add dynamodb scanning

moto/dynamodb/comparisons.py

@@ -1,76 +1,20 @@
+# TODO add tests for all of these
 COMPARISON_FUNCS = {
     'EQ': lambda item_value, test_value: item_value == test_value,
-    'GT': lambda item_value, test_value: item_value > test_value
+    'NE': lambda item_value, test_value: item_value != test_value,
+    'LE': lambda item_value, test_value: item_value <= test_value,
+    'LT': lambda item_value, test_value: item_value < test_value,
+    'GE': lambda item_value, test_value: item_value >= test_value,
+    'GT': lambda item_value, test_value: item_value > test_value,
+    'NULL': lambda item_value: item_value is None,
+    'NOT_NULL': lambda item_value: item_value is not None,
+    'CONTAINS': lambda item_value, test_value: test_value in item_value,
+    'NOT_CONTAINS': lambda item_value, test_value: test_value not in item_value,
+    'BEGINS_WITH': lambda item_value, test_value: item_value.startswith(test_value),
+    'IN': lambda item_value, test_value: item_value in test_value,
+    'BETWEEN': lambda item_value, test_values: test_values[0] <= item_value <= test_values[1],
 }
 
 
 def get_comparison_func(range_comparison):
     return COMPARISON_FUNCS.get(range_comparison)
-
-# class EQ(ConditionOneArg):
-
-#     pass
-
-
-# class NE(ConditionOneArg):
-
-#     pass
-
-
-# class LE(ConditionOneArg):
-
-#     pass
-
-
-# class LT(ConditionOneArg):
-
-#     pass
-
-
-# class GE(ConditionOneArg):
-
-#     pass
-
-
-# class GT(ConditionOneArg):
-
-#     pass
-
-
-# class NULL(ConditionNoArgs):
-
-#     pass
-
-
-# class NOT_NULL(ConditionNoArgs):
-
-#     pass
-
-
-# class CONTAINS(ConditionOneArg):
-
-#     pass
-
-
-# class NOT_CONTAINS(ConditionOneArg):
-
-#     pass
-
-
-# class BEGINS_WITH(ConditionOneArg):
-
-#     pass
-
-
-# class IN(ConditionOneArg):
-
-#     pass
-
-
-# class BEGINS_WITH(ConditionOneArg):
-
-#     pass
-
-# class BETWEEN(ConditionTwoArgs):
-
-#     pass

moto/dynamodb/models.py

@@ -108,6 +108,30 @@ class Table(object):
                 results.append(result)
         return results, last_page
 
+    def all_items(self):
+        for hash_set in self.items.values():
+            for item in hash_set.values():
+                yield item
+
+    def scan(self, filters):
+        results = []
+        scanned_count = 0
+        last_page = True  # Once pagination is implemented, change this
+
+        for result in self.all_items():
+            scanned_count += 1
+            passes_all_conditions = True
+            for attribute_name, (comparison_operator, comparison_value) in filters.iteritems():
+                comparison_func = get_comparison_func(comparison_operator)
+                attribute_value = result.attrs[attribute_name].values()[0]
+                if not comparison_func(attribute_value, comparison_value):
+                    passes_all_conditions = False
+                    break
+            if passes_all_conditions:
+                results.append(result)
+
+        return results, scanned_count, last_page
+
     def delete_item(self, hash_key, range_key):
         try:
             return self.items[hash_key].pop(range_key)
@@ -155,6 +179,13 @@ class DynamoDBBackend(BaseBackend):
 
         return table.query(hash_key, range_comparison, range_value)
 
+    def scan(self, table_name, filters):
+        table = self.tables.get(table_name)
+        if not table:
+            return None
+
+        return table.scan(filters)
+
     def delete_item(self, table_name, hash_key, range_key):
         table = self.tables.get(table_name)
         if not table:

moto/dynamodb/responses.py

@@ -144,6 +144,33 @@ class DynamoHandler(object):
             }
         return json.dumps(result)
 
+    def Scan(self, uri, body, headers):
+        name = body['TableName']
+
+        filters = {}
+        scan_filters = body['ScanFilter']
+        for attribute_name, scan_filter in scan_filters.iteritems():
+            # Keys are attribute names. Values are tuples of (comparison, comparison_value)
+            comparison_operator = scan_filter["ComparisonOperator"]
+            comparison_value = scan_filter["AttributeValueList"][0].values()[0]
+            filters[attribute_name] = (comparison_operator, comparison_value)
+
+        items, scanned_count, last_page = dynamodb_backend.scan(name, filters)
+
+        result = {
+            "Count": len(items),
+            "Items": [item.attrs for item in items],
+            "ConsumedCapacityUnits": 1,
+            "ScannedCount": scanned_count
+        }
+
+        if not last_page:
+            result["LastEvaluatedKey"] = {
+                "HashKeyElement": items[-1].hash_key,
+                "RangeKeyElement": items[-1].range_key,
+            }
+        return json.dumps(result)
+
     def DeleteItem(self, uri, body, headers):
         name = body['TableName']
         hash_key = body['Key']['HashKeyElement'].values()[0]

tests/test_dynamodb/test_dynamodb.py

@@ -5,7 +5,7 @@ from freezegun import freeze_time
 from moto import mock_dynamodb
 from moto.dynamodb import dynamodb_backend
 
-from boto.dynamodb.condition import GT
+from boto.dynamodb import condition
 from boto.exception import DynamoDBResponseError
 
 
@@ -215,15 +215,54 @@ def test_query():
     )
     item.put()
 
-    results = table.query(hash_key='the-key', range_key_condition=GT('1'))
+    results = table.query(hash_key='the-key', range_key_condition=condition.GT('1'))
     results.response['Items'].should.have.length_of(3)
 
-    results = table.query(hash_key='the-key', range_key_condition=GT('234'))
+    results = table.query(hash_key='the-key', range_key_condition=condition.GT('234'))
     results.response['Items'].should.have.length_of(2)
 
-    results = table.query(hash_key='the-key', range_key_condition=GT('9999'))
+    results = table.query(hash_key='the-key', range_key_condition=condition.GT('9999'))
     results.response['Items'].should.have.length_of(0)
 
+
+@mock_dynamodb
+def test_scan():
+    conn = boto.connect_dynamodb()
+    table = create_table(conn)
+
+    item_data = {
+        'Body': 'http://url_to_lolcat.gif',
+        'SentBy': 'User A',
+        'ReceivedTime': '12/9/2011 11:36:03 PM',
+    }
+    item = table.new_item(
+        hash_key='the-key',
+        range_key='456',
+        attrs=item_data,
+    )
+    item.put()
+
+    item = table.new_item(
+        hash_key='the-key',
+        range_key='123',
+        attrs=item_data,
+    )
+    item.put()
+
+    item = table.new_item(
+        hash_key='the-key',
+        range_key='789',
+        attrs=item_data,
+    )
+    item.put()
+
+    results = table.scan(scan_filter={'SentBy': condition.EQ('User B')})
+    results.response['Items'].should.have.length_of(0)
+
+    results = table.scan(scan_filter={'Body': condition.BEGINS_WITH('http')})
+    results.response['Items'].should.have.length_of(3)
+
+
 # Batch read
 # Batch write
 # scan