More convenient tag access

src/MinedMap.cpp

@@ -40,5 +40,11 @@ int main(int argc, char *argv[]) {
 
 	World::Region region(argv[1]);
 
+	const World::Chunk &chunk = *region(0, 0);
+
+	for (auto &entry : std::dynamic_pointer_cast<const NBT::CompoundTag>(chunk->get("Level"))->getValues()) {
+		std::cout << entry.first << " " << entry.second->getType() << std::endl;
+	}
+
 	return 0;
 }

src/NBT/CompoundTag.hpp

@@ -39,15 +39,15 @@ class CompoundTag : public Tag {
 private:
 	friend class Tag;
 
-	std::unordered_map<std::string, std::shared_ptr<Tag>> value;
+	std::unordered_map<std::string, std::shared_ptr<const Tag>> values;
 
 	CompoundTag(Buffer *buffer) {
 		while (true) {
-			std::pair<std::string, std::shared_ptr<Tag>> v = Tag::readNamedTag(buffer);
+			std::pair<std::string, std::shared_ptr<const Tag>> v = Tag::readNamedTag(buffer);
 			if (v.second->getType() == Type::End)
 				break;
 
-			value.insert(std::move(v));
+			values.insert(std::move(v));
 		}
 	}
 
@@ -55,6 +55,22 @@ public:
 	virtual Type getType() const {
 		return Type::Compound;
 	}
+
+	const std::unordered_map<std::string, std::shared_ptr<const Tag>> & getValues() const {
+		return values;
+	}
+
+	const std::shared_ptr<const Tag> & get(const std::string &key) const {
+		return values.at(key);
+	}
+
+	template<typename... Args> const std::shared_ptr<const Tag> & get(const std::string &key, const Args &...args) const {
+		std::shared_ptr<const CompoundTag> tag = std::dynamic_pointer_cast<const CompoundTag>(get(key));
+		if (!tag)
+			return std::shared_ptr<Tag>(nullptr);
+
+		tag->get(args...);
+	}
 };
 
 }

src/NBT/ListTag.hpp

@@ -38,7 +38,7 @@ class ListTag : public Tag {
 private:
 	friend class Tag;
 
-	std::vector<std::shared_ptr<Tag>> value;
+	std::vector<std::shared_ptr<const Tag>> value;
 
 
 	ListTag(Buffer *buffer) {

src/NBT/StringTag.hpp

@@ -49,6 +49,10 @@ public:
 	virtual Type getType() const {
 		return Type::String;
 	}
+
+	const std::string & getValue() const {
+		return value;
+	}
 };
 
 }

src/NBT/Tag.cpp

@@ -46,7 +46,7 @@
 namespace MinedMap {
 namespace NBT {
 
-std::shared_ptr<Tag> Tag::readTag(Type type, Buffer *buffer) {
+std::shared_ptr<const Tag> Tag::readTag(Type type, Buffer *buffer) {
 	switch (type) {
 	case Type::End:
 		return std::shared_ptr<EndTag>(new EndTag());
@@ -89,7 +89,7 @@ std::shared_ptr<Tag> Tag::readTag(Type type, Buffer *buffer) {
 	}
 }
 
-std::pair<std::string, std::shared_ptr<Tag>> Tag::readNamedTag(Buffer *buffer) {
+std::pair<std::string, std::shared_ptr<const Tag>> Tag::readNamedTag(Buffer *buffer) {
 	Type type = static_cast<Type>(buffer->get());
 	if (type == Type::End)
 		return std::make_pair("", std::shared_ptr<EndTag>(new EndTag()));
@@ -101,5 +101,62 @@ std::pair<std::string, std::shared_ptr<Tag>> Tag::readNamedTag(Buffer *buffer) {
 	return std::make_pair(name, readTag(type, buffer));
 }
 
+std::ostream& operator<<(std::ostream& os, Tag::Type type) {
+	switch (type) {
+	case Tag::Type::End:
+		os << "End";
+		break;
+
+	case Tag::Type::Byte:
+		os << "Byte";
+		break;
+
+	case Tag::Type::Short:
+		os << "Short";
+		break;
+
+	case Tag::Type::Int:
+		os << "Int";
+		break;
+
+	case Tag::Type::Long:
+		os << "Long";
+		break;
+
+	case Tag::Type::Float:
+		os << "Float";
+		break;
+
+	case Tag::Type::Double:
+		os << "Double";
+		break;
+
+	case Tag::Type::ByteArray:
+		os << "ByteArray";
+		break;
+
+	case Tag::Type::String:
+		os << "String";
+		break;
+
+	case Tag::Type::List:
+		os << "List";
+		break;
+
+	case Tag::Type::Compound:
+		os << "Compound";
+		break;
+
+	case Tag::Type::IntArray:
+		os << "IntArray";
+		break;
+
+	default:
+		os.setstate(std::ios_base::failbit);
+	}
+
+	return os;
+}
+
 }
 }

src/NBT/Tag.hpp

@@ -28,6 +28,7 @@
 
 #include <cstdint>
 #include <memory>
+#include <ostream>
 
 #include "../Buffer.hpp"
 
@@ -52,14 +53,16 @@ public:
 		IntArray = 11,
 	};
 
-	static std::shared_ptr<Tag> readTag(Type type, Buffer *buffer);
+	static std::shared_ptr<const Tag> readTag(Type type, Buffer *buffer);
 
-	static std::pair<std::string, std::shared_ptr<Tag>> readNamedTag(Buffer *buffer);
+	static std::pair<std::string, std::shared_ptr<const Tag>> readNamedTag(Buffer *buffer);
 
 	virtual Type getType() const = 0;
 
 	virtual ~Tag() {}
 };
 
+std::ostream& operator<<(std::ostream& os, Tag::Type type);
+
 }
 }

src/World/Chunk.cpp

@@ -36,7 +36,7 @@
 namespace MinedMap {
 namespace World {
 
-std::tuple<UniqueCPtr<uint8_t[]>, size_t> Chunk::inflateChunk(uint8_t *data, size_t len) {
+std::pair<UniqueCPtr<uint8_t[]>, size_t> Chunk::inflateChunk(uint8_t *data, size_t len) {
 	size_t outlen = 0;
 	uint8_t *output = nullptr;
 
@@ -67,7 +67,7 @@ std::tuple<UniqueCPtr<uint8_t[]>, size_t> Chunk::inflateChunk(uint8_t *data, siz
 
 	inflateEnd(&stream);
 
-	return std::make_tuple(UniqueCPtr<uint8_t[]>(output), stream.total_out);
+	return std::make_pair(UniqueCPtr<uint8_t[]>(output), stream.total_out);
 }
 
 Chunk::Chunk(uint8_t *buffer, size_t buflen) {
@@ -89,12 +89,12 @@ Chunk::Chunk(uint8_t *buffer, size_t buflen) {
 	std::cerr << "Chunk has size " << size << " (" << len << " inflated)" << std::endl;
 
 	Buffer nbt(data.get(), len);
+	std::pair<std::string, std::shared_ptr<const NBT::Tag>> tag = NBT::Tag::readNamedTag(&nbt);
 
-	std::pair<std::string, std::shared_ptr<NBT::Tag>> tag = NBT::Tag::readNamedTag(&nbt);
-	if (tag.first != "")
-		throw std::invalid_argument("non-empty root tag");
+	std::shared_ptr<const NBT::CompoundTag>::operator=(std::dynamic_pointer_cast<const NBT::CompoundTag>(tag.second));
 
-	content = std::move(tag.second);
+	if (!(*this) || tag.first != "")
+		throw std::invalid_argument("invalid root tag");
 }
 
 }

src/World/Chunk.hpp

@@ -28,7 +28,7 @@
 
 
 #include "../UniqueCPtr.hpp"
-#include "../NBT/Tag.hpp"
+#include "../NBT/CompoundTag.hpp"
 
 #include <cstdint>
 #include <tuple>
@@ -37,14 +37,12 @@
 namespace MinedMap {
 namespace World {
 
-class Chunk {
+class Chunk : public std::shared_ptr<const NBT::CompoundTag> {
 public:
 	static const size_t SIZE = 16;
 
 private:
-	static std::tuple<UniqueCPtr<uint8_t[]>, size_t> inflateChunk(uint8_t *data, size_t len);
-
-	std::shared_ptr<NBT::Tag> content;
+	static std::pair<UniqueCPtr<uint8_t[]>, size_t> inflateChunk(uint8_t *data, size_t len);
 
 public:
 	Chunk(uint8_t *buffer, size_t buflen);