From c196e15cf7562695f871c5b2f65837aa5e9d9dd3 Mon Sep 17 00:00:00 2001
From: zmsmith <zach@yipit.com>
Date: Sun, 10 Mar 2013 21:16:44 -0400
Subject: [PATCH] Table listing now supports limits and continuations

---
 moto/dynamodb/models.py              |  4 +++-
 moto/dynamodb/responses.py           | 17 +++++++++++++++--
 tests/test_dynamodb/test_dynamodb.py | 14 ++++++++++++++
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/moto/dynamodb/models.py b/moto/dynamodb/models.py
index 1c0f1521..3eab73db 100644
--- a/moto/dynamodb/models.py
+++ b/moto/dynamodb/models.py
@@ -1,5 +1,7 @@
 import datetime
 
+from collections import OrderedDict
+
 from moto.core import BaseBackend
 from .utils import unix_time
 
@@ -48,7 +50,7 @@ class Table(object):
 class DynamoDBBackend(BaseBackend):
 
     def __init__(self):
-        self.tables = {}
+        self.tables = OrderedDict()
 
     def create_table(self, name, **params):
         self.tables[name] = Table(name, **params)
diff --git a/moto/dynamodb/responses.py b/moto/dynamodb/responses.py
index add8fd5d..bac64729 100644
--- a/moto/dynamodb/responses.py
+++ b/moto/dynamodb/responses.py
@@ -32,12 +32,24 @@ class DynamoHandler(object):
             return "", dict(status=404)
 
     def ListTables(self, uri, body, headers):
-        tables = dynamodb_backend.tables.keys()
+        limit = body.get('Limit')
+        if body.get("ExclusiveStartTableName"):
+            last = body.get("ExclusiveStartTableName")
+            start = dynamodb_backend.tables.keys().index(last) + 1
+        else:
+            start = 0
+        all_tables = dynamodb_backend.tables.keys()
+        if limit:
+            tables = all_tables[start:start + limit]
+        else:
+            tables = all_tables[start:]
         response = {"TableNames": tables}
+        if limit and len(all_tables) > start + limit:
+            response["LastEvaluatedTableName"] = tables[-1]
         return json.dumps(response)
 
     def DescribeTable(self, uri, body, headers):
-        name = json.loads(body)['TableName']
+        name = body['TableName']
         try:
             table = dynamodb_backend.tables[name]
         except KeyError:
@@ -47,4 +59,5 @@ class DynamoHandler(object):
 
 
 def handler(uri, body, headers):
+    body = json.loads(body or '{}')
     return DynamoHandler(uri, body, headers_to_dict(headers)).dispatch()
diff --git a/tests/test_dynamodb/test_dynamodb.py b/tests/test_dynamodb/test_dynamodb.py
index a5df4a0a..366994fc 100644
--- a/tests/test_dynamodb/test_dynamodb.py
+++ b/tests/test_dynamodb/test_dynamodb.py
@@ -16,6 +16,20 @@ def test_list_tables():
     assert conn.list_tables() == ['TestTable']
 
 
+@mock_dynamodb
+def test_list_tables_layer_1():
+    dynamodb_backend.create_table("test_1")
+    dynamodb_backend.create_table("test_2")
+    conn = boto.connect_dynamodb('the_key', 'the_secret')
+    res = conn.layer1.list_tables(limit=1)
+    expected = {"TableNames": ["test_1"], "LastEvaluatedTableName": "test_1"}
+    res.should.equal(expected)
+
+    res = conn.layer1.list_tables(limit=1, start_table="test_1")
+    expected = {"TableNames": ["test_2"]}
+    res.should.equal(expected)
+
+
 @mock_dynamodb
 def test_describe_missing_table():
     conn = boto.connect_dynamodb('the_key', 'the_secret')