lib/file: Ensure a file is actually open before attempting to read

This is just way easier to implement and less messy.

src/lib/error.hpp

@@ -91,8 +91,7 @@ namespace ErrorCodes {
 
     const uint8_t INVALID_TYPE = 8;
 
-    //file errors
-    const uint8_t FILE_READ_FAILED = 9;
+    const uint8_t FILE_NOT_OPEN = 9;
     const uint8_t FILE_NOT_FOUND = 10;
 
     const uint8_t UNIMPLEMENTED = 254;

src/lib/file.cpp

@@ -29,7 +29,6 @@ File::File(std::string path, char mode, uint64_t cursorPosition): mode(mode), pa
     this->size = ErrorOr<uint64_t>(std::filesystem::file_size(filePath));
     this->open();
     this->isOpen = true;
-    this->eof = false;
 }
 
 
@@ -57,36 +56,60 @@ void File::close(){
     this->isOpen = false;
 }
 
-ErrorOr<uint8_t> File::readByte(){
-    this->fileStream.seekg(this->cursorPosition);
+bool File::eof() {
+    return !this->size.isError && this->cursorPosition >= this->size.value;
+}
 
-    char* byte = new char;
-    try{
-        this->fileStream.read(byte, 1);
-    }catch(std::exception& e){
-        return ErrorOr<uint8_t>(true, ErrorCodes::FILE_READ_FAILED);
+ErrorOr<uint8_t> File::readByte(){
+    uint8_t* nextPointer = new uint8_t;
+    uint8_t nextByte;
+    bool failure = false;
+
+    if (!this->isOpen) {
+        return ErrorOr<uint8_t>(true, ErrorCodes::FILE_NOT_OPEN);
+    }
+    if (!this->size.isError && this->cursorPosition >= this->size.value) {
+        return ErrorOr<uint8_t>(true, ErrorCodes::OVERRUN);
     }
 
-    this->cursorPosition += 1;
-    return ErrorOr<uint8_t>((uint8_t) *byte);
+    try {
+        this->fileStream.seekg(this->cursorPosition);
+        this->fileStream.read(reinterpret_cast<char*>(nextPointer), 1);
+        nextByte = *nextPointer;
+        this->cursorPosition++;
+
+    } catch (std::exception& e) {
+        failure = true;
+    }
+
+    delete nextPointer;
+    return failure? ErrorOr<uint8_t>(true, ErrorCodes::UNKNOWN) : ErrorOr<uint8_t>(nextByte);
 }
 
 ErrorOr<std::vector<uint8_t>> File::read(uint64_t bytes){
-    this->fileStream.seekg(this->cursorPosition);
-
-    char* buffer = new char[bytes];
+    uint8_t* buffer = new uint8_t[bytes];
     std::vector<uint8_t> data;
-    try{
-        this->fileStream.read(buffer, bytes);
-        for(uint64_t i=0; i<bytes; i++){
-            data.push_back((uint8_t) buffer[i]);
-        }
-        delete[] buffer;
-    }catch(std::exception& e){
-        return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::FILE_READ_FAILED);
+    bool failure = false;
+
+    if (!this->isOpen) {
+        return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::FILE_NOT_OPEN);
     }
-    this->cursorPosition += bytes;
-    return ErrorOr<std::vector<uint8_t>>(data);
+    if (!this->size.isError && this->cursorPosition >= this->size.value+bytes) {
+        return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::OVERRUN);
+    }
+
+    try {
+        this->fileStream.seekg(this->cursorPosition);
+        this->fileStream.read(reinterpret_cast<char*>(buffer), bytes);
+        data = std::vector<uint8_t>(buffer, buffer+bytes);
+        this->cursorPosition += bytes;
+
+    } catch (std::exception& e) {
+        failure = true;
+    }
+
+    delete[] buffer;
+    return failure? ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::UNKNOWN) : ErrorOr<std::vector<uint8_t>>(data);
 }
 
 ErrorOr<tiny_utf8::string> File::readString(uint64_t bytes){

src/lib/file.hpp

@@ -39,7 +39,6 @@ class File {
         File(std::string path, char mode, uint64_t cursorPosition);
     public:
         bool isOpen;
-        bool eof;
         std::string path;
         uint64_t cursorPosition;
         // may be error if not a regular file or size cannot be determined
@@ -49,15 +48,12 @@ class File {
         void open();
         void close();
 
+        bool eof();
+
         // only applicable to read and edit modes
         // moves the cursor to the right of the read section
         ErrorOr<uint8_t> readByte();
         ErrorOr<std::vector<uint8_t>> read(uint64_t bytes);
-        // @SodaFountain (or whoever ends up implementing this):
-        // Tiny-UTF8 uses UTF-32 internally IIRC.
-        // There is a constructor for it that takes std::string and
-        // converts it to the internal format.
-        //TODO: remove this comment when it served its purpose
         ErrorOr<tiny_utf8::string> readString(uint64_t bytes);
 
         // only applicable to write, modify, append, and edit modes