Added filesystem-only starshatter::data DataLoader replacement

Step by step. The intent is to find a good spot between current data
representations and the standard library and put the intermediate
stage there. After it matures a bit, we can move further away.

11 files changed, 304 insertions, 20 deletions

diff --git a/FoundationEx/CMakeLists.txt b/FoundationEx/CMakeLists.txt
index 646ee58..972a242 100644
--- a/FoundationEx/CMakeLists.txt
+++ b/FoundationEx/CMakeLists.txt
@@ -5,9 +5,11 @@ add_library(
 	src/Text.cpp
 	src/Utils.cpp
 	src/reader.cpp
+	src/data.cpp
+	src/reader/file.cpp
 	)
 target_include_directories(${PROJECT_NAME} PUBLIC include)
-add_executable(${PROJECT_NAME}_test test/Text.cpp test/reader.cpp)
+add_executable(${PROJECT_NAME}_test test/Text.cpp test/reader.cpp test/data.cpp)
 target_link_libraries(${PROJECT_NAME}_test PRIVATE ${PROJECT_NAME} GTest::gtest_main)
 generate_emulator(${PROJECT_NAME}_test)
 gtest_discover_tests(${PROJECT_NAME}_test DISCOVERY_TIMEOUT 60)
diff --git a/FoundationEx/include/starshatter/foundation/data.h b/FoundationEx/include/starshatter/foundation/data.h
new file mode 100644
index 0000000..20308a2
--- /dev/null
+++ b/FoundationEx/include/starshatter/foundation/data.h
@@ -0,0 +1,26 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+*/
+
+#pragma once
+
+#include "reader.h"
+
+
+namespace starshatter
+{
+namespace foundation
+{
+namespace data
+{
+
+
+bool toggle_filesystem(bool enabled);
+Reader open(const char* pathname);
+
+
+}  // namespace data
+}  // namespace foundation
+}  // namespace starshatter
diff --git a/FoundationEx/include/starshatter/foundation/reader.h b/FoundationEx/include/starshatter/foundation/reader.h
index 7ec81b4..69472c8 100644
--- a/FoundationEx/include/starshatter/foundation/reader.h
+++ b/FoundationEx/include/starshatter/foundation/reader.h
@@ -9,6 +9,8 @@
 #include <cstddef>
 #include <memory>
 
+#include <Text.h>
+
 
 namespace starshatter
 {
@@ -40,7 +42,7 @@ struct BaseReader
 	virtual Count read(Char* dest, Count bytes) = 0;
 	virtual Count peek(Char* dest) const = 0;
 	virtual Count peek(Char* dest, Count bytes) const = 0;
-	virtual const Char* data() const = 0;
+	virtual Text more() = 0;
 };
 
 
@@ -73,7 +75,7 @@ struct Reader : public BaseReader<char>
 	Count read(char* dest, Count bytes) override;
 	Count peek(char* dest) const override;
 	Count peek(char* dest, Count bytes) const override;
-	const char* data() const override;
+	Text more() override;
 private:
 	Base actual;
 };
diff --git a/FoundationEx/src/data.cpp b/FoundationEx/src/data.cpp
new file mode 100644
index 0000000..643e823
--- /dev/null
+++ b/FoundationEx/src/data.cpp
@@ -0,0 +1,42 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+*/
+
+#include <starshatter/foundation/data.h>
+
+#include <fstream>
+#include <memory>
+
+#include <starshatter/foundation/reader.h>
+
+#include "reader/file.h"
+
+
+
+namespace starshatter
+{
+namespace foundation
+{
+namespace data
+{
+
+
+bool
+toggle_filesystem(bool)
+{
+	return true;
+}
+
+
+Reader
+open(const char* pathname)
+{
+	return {std::make_unique<FileReader>(std::fstream(pathname, std::ios::binary | std::ios::in))};
+}
+
+
+}  // namespace data
+}  // namespace foundation
+}  // namespace starshatter
diff --git a/FoundationEx/src/reader.cpp b/FoundationEx/src/reader.cpp
index 7bce34d..0a3a2ba 100644
--- a/FoundationEx/src/reader.cpp
+++ b/FoundationEx/src/reader.cpp
@@ -9,6 +9,8 @@
 #include <memory>
 #include <utility>
 
+#include <Text.h>
+
 #include "reader/buffer.h"
 
 
@@ -75,7 +77,7 @@ Count Reader::read(char* dest) { return actual->read(dest); }
 Count Reader::read(char* dest, Count bytes) { return actual->read(dest, bytes); }
 Count Reader::peek(char* dest) const { return actual->peek(dest); }
 Count Reader::peek(char* dest, Count bytes) const { return actual->peek(dest, bytes); }
-const char* Reader::data() const { return actual->data(); }
+Text Reader::more() { return actual->more(); }
 
 
 }  // namespace foundation
diff --git a/FoundationEx/src/reader/buffer.h b/FoundationEx/src/reader/buffer.h
index c36310a..532a8f9 100644
--- a/FoundationEx/src/reader/buffer.h
+++ b/FoundationEx/src/reader/buffer.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <starshatter/foundation/reader.h>
+#include <Text.h>
 
 
 namespace starshatter
@@ -35,12 +36,12 @@ struct BufferReader : public BaseReader<char>
 	Count read(char* dest, Count bytes) override;
 	Count peek(char* dest) const override;
 	Count peek(char* dest, Count bytes) const override;
-	const char* data() const override;
+	Text more() override;
 
 private:
-	Source buffer;
-	Count size;
-	Count position;
+	Source buffer = {};
+	Count size = {};
+	Count position = {};
 };
 
 
diff --git a/FoundationEx/src/reader/buffer.inl.h b/FoundationEx/src/reader/buffer.inl.h
index 3b739e4..c452878 100644
--- a/FoundationEx/src/reader/buffer.inl.h
+++ b/FoundationEx/src/reader/buffer.inl.h
@@ -8,8 +8,9 @@
 #include <cstring>
 #include <memory>
 #include <utility>
+#include <vector>
 
-#include <starshatter/foundation/reader.h>
+#include <Text.h>
 
 
 namespace starshatter
@@ -124,16 +125,21 @@ Count
 BufferReader<Source>::peek(char* dest, Count bytes) const
 {
 	bytes = std::min(bytes, available());
-	std::copy(data(), data() + bytes, dest);
+	std::copy(at(buffer) + position, at(buffer) + position + bytes, dest);
 	return bytes;
 }
 
 
 template <typename Source>
-const char*
-BufferReader<Source>::data() const
+Text
+BufferReader<Source>::more()
 {
-	return at(buffer) + position;
+	const auto size = available();
+	if (size < 1)
+		return Text();
+	std::vector<char> tmp(size);
+	read(tmp.data(), size);
+	return Text(tmp.data(), size);
 }
 
 
diff --git a/FoundationEx/src/reader/file.cpp b/FoundationEx/src/reader/file.cpp
new file mode 100644
index 0000000..f9e9ae2
--- /dev/null
+++ b/FoundationEx/src/reader/file.cpp
@@ -0,0 +1,129 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+*/
+
+#include "file.h"
+
+#include <algorithm>
+#include <fstream>
+#include <ios>
+#include <limits>
+#include <utility>
+#include <vector>
+
+#include <Text.h>
+
+
+namespace starshatter
+{
+namespace foundation
+{
+
+
+FileReader::FileReader(std::fstream src) :
+	file {std::move(src)}
+{
+	file.seekg(0);
+	file.ignore(std::numeric_limits<std::streamsize>::max());
+	size = file.gcount();
+	file.clear();
+	file.seekg(0);
+	position = 0;
+}
+
+
+bool
+FileReader::valid() const
+{
+	return static_cast<bool>(file) && file.is_open();
+}
+
+
+Count
+FileReader::available() const
+{
+	return size - position;
+}
+
+
+Count
+FileReader::seek(Count pos)
+{
+	position = pos;
+	if (position > size)
+		position = size;
+	file.seekg(position);
+	return position;
+}
+
+
+Count
+FileReader::seek(Offset offset, Direction dir)
+{
+	switch (dir) {
+	case Direction::Start:
+		break;  // no-op
+	case Direction::End:
+		offset = size + offset;
+		break;
+	case Direction::Current:
+		offset = position + offset;
+		break;
+	}
+	if (offset < 0)
+		offset = 0;
+	return seek(static_cast<Count>(offset));
+}
+
+
+Count
+FileReader::read(char* dest)
+{
+	return read(dest, available());
+}
+
+
+Count
+FileReader::read(char* dest, Count bytes)
+{
+	bytes = std::min(bytes, available());
+	file.read(dest, bytes);
+	position += bytes;
+	return bytes;
+}
+
+
+Count
+FileReader::peek(char* dest) const
+{
+	return peek(dest, available());
+}
+
+
+Count
+FileReader::peek(char* dest, Count bytes) const
+{
+	bytes = std::min(bytes, available());
+	const auto before = file.tellg();
+	file.read(dest, bytes);
+	file.seekg(before);
+	return bytes;
+}
+
+
+Text
+FileReader::more()
+{
+	const auto size = available();
+	if (size < 1)
+		return Text();
+	std::vector<char> tmp(size);
+	read(tmp.data(), size);
+	return Text(tmp.data(), size);
+}
+
+
+}  // namespace foundation
+}  // namespace starshatter
diff --git a/FoundationEx/src/reader/file.h b/FoundationEx/src/reader/file.h
new file mode 100644
index 0000000..22810b6
--- /dev/null
+++ b/FoundationEx/src/reader/file.h
@@ -0,0 +1,49 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+*/
+
+#pragma once
+
+#include <fstream>
+
+#include <starshatter/foundation/reader.h>
+#include <Text.h>
+
+
+namespace starshatter
+{
+namespace foundation
+{
+
+
+struct FileReader : public BaseReader<char>
+{
+	FileReader() = default;
+	FileReader(std::fstream src);
+	FileReader(const FileReader& other) = delete;
+	FileReader& operator=(const FileReader& other) = delete;
+	FileReader(FileReader&& other) = default;
+	FileReader& operator=(FileReader&& other) = default;
+	~FileReader() override = default;
+
+	bool valid() const override;
+	Count available() const override;
+	Count seek(Count pos) override;
+	Count seek(Offset offset, Direction dir) override;
+	Count read(char* dest) override;
+	Count read(char* dest, Count bytes) override;
+	Count peek(char* dest) const override;
+	Count peek(char* dest, Count bytes) const override;
+	Text more() override;
+
+private:
+	mutable std::fstream file = {};
+	Count size = {};
+	Count position = {};
+};
+
+
+}  // namespace foundation
+}  // namespace starshatter
diff --git a/FoundationEx/test/data.cpp b/FoundationEx/test/data.cpp
new file mode 100644
index 0000000..09ab49b
--- /dev/null
+++ b/FoundationEx/test/data.cpp
@@ -0,0 +1,26 @@
+#include <filesystem>
+#include <fstream>
+
+#include <gtest/gtest.h>
+
+#include <starshatter/foundation/data.h>
+
+
+namespace data = starshatter::foundation::data;
+namespace fs = std::filesystem;
+
+
+TEST(FoundationEx, OpenRelativePathOnFilesystem)
+{
+	fs::current_path(fs::temp_directory_path());
+	{
+		std::fstream tmp("sample", tmp.out | tmp.binary);
+		tmp << "Hello, there!\n";
+	}
+	data::toggle_filesystem(true);
+	auto file = data::open("sample");
+	ASSERT_TRUE(file.valid());
+	ASSERT_LT(0, file.available());
+	const auto text = file.more();
+	ASSERT_STREQ("Hello, there!\n", text);
+}
diff --git a/FoundationEx/test/reader.cpp b/FoundationEx/test/reader.cpp
index 395ad81..4bc4882 100644
--- a/FoundationEx/test/reader.cpp
+++ b/FoundationEx/test/reader.cpp
@@ -17,7 +17,8 @@ TEST(FoundationEx, ReadFromView)
 {
 	Reader reader("Hello, World!");
 	ASSERT_TRUE(reader.valid());
-	std::vector<char> buffer(reader.available());
+	const auto s = reader.available();
+	std::vector<char> buffer(s);
 	ASSERT_EQ(14, buffer.size());
 	const auto bytes = reader.read(buffer.data());
 	ASSERT_EQ(14, bytes);
@@ -54,12 +55,10 @@ TEST(FoundationEx, RelativeSeek)
 TEST(FoundationEx, CreateTextFromReader)
 {
 	const char* ref = "Hello!";
-	const auto size = 7;
-	auto ptr = std::make_unique<char[]>(size);
-	for (auto i = 0; i < size; ++i)
-		ptr[i] = ref[i];
+	auto ptr = std::make_unique<char[]>(std::strlen(ref) + 1);
+	std::strcpy(ptr.get(), ref);
 	Reader reader(std::move(ptr));
 	ASSERT_TRUE(reader.valid());
-	Text text(reader.data());
-	ASSERT_EQ("Hello!", text);
+	const auto text = reader.more();
+	ASSERT_STREQ(ref, text);
 }