Add flatbuffers schema

1 files changed, 56 insertions, 0 deletions

diff --git a/generate-flatbuffers.py b/generate-flatbuffers.py
new file mode 100644
index 00000000..986e6e8f
--- /dev/null
+++ b/generate-flatbuffers.py
@@ -0,0 +1,56 @@
+import os
+import pathlib
+import re
+import shutil
+import subprocess
+import tempfile
+
+
+def _main():
+    os.chdir(os.path.dirname(__file__))
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        temp_dir = pathlib.Path(temp_dir)
+        schema_filenames = ["sources.fbs", "patio.fbs"]
+        namespace_map = {}
+        type_map = {}
+
+        for schema_filename in schema_filenames:
+            with open(pathlib.Path("flatbuffers") / schema_filename, "rt") as source_schema_file:
+                source_schema = list(source_schema_file)
+
+            for line_index, line in enumerate(source_schema):
+                namespace_match = re.match("^namespace (.*);$", line)
+                if namespace_match is not None:
+                    source_namespace = namespace_match[1]
+                    dest_namespace = f"org.shedlang.compiler.{source_namespace.lower()}.flatbuffers"
+                    namespace_map[source_namespace] = dest_namespace
+                    source_schema[line_index] = f"namespace {dest_namespace};"
+
+                type_match = re.match(r"^((?:enum|table|union)\s+)(\S+)(\s+.*{)", line)
+                if type_match is not None:
+                    source_type = type_match[2]
+                    dest_type = f"{source_type}Flatbuffers"
+                    type_map[source_type] = dest_type
+                    source_schema[line_index] = f"{type_match[1]}{dest_type}{type_match[3]}"
+
+            with open(temp_dir / schema_filename, "wt") as dest_schema_file:
+                for line in source_schema:
+                    for source_namespace, dest_namespace in namespace_map.items():
+                        line = line.replace(f":{source_namespace}.", f":{dest_namespace}.")
+                    for source_type, dest_type in type_map.items():
+                        line = re.sub(rf"\b{source_type}\b", dest_type, line)
+
+                    dest_schema_file.write(line)
+
+        gen_path = pathlib.Path("src/gen/java")
+        subprocess.run(
+            ["flatc", "-o", gen_path, "--java"] + [
+                temp_dir / schema_filename
+                for schema_filename in schema_filenames
+            ],
+            check=True,
+        )
+
+
+_main()