Rename the datafacades to more clearly describe what they do.

include/engine/datafacade/contiguous_internalmem_datafacade_base.hpp

@@ -1,7 +1,5 @@
-#ifndef MEMORYBLOCK_DATAFACADE_HPP
-#define MEMORYBLOCK_DATAFACADE_HPP
-
-// implements all data storage when shared memory _IS_ used
+#ifndef CONTIGUOUS_INTERNALMEM_DATAFACADE_HPP
+#define CONTIGUOUS_INTERNALMEM_DATAFACADE_HPP
 
 #include "engine/datafacade/datafacade_base.hpp"
 
@@ -57,9 +55,12 @@ using OSMNodeArrayRef = ConstArrayRef<const OSMNodeID *>;
 
 /**
  * This base class implements the Datafacade interface for accessing
- * data that's stored in a single large block of memory.
+ * data that's stored in a single large block of memory (RAM).
+ *
+ * In this case "internal memory" refers to RAM - as opposed to "external memory",
+ * which usually refers to disk.
  */
-class BigRAMBlockDataFacadeBase : public BaseDataFacade
+class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
 {
   private:
     using super = BaseDataFacade;
@@ -940,4 +941,4 @@ class BigRAMBlockDataFacadeBase : public BaseDataFacade
 }
 }
 
-#endif // MEMORYBLOCK_DATAFACADE_HPP
+#endif // CONTIGUOUS_INTERNALMEM_DATAFACADE_HPP

include/engine/datafacade/process_memory_datafacade.hpp

@@ -1,9 +1,9 @@
-#ifndef INTERNAL_DATAFACADE_HPP
-#define INTERNAL_DATAFACADE_HPP
+#ifndef PROCESS_MEMORY_DATAFACADE_HPP
+#define PROCESS_MEMORY_DATAFACADE_HPP
 
 // implements all data storage when shared memory is _NOT_ used
 
-#include "engine/datafacade/bigramblock_datafacade_base.hpp"
+#include "engine/datafacade/contiguous_internalmem_datafacade_base.hpp"
 #include "storage/storage.hpp"
 
 namespace osrm
@@ -16,12 +16,12 @@ namespace datafacade
 /**
  * This datafacade uses a process-local memory block to load
  * data into.  The structure and layout is the same as when using
- * shared memory, so this class, and the SharedDatafacade both
+ * shared memory, so this class, and the SharedMemoryDataFacade both
  * share a common base.
  * This class holds a unique_ptr to the memory block, so it
  * is auto-freed upon destruction.
  */
-class InternalDataFacade final : public BigRAMBlockDataFacadeBase
+class ProcessMemoryDataFacade final : public ContiguousInternalMemoryDataFacadeBase
 {
 
   private:
@@ -29,7 +29,7 @@ class InternalDataFacade final : public BigRAMBlockDataFacadeBase
     std::unique_ptr<storage::DataLayout> internal_layout;
 
   public:
-    explicit InternalDataFacade(const storage::StorageConfig &config)
+    explicit ProcessMemoryDataFacade(const storage::StorageConfig &config)
     {
         storage::Storage storage(config);
 
@@ -49,4 +49,4 @@ class InternalDataFacade final : public BigRAMBlockDataFacadeBase
 }
 }
 
-#endif // INTERNAL_DATAFACADE_HPP
+#endif // PROCESS_MEMORY_DATAFACADE_HPP

include/engine/datafacade/shared_memory_datafacade.hpp

@@ -6,7 +6,7 @@
 #include "storage/shared_barriers.hpp"
 #include "storage/shared_datatype.hpp"
 #include "storage/shared_memory.hpp"
-#include "engine/datafacade/bigramblock_datafacade_base.hpp"
+#include "engine/datafacade/contiguous_internalmem_datafacade_base.hpp"
 
 namespace osrm
 {
@@ -17,10 +17,10 @@ namespace datafacade
 
 /**
  * This datafacade uses an IPC shared memory block as the data location.
- * Many SharedDataFacade objects can be created that point to the same shared
+ * Many SharedMemoryDataFacade objects can be created that point to the same shared
  * memory block.
  */
-class SharedDataFacade : public BigRAMBlockDataFacadeBase
+class SharedMemoryDataFacade : public ContiguousInternalMemoryDataFacadeBase
 {
 
   protected:
@@ -31,12 +31,12 @@ class SharedDataFacade : public BigRAMBlockDataFacadeBase
     storage::SharedDataType data_region;
     unsigned shared_timestamp;
 
-    SharedDataFacade() {}
+    SharedMemoryDataFacade() {}
 
   public:
     // this function handle the deallocation of the shared memory it we can prove it will not be
     // used anymore.  We crash hard here if something goes wrong (noexcept).
-    virtual ~SharedDataFacade() noexcept
+    virtual ~SharedMemoryDataFacade() noexcept
     {
         boost::interprocess::scoped_lock<boost::interprocess::named_sharable_mutex> exclusive_lock(
             data_region == storage::DATA_1 ? shared_barriers->regions_1_mutex
@@ -67,10 +67,10 @@ class SharedDataFacade : public BigRAMBlockDataFacadeBase
         }
     }
 
-    SharedDataFacade(const std::shared_ptr<storage::SharedBarriers> &shared_barriers_,
-                     storage::SharedDataType layout_region_,
-                     storage::SharedDataType data_region_,
-                     unsigned shared_timestamp_)
+    SharedMemoryDataFacade(const std::shared_ptr<storage::SharedBarriers> &shared_barriers_,
+                           storage::SharedDataType layout_region_,
+                           storage::SharedDataType data_region_,
+                           unsigned shared_timestamp_)
         : shared_barriers(shared_barriers_), layout_region(layout_region_),
           data_region(data_region_), shared_timestamp(shared_timestamp_)
     {