lib/nbt: Start implementing NBT data types, make NBT::Helper::writeString() return an error instead of aborting the program

The former is finally some progress on getting NBT going,
though at this point it is all unvalidated work.
For all I know it might cause your computer to burst into flames,
grow an arm and a leg and an eye, and attack you with a sword.
But probably, it won’t do that and instead start working after I
have debugged it so much that I wish I could attack my PC with a sword.

The latter is the implementation of a change I prepared in a previous commit
when i added ErrorOrVoid.

scripts/test.sh

@@ -36,7 +36,6 @@ COMPILE_COMMANDS=(
     "$CXX_WITH_FLAGS src/test/nbt_read_write_helpers.cpp -I./include -Lbin/lib -l:nbt.so -l:javacompat.so -o bin/test/nbt_read_write_helpers"
     "$CXX_WITH_FLAGS src/test/cli_argument_parser.cpp -Lbin/lib -l:cli.so -o bin/test/cli_argument_parser"
     "$CXX_WITH_FLAGS src/test/javacompat.cpp -I./include -Lbin/lib -l:javacompat.so -o bin/test/javacompat"
-    "$CXX_WITH_FLAGS src/test/nbt_write_string_failure_mode.cpp -I./include -Lbin/lib -l:nbt.so -l:javacompat.so -o bin/test/nbt_write_string_failure_mode"
     "$CXX_WITH_FLAGS src/test/nbt_tags.cpp -I./include -Lbin/lib -l:nbt.so -l:javacompat.so -o bin/test/nbt_tags"
     "$CXX_WITH_FLAGS src/test/nbt_size_helpers.cpp -I./include -Lbin/lib -l:nbt.so -l:javacompat.so -o bin/test/nbt_size_helpers"
 )

src/lib/nbt.cpp

@@ -17,7 +17,6 @@
 #include <cstdint>
 #include <vector>
 #include <tinyutf8/tinyutf8.h>
-#include <iostream>
 
 #include "nbt.hpp"
 #include "error.hpp"
@@ -360,13 +359,13 @@ namespace NBT {
             }
         }
 
-        void writeString(std::vector<uint8_t>* destination, tiny_utf8::string data) {
+        ErrorOrVoid writeString(std::vector<uint8_t>* destination, tiny_utf8::string data) {
             ErrorOr<std::vector<uint8_t>> exportedString = JavaCompat::exportJavaString(data);
             if(exportedString.isError){
-                std::cerr << "NBT::Helpers::writeString encountered an error: " << (int) exportedString.errorCode << std::endl;
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
-                std::abort();
             }
             *destination = exportedString.value;
+            return ErrorOrVoid();
         }
 
         void writeInt32Array(std::vector<uint8_t>* destination, std::vector<int32_t> data) {
@@ -543,15 +542,241 @@ namespace NBT {
         }
     }
 
-    // generic class that all tag types are derived from
+    namespace Tag {
-    template <typename T>
-    Tag<T>::Tag() {
 
+        Generic::Generic() {
+            this->type = TagType::INVALID;
         }
 
-    template <typename T>
+        Generic::~Generic() {}
-    ErrorOr<std::vector<uint8_t>> Tag<T>::toRawData() {
+
-        return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::INVALID_TYPE);
+        ErrorOrVoid Generic::toRawData([[maybe_unused]] std::vector<uint8_t>* rawData) {
+            return ErrorOrVoid(true, ErrorCodes::INVALID_TYPE);
+        }
+
+        uint8_t Generic::getTagType(){
+            return this->type;
+        }
+
+
+        End::End() {
+            this->type = TagType::END;
+        }
+
+        ErrorOrVoid End::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+            return ErrorOrVoid();
+        }
+
+        Int8::Int8() {
+            this->type = TagType::INT8;
+        }
+
+        Int8::Int8(tiny_utf8::string name, int8_t value) {
+            this->type = TagType::INT8;
+            this->name = name;
+            this->value = value;
+        }
+
+        ErrorOrVoid Int8::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+
+            if (Helper::writeString(rawData, this->name).isError) {
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
+            }
+
+            Helper::writeInt8(rawData, this->value);
+
+            return ErrorOrVoid();
+        }
+
+        int8_t Int8::getValue() {
+            this->mutex.lock();
+            int8_t value = this->value;
+            this->mutex.unlock();
+            return value;
+        }
+
+        void Int8::setValue(int8_t value) {
+            this->mutex.lock();
+            this->value = value;
+            this->mutex.unlock();
+        }
+
+        Int16::Int16() {
+            this->type = TagType::INT16;
+        }
+
+        Int16::Int16(tiny_utf8::string name, int16_t value) {
+            this->type = TagType::INT16;
+            this->name = name;
+            this->value = value;
+        }
+
+        ErrorOrVoid Int16::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+
+            if (Helper::writeString(rawData, this->name).isError) {
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
+            }
+
+            Helper::writeInt16(rawData, this->value);
+
+            return ErrorOrVoid();
+        }
+
+        int16_t Int16::getValue() {
+            this->mutex.lock();
+            int16_t value = this->value;
+            this->mutex.unlock();
+            return value;
+        }
+
+        void Int16::setValue(int16_t value) {
+            this->mutex.lock();
+            this->value = value;
+            this->mutex.unlock();
+        }
+
+        Int32::Int32() {
+            this->type = TagType::INT32;
+        }
+
+        Int32::Int32(tiny_utf8::string name, int32_t value) {
+            this->type = TagType::INT32;
+            this->name = name;
+            this->value = value;
+        }
+
+        ErrorOrVoid Int32::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+
+            if (Helper::writeString(rawData, this->name).isError) {
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
+            }
+
+            Helper::writeInt32(rawData, this->value);
+
+            return ErrorOrVoid();
+        }
+
+        int32_t Int32::getValue() {
+            this->mutex.lock();
+            int32_t value = this->value;
+            this->mutex.unlock();
+            return value;
+        }
+
+        void Int32::setValue(int32_t value) {
+            this->mutex.lock();
+            this->value = value;
+            this->mutex.unlock();
+        }
+
+        Int64::Int64() {
+            this->type = TagType::INT64;
+        }
+
+        Int64::Int64(tiny_utf8::string name, int64_t value) {
+            this->type = TagType::INT64;
+            this->name = name;
+            this->value = value;
+        }
+
+        ErrorOrVoid Int64::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+
+            if (Helper::writeString(rawData, this->name).isError) {
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
+            }
+
+            Helper::writeInt64(rawData, this->value);
+
+            return ErrorOrVoid();
+        }
+
+        int64_t Int64::getValue() {
+            this->mutex.lock();
+            int64_t value = this->value;
+            this->mutex.unlock();
+            return value;
+        }
+
+        void Int64::setValue(int64_t value) {
+            this->mutex.lock();
+            this->value = value;
+            this->mutex.unlock();
+        }
+
+        Float::Float() {
+            this->type = TagType::FLOAT;
+        }
+
+        Float::Float(tiny_utf8::string name, float value) {
+            this->type = TagType::FLOAT;
+            this->name = name;
+            this->value = value;
+        }
+
+        ErrorOrVoid Float::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+
+            if (Helper::writeString(rawData, this->name).isError) {
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
+            }
+
+            Helper::writeFloat(rawData, this->value);
+
+            return ErrorOrVoid();
+        }
+
+        float Float::getValue() {
+            this->mutex.lock();
+            float value = this->value;
+            this->mutex.unlock();
+            return value;
+        }
+
+        void Float::setValue(float value) {
+            this->mutex.lock();
+            this->value = value;
+            this->mutex.unlock();
+        }
+
+        Double::Double() {
+            this->type = TagType::DOUBLE;
+        }
+
+        Double::Double(tiny_utf8::string name, double value) {
+            this->type = TagType::DOUBLE;
+            this->name = name;
+            this->value = value;
+        }
+
+        ErrorOrVoid Double::toRawData(std::vector<uint8_t>* rawData) {
+            rawData->push_back(this->type);
+
+            if (Helper::writeString(rawData, this->name).isError) {
+                return ErrorOrVoid(true, ErrorCodes::OVERRUN);
+            }
+
+            Helper::writeDouble(rawData, this->value);
+
+            return ErrorOrVoid();
+        }
+
+        double Double::getValue() {
+            this->mutex.lock();
+            double value = this->value;
+            this->mutex.unlock();
+            return value;
+        }
+
+        void Double::setValue(double value) {
+            this->mutex.lock();
+            this->value = value;
+            this->mutex.unlock();
+        }
     }
 
     bool validateRawListContents(uint8_t data[], uint64_t dataSize, uint64_t initialPosition, uint64_t* processedDataSize) {

src/lib/nbt.hpp

@@ -38,6 +38,8 @@
 #include <cstdint>
 #include <vector>
 #include <tinyutf8/tinyutf8.h>
+#include <mutex>
+
 #include "error.hpp"
 
 namespace NBT {
@@ -61,7 +63,7 @@ namespace NBT {
         void writeDouble(std::vector<uint8_t>* destination, double data);
         void writeInt8Array(std::vector<uint8_t>* destination, std::vector<int8_t> data);
         void writeInt8Array(std::vector<uint8_t>* destination, int8_t data[], uint32_t dataSize);
-        void writeString(std::vector<uint8_t>* destination, tiny_utf8::string data);
+        ErrorOrVoid writeString(std::vector<uint8_t>* destination, tiny_utf8::string data);
         void writeInt32Array(std::vector<uint8_t>* destination, std::vector<int32_t> data);
         void writeInt32Array(std::vector<uint8_t>* destination, int32_t data[], uint32_t dataSize);
         void writeInt64Array(std::vector<uint8_t>* destination, std::vector<int64_t> data);
@@ -87,20 +89,103 @@ namespace NBT {
         const uint8_t INT64_ARRAY=  12;
         // This is a workaround that's not part of the spec.
         const uint8_t INVALID    = 255;
-
-        // This class is used as a placeholder for implementing the end tag.
-        class End {};
     }
 
-    // generic class that all tag types are derived from
+    namespace Tag {
-    template <typename T>
-    struct Tag {
-        const uint8_t type = TagType::INVALID;
-        T* containedData;
 
-        Tag();
+        class Generic {
-        ErrorOr<std::vector<uint8_t>> toRawData();
+            protected:
+                std::mutex mutex;
+                uint8_t type;
+            public:
+                tiny_utf8::string name;
+
+                Generic();
+                virtual ~Generic();
+
+                virtual ErrorOrVoid toRawData(std::vector<uint8_t>* rawData);
+                uint8_t getTagType();
         };
 
+        class End: public Generic {
+            public:
+                End();
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+        };
+
+        class Int8: public Generic {
+            private:
+                int8_t value;
+            public:
+                Int8();
+                Int8(tiny_utf8::string name, int8_t value);
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+                int8_t getValue();
+                void setValue(int8_t value);
+        };
+
+        class Int16: public Generic {
+            private:
+                int16_t value;
+            public:
+                Int16();
+                Int16(tiny_utf8::string name, int16_t value);
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+                int16_t getValue();
+                void setValue(int16_t value);
+        };
+
+        class Int32: public Generic {
+            private:
+                int32_t value;
+            public:
+                Int32();
+                Int32(tiny_utf8::string name, int32_t value);
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+                int32_t getValue();
+                void setValue(int32_t value);
+        };
+
+        class Int64: public Generic {
+            private:
+                int64_t value;
+            public:
+                Int64();
+                Int64(tiny_utf8::string name, int64_t value);
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+                int64_t getValue();
+                void setValue(int64_t value);
+        };
+
+        class Float: public Generic {
+            private:
+                float value;
+            public:
+                Float();
+                Float(tiny_utf8::string name, float value);
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+                float getValue();
+                void setValue(float value);
+        };
+
+        class Double: public Generic {
+            private:
+                double value;
+            public:
+                Double();
+                Double(tiny_utf8::string name, double value);
+
+                ErrorOrVoid toRawData(std::vector<uint8_t>* rawData) override;
+                double getValue();
+                void setValue(double value);
+        };
+    }
+
     bool validateRawNBTData(uint8_t data[], uint64_t dataSize, uint64_t initialPosition=0, uint64_t* processedDataSize=nullptr);
 }

src/test/nbt_read_write_helpers.cpp

@@ -573,6 +573,11 @@ int main(){
     NBT::Helper::writeString(exportedString, normalString);
     ASSERT(javaStdString1 == *exportedString);
 
+    //check that we get an error when trying to write a string that is too long
+    std::string overrunString = std::string(0xFFFFF, '.');
+    ASSERT(NBT::Helper::writeString(exportedString, tiny_utf8::string(overrunString)).isError);
+    ASSERT(NBT::Helper::writeString(exportedString, tiny_utf8::string(overrunString)).errorCode == ErrorCodes::OVERRUN);
+
     std::cout << "Passed writeString NBT helper test." << std::endl;
 
     return 0;

src/test/nbt_tags.cpp

@@ -30,15 +30,15 @@ int main(){
     std::cout << "################################################################################" << std::endl;
 
     //Byte tag constructor test
-    uint8_t bytetest[] = {0x01, 0x00, 0x02, 0x68, 0x69, 0x32};
+    //uint8_t bytetest[] = {0x01, 0x00, 0x02, 0x68, 0x69, 0x32};
-    NBT::Byte byte = NBT::Byte(bytetest);
+    //NBT::Byte byte = NBT::Byte(bytetest);
 
-    ASSERT(byte.tagType == 1);
+    //ASSERT(byte.tagType == 1);
-    ASSERT(byte.nameSize == 2);
+    //ASSERT(byte.nameSize == 2);
-    ASSERT(byte.content = 0x32);
+    //ASSERT(byte.content = 0x32);
-    ASSERT(byte.name == tiny_utf8::string("hi"));
+    //ASSERT(byte.name == tiny_utf8::string("hi"));
 
-    std::cout << "Passed Byte Tag constructor test." << std::endl;
+    //std::cout << "Passed Byte Tag constructor test." << std::endl;
 
     return 0;
 }

src/test/nbt_write_string_failure_mode.cpp

@@ -1,31 +0,0 @@
-// Copyright 2022, FOSS-VG Developers and Contributers
-//
-// This program is free software: you can redistribute it and/or modify it
-// under the terms of the GNU Affero General Public License as published
-// by the Free Software Foundation, version 3.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-// See the GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// version 3 along with this program.
-// If not, see https://www.gnu.org/licenses/agpl-3.0.en.html
-
-#include <string>
-#include <vector>
-#include <iostream>
-#include "../lib/nbt.hpp"
-#include "../lib/error.hpp"
-#include "../lib/javacompat.hpp"
-
-int main() {
-    std::cout << "================================================================================" << std::endl;
-    std::cout << "NBT write string helper failure mode test" << std::endl;
-    std::cout << "================================================================================" << std::endl;
-    std::cout << "This is supposed to abort." << std::endl;
-    std::vector<uint8_t>* exportedString = new std::vector<uint8_t>();
-    std::string overrunString = std::string(0xFFFFF, '.');
-    NBT::Helper::writeString(exportedString, tiny_utf8::string(overrunString));
-}