Add model and serd-sort utility

With all the new functionality, the complexity of the serd-pipe command-line
interface is starting to push the limits of available flags. So, instead of
grafting on further options to control a model, this commit adds a new tool,
serd-sort, which acts somewhat like a stripped-down serd-pipe that stores
statements in a model in memory.

This keeps the complexity (including the user-facing complexity) of any one
tool down, since other more focused tools can be used for streaming tasks in a
pipeline.

In other words, abandon Swissarmyknifeism, take a page from the Unix
philosophy, and try to expose the model functionality to the command-line in a
dedicated focused tool.  The model implementation is tested by using this tool
to run a subset of the usual test suites, and a special suite to test statement
sorting.

1 files changed, 29 insertions, 0 deletions

diff --git a/src/model.h b/src/model.h
new file mode 100644
index 00000000..a67ba087
--- /dev/null
+++ b/src/model.h
@@ -0,0 +1,29 @@
+// Copyright 2011-2020 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#ifndef SERD_SRC_MODEL_H
+#define SERD_SRC_MODEL_H
+
+#include "cursor.h"
+
+#include "serd/cursor.h"
+#include "serd/memory.h"
+#include "serd/model.h"
+#include "serd/nodes.h"
+#include "serd/world.h"
+#include "zix/btree.h"
+
+#include <stddef.h>
+
+struct SerdModelImpl {
+  SerdAllocator*     allocator;     ///< Allocator for everything in this model
+  SerdWorld*         world;         ///< World this model is a part of
+  SerdNodes*         nodes;         ///< Interned nodes in this model
+  ZixBTree*          indices[12];   ///< Trees of SerdStatement pointers
+  SerdCursor         end;           ///< End cursor (always the same)
+  size_t             version;       ///< Version incremented on every change
+  SerdStatementOrder default_order; ///< Order for main statement-owning index
+  SerdModelFlags     flags;         ///< Active indices and features
+};
+
+#endif // SERD_SRC_MODEL_H