lib/nbt.cpp: Implement writeString function

src/lib/javacompat.cpp

@@ -30,8 +30,6 @@
 #endif
 
 namespace JavaCompat {
-    //FIXME: contrary to what I said, we need to explicitly pass the data
-    // size because files could have been tampered with or corrupted
     ErrorOr<tiny_utf8::string> importJavaString(uint8_t data[], uint16_t size) {
         std::string stdString;
         uint16_t encodedSize = static_cast<uint16_t>(data[0])<<8 | static_cast<uint16_t>(data[1]);

src/lib/nbt.cpp

@@ -17,6 +17,7 @@
 #include <cstdint>
 #include <vector>
 #include <tinyutf8/tinyutf8.h>
+#include <iostream>
 
 #include "nbt.h++"
 #include "error.h++"
@@ -342,8 +343,14 @@ namespace NBT {
             }
         }
 
-        //void writeString(std::vector<uint8_t>* destination, <string type> data) {
-        //}
+        void 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;
+                std::abort();
+            }
+            *destination = exportedString.value;
+        }
 
         void writeInt32Array(std::vector<uint8_t>* destination, std::vector<int32_t> data) {
             writeInt32(destination, data.size());

src/lib/nbt.h++

@@ -69,7 +69,7 @@ namespace NBT {
         void writeFloat64(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, <string type> data);
+        void 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);

src/test/nbt_helpers.cpp

@@ -495,5 +495,35 @@ int main(){
     ASSERT(NBT::helper::readString(reinterpret_cast<uint8_t*>(javaStdString.data()), 0xF, 0).errorCode == ErrorCodes::MISMATCHEDSIZE);
     std::cout << "Passed readString NBT helper test." << std::endl;
     delete nextChar;
+
+    char* nextChar1 = new char;
+
+    //reading data from the java modified utf8 file
+    std::streampos javaSize1;
+    std::vector<uint8_t> javaStdString1;
+    const char* javaFilePath1 = "./resources/unicode_data/java-style_unicode";
+    std::ifstream javaFile1(javaFilePath1, std::ios::in | std::ios::binary | std::ios::ate);
+    if(javaFile1.is_open()){
+        javaSize1 = javaFile1.tellg();
+        javaFile1.seekg(0, std::ios::beg);
+
+        for (int i=0; i<javaSize1; i++) {
+            javaFile1.read(nextChar1, 1);
+            javaStdString1.push_back(*nextChar1);
+        }
+
+        javaFile1.close();
+    } else {
+        std::cerr << "Failed to open file: " << javaFilePath1 << std::endl;
+        return 2;
+    }
+
+    std::vector<uint8_t>* exportedString = new std::vector<uint8_t>();
+    NBT::helper::writeString(exportedString, normalString);
+    ASSERT(javaStdString1 == *exportedString);
+
+    std::string overrunString = std::string(0xFFFFF, '.');
+    NBT::helper::writeString(exportedString, tiny_utf8::string(overrunString));
+    std::cout << "Passed writeString NBT helper test." << std::endl;
     return 0;
 }