Added `beginning_offsets` and `end_offsets` API's and fixed @jeffwidman review issues

3 files changed, 96 insertions, 16 deletions

diff --git a/kafka/conn.py b/kafka/conn.py
index d042300..61d63bf 100644
--- a/kafka/conn.py
+++ b/kafka/conn.py
@@ -887,7 +887,7 @@ class BrokerConnection(object):
 
     def _infer_broker_version_from_api_versions(self, api_versions):
         # The logic here is to check the list of supported request versions
-        # in descending order. As soon as we find one that works, return it
+        # in reverse order. As soon as we find one that works, return it
         test_cases = [
             # format (<broker verion>, <needed struct>)
             ((0, 11, 0), MetadataRequest[4]),
diff --git a/kafka/consumer/fetcher.py b/kafka/consumer/fetcher.py
index 1a3dfd5..6a7b794 100644
--- a/kafka/consumer/fetcher.py
+++ b/kafka/consumer/fetcher.py
@@ -193,6 +193,21 @@ class Fetcher(six.Iterator):
                 offsets[tp] = OffsetAndTimestamp(offset, timestamp)
         return offsets
 
+    def beginning_offsets(self, partitions, timeout_ms):
+        return self.beginning_or_end_offset(
+            partitions, OffsetResetStrategy.EARLIEST, timeout_ms)
+
+    def end_offsets(self, partitions, timeout_ms):
+        return self.beginning_or_end_offset(
+            partitions, OffsetResetStrategy.LATEST, timeout_ms)
+
+    def beginning_or_end_offset(self, partitions, timestamp, timeout_ms):
+        timestamps = dict([(tp, timestamp) for tp in partitions])
+        offsets = self._retrieve_offsets(timestamps, timeout_ms)
+        for tp in timestamps:
+            offsets[tp] = offsets[tp][0]
+        return offsets
+
     def _reset_offset(self, partition):
         """Reset offsets for the given partition using the offset reset strategy.
 
@@ -222,10 +237,10 @@ class Fetcher(six.Iterator):
             self._subscriptions.seek(partition, offset)
 
     def _retrieve_offsets(self, timestamps, timeout_ms=float("inf")):
-        """ Fetch offset for each partition passed in ``timestamps`` map.
+        """Fetch offset for each partition passed in ``timestamps`` map.
 
         Blocks until offsets are obtained, a non-retriable exception is raised
-        or ``timeout_ms`` passed (if it's not ``None``).
+        or ``timeout_ms`` passed.
 
         Arguments:
             timestamps: {TopicPartition: int} dict with timestamps to fetch
@@ -268,7 +283,7 @@ class Fetcher(six.Iterator):
             remaining_ms = timeout_ms - elapsed_ms
 
         raise Errors.KafkaTimeoutError(
-            "Failed to get offsets by times in %s ms" % timeout_ms)
+            "Failed to get offsets by timestamps in %s ms" % timeout_ms)
 
     def _raise_if_offset_out_of_range(self):
         """Check FetchResponses for offset out of range.
@@ -613,7 +628,7 @@ class Fetcher(six.Iterator):
         return f(bytes_)
 
     def _send_offset_requests(self, timestamps):
-        """ Fetch offsets for each partition in timestamps dict. This may send
+        """Fetch offsets for each partition in timestamps dict. This may send
         request to multiple nodes, based on who is Leader for partition.
 
         Arguments:
diff --git a/kafka/consumer/group.py b/kafka/consumer/group.py
index 48a88b2..54a3711 100644
--- a/kafka/consumer/group.py
+++ b/kafka/consumer/group.py
@@ -862,33 +862,37 @@ class KafkaConsumer(six.Iterator):
         return metrics
 
     def offsets_for_times(self, timestamps):
-        """
-        Look up the offsets for the given partitions by timestamp. The returned
-        offset for each partition is the earliest offset whose timestamp is
-        greater than or equal to the given timestamp in the corresponding
-        partition.
+        """Look up the offsets for the given partitions by timestamp. The
+        returned offset for each partition is the earliest offset whose
+        timestamp is greater than or equal to the given timestamp in the
+        corresponding partition.
 
         This is a blocking call. The consumer does not have to be assigned the
         partitions.
 
         If the message format version in a partition is before 0.10.0, i.e.
         the messages do not have timestamps, ``None`` will be returned for that
-        partition.
+        partition. ``None`` will also be returned for the partition if there
+        are no messages in it.
 
         Note:
-            Notice that this method may block indefinitely if the partition
-            does not exist.
+            This method may block indefinitely if the partition does not exist.
 
         Arguments:
             timestamps (dict): ``{TopicPartition: int}`` mapping from partition
                 to the timestamp to look up. Unit should be milliseconds since
                 beginning of the epoch (midnight Jan 1, 1970 (UTC))
 
+        Returns:
+            ``{TopicPartition: OffsetAndTimestamp}``: mapping from partition
+            to the timestamp and offset of the first message with timestamp
+            greater than or equal to the target timestamp.
+
         Raises:
-            ValueError: if the target timestamp is negative
-            UnsupportedVersionError: if the broker does not support looking
+            ValueError: If the target timestamp is negative
+            UnsupportedVersionError: If the broker does not support looking
                 up the offsets by timestamp.
-            KafkaTimeoutError: if fetch failed in request_timeout_ms
+            KafkaTimeoutError: If fetch failed in request_timeout_ms
         """
         if self.config['api_version'] <= (0, 10, 0):
             raise UnsupportedVersionError(
@@ -903,6 +907,67 @@ class KafkaConsumer(six.Iterator):
         return self._fetcher.get_offsets_by_times(
             timestamps, self.config['request_timeout_ms'])
 
+    def beginning_offsets(self, partitions):
+        """Get the first offset for the given partitions.
+
+        This method does not change the current consumer position of the
+        partitions.
+
+        Note:
+            This method may block indefinitely if the partition does not exist.
+
+        Arguments:
+            partitions (list): List of TopicPartition instances to fetch
+                offsets for.
+
+        Returns:
+            ``{TopicPartition: int}``: The earliest available offsets for the
+            given partitions.
+
+        Raises:
+            UnsupportedVersionError: If the broker does not support looking
+                up the offsets by timestamp.
+            KafkaTimeoutError: If fetch failed in request_timeout_ms.
+        """
+        if self.config['api_version'] <= (0, 10, 0):
+            raise UnsupportedVersionError(
+                "offsets_for_times API not supported for cluster version {}"
+                .format(self.config['api_version']))
+        offsets = self._fetcher.beginning_offsets(
+            partitions, self.config['request_timeout_ms'])
+        return offsets
+
+    def end_offsets(self, partitions):
+        """Get the last offset for the given partitions. The last offset of a
+        partition is the offset of the upcoming message, i.e. the offset of the
+        last available message + 1.
+
+        This method does not change the current consumer position of the
+        partitions.
+
+        Note:
+            This method may block indefinitely if the partition does not exist.
+
+        Arguments:
+            partitions (list): List of TopicPartition instances to fetch
+                offsets for.
+
+        Returns:
+            ``{TopicPartition: int}``: The end offsets for the given partitions.
+
+        Raises:
+            UnsupportedVersionError: If the broker does not support looking
+                up the offsets by timestamp.
+            KafkaTimeoutError: If fetch failed in request_timeout_ms
+        """
+        if self.config['api_version'] <= (0, 10, 0):
+            raise UnsupportedVersionError(
+                "offsets_for_times API not supported for cluster version {}"
+                .format(self.config['api_version']))
+        offsets = self._fetcher.end_offsets(
+            partitions, self.config['request_timeout_ms'])
+        return offsets
+
     def _use_consumer_group(self):
         """Return True iff this consumer can/should join a broker-coordinated group."""
         if self.config['api_version'] < (0, 9):