sarc: Add operator== (and !=) for oead::Sarc

And add AreFilesEqual too.

Author: leoetlino

py/py_sarc.cpp

@@ -29,6 +29,8 @@ void BindSarc(py::module& m) {
   py::class_<Sarc::File> file_cl(m, "File");
 
   cl.def(py::init<tcb::span<const u8>>(), "data"_a, py::keep_alive<1, 2>())
+      .def(py::self == py::self)
+      .def("are_files_equal", &Sarc::AreFilesEqual)
       .def("get_num_files", &Sarc::GetNumFiles)
       .def("get_data_offset", &Sarc::GetDataOffset)
       .def("get_endianness", &Sarc::GetEndianness)

src/include/oead/sarc.h

@@ -19,6 +19,7 @@
 
 #pragma once
 
+#include <absl/algorithm/container.h>
 #include <absl/container/btree_map.h>
 #include <absl/container/flat_hash_map.h>
 #include <easy_iterator.h>
@@ -41,6 +42,12 @@ class Sarc {
     std::string_view name;
     /// File data (as a view).
     tcb::span<const u8> data;
+
+    bool operator==(const File& other) const {
+      return name == other.name && absl::c_equal(data, other.data);
+    }
+
+    bool operator!=(const File& other) const { return !(*this == other); }
   };
 
   /// File iterator.
@@ -75,6 +82,12 @@ class Sarc {
   /// Guess the minimum data alignment for files that are stored in the archive.
   size_t GuessMinAlignment() const;
 
+  /// Returns true if and only if the raw archive data is identical.
+  bool operator==(const Sarc& other) const;
+  bool operator!=(const Sarc& other) const { return !(*this == other); }
+
+  bool AreFilesEqual(const Sarc& other) const;
+
 private:
   u16 m_num_files;
   u16 m_entries_offset;

src/sarc.cpp

@@ -168,6 +168,21 @@ std::optional<Sarc::File> Sarc::GetFile(std::string_view name) const {
   return std::nullopt;
 }
 
+bool Sarc::operator==(const Sarc& other) const {
+  return absl::c_equal(m_reader.span(), other.m_reader.span());
+}
+
+bool Sarc::AreFilesEqual(const Sarc& other) const {
+  if (GetNumFiles() != other.GetNumFiles())
+    return false;
+
+  for (const auto& [file1, file2] : easy_iterator::zip(GetFiles(), other.GetFiles())) {
+    if (file1 != file2)
+      return false;
+  }
+  return true;
+}
+
 static constexpr bool IsValidAlignment(size_t alignment) {
   return alignment != 0 && (alignment & (alignment - 1)) == 0;
 }