From df55a02fa7454b7bb4f12f852116d033c75ba1ad Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Sun, 8 May 2022 15:50:59 +0200
Subject: [PATCH] Core/VirtualDirectory: Add GetFileContent method

---
 include/Nazara/Core/VirtualDirectory.hpp   |  1 +
 include/Nazara/Core/VirtualDirectory.inl   | 40 ++++++++++++++++++++++
 tests/Engine/Core/VirtualDirectoryTest.cpp | 36 +++++++++++++++++--
 3 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/include/Nazara/Core/VirtualDirectory.hpp b/include/Nazara/Core/VirtualDirectory.hpp
index 6d9fa25ee..db6d15aa0 100644
--- a/include/Nazara/Core/VirtualDirectory.hpp
+++ b/include/Nazara/Core/VirtualDirectory.hpp
@@ -44,6 +44,7 @@ namespace Nz
 			template<typename F> void Foreach(F&& callback, bool includeDots = false);
 
 			template<typename F> bool GetEntry(std::string_view path, F&& callback);
+			template<typename F> bool GetFileContent(std::string_view path, F&& callback);
 
 			inline DirectoryEntry& StoreDirectory(std::string_view path, VirtualDirectoryPtr directory);
 			inline PhysicalDirectoryEntry& StoreDirectory(std::string_view path, std::filesystem::path directoryPath);
diff --git a/include/Nazara/Core/VirtualDirectory.inl b/include/Nazara/Core/VirtualDirectory.inl
index f37f9f163..4fbaa099e 100644
--- a/include/Nazara/Core/VirtualDirectory.inl
+++ b/include/Nazara/Core/VirtualDirectory.inl
@@ -3,6 +3,7 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/Core/VirtualDirectory.hpp>
+#include <Nazara/Core/File.hpp>
 #include <Nazara/Core/StringExt.hpp>
 #include <algorithm>
 #include <cassert>
@@ -153,6 +154,45 @@ namespace Nz
 		});
 	}
 
+	template<typename F>
+	bool VirtualDirectory::GetFileContent(std::string_view path, F&& callback)
+	{
+		return GetEntry(path, [&](const Entry& entry)
+		{
+			return std::visit([&](auto&& entry)
+			{
+				using T = std::decay_t<decltype(entry)>;
+
+				using P1 = const void*;
+				using P2 = std::size_t;
+
+				if constexpr (std::is_same_v<T, DataPointerEntry>)
+				{
+					return CallbackReturn(callback, static_cast<P1>(entry.data), SafeCast<P2>(entry.size));
+				}
+				else if constexpr (std::is_same_v<T, FileContentEntry>)
+				{
+					return CallbackReturn(callback, static_cast<P1>(entry.data.data()), SafeCast<P2>(entry.data.size()));
+				}
+				else if constexpr (std::is_same_v<T, PhysicalFileEntry>)
+				{
+					std::optional<std::vector<UInt8>> source = File::ReadWhole(entry.filePath);
+					if (!source.has_value())
+						return false;
+
+					return CallbackReturn(callback, static_cast<P1>(source->data()), SafeCast<P2>(source->size()));
+				}
+				else if constexpr (std::is_same_v<T, DirectoryEntry> || std::is_same_v<T, PhysicalDirectoryEntry>)
+				{
+					NazaraError("entry is a directory");
+					return false;
+				}
+				else
+					static_assert(AlwaysFalse<T>(), "incomplete visitor");
+			}, entry);
+		});
+	}
+
 	inline auto VirtualDirectory::StoreDirectory(std::string_view path, VirtualDirectoryPtr directory) -> DirectoryEntry&
 	{
 		assert(!path.empty());
diff --git a/tests/Engine/Core/VirtualDirectoryTest.cpp b/tests/Engine/Core/VirtualDirectoryTest.cpp
index 04879f4af..e18a9f944 100644
--- a/tests/Engine/Core/VirtualDirectoryTest.cpp
+++ b/tests/Engine/Core/VirtualDirectoryTest.cpp
@@ -105,8 +105,21 @@ TEST_CASE("VirtualDirectory", "[Core][VirtualDirectory]")
 				}
 
 				const auto& contentEntry = std::get<Nz::VirtualDirectory::FileContentEntry>(entry);
-				CHECK(std::equal(expectedData.begin(), expectedData.end(), contentEntry.data.begin(), contentEntry.data.end()));
-				return true;
+				return std::equal(expectedData.begin(), expectedData.end(), contentEntry.data.begin(), contentEntry.data.end());
+			});
+		};
+
+		auto CheckFileContent = [&](std::string_view path, const std::vector<Nz::UInt8>& expectedData)
+		{
+			return virtualDir->GetFileContent(path, [&](const void* data, std::size_t size)
+			{
+				if (expectedData.size() != size)
+				{
+					FAIL("size doesn't match");
+					return false;
+				}
+
+				return std::memcmp(expectedData.data(), data, expectedData.size()) == 0;
 			});
 		};
 
@@ -118,6 +131,7 @@ TEST_CASE("VirtualDirectory", "[Core][VirtualDirectory]")
 			WHEN("We retrieve it")
 			{
 				CHECK(CheckFile("File.bin", randomData));
+				CHECK(CheckFileContent("File.bin", randomData));
 			}
 		}
 
@@ -165,6 +179,8 @@ TEST_CASE("VirtualDirectory", "[Core][VirtualDirectory]")
 			{
 				INFO("Retrieving " << file.path);
 				CHECK(CheckFile(file.path, file.data));
+				INFO("Retrieving " << file.path << " using GetFileContent");
+				CHECK(CheckFileContent(file.path, file.data));
 			}
 		}
 	}
@@ -208,6 +224,20 @@ TEST_CASE("VirtualDirectory", "[Core][VirtualDirectory]")
 			});
 		};
 
+		auto CheckFileContentHash = [&](const char* filepath, const char* expectedHash)
+		{
+			return virtualDir->GetFileContent(filepath, [&](const void* data, std::size_t size)
+			{
+				Nz::SHA256Hash hash;
+				WHEN("We compute " << hash.GetHashName() << " of " << filepath << " file")
+				{
+					hash.Begin();
+					hash.Append(static_cast<const Nz::UInt8*>(data), size);
+					CHECK(Nz::ToUpper(hash.End().ToHex()) == expectedHash);
+				}
+			});
+		};
+
 		WHEN("Accessing files")
 		{
 			CHECK(CheckFileHash("Logo.png", "5C4B9387327C039A6CE9ED51983D6C2ADA9F9DD01D024C2D5D588237ADFC7423"));
@@ -244,6 +274,8 @@ TEST_CASE("VirtualDirectory", "[Core][VirtualDirectory]")
 			virtualDir->StoreFile("Logo.png", GetResourceDir() / "ambience.ogg");
 			CHECK(CheckFileHash("ambience.ogg", "49C486F44E43F023D54C9F375D902C21375DDB2748D3FA1863C9581D30E17F94"));
 			CHECK(CheckFileHash("Logo.png", "49C486F44E43F023D54C9F375D902C21375DDB2748D3FA1863C9581D30E17F94"));
+			CHECK(CheckFileContentHash("ambience.ogg", "49C486F44E43F023D54C9F375D902C21375DDB2748D3FA1863C9581D30E17F94"));
+			CHECK(CheckFileContentHash("Logo.png", "49C486F44E43F023D54C9F375D902C21375DDB2748D3FA1863C9581D30E17F94"));
 		}
 	}
 }