1 files changed, 90 insertions, 0 deletions
diff --git a/src/devices/file.rs b/src/devices/file.rs
new file mode 100644
index 0000000..f442dd8
--- /dev/null
+++ b/src/devices/file.rs
@@ -0,0 +1,90 @@
+use std::io::{ErrorKind, Read, Seek, SeekFrom};
+use std::fs::{File, OpenOptions};
+
+pub struct FileDevice {
+    pub name: Vec<u8>,
+    pub rename: Vec<u8>,
+
+    pub file: Option<File>,
+    pub operation_state: bool,
+    pub pointer: u32,
+    pub file_size: u32,
+}
+
+impl FileDevice {
+    pub fn new() -> Self {
+        Self {
+            name: Vec::new(),
+            rename: Vec::new(),
+
+            file: None,
+            operation_state: false,
+            pointer: 0,
+            file_size: 0,
+        }
+    }
+
+    pub fn push_name_byte(&mut self, byte: u8) {
+        if byte != 0 { self.name.push(byte); return }
+        // If char was null, attempt to open the file and read file size.
+        let path: std::ffi::OsString = std::os::unix::ffi::OsStringExt::from_vec(
+                std::mem::take(&mut self.name));
+        let try_open = OpenOptions::new().read(true).write(true).open(path);
+        if let Ok(file) = try_open {
+            if let Ok(metadata) = file.metadata() {
+                // Success.
+                self.file = Some(file);
+                match u32::try_from(metadata.len()) {
+                    Ok(len) => self.file_size = len,
+                    Err(_)  => self.file_size = u32::MAX,
+                }
+                return;
+            }
+        }
+        // Failure.
+        self.close();
+    }
+
+    pub fn set_file_size(&mut self) {
+        if let Some(file) = &self.file {
+            if let Ok(()) = file.set_len(self.file_size.into()) {
+                return;
+            };
+        }
+        self.close();
+    }
+
+    pub fn read(&mut self) -> u8 {
+        if let Some(file) = &mut self.file {
+            let mut buffer: [u8; 1] = [0; 1];
+            match file.read_exact(&mut buffer) {
+                Ok(()) => return buffer[0],
+                Err(err) => match err.kind() {
+                    ErrorKind::UnexpectedEof => return 0,
+                    _ => unimplemented!("File read error: ErrorKind::{:?}", err.kind()),
+                }
+            }
+        }
+        self.close();
+        return 0;
+    }
+
+    pub fn seek(&mut self) {
+        if let Some(file) = &mut self.file {
+            let point = SeekFrom::Start(self.pointer.into());
+            if let Ok(pointer) = file.seek(point) {
+                if let Ok(pointer_u32) = pointer.try_into() {
+                    self.pointer = pointer_u32;
+                    return;
+                }
+            };
+        }
+        self.close();
+    }
+
+    pub fn close(&mut self) {
+        self.file = None;
+        self.pointer = 0;
+        self.file_size = 0;
+    }
+}