Specification for postgres uuid functions.

Author: pmart123

postpy/uuids.py

@@ -0,0 +1,65 @@
+"""Configure psycopg2 to support UUID conversion."""
+
+import psycopg2.extras
+
+from postpy.admin import install_extensions
+
+
+CRYPTO_EXTENSION = 'pgcrypto'
+UUID_OSSP_EXTENSION = 'uuid-ossp'
+
+
+def register_client():
+    """Have psycopg2 marshall UUID objects automatically."""
+
+    psycopg2.extras.register_uuid()
+
+
+def register_crypto():
+    """Support for UUID's on server side.
+
+    Lighter dependency than uuid-ossp supporting
+    random_uuid_function for UUID generation.
+    """
+
+    install_extensions([CRYPTO_EXTENSION])
+
+
+def register_uuid():
+    """Support for UUID's on server side.
+
+    Notes
+    -----
+    uuid-ossp can be problematic on some platforms. See:
+    https://www.postgresql.org/docs/current/static/uuid-ossp.html
+    """
+
+    install_extensions([UUID_OSSP_EXTENSION])
+
+
+def random_uuid_function(schema=None):
+    """Cryptographic random UUID function.
+
+    Generates random database side UUID's.
+
+    Notes
+    -----
+    Lighter dependency than uuid-ossp, but higher
+    fragmentation on disk if used as auto-generating primary key UUID.
+    """
+
+    return '{}gen_random_uuid()'.format(_format_schema(schema))
+
+
+def uuid_sequence_function(schema=None):
+    """Sequential UUID generation.
+
+    Sequential UUID creation on database side offering
+    less table fragmentation issues when used as UUID primary key.
+    """
+
+    return '{}uuid_generate_v1mc()'.format(_format_schema(schema))
+
+
+def _format_schema(schema):
+    return '{}.'.format(schema) if schema else ''

tests/test_uuids.py

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+import unittest
+
+from postpy import uuids
+
+
+class TestUUIDFunctions(unittest.TestCase):
+
+    def test_function_formatters(self):
+
+        expected = 'gen_random_uuid()'
+        result = uuids.random_uuid_function()
+
+        self.assertEqual(expected, result)
+
+        expected = 'my_schema.uuid_generate_v1mc()'
+        result = uuids.uuid_sequence_function('my_schema')
+
+        self.assertEqual(expected, result)