Refactor logic from new dump tools into library crate

src/io/data.rs

@@ -0,0 +1,28 @@
+use std::{fs::File, io::prelude::*, path::Path};
+
+use anyhow::{Context, Result};
+use flate2::read::GzDecoder;
+use serde::de::DeserializeOwned;
+
+pub fn from_reader<R, T>(reader: R) -> Result<T>
+where
+	R: Read,
+	T: DeserializeOwned,
+{
+	let mut decoder = GzDecoder::new(reader);
+	let mut buf = vec![];
+	decoder
+		.read_to_end(&mut buf)
+		.context("Failed to read file")?;
+
+	fastnbt::from_bytes(&buf[..]).context("Failed to decode NBT data")
+}
+
+pub fn from_file<P, T>(path: P) -> Result<T>
+where
+	P: AsRef<Path>,
+	T: DeserializeOwned,
+{
+	let file = File::open(path).context("Failed to open file")?;
+	from_reader(file)
+}