Implement select object

Selects and filters out data from stored object.
Client for select feature

Author: sinhaashish

docs/API.md

@@ -40,6 +40,7 @@ s3Client = Minio('s3.amazonaws.com',
 |                                                       | [`fput_object`](#fput_object)                           |                                                   |                                                                     |
 |                                                       | [`fget_object`](#fget_object)                           |                                                   |                                                                     |
 |                                                       | [`get_partial_object`](#get_partial_object)             |                                                   |                                                                     |
+|                                                       | [`select_object_content`](#select_object_content)       |                                                   |                                                                     |
 
 ## 1. Constructor
 
@@ -668,6 +669,79 @@ except ResponseError as err:
     print(err)
 ```
 
+<a name="select_object_content"></a>
+### select_object_content(self, bucket_name, object_name, options)
+Select object content filters the contents of object based on a simple structured query language (SQL).
+
+__Parameters__
+
+|Param   |Type   |Description   |
+|:---|:---|:---|
+|``bucket_name``   |_string_   |Name of the bucket.   |
+|``object_name``   |_string_   |Name of the object.   |
+|``options`` | _Object_ | Query Options   |
+
+
+__Return Value__
+
+|Param   |Type   |Description   |
+|:---|:---|:---|
+|``obj``|_Object_  |Select_object_reader object.  |
+
+
+
+__Example__
+
+
+```py
+client = Minio('s3.amazonaws.com',
+               access_key='YOUR-ACCESSKEY',
+               secret_key='YOUR-SECRETKEY')
+
+options = SelectObjectOptions(
+    expression=" select * from s3object",
+    input_serialization=InputSerialization(
+        compression_type="NONE",
+        csv=CSVInput(FileHeaderInfo="USE",
+                     RecordDelimiter="\n",
+                     FieldDelimiter=",",
+                     QuoteCharacter='"',
+                     QuoteEscapeCharacter='"',
+                     Comments="#",
+                     AllowQuotedRecordDelimiter="FALSE",
+                     ),
+        ),
+
+    output_serialization=OutputSerialization(
+        csv=CSVOutput(QuoteFields="ASNEEDED",
+                      RecordDelimiter="\n",
+                      FieldDelimiter=",",
+                      QuoteCharacter='"',
+                      QuoteEscapeCharacter='"',)
+                      ),
+    request_progress=RequestProgress(
+        enabled="FLASE"
+        )
+    )
+
+try:
+    data = client.select_object_content('my-bucket', 'my-object', options)
+
+    # Get the records
+    with open('my-record-file', 'w') as record_data:
+        for d in data.stream(10*1024):
+            record_data.write(d)
+
+    # Get the stats
+    print(data.stats)
+
+except CRCValidationError as err:
+    print(err)
+except ResponseError as err:
+    print(err)
+
+```
+
 <a name="fget_object"></a>
 ### fget_object(bucket_name, object_name, file_path, request_headers=None)
 Downloads and saves the object as a file in the local filesystem.

examples/select_object_content.py

@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+# MinIO Python Library for Amazon S3 Compatible Cloud Storage, (C)
+#  2019 MinIO, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from minio import Minio
+from minio.error import ResponseError
+from minio.select_object_reader import CRCValidationError
+from minio.select_object_options import (SelectObjectOptions, CSVInput,
+                                         JSONInput, RequestProgress,
+                                         ParquetInput, InputSerialization,
+                                         OutputSerialization, CSVOutput,
+                                         JsonOutput)
+
+client = Minio('s3.amazonaws.com',
+               access_key='YOUR-ACCESSKEY',
+               secret_key='YOUR-SECRETKEY')
+
+options = SelectObjectOptions(
+    expression="select * from s3object",
+    input_serialization=InputSerialization(
+        compression_type="NONE",
+        csv=CSVInput(FileHeaderInfo="USE",
+                     RecordDelimiter="\n",
+                     FieldDelimiter=",",
+                     QuoteCharacter='"',
+                     QuoteEscapeCharacter='"',
+                     Comments="#",
+                     AllowQuotedRecordDelimiter="FALSE",
+                    ),
+        # If input is JSON
+        # json=JSONInput(Type="DOCUMENT",)
+        ),
+
+    output_serialization=OutputSerialization(
+        csv=CSVOutput(QuoteFields="ASNEEDED",
+                      RecordDelimiter="\n",
+                      FieldDelimiter=",",
+                      QuoteCharacter='"',
+                      QuoteEscapeCharacter='"',)
+
+        # json = JsonOutput(
+        #     RecordDelimiter="\n",
+        #     )
+        ),
+    request_progress=RequestProgress(
+        enabled="False"
+        )
+    )
+
+try:
+    data = client.select_object_content('your-bucket', 'your-object', options)
+
+    # Get the records
+    with open('my-record-file', 'w') as record_data:
+        for d in data.stream(10*1024):
+            record_data.write(d)
+
+    # Get the stats
+    print(data.stats())
+
+except CRCValidationError as err:
+    print(err)
+except ResponseError as err:
+    print(err)

minio/__init__.py

@@ -31,10 +31,13 @@
 __author__ = 'MinIO, Inc.'
 __version__ = '4.0.19'
 __license__ = 'Apache 2.0'
-__copyright__ = 'Copyright 2015, 2016, 2017 MinIO, Inc.'
+__copyright__ = 'Copyright 2015, 2016, 2017, 2018, 2019 MinIO, Inc.'
 
 from .api import Minio
 from .error import ResponseError
 from .post_policy import PostPolicy
 from .copy_conditions import CopyConditions
 from .definitions import Bucket, Object
+from .select_object_reader import SelectObjectReader
+
+

minio/api.py

@@ -90,9 +90,11 @@
 from .xml_marshal import (xml_marshal_bucket_constraint,
                           xml_marshal_complete_multipart_upload,
                           xml_marshal_bucket_notifications,
-                          xml_marshal_delete_objects)
+                          xml_marshal_delete_objects,
+                          xml_marshal_select)
 from .fold_case_dict import FoldCaseDict
 from .thread_pool import ThreadPool
+from .select_object_reader import SelectObjectReader
 
 # Comment format.
 _COMMENTS = '({0}; {1})'
@@ -235,6 +237,45 @@ def trace_off(self):
         """
         self._trace_output_stream = None
 
+    # Select Object Content
+    def select_object_content(self, bucket_name, object_name, opts):
+        """
+        It filters the contents of an object based on a simple
+        structured query language (SQL).
+
+        Examples:
+            data = client.select_object_content('foo', 'test.csv', options)
+
+        :param bucket_name: Bucket to read object from
+        :param object_name: Name of object to read
+        :param options: Options for select object
+        """
+        is_valid_bucket_name(bucket_name)
+        is_non_empty_string(object_name)
+
+        content = xml_marshal_select(opts)
+        url_values = dict()
+        url_values["select"] = ""
+        url_values["select-type"] = "2"
+
+        headers = {
+            'Content-Length': str(len(content)),
+            'Content-Md5': get_md5_base64digest(content)
+        }
+        content_sha256_hex = get_sha256_hexdigest(content)
+        response = self._url_open(
+            'POST',
+            bucket_name=bucket_name,
+            object_name=object_name,
+            query=url_values,
+            headers=headers,
+            body=content,
+            content_sha256=content_sha256_hex,
+            preload_content=False)
+
+        return SelectObjectReader(response)
+          
+
     # Bucket level
     def make_bucket(self, bucket_name, location='us-east-1'):
         """

minio/helpers.py

@@ -48,12 +48,23 @@
                     InvalidArgumentError)
 
 # Constants
-MAX_MULTIPART_COUNT = 10000 # 10000 parts
+MAX_MULTIPART_COUNT = 10000  # 10000 parts
 MAX_MULTIPART_OBJECT_SIZE = 5 * 1024 * 1024 * 1024 * 1024  # 5TiB
 MAX_PART_SIZE = 5 * 1024 * 1024 * 1024  # 5GiB
 MAX_POOL_SIZE = 10
 MIN_PART_SIZE = 5 * 1024 * 1024  # 5MiB
-DEFAULT_PART_SIZE = MIN_PART_SIZE # Currently its 5MiB
+DEFAULT_PART_SIZE = MIN_PART_SIZE  # Currently its 5MiB
+
+
+# Select Object Content
+READ_SIZE_SELECT = 32 * 1024  # Buffer size
+SQL = 'SQL'  # Value for ExpressionType
+EVENT_RECORDS = 'Records'  # Event Type is Records
+EVENT_PROGRESS = 'Progress'  # Event Type Progress
+EVENT_STATS = 'Stats'  # Event Type Stats
+EVENT = 'event'  # Message Type is event
+EVENT_END = 'End'  # Event Type is End
+ERROR = 'error'  # Message Type is error
 
 _VALID_BUCKETNAME_REGEX = re.compile('^[a-z0-9][a-z0-9\\.\\-]+[a-z0-9]$')
 _ALLOWED_HOSTNAME_REGEX = re.compile(

minio/select_object_options.py

@@ -0,0 +1,121 @@
+# -*- coding: utf-8 -*-
+# MinIO Python Library for Amazon S3 Compatible Cloud Storage, (C)
+# 2019 MinIO, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+
+This module creates the request for Select
+
+:copyright: (c) 2019 by MinIO, Inc.
+:license: Apache 2.0, see LICENSE for more details.
+
+"""
+from .helpers import (SQL)
+
+
+class CSVInput:
+    """
+    CSVInput: Input Format as CSV.
+    """
+    def __init__(self, FileHeaderInfo=None, RecordDelimiter="\n",
+                 FieldDelimiter=",", QuoteCharacter='"',
+                 QuoteEscapeCharacter='"', Comments="#",
+                 AllowQuotedRecordDelimiter=False):
+        self.FileHeaderInfo = FileHeaderInfo
+        self.RecordDelimiter = RecordDelimiter
+        self.FieldDelimiter = FieldDelimiter
+        self.QuoteCharacter = QuoteCharacter
+        self.QuoteEscapeCharacter = QuoteEscapeCharacter
+        self.Comments = Comments
+        self.AllowQuotedRecordDelimiter = AllowQuotedRecordDelimiter
+
+
+class JSONInput:
+    """
+    JSONInput: Input format as JSON.
+    """
+    def __init__(self, Type=None):
+        self.Type = Type
+
+
+class ParquetInput:
+    """
+    ParquetInput: Input format as Parquet
+    """
+
+
+class InputSerialization:
+    """
+    InputSerialization: nput Format.
+    """
+    def __init__(self, compression_type="NONE", csv=None, json=None, par=None):
+        self.compression_type = compression_type
+        self.csv_input = csv
+        self.json_input = json
+        self.parquet_input = par
+
+
+class CSVOutput:
+    """
+    CSVOutput: Output as CSV.
+
+    """
+    def __init__(self, QuoteFields="ASNEEDED", RecordDelimiter="\n",
+                 FieldDelimiter=",", QuoteCharacter='"',
+                 QuoteEscapeCharacter='"'):
+        self.QuoteFields = QuoteFields
+        self.RecordDelimiter = RecordDelimiter
+        self.FieldDelimiter = FieldDelimiter
+        self.QuoteCharacter = QuoteCharacter
+        self.QuoteEscapeCharacter = QuoteEscapeCharacter
+
+
+class JsonOutput:
+    """
+    JsonOutput- Output as JSON.
+    """
+    def __init__(self, RecordDelimiter="\n"):
+        self.RecordDelimiter = RecordDelimiter
+
+
+class OutputSerialization:
+    """
+    OutputSerialization: Output Format.
+    """
+    def __init__(self,  csv=None, json=None):
+        self.csv_output = csv
+        self.json_output = json
+
+
+class RequestProgress:
+    """
+    RequestProgress: Sends progress message.
+    """
+    def __init__(self, enabled=False):
+        self.enabled = enabled
+
+
+class SelectObjectOptions:
+    """
+    SelectObjectOptions: Options for select object
+    """
+    expression_type = SQL
+
+    def __init__(self, expression, input_serialization,
+                 output_serialization, request_progress):
+        self.expression = expression
+        self.in_ser = input_serialization
+        self.out_ser = output_serialization
+        self.req_progress = request_progress