From cc8751a752b6a5d878e1044509fbd89bd436fc9c Mon Sep 17 00:00:00 2001
From: poojanilangekar <nilangekar.pooja@gmail.com>
Date: Fri, 11 May 2018 21:12:42 -0400
Subject: [PATCH] Changed after Prashanth's review

---
 src/catalog/catalog.cpp            |  2 +-
 src/include/common/exception.h     | 13 ++++++++++++-
 src/include/storage/layout.h       |  4 ++--
 src/storage/layout.cpp             |  4 ++--
 src/storage/tile_group_factory.cpp |  4 ++++
 5 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/catalog/catalog.cpp b/src/catalog/catalog.cpp
index fe91b340ed3..a36eb71c4bd 100644
--- a/src/catalog/catalog.cpp
+++ b/src/catalog/catalog.cpp
@@ -579,7 +579,7 @@ std::shared_ptr<const storage::Layout> Catalog::CreateLayout(
   bool result =
       pg_layout->InsertLayout(table_oid, new_layout, pool_.get(), txn);
   if (!result) {
-    LOG_DEBUG("Failed to create a new layout for table %u", table_oid);
+    LOG_ERROR("Failed to create a new layout for table %u", table_oid);
     return nullptr;
   }
   return new_layout;
diff --git a/src/include/common/exception.h b/src/include/common/exception.h
index 4c201891751..7f25ec20e9f 100644
--- a/src/include/common/exception.h
+++ b/src/include/common/exception.h
@@ -59,7 +59,8 @@ enum class ExceptionType {
   SETTINGS = 23,          // settings related
   BINDER = 24,            // binder related
   NETWORK = 25,           // network related
-  OPTIMIZER = 26          // optimizer related
+  OPTIMIZER = 26,         // optimizer related
+  NULL_POINTER = 27       // nullptr exception
 };
 
 class Exception : public std::runtime_error {
@@ -132,6 +133,8 @@ class Exception : public std::runtime_error {
         return "Settings";
       case ExceptionType::OPTIMIZER:
         return "Optimizer";
+      case ExceptionType::NULL_POINTER:
+        return "NullPointer";
       default:
         return "Unknown";
     }
@@ -467,4 +470,12 @@ class OptimizerException : public Exception {
       : Exception(ExceptionType::OPTIMIZER, msg) {}
 };
 
+class NullPointerException : public Exception {
+  NullPointerException() = delete;
+
+ public:
+  NullPointerException(std::string msg)
+      : Exception(ExceptionType::NULL_POINTER, msg) {}
+};
+
 }  // namespace peloton
diff --git a/src/include/storage/layout.h b/src/include/storage/layout.h
index d06fe93427e..ce726d5d729 100644
--- a/src/include/storage/layout.h
+++ b/src/include/storage/layout.h
@@ -34,7 +34,7 @@ namespace storage {
 /** @brief used to store the mapping between a tile and its columns
  * <tile index> to vector{<original column index, tile column offset>}
  */
-typedef std::map<oid_t, std::vector<std::pair<oid_t, oid_t>>> tile_map_type;
+typedef std::map<oid_t, std::vector<std::pair<oid_t, oid_t>>> TileToColumnMap;
 
 /**
  * @brief   Class to store the physical layout of a TileGroup.
@@ -100,7 +100,7 @@ class Layout : public Printable {
   uint32_t GetColumnCount() const { return num_columns_; }
 
   /** @brief Returns the tile-columns map for each tile in the TileGroup. */
-  tile_map_type GetTileMap() const;
+  TileToColumnMap GetTileMap() const;
 
   /** @brief  Constructs the schema for the given layout.  This function
    *          is used only in TempTables and LogicalTiles.
diff --git a/src/storage/layout.cpp b/src/storage/layout.cpp
index 37664a42f77..c03b721087f 100644
--- a/src/storage/layout.cpp
+++ b/src/storage/layout.cpp
@@ -137,8 +137,8 @@ oid_t Layout::GetTileIdFromColumnId(oid_t column_id) const {
   return tile_offset;
 }
 
-tile_map_type Layout::GetTileMap() const {
-  tile_map_type tile_map;
+TileToColumnMap Layout::GetTileMap() const {
+  TileToColumnMap tile_map;
 
   if (layout_type_ == LayoutType::ROW) {
     // Row store layout, hence all columns are contained in tile 0.
diff --git a/src/storage/tile_group_factory.cpp b/src/storage/tile_group_factory.cpp
index c1fd897c09b..2c0da483619 100644
--- a/src/storage/tile_group_factory.cpp
+++ b/src/storage/tile_group_factory.cpp
@@ -31,6 +31,10 @@ TileGroup *TileGroupFactory::GetTileGroup(
   // Allocate the data on appropriate backend
   BackendType backend_type = BackendType::MM;
       // logging::LoggingUtil::GetBackendType(peloton_logging_mode);
+  // Ensure that the layout of the new TileGroup is not null.
+  if (layout == nullptr) {
+    throw NullPointerException("Layout of the TileGroup must be non-null.");
+  }
 
   TileGroupHeader *tile_header = new TileGroupHeader(backend_type, tuple_count);
   TileGroup *tile_group = new TileGroup(backend_type, tile_header, table,