size = len(data[-1])
+        while (data_size < size) and ('\n' not in data[-1]):
+            next_read = self.read(2 ** 20, num_retries=num_retries)
+            if not next_read:
+                break
+            data.append(next_read)
+            data_size += len(next_read)
+        data = ''.join(data)
+        try:
+            nextline_index = data.index('\n') + 1
+        except ValueError:
+            nextline_index = len(data)
+        nextline_index = min(nextline_index, size)
+        self._readline_cache = (self.tell(), data[nextline_index:])
+        return data[:nextline_index]
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def decompress(self, decompress, size, num_retries=None):
+        for segment in self.readall(size, num_retries):
+            data = decompress(segment)
+            if data:
+                yield data
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readall_decompressed(self, size=2**20, num_retries=None):
+        self.seek(0)
+        if self.name.endswith('.bz2'):
+            dc = bz2.BZ2Decompressor()
+            return self.decompress(dc.decompress, size,
+                                   num_retries=num_retries)
+        elif self.name.endswith('.gz'):
+            dc = zlib.decompressobj(16+zlib.MAX_WBITS)
+            return self.decompress(lambda segment: dc.decompress(dc.unconsumed_tail + segment),
+                                   size, num_retries=num_retries)
+        else:
+            return self.readall(size, num_retries=num_retries)
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readlines(self, sizehint=float('inf'), num_retries=None):
+        data = []
+        data_size = 0
+        for s in self.readall(num_retries=num_retries):
+            data.append(s)
+            data_size += len(s)
+            if data_size >= sizehint:
+                break
+        return ''.join(data).splitlines(True)
+
+
+class StreamFileReader(ArvadosFileReaderBase):
+    def __init__(self, stream, segments, name):
+        super(StreamFileReader, self).__init__(name, 'rb', num_retries=stream.num_retries)
+        self._stream = stream
+        self.segments = segments
+
+    def stream_name(self):
+        return self._stream.name()
+
+    def size(self):
+        n = self.segments[-1]
+        return n.range_start + n.range_size
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def read(self, size, num_retries=None):
+        """Read up to 'size' bytes from the stream, starting at the current file position"""
+        if size == 0:
+            return ''
+
+        data = ''
+        available_chunks = locators_and_ranges(self.segments, self._filepos, size)
+        if available_chunks:
+            lr = available_chunks[0]
+            data = self._stream._readfrom(lr.locator+lr.segment_offset,
+                                          lr.segment_size,
+                                          num_retries=num_retries)
+
+        self._filepos += len(data)
+        return data
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readfrom(self, start, size, num_retries=None):
+        """Read up to 'size' bytes from the stream, starting at 'start'"""
+        if size == 0:
+            return ''
+
+        data = []
+        for lr in locators_and_ranges(self.segments, start, size):
+            data.append(self._stream._readfrom(lr.locator+lr.segment_offset, lr.segment_size,
+                                              num_retries=num_retries))
+        return ''.join(data)
+
+    def as_manifest(self):
+        from stream import normalize_stream
+        segs = []
+        for r in self.segments:
+            segs.extend(self._stream.locators_and_ranges(r.locator, r.range_size))
+        return " ".join(normalize_stream(".", {self.name: segs})) + "\n"
+
+
+class BufferBlock(object):
+    WRITABLE = 0
+    PENDING = 1
+    COMMITTED = 2
+
+    def __init__(self, blockid, starting_size):
+        self.blockid = blockid
+        self.buffer_block = bytearray(starting_size)
+        self.buffer_view = memoryview(self.buffer_block)
+        self.write_pointer = 0
+        self.state = BufferBlock.WRITABLE
+        self._locator = None
+
+    def append(self, data):
+        if self.state == BufferBlock.WRITABLE:
+            while (self.write_pointer+len(data)) > len(self.buffer_block):
+                new_buffer_block = bytearray(len(self.buffer_block) * 2)
+                new_buffer_block[0:self.write_pointer] = self.buffer_block[0:self.write_pointer]
+                self.buffer_block = new_buffer_block
+                self.buffer_view = memoryview(self.buffer_block)
+            self.buffer_view[self.write_pointer:self.write_pointer+len(data)] = data
+            self.write_pointer += len(data)
+            self._locator = None
+        else:
+            raise AssertionError("Buffer block is not writable")
+
+    def size(self):
+        return self.write_pointer
+
+    def locator(self):
+        if self._locator is None:
+            self._locator = "%s+%i" % (hashlib.md5(self.buffer_view[0:self.write_pointer]).hexdigest(), self.size())
+        return self._locator
+
+class AsyncKeepWriteErrors(Exception):
+    def __init__(self, errors):
+        self.errors = errors
+
+    def __repr__(self):
+        return "\n".join(self.errors)
+
+class BlockManager(object):
+    def __init__(self, keep):
+        self._keep = keep
+        self._bufferblocks = {}
+        self._put_queue = None
+        self._put_errors = None
+        self._put_threads = None
+        self._prefetch_queue = None
+        self._prefetch_threads = None
+
+    def alloc_bufferblock(self, blockid=None, starting_size=2**14):
+        if blockid is None:
+            blockid = "bufferblock%i" % len(self._bufferblocks)
+        bb = BufferBlock(blockid, starting_size=starting_size)
+        self._bufferblocks[bb.blockid] = bb
+        return bb
+
+    def stop_threads(self):
+        if self._put_threads is not None:
+            for t in self._put_threads:
+                self._put_queue.put(None)
+            for t in self._put_threads:
+                t.join()
+        self._put_threads = None
+        self._put_queue = None
+        self._put_errors = None
+
+        if self._prefetch_threads is not None:
+            for t in self._prefetch_threads:
+                self._prefetch_queue.put(None)
+            for t in self._prefetch_threads:
+                t.join()
+        self._prefetch_threads = None
+        self._prefetch_queue = None
+
+    def commit_bufferblock(self, block):
+        def worker(self):
+            while True:
+                try:
+                    b = self._put_queue.get()
+                    if b is None:
+                        return
+                    b._locator = self._keep.put(b.buffer_view[0:b.write_pointer].tobytes())
+                    b.state = BufferBlock.COMMITTED
+                    b.buffer_view = None
+                    b.buffer_block = None
+                except Exception as e:
+                    print e
+                    self._put_errors.put(e)
+                finally:
+                    if self._put_queue is not None:
+                        self._put_queue.task_done()
+
+        if self._put_threads is None:
+            self._put_queue = Queue.Queue(maxsize=2)
+            self._put_errors = Queue.Queue()
+            self._put_threads = [threading.Thread(target=worker, args=(self,)), threading.Thread(target=worker, args=(self,))]
+            for t in self._put_threads:
+                t.start()
+
+        block.state = BufferBlock.PENDING
+        self._put_queue.put(block)
+
+    def get_block(self, locator, num_retries):
+        if locator in self._bufferblocks:
+            bb = self._bufferblocks[locator]
+            if bb.state != BufferBlock.COMMITTED:
+                return bb.buffer_view[0:bb.write_pointer].tobytes()
+            else:
+                locator = bb._locator
+        return self._keep.get(locator, num_retries=num_retries)
+
+    def commit_all(self):
+        for k,v in self._bufferblocks.items():
+            if v.state == BufferBlock.WRITABLE:
+                self.commit_bufferblock(v)
+        if self._put_queue is not None:
+            self._put_queue.join()
+            if not self._put_errors.empty():
+                e = []
+                try:
+                    while True:
+                        e.append(self._put_errors.get(False))
+                except Queue.Empty:
+                    pass
+                raise AsyncKeepWriteErrors(e)
+
+    def block_prefetch(self, locator):
+        def worker(self):
+            while True:
+                try:
+                    b = self._prefetch_queue.get()
+                    if b is None:
+                        return
+                    self._keep.get(b)
+                except:
+                    pass
+
+        if locator in self._bufferblocks:
+            return
+        if self._prefetch_threads is None:
+            self._prefetch_queue = Queue.Queue()
+            self._prefetch_threads = [threading.Thread(target=worker, args=(self,)),
+                                      threading.Thread(target=worker, args=(self,))]
+            self._prefetch_threads[0].start()
+            self._prefetch_threads[1].start()
+        self._prefetch_queue.put(locator)
+
+class ArvadosFile(object):
+    def __init__(self, parent, stream=[], segments=[]):
+        '''
+        stream: a list of Range objects representing a block stream
+        segments: a list of Range objects representing segments
+        '''
+        self.parent = parent
+        self._modified = True
+        self.segments = []
+        for s in segments:
+            self.add_segment(stream, s.range_start, s.range_size)
+        self._current_bblock = None
+
+    def set_unmodified(self):
+        self._modified = False
+
+    def modified(self):
+        return self._modified
+
+    def truncate(self, size):
+        new_segs = []
+        for r in self.segments:
+            range_end = r.range_start+r.range_size
+            if r.range_start >= size:
+                # segment is past the trucate size, all done
+                break
+            elif size < range_end:
+                nr = Range(r.locator, r.range_start, size - r.range_start)
+                nr.segment_offset = r.segment_offset
+                new_segs.append(nr)
+                break
+            else:
+                new_segs.append(r)
+
+        self.segments = new_segs
+        self._modified = True
+
+    def readfrom(self, offset, size, num_retries):
+        if size == 0 or offset >= self.size():
+            return ''
+        data = []
+
+        for lr in locators_and_ranges(self.segments, offset, size + config.KEEP_BLOCK_SIZE):
+            self.parent._my_block_manager().block_prefetch(lr.locator)
+
+        for lr in locators_and_ranges(self.segments, offset, size):
+            # TODO: if data is empty, wait on block get, otherwise only
+            # get more data if the block is already in the cache.
+            data.append(self.parent._my_block_manager().get_block(lr.locator, num_retries=num_retries)[lr.segment_offset:lr.segment_offset+lr.segment_size])
+        return ''.join(data)
+
+    def _repack_writes(self):
+        '''Test if the buffer block has more data than is referenced by actual segments
+        (this happens when a buffered write over-writes a file range written in
+        a previous buffered write).  Re-pack the buffer block for efficiency
+        and to avoid leaking information.
+        '''
+        segs = self.segments
+
+        # Sum up the segments to get the total bytes of the file referencing
+        # into the buffer block.
+        bufferblock_segs = [s for s in segs if s.locator == self._current_bblock.blockid]
+        write_total = sum([s.range_size for s in bufferblock_segs])
+
+        if write_total < self._current_bblock.size():
+            # There is more data in the buffer block than is actually accounted for by segments, so
+            # re-pack into a new buffer by copying over to a new buffer block.
+            new_bb = self.parent._my_block_manager().alloc_bufferblock(self._current_bblock.blockid, starting_size=write_total)
+            for t in bufferblock_segs:
+                new_bb.append(self._current_bblock.buffer_view[t.segment_offset:t.segment_offset+t.range_size].tobytes())
+                t.segment_offset = new_bb.size() - t.range_size
+
+            self._current_bblock = new_bb
+
+    def writeto(self, offset, data, num_retries):
+        if len(data) == 0:
+            return
+
+        if offset > self.size():
+            raise ArgumentError("Offset is past the end of the file")
+
+        if len(data) > config.KEEP_BLOCK_SIZE:
+            raise ArgumentError("Please append data in chunks smaller than %i bytes (config.KEEP_BLOCK_SIZE)" % (config.KEEP_BLOCK_SIZE))
+
+        self._modified = True
+
+        if self._current_bblock is None or self._current_bblock.state != BufferBlock.WRITABLE:
+            self._current_bblock = self.parent._my_block_manager().alloc_bufferblock()
+
+        if (self._current_bblock.size() + len(data)) > config.KEEP_BLOCK_SIZE:
+            self._repack_writes()
+            if (self._current_bblock.size() + len(data)) > config.KEEP_BLOCK_SIZE:
+                self.parent._my_block_manager().commit_bufferblock(self._current_bblock)
+                self._current_bblock = self.parent._my_block_manager().alloc_bufferblock()
+
+        self._current_bblock.append(data)
+        replace_range(self.segments, offset, len(data), self._current_bblock.blockid, self._current_bblock.write_pointer - len(data))
+
+    def add_segment(self, blocks, pos, size):
+        self._modified = True
+        for lr in locators_and_ranges(blocks, pos, size):
+            last = self.segments[-1] if self.segments else Range(0, 0, 0)
+            r = Range(lr.locator, last.range_start+last.range_size, lr.segment_size, lr.segment_offset)
+            self.segments.append(r)
+
+    def size(self):
+        if self.segments:
+            n = self.segments[-1]
+            return n.range_start + n.range_size
+        else:
+            return 0
+
+
+class ArvadosFileReader(ArvadosFileReaderBase):
+    def __init__(self, arvadosfile, name, mode="r", num_retries=None):
+        super(ArvadosFileReader, self).__init__(name, mode, num_retries=num_retries)
+        self.arvadosfile = arvadosfile
+
+    def size(self):
+        return self.arvadosfile.size()
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def read(self, size, num_retries=None):
+        """Read up to 'size' bytes from the stream, starting at the current file position"""
+        data = self.arvadosfile.readfrom(self._filepos, size, num_retries=num_retries)
+        self._filepos += len(data)
+        return data
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readfrom(self, offset, size, num_retries=None):
+        """Read up to 'size' bytes from the stream, starting at the current file position"""
+        return self.arvadosfile.readfrom(offset, size, num_retries)
+
+    def flush(self):
+        pass
+
+class ArvadosFileWriter(ArvadosFileReader):
+    def __init__(self, arvadosfile, name, mode, num_retries=None):
+        super(ArvadosFileWriter, self).__init__(arvadosfile, name, mode, num_retries=num_retries)
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def write(self, data, num_retries=None):
+        if self.mode[0] == "a":
+            self.arvadosfile.writeto(self.size(), data)
+        else:
+            self.arvadosfile.writeto(self._filepos, data, num_retries)
+            self._filepos += len(data)
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def writelines(self, seq, num_retries=None):
+        for s in seq:
+            self.write(s)
+
+    def truncate(self, size=None):
+        if size is None:
+            size = self._filepos
+        self.arvadosfile.truncate(size)
+        if self._filepos > self.size():
+            self._filepos = self.size()