[bug] fail locally if blob exists

We can't let the local DB try an isertion before making sure doc isn't
already there.

- Resolves: #8845

2 files changed, 24 insertions, 0 deletions

diff --git a/client/src/leap/soledad/client/_blobs.py b/client/src/leap/soledad/client/_blobs.py
index 6f692f6b..1475b302 100644
--- a/client/src/leap/soledad/client/_blobs.py
+++ b/client/src/leap/soledad/client/_blobs.py
@@ -194,6 +194,9 @@ class BlobManager(object):
 
     @defer.inlineCallbacks
     def put(self, doc, size):
+        if (yield self.local.exists(doc.blob_id)):
+            error_message = "Blob already exists: %s" % doc.blob_id
+            raise BlobAlreadyExistsError(error_message)
         fd = doc.blob_fd
         # TODO this is a tee really, but ok... could do db and upload
         # concurrently. not sure if we'd gain something.
@@ -326,6 +329,12 @@ class SQLiteBlobBackend(object):
         else:
             defer.returnValue([])
 
+    @defer.inlineCallbacks
+    def exists(self, blob_id):
+        query = 'SELECT blob_id from blobs WHERE blob_id = ?'
+        result = yield self.dbpool.runQuery(query, (blob_id,))
+        defer.returnValue(bool(len(result)))
+
 
 def _init_blob_table(conn):
     maybe_create = (
diff --git a/testing/tests/blobs/test_local_backend.py b/testing/tests/blobs/test_local_backend.py
index 5caa7463..b5a14de4 100644
--- a/testing/tests/blobs/test_local_backend.py
+++ b/testing/tests/blobs/test_local_backend.py
@@ -20,6 +20,7 @@ Tests for sqlcipher backend on blobs client.
 from twisted.trial import unittest
 from twisted.internet import defer
 from leap.soledad.client._blobs import BlobManager, BlobDoc, FIXED_REV
+from leap.soledad.client._blobs import BlobAlreadyExistsError
 from io import BytesIO
 from mock import Mock
 import pytest
@@ -115,3 +116,17 @@ class BlobManagerTestCase(unittest.TestCase):
         call_blob_id, call_fd = call_list[0][0]
         self.assertEquals('missing_id', call_blob_id)
         self.assertEquals('test', call_fd.getvalue())
+
+    @defer.inlineCallbacks
+    @pytest.mark.usefixtures("method_tmpdir")
+    def test_duplicated_blob_error_on_put(self):
+        self.manager._encrypt_and_upload = Mock(return_value=None)
+        content = "Blob content"
+        doc1 = BlobDoc(BytesIO(content), 'existing_id')
+        yield self.manager.put(doc1, len(content))
+        doc2 = BlobDoc(BytesIO(content), 'existing_id')
+        # reset mock, so we can check that upload wasnt called
+        self.manager._encrypt_and_upload = Mock(return_value=None)
+        with pytest.raises(BlobAlreadyExistsError):
+            yield self.manager.put(doc2, len(content))
+        self.assertFalse(self.manager._encrypt_and_upload.called)