feat(repository): add ability to get repository config

lib/src/bindings/config.dart

@@ -10,21 +10,21 @@ import '../util.dart';
 /// anything with it.
 ///
 /// Throws a [LibGit2Error] if error occured.
-Pointer<Pointer<git_config>> newConfig() {
+Pointer<git_config> newConfig() {
   final out = calloc<Pointer<git_config>>();
   final error = libgit2.git_config_new(out);
 
   if (error < 0) {
     throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
   }
-
-  return out;
 }
 
 /// Create a new config instance containing a single on-disk file
 ///
 /// Throws a [LibGit2Error] if error occured.
-Pointer<Pointer<git_config>> open(String path) {
+Pointer<git_config> open(String path) {
   final out = calloc<Pointer<git_config>>();
   final pathC = path.toNativeUtf8().cast<Int8>();
   final error = libgit2.git_config_open_ondisk(out, pathC);
@@ -32,9 +32,9 @@ Pointer<Pointer<git_config>> open(String path) {
 
   if (error < 0) {
     throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
   }
-
-  return out;
 }
 
 /// Open the global, XDG and system configuration files
@@ -44,15 +44,15 @@ Pointer<Pointer<git_config>> open(String path) {
 /// be used when accessing default config data outside a repository.
 ///
 /// Throws a [LibGit2Error] if error occured.
-Pointer<Pointer<git_config>> openDefault() {
+Pointer<git_config> openDefault() {
   final out = calloc<Pointer<git_config>>();
   final error = libgit2.git_config_open_default(out);
 
   if (error < 0) {
     throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
   }
-
-  return out;
 }
 
 /// Locate the path to the global configuration file
@@ -67,18 +67,18 @@ Pointer<Pointer<git_config>> openDefault() {
 /// This method will not guess the path to the xdg compatible config file
 /// (`.config/git/config`).
 ///
-/// Throws a [LibGit2Error] if error occured.
+/// Throws an error if file has not been found.
 String findGlobal() {
-  final out = calloc<git_buf>();
+  final out = calloc<git_buf>(2);
   final error = libgit2.git_config_find_global(out);
   final path = out.ref.ptr.cast<Utf8>().toDartString();
   calloc.free(out);
 
-  if (error < 0) {
-    throw LibGit2Error(libgit2.git_error_last());
+  if (error != 0) {
+    throw Error();
+  } else {
+    return path;
   }
-
-  return path;
 }
 
 /// Locate the path to the system configuration file
@@ -94,9 +94,9 @@ String findSystem() {
 
   if (error < 0) {
     throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return path;
   }
-
-  return path;
 }
 
 /// Locate the path to the global xdg compatible configuration file
@@ -113,9 +113,27 @@ String findXdg() {
 
   if (error < 0) {
     throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return path;
   }
+}
 
-  return path;
+/// Create a snapshot of the configuration.
+///
+/// Create a snapshot of the current state of a configuration, which allows you to look
+/// into a consistent view of the configuration for looking up complex values
+/// (e.g. a remote, submodule).
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_config> snapshot(Pointer<git_config> config) {
+  final out = calloc<Pointer<git_config>>();
+  final error = libgit2.git_config_snapshot(out, config);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
 }
 
 /// Get the value of a config variable.
@@ -131,9 +149,9 @@ String getValue(Pointer<git_config> cfg, String variable) {
 
   if (error < 0) {
     throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return value.ref.value.cast<Utf8>().toDartString();
   }
-
-  return value.ref.value.cast<Utf8>().toDartString();
 }
 
 /// Set the value of a boolean config variable in the config file with the

lib/src/bindings/repository.dart

@@ -192,6 +192,44 @@ Map<String, String> identity(Pointer<git_repository> repo) {
   return identity;
 }
 
+/// Get the configuration file for this repository.
+///
+/// If a configuration file has not been set, the default config set for the repository
+/// will be returned, including global and system configurations (if they are available).
+///
+/// The configuration file must be freed once it's no longer being used by the user.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_config> config(Pointer<git_repository> repo) {
+  final out = calloc<Pointer<git_config>>();
+  final error = libgit2.git_repository_config(out, repo);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
+/// Get a snapshot of the repository's configuration.
+///
+/// Convenience function to take a snapshot from the repository's configuration.
+/// The contents of this snapshot will not change, even if the underlying config files are modified.
+///
+/// The configuration file must be freed once it's no longer being used by the user.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_config> configSnapshot(Pointer<git_repository> repo) {
+  final out = calloc<Pointer<git_config>>();
+  final error = libgit2.git_repository_config_snapshot(out, repo);
+
+  if (error < 0) {
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
 /// Get the Index file for this repository.
 ///
 /// If a custom index has not been set, the default index for the repository

lib/src/config.dart

@@ -7,9 +7,13 @@ import 'util.dart';
 /// [Config] provides management of global configuration options
 /// (system, global, XDG, excluding repository config)
 class Config {
-  Config();
+  /// Initializes a new instance of [Config] class from provided
+  /// pointer to config object in memory.
+  Config(this._configPointer) {
+    libgit2.git_libgit2_init();
+  }
 
-  /// Initializes a new instance of [Config] class.
+  /// Initializes a new instance of [Config] class from provided [path].
   ///
   /// If [path] isn't provided, opens global, XDG and system config files.
   ///
@@ -17,14 +21,14 @@ class Config {
   /// Git config file following the default Git config syntax (see man git-config).
   ///
   /// [Config] object should be closed with [free] function to release allocated memory.
-  Config.open({this.path}) {
+  Config.open([String? path]) {
     libgit2.git_libgit2_init();
 
     if (path == null) {
-      _configPointer = bindings.openDefault().value;
+      _configPointer = bindings.openDefault();
     } else {
-      if (File(path!).existsSync()) {
-        _configPointer = bindings.open(path!).value;
+      if (File(path).existsSync()) {
+        _configPointer = bindings.open(path);
       } else {
         throw Exception('File not found');
       }
@@ -39,30 +43,20 @@ class Config {
   Config.system() {
     libgit2.git_libgit2_init();
 
-    try {
-      final systemPath = bindings.findSystem();
-      _configPointer = bindings.open(systemPath).value;
-    } catch (e) {
-      _configPointer = nullptr;
-      rethrow;
-    }
+    final systemPath = bindings.findSystem();
+    _configPointer = bindings.open(systemPath);
   }
 
   /// Initializes a new instance of [Config] class.
   ///
   /// Opens the global configuration file.
   ///
-  /// Throws a [LibGit2Error] if error occured.
+  /// Throws an error if file has not been found.
   Config.global() {
     libgit2.git_libgit2_init();
 
-    try {
-      final globalPath = bindings.findGlobal();
-      _configPointer = bindings.open(globalPath).value;
-    } catch (e) {
-      _configPointer = nullptr;
-      rethrow;
-    }
+    final globalPath = bindings.findGlobal();
+    _configPointer = bindings.open(globalPath);
   }
 
   /// Initializes a new instance of [Config] class.
@@ -73,21 +67,22 @@ class Config {
   Config.xdg() {
     libgit2.git_libgit2_init();
 
-    try {
-      final xdgPath = bindings.findXdg();
-      _configPointer = bindings.open(xdgPath).value;
-    } catch (e) {
-      _configPointer = nullptr;
-      rethrow;
-    }
+    final xdgPath = bindings.findXdg();
+    _configPointer = bindings.open(xdgPath);
   }
 
-  /// Path to on-disk config file provided by user.
-  String? path;
-
   /// Pointer to memory address for allocated config object.
   late final Pointer<git_config> _configPointer;
 
+  /// Create a snapshot of the configuration.
+  ///
+  /// Create a snapshot of the current state of a configuration, which allows you to look
+  /// into a consistent view of the configuration for looking up complex values
+  /// (e.g. a remote, submodule).
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Config get snapshot => Config(bindings.snapshot(_configPointer));
+
   /// Returns map of all the config variables and their values.
   Map<String, String> getEntries() {
     return bindings.getEntries(_configPointer);

lib/src/repository.dart

@@ -1,4 +1,5 @@
 import 'dart:ffi';
+import 'config.dart';
 import 'index.dart';
 import 'odb.dart';
 import 'oid.dart';
@@ -188,6 +189,26 @@ class Repository {
     libgit2.git_libgit2_shutdown();
   }
 
+  /// Returns the configuration file for this repository.
+  ///
+  /// If a configuration file has not been set, the default config set for the repository
+  /// will be returned, including global and system configurations (if they are available).
+  ///
+  /// The configuration file must be freed once it's no longer being used by the user.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Config get config => Config(bindings.config(_repoPointer));
+
+  /// Returns a snapshot of the repository's configuration.
+  ///
+  /// Convenience function to take a snapshot from the repository's configuration.
+  /// The contents of this snapshot will not change, even if the underlying config files are modified.
+  ///
+  /// The configuration file must be freed once it's no longer being used by the user.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Config get configSnapshot => Config(bindings.configSnapshot(_repoPointer));
+
   /// Returns [Reference] object pointing to repository head.
   ///
   /// Must be freed once it's no longer being used.