Add cloud event to core

sdk/core/azure-core/CHANGELOG.md

@@ -1,7 +1,11 @@
 # Release History
 
-## 1.11.1 (Unreleased)
+## 1.12.0 (Unreleased)
 
+### Features
+
+- Added `azure.core.messaging.CloudEvent` model that follows the cloud event spec.
+- Added `azure.core.serialization.NULL` sentinel value 
 
 ## 1.11.0 (2021-02-08)
 

sdk/core/azure-core/azure/core/_utils.py

@@ -0,0 +1,70 @@
+# coding=utf-8
+# --------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import datetime
+
+
+class _FixedOffset(datetime.tzinfo):
+    """Fixed offset in minutes east from UTC.
+
+    Copy/pasted from Python doc
+
+    :param int offset: offset in minutes
+    """
+
+    def __init__(self, offset):
+        self.__offset = datetime.timedelta(minutes=offset)
+
+    def utcoffset(self, dt):
+        return self.__offset
+
+    def tzname(self, dt):
+        return str(self.__offset.total_seconds() / 3600)
+
+    def __repr__(self):
+        return "<FixedOffset {}>".format(self.tzname(None))
+
+    def dst(self, dt):
+        return datetime.timedelta(0)
+
+
+try:
+    from datetime import timezone
+
+    TZ_UTC = timezone.utc  # type: ignore
+except ImportError:
+    TZ_UTC = _FixedOffset(0)  # type: ignore
+
+
+def _convert_to_isoformat(date_time):
+    """Deserialize a date in RFC 3339 format to datetime object.
+    Check https://tools.ietf.org/html/rfc3339#section-5.8 for examples.
+    """
+    if not date_time:
+        return None
+    if date_time[-1] == "Z":
+        delta = 0
+        timestamp = date_time[:-1]
+    else:
+        timestamp = date_time[:-6]
+        sign, offset = date_time[-6], date_time[-5:]
+        delta = int(sign + offset[:1]) * 60 + int(sign + offset[-2:])
+
+    if delta == 0:
+        tzinfo = TZ_UTC
+    else:
+        try:
+            tzinfo = datetime.timezone(datetime.timedelta(minutes=delta))
+        except AttributeError:
+            tzinfo = _FixedOffset(delta)
+
+    try:
+        deserialized = datetime.datetime.strptime(timestamp, "%Y-%m-%dT%H:%M:%S.%f")
+    except ValueError:
+        deserialized = datetime.datetime.strptime(timestamp, "%Y-%m-%dT%H:%M:%S")
+
+    deserialized = deserialized.replace(tzinfo=tzinfo)
+    return deserialized

sdk/core/azure-core/azure/core/_version.py

@@ -9,4 +9,4 @@
 # regenerated.
 # --------------------------------------------------------------------------
 
-VERSION = "1.11.1"
+VERSION = "1.12.0"

sdk/core/azure-core/azure/core/messaging.py

@@ -0,0 +1,168 @@
+# coding=utf-8
+# --------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import uuid
+from base64 import b64decode
+from datetime import datetime
+from azure.core._utils import _convert_to_isoformat, TZ_UTC
+from azure.core.serialization import NULL
+
+try:
+    from typing import TYPE_CHECKING, cast, Union
+except ImportError:
+    TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Any, Optional, Dict
+
+
+__all__ = ["CloudEvent"]
+
+
+class CloudEvent(object):  # pylint:disable=too-many-instance-attributes
+    """Properties of the CloudEvent 1.0 Schema.
+    All required parameters must be populated in order to send to Azure.
+
+    :param source: Required. Identifies the context in which an event happened. The combination of id and source must
+     be unique for each distinct event. If publishing to a domain topic, source must be the domain name.
+    :type source: str
+    :param type: Required. Type of event related to the originating occurrence.
+    :type type: str
+    :keyword data: Optional. Event data specific to the event type.
+    :type data: object
+    :keyword time: Optional. The time (in UTC) the event was generated.
+    :type time: ~datetime.datetime
+    :keyword dataschema: Optional. Identifies the schema that data adheres to.
+    :type dataschema: str
+    :keyword datacontenttype: Optional. Content type of data value.
+    :type datacontenttype: str
+    :keyword subject: Optional. This describes the subject of the event in the context of the event producer
+     (identified by source).
+    :type subject: str
+    :keyword specversion: Optional. The version of the CloudEvent spec. Defaults to "1.0"
+    :type specversion: str
+    :keyword id: Optional. An identifier for the event. The combination of id and source must be
+     unique for each distinct event. If not provided, a random UUID will be generated and used.
+    :type id: Optional[str]
+    :keyword extensions: Optional. A CloudEvent MAY include any number of additional context attributes
+     with distinct names represented as key - value pairs. Each extension must be alphanumeric, lower cased
+     and must not exceed the length of 20 characters.
+    :type extensions: Optional[Dict]
+    :ivar source: Identifies the context in which an event happened. The combination of id and source must
+     be unique for each distinct event. If publishing to a domain topic, source must be the domain name.
+    :vartype source: str
+    :ivar data: Event data specific to the event type.
+    :vartype data: object
+    :ivar type: Type of event related to the originating occurrence.
+    :vartype type: str
+    :ivar time: The time (in UTC) the event was generated.
+    :vartype time: ~datetime.datetime
+    :ivar dataschema: Identifies the schema that data adheres to.
+    :vartype dataschema: str
+    :ivar datacontenttype: Content type of data value.
+    :vartype datacontenttype: str
+    :ivar subject: This describes the subject of the event in the context of the event producer
+     (identified by source).
+    :vartype subject: str
+    :ivar specversion: Optional. The version of the CloudEvent spec. Defaults to "1.0"
+    :vartype specversion: str
+    :ivar id: An identifier for the event. The combination of id and source must be
+     unique for each distinct event. If not provided, a random UUID will be generated and used.
+    :vartype id: str
+    :ivar extensions: A CloudEvent MAY include any number of additional context attributes
+     with distinct names represented as key - value pairs. Each extension must be alphanumeric, lower cased
+     and must not exceed the length of 20 characters.
+    :vartype extensions: Dict
+    """
+
+    def __init__(self, source, type, **kwargs):  # pylint: disable=redefined-builtin
+        # type: (str, str, **Any) -> None
+        self.source = source  # type: str
+        self.type = type  # type: str
+        self.specversion = kwargs.pop("specversion", "1.0")  # type: Optional[str]
+        self.id = kwargs.pop("id", str(uuid.uuid4()))  # type: Optional[str]
+        self.time = kwargs.pop("time", datetime.now(TZ_UTC))  # type: Optional[datetime]
+
+        self.datacontenttype = kwargs.pop("datacontenttype", None)  # type: Optional[str]
+        self.dataschema = kwargs.pop("dataschema", None)  # type: Optional[str]
+        self.subject = kwargs.pop("subject", None)  # type: Optional[str]
+        self.data = kwargs.pop("data", None)  # type: Optional[object]
+
+        try:
+            self.extensions = kwargs.pop("extensions")  # type: Optional[Dict]
+            for key in self.extensions.keys():  # type:ignore # extensions won't be None here
+                if not key.islower() or not key.isalnum():
+                    raise ValueError(
+                        "Extension attributes should be lower cased and alphanumeric."
+                    )
+        except KeyError:
+            self.extensions = None
+
+        if kwargs:
+            remaining = ", ".join(kwargs.keys())
+            raise ValueError(
+                "Unexpected keyword arguments {}. Any extension attributes must be passed explicitly using extensions."
+                .format(remaining)
+            )
+
+    def __repr__(self):
+        return "CloudEvent(source={}, type={}, specversion={}, id={}, time={})".format(
+            self.source, self.type, self.specversion, self.id, self.time
+        )[:1024]
+
+    @classmethod
+    def from_dict(cls, event):
+        # type: (Dict) -> CloudEvent
+        """
+        Returns the deserialized CloudEvent object when a dict is provided.
+        :param event: The dict representation of the event which needs to be deserialized.
+        :type event: dict
+        :rtype: CloudEvent
+        """
+        kwargs = {}  # type: Dict[Any, Any]
+        reserved_attr = [
+            "data",
+            "data_base64",
+            "id",
+            "source",
+            "type",
+            "specversion",
+            "time",
+            "dataschema",
+            "datacontenttype",
+            "subject",
+        ]
+
+        if "data" in event and "data_base64" in event:
+            raise ValueError(
+                "Invalid input. Only one of data and data_base64 must be present."
+            )
+
+        if "data" in event:
+            data = event.get("data")
+            kwargs["data"] = data if data is not None else NULL
+        elif "data_base64" in event:
+            kwargs["data"] = b64decode(
+                cast(Union[str, bytes], event.get("data_base64"))
+            )
+
+        for item in ["datacontenttype", "dataschema", "subject"]:
+            if item in event:
+                val = event.get(item)
+                kwargs[item] = val if val is not None else NULL
+
+        extensions = {k: v for k, v in event.items() if k not in reserved_attr}
+        if extensions:
+            kwargs["extensions"] = extensions
+
+        return cls(
+            id=event.get("id"),
+            source=event["source"],
+            type=event["type"],
+            specversion=event.get("specversion"),
+            time=_convert_to_isoformat(event.get("time")),
+            **kwargs
+        )

sdk/core/azure-core/azure/core/pipeline/policies/_utils.py

@@ -26,29 +26,7 @@
 import datetime
 import email.utils
 from requests.structures import CaseInsensitiveDict
-
-class _FixedOffset(datetime.tzinfo):
-    """Fixed offset in minutes east from UTC.
-
-    Copy/pasted from Python doc
-
-    :param int offset: offset in minutes
-    """
-
-    def __init__(self, offset):
-        self.__offset = datetime.timedelta(minutes=offset)
-
-    def utcoffset(self, dt):
-        return self.__offset
-
-    def tzname(self, dt):
-        return str(self.__offset.total_seconds()/3600)
-
-    def __repr__(self):
-        return "<FixedOffset {}>".format(self.tzname(None))
-
-    def dst(self, dt):
-        return datetime.timedelta(0)
+from ..._utils import _FixedOffset
 
 def _parse_http_date(text):
     """Parse a HTTP date format into datetime."""

sdk/core/azure-core/azure/core/serialization.py

@@ -0,0 +1,23 @@
+# coding=utf-8
+# --------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+
+__all__ = ["NULL"]
+
+class _Null(object):
+    """To create a Falsy object
+    """
+    def __bool__(self):
+        return False
+
+    __nonzero__ = __bool__ # Python2 compatibility
+
+
+NULL = _Null()
+"""
+A falsy sentinel object which is supposed to be used to specify attributes
+with no data. This gets serialized to `null` on the wire.
+"""

sdk/core/azure-core/doc/azure.core.rst

@@ -41,6 +41,14 @@ azure.core.exceptions
    :members:
    :undoc-members:
 
+azure.core.messaging
+-------------------
+
+.. automodule:: azure.core.messaging
+   :members:
+   :undoc-members:
+   :inherited-members:
+
 azure.core.paging
 -----------------
 
@@ -57,3 +65,10 @@ azure.core.settings
    :undoc-members:
    :inherited-members:
 
+azure.core.serialization
+-------------------
+
+.. automodule:: azure.core.serialization
+   :members:
+   :undoc-members:
+   :inherited-members: