Merge remote-tracking branch 'origin/fix_blob_reader_closing'

CHANGELOG.md

@@ -19,6 +19,7 @@ at anytime.
 ### Fixed
   * Fixed handling cancelled blob and availability requests
   * Fixed redundant blob requests to a peer
+  * Fixed https://github.com/lbryio/lbry/issues/923
 
 ### Deprecated
   * Deprecated `blob_announce_all` JSONRPC command. Use `blob_announce` instead.

lbrynet/blob/blob_file.py

@@ -9,7 +9,7 @@ from lbrynet import conf
 from lbrynet.core.Error import DownloadCanceledError, InvalidDataError, InvalidBlobHashError
 from lbrynet.core.utils import is_valid_blobhash
 from lbrynet.blob.writer import HashBlobWriter
-from lbrynet.blob.reader import HashBlobReader
+from lbrynet.blob.reader import HashBlobReader, HashBlobReader_v0
 
 
 log = logging.getLogger(__name__)
@@ -75,19 +75,13 @@ class BlobFile(object):
         """
         open blob for reading
 
-        returns a file handle that can be read() from.
-        once finished with the file handle, user must call close_read_handle()
-        otherwise blob cannot be deleted.
+        returns a file like object that can be read() from, and closed() when
+        finished
         """
         if self._verified is True:
-            file_handle = None
-            try:
-                file_handle = open(self.file_path, 'rb')
+            reader = HashBlobReader(self.file_path, self.reader_finished)
             self.readers += 1
-                return file_handle
-            except IOError:
-                log.exception('Failed to open %s', self.file_path)
-                self.close_read_handle(file_handle)
+            return reader
         return None
 
     def delete(self):
@@ -150,12 +144,16 @@ class BlobFile(object):
         return False
 
     def read(self, write_func):
+        """
+        This function is only used in StreamBlobDecryptor
+        and should be deprecated in favor of open_for_reading()
+        """
         def close_self(*args):
             self.close_read_handle(file_handle)
             return args[0]
 
         file_sender = FileSender()
-        reader = HashBlobReader(write_func)
+        reader = HashBlobReader_v0(write_func)
         file_handle = self.open_for_reading()
         if file_handle is not None:
             d = file_sender.beginFileTransfer(file_handle, reader)
@@ -164,6 +162,19 @@ class BlobFile(object):
             d = defer.fail(IOError("Could not read the blob"))
         return d
 
+    def close_read_handle(self, file_handle):
+        """
+        This function is only used in StreamBlobDecryptor
+        and should be deprecated in favor of open_for_reading()
+        """
+        if file_handle is not None:
+            file_handle.close()
+            self.readers -= 1
+
+    def reader_finished(self, reader):
+        self.readers -= 1
+        return defer.succeed(True)
+
     def writer_finished(self, writer, err=None):
         def fire_finished_deferred():
             self._verified = True
@@ -208,11 +219,6 @@ class BlobFile(object):
         d.addBoth(lambda _: writer.close_handle())
         return d
 
-    def close_read_handle(self, file_handle):
-        if file_handle is not None:
-            file_handle.close()
-            self.readers -= 1
-
     @defer.inlineCallbacks
     def _save_verified_blob(self, writer):
         with self.setting_verified_blob_lock:

lbrynet/blob/reader.py

@@ -5,7 +5,11 @@ from zope.interface import implements
 log = logging.getLogger(__name__)
 
 
-class HashBlobReader(object):
+class HashBlobReader_v0(object):
+    """
+    This is a class that is only used in StreamBlobDecryptor
+    and should be deprecated
+    """
     implements(interfaces.IConsumer)
 
     def __init__(self, write_func):
@@ -28,3 +32,28 @@ class HashBlobReader(object):
         self.write_func(data)
         if self.streaming is False:
             reactor.callLater(0, self.producer.resumeProducing)
+
+class HashBlobReader(object):
+    """
+    This is a file like reader class that supports
+    read(size) and close()
+    """
+    def __init__(self, file_path, finished_cb):
+        self.finished_cb = finished_cb
+        self.finished_cb_d = None
+        self.read_handle = open(file_path, 'rb')
+
+    def __del__(self):
+        self.close()
+
+    def read(self, size=-1):
+        return self.read_handle.read(size)
+
+    def close(self):
+        # if we've already closed and called finished_cb, do nothing
+        if self.finished_cb_d is not None:
+            return
+        self.read_handle.close()
+        self.finished_cb_d = self.finished_cb(self)
+
+

lbrynet/core/StreamDescriptor.py

@@ -55,7 +55,7 @@ class BlobStreamDescriptorReader(StreamDescriptorReader):
             f = self.blob.open_for_reading()
             if f is not None:
                 raw_data = f.read()
-                self.blob.close_read_handle(f)
+                f.close()
                 return raw_data
             else:
                 raise ValueError("Could not open the blob for reading")

lbrynet/core/server/BlobRequestHandler.py

@@ -89,7 +89,7 @@ class BlobRequestHandler(object):
 
     def cancel_send(self, err):
         if self.currently_uploading is not None:
-            self.currently_uploading.close_read_handle(self.read_handle)
+            self.read_handle.close()
         self.read_handle = None
         self.currently_uploading = None
         return err
@@ -225,7 +225,7 @@ class BlobRequestHandler(object):
 
         def set_not_uploading(reason=None):
             if self.currently_uploading is not None:
-                self.currently_uploading.close_read_handle(self.read_handle)
+                self.read_handle.close()
                 self.read_handle = None
                 self.currently_uploading = None
             self.file_sender = None

lbrynet/daemon/Daemon.py

@@ -2433,7 +2433,7 @@ class Daemon(AuthJSONRPCServer):
         if encoding and encoding in decoders:
             blob_file = blob.open_for_reading()
             result = decoders[encoding](blob_file.read())
-            blob.close_read_handle(blob_file)
+            blob_file.close()
         else:
             result = "Downloaded blob %s" % blob_hash
 
@@ -2682,7 +2682,7 @@ class Daemon(AuthJSONRPCServer):
         def read_sd_blob(sd_blob):
             sd_blob_file = sd_blob.open_for_reading()
             decoded_sd_blob = json.loads(sd_blob_file.read())
-            sd_blob.close_read_handle(sd_blob_file)
+            sd_blob_file.close()
             return decoded_sd_blob
 
         resolved_result = yield self.session.wallet.resolve(uri)

lbrynet/reflector/client/blob.py

@@ -94,7 +94,7 @@ class BlobReflectorClient(Protocol):
 
     def set_not_uploading(self):
         if self.next_blob_to_send is not None:
-            self.next_blob_to_send.close_read_handle(self.read_handle)
+            self.read_handle.close()
             self.read_handle = None
             self.next_blob_to_send = None
         self.file_sender = None
@@ -105,6 +105,7 @@ class BlobReflectorClient(Protocol):
         assert self.read_handle is not None, \
             "self.read_handle was None when trying to start the transfer"
         d = self.file_sender.beginFileTransfer(self.read_handle, self)
+        d.addCallback(lambda _: self.read_handle.close())
         return d
 
     def handle_handshake_response(self, response_dict):

lbrynet/reflector/client/client.py

@@ -179,7 +179,7 @@ class EncryptedFileReflectorClient(Protocol):
     def set_not_uploading(self):
         if self.next_blob_to_send is not None:
             log.debug("Close %s", self.next_blob_to_send)
-            self.next_blob_to_send.close_read_handle(self.read_handle)
+            self.read_handle.close()
             self.read_handle = None
             self.next_blob_to_send = None
         if self.file_sender is not None:
@@ -191,6 +191,7 @@ class EncryptedFileReflectorClient(Protocol):
         assert self.read_handle is not None, \
             "self.read_handle was None when trying to start the transfer"
         d = self.file_sender.beginFileTransfer(self.read_handle, self)
+        d.addCallback(lambda _: self.read_handle.close())
         return d
 
     def handle_handshake_response(self, response_dict):

tests/unit/core/test_HashBlob.py

@@ -44,9 +44,15 @@ class BlobFileTest(unittest.TestCase):
         blob_file = BlobFile(self.blob_dir, self.fake_content_hash, self.fake_content_len)
         self.assertTrue(blob_file.verified)
         f = blob_file.open_for_reading()
+        self.assertEqual(1, blob_file.readers)
         c = f.read()
         self.assertEqual(c, self.fake_content)
 
+        # close reader
+        f.close()
+        self.assertEqual(0, blob_file.readers)
+
+
     @defer.inlineCallbacks
     def test_delete(self):
         blob_file = BlobFile(self.blob_dir, self.fake_content_hash, self.fake_content_len)
@@ -58,6 +64,21 @@ class BlobFileTest(unittest.TestCase):
         blob_file = BlobFile(self.blob_dir, self.fake_content_hash)
         self.assertFalse(blob_file.verified)
 
+    @defer.inlineCallbacks
+    def test_delete_fail(self):
+        # deletes should fail if being written to
+        blob_file = BlobFile(self.blob_dir, self.fake_content_hash, self.fake_content_len)
+        writer, finished_d = blob_file.open_for_writing(peer=1)
+        yield self.assertFailure(blob_file.delete(), ValueError)
+        writer.write(self.fake_content)
+        writer.close()
+
+        # deletes should fail if being read and not closed
+        blob_file = BlobFile(self.blob_dir, self.fake_content_hash, self.fake_content_len)
+        self.assertTrue(blob_file.verified)
+        f = blob_file.open_for_reading()
+        yield self.assertFailure(blob_file.delete(), ValueError)
+
     @defer.inlineCallbacks
     def test_too_much_write(self):
         # writing too much data should result in failure