feat(treebuilder): add bindings and api

lib/src/bindings/treebuilder.dart

@@ -0,0 +1,126 @@
+import 'dart:ffi';
+import 'package:ffi/ffi.dart';
+import '../error.dart';
+import 'libgit2_bindings.dart';
+import '../util.dart';
+
+/// Create a new tree builder.
+///
+/// The tree builder can be used to create or modify trees in memory and write them
+/// as tree objects to the database.
+///
+/// If the source parameter is not null, the tree builder will be initialized with
+/// the entries of the given tree.
+///
+/// If the source parameter is null, the tree builder will start with no entries
+/// and will have to be filled manually.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_treebuilder> create(
+  Pointer<git_repository> repo,
+  Pointer<git_tree> source,
+) {
+  final out = calloc<Pointer<git_treebuilder>>();
+  final error = libgit2.git_treebuilder_new(out, repo, source);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
+/// Write the contents of the tree builder as a tree object.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_oid> write(Pointer<git_treebuilder> bld) {
+  final out = calloc<git_oid>();
+  final error = libgit2.git_treebuilder_write(out, bld);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out;
+  }
+}
+
+/// Clear all the entires in the builder.
+///
+/// Throws a [LibGit2Error] if error occured.
+void clear(Pointer<git_treebuilder> bld) {
+  final error = libgit2.git_treebuilder_clear(bld);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  }
+}
+
+/// Get the number of entries listed in a treebuilder.
+int entryCount(Pointer<git_treebuilder> bld) =>
+    libgit2.git_treebuilder_entrycount(bld);
+
+/// Get an entry from the builder from its filename.
+///
+/// The returned entry is owned by the builder and should not be freed manually.
+///
+/// Throws [ArgumentError] if nothing found for provided filename.
+Pointer<git_tree_entry> getByFilename(
+  Pointer<git_treebuilder> bld,
+  String filename,
+) {
+  final filenameC = filename.toNativeUtf8().cast<Int8>();
+  final result = libgit2.git_treebuilder_get(bld, filenameC);
+
+  calloc.free(filenameC);
+
+  if (result == nullptr) {
+    throw ArgumentError.value('$filename was not found');
+  } else {
+    return result;
+  }
+}
+
+/// Add or update an entry to the builder.
+///
+/// Insert a new entry for filename in the builder with the given attributes.
+///
+/// If an entry named filename already exists, its attributes will be updated with
+/// the given ones.
+///
+/// By default the entry that you are inserting will be checked for validity;
+/// that it exists in the object database and is of the correct type.
+///
+/// Throws a [LibGit2Error] if error occured.
+void add(
+  Pointer<git_treebuilder> bld,
+  String filename,
+  Pointer<git_oid> id,
+  int filemode,
+) {
+  final filenameC = filename.toNativeUtf8().cast<Int8>();
+  final error =
+      libgit2.git_treebuilder_insert(nullptr, bld, filenameC, id, filemode);
+
+  calloc.free(filenameC);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  }
+}
+
+/// Remove an entry from the builder by its filename.
+///
+/// Throws a [LibGit2Error] if error occured.
+void remove(Pointer<git_treebuilder> bld, String filename) {
+  final filenameC = filename.toNativeUtf8().cast<Int8>();
+  final error = libgit2.git_treebuilder_remove(bld, filenameC);
+
+  calloc.free(filenameC);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  }
+}
+
+/// Free a tree builder to release memory.
+void free(Pointer<git_treebuilder> bld) => libgit2.git_treebuilder_free(bld);