Add reader and writer compatible functions for encoding and decoding

Signed-off-by: trivernis <trivernis@protonmail.com>

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "uwucodec"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2018"
 license = "Apache-2.0"
 authors = ["trivernis <trivernis@protonmail.com>"]

src/bin/uwudecode.rs

@@ -1,8 +1,9 @@
-use std::fs::{read_to_string, write};
+use std::fs::OpenOptions;
 use std::io;
+use std::io::{BufReader, BufWriter, Write};
 use std::path::PathBuf;
 use structopt::StructOpt;
-use uwucodec::decode;
+use uwucodec::decode_stream;
 
 #[derive(StructOpt, Debug)]
 #[structopt()]
@@ -17,7 +18,14 @@ struct Opt {
 }
 fn main() -> io::Result<()> {
     let opt: Opt = Opt::from_args();
-    let encoded_data = read_to_string(opt.input)?;
-    let data = decode(&encoded_data);
-    write(opt.output, data)
+    let input_file = OpenOptions::new().read(true).open(opt.input)?;
+    let mut input_reader = BufReader::new(input_file);
+    let output_file = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .truncate(true)
+        .open(opt.output)?;
+    let mut output_writer = BufWriter::new(output_file);
+    decode_stream(&mut input_reader, &mut output_writer)?;
+    output_writer.flush()
 }

src/bin/uwuencode.rs

@@ -1,8 +1,9 @@
-use std::fs::{read, write};
+use std::fs::OpenOptions;
 use std::io;
+use std::io::{BufReader, BufWriter, Write};
 use std::path::PathBuf;
 use structopt::StructOpt;
-use uwucodec::encode;
+use uwucodec::encode_stream;
 
 #[derive(StructOpt, Debug)]
 #[structopt()]
@@ -17,7 +18,14 @@ struct Opt {
 }
 fn main() -> io::Result<()> {
     let opt: Opt = Opt::from_args();
-    let data = read(opt.input)?;
-    let encoded_data = encode(&data);
-    write(opt.output, encoded_data)
+    let input_file = OpenOptions::new().read(true).open(opt.input)?;
+    let mut input_reader = BufReader::new(input_file);
+    let output_file = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .truncate(true)
+        .open(opt.output)?;
+    let mut output_writer = BufWriter::new(output_file);
+    encode_stream(&mut input_reader, &mut output_writer)?;
+    output_writer.flush()
 }

src/lib.rs

@@ -19,6 +19,7 @@
 
 use std::cell::RefCell;
 use std::collections::HashMap;
+use std::io::{BufRead, Read, Write};
 
 static VALUE_MAPPINGS: [&str; 16] = [
     "uwu", "owo", "umu", "nya", "omo", "o_o", "q_p", "u_u", "o~o", "UwU", "OwO", "UmU", "OmO",
@@ -27,6 +28,19 @@ static VALUE_MAPPINGS: [&str; 16] = [
 thread_local! { static WORD_MAP: RefCell<HashMap<&'static str, u8>> = RefCell::new(get_word_map()); }
 static SEPARATOR: &str = " ";
 
+/// Encodes bytes from a reader to a sink writer
+pub fn encode_stream<R: Read, W: Write>(src: &mut R, sink: &mut W) -> std::io::Result<()> {
+    let mut buf = [0u8; 1024];
+    while let Ok(num_bytes) = src.read(&mut buf) {
+        if num_bytes == 0 {
+            break;
+        }
+        sink.write_all(encode(&buf[0..num_bytes]).as_bytes())?;
+    }
+
+    Ok(())
+}
+
 /// Encodes into the best encoding in existence
 pub fn encode<'a, I: IntoIterator<Item = &'a u8> + 'a>(data: I) -> String {
     data.into_iter()
@@ -43,6 +57,19 @@ fn encode_byte(byte: u8) -> [&'static str; 2] {
     ]
 }
 
+/// Decodes a stream of bytes into the raw data
+pub fn decode_stream<R: BufRead, W: Write>(src: &mut R, sink: &mut W) -> std::io::Result<()> {
+    let mut buf = String::new();
+    while let Ok(num_bytes) = src.read_line(&mut buf) {
+        if num_bytes == 0 {
+            break;
+        }
+        sink.write_all(&mut decode(&buf))?;
+    }
+
+    Ok(())
+}
+
 /// Decodes the best encoding in existence back into bytes
 pub fn decode<S: AsRef<str>>(encoded_data: S) -> Vec<u8> {
     let mut data = Vec::new();
@@ -78,7 +105,8 @@ fn get_word_map() -> HashMap<&'static str, u8> {
 
 #[cfg(test)]
 mod tests {
-    use crate::{decode, encode};
+    use crate::{decode, decode_stream, encode, encode_stream};
+    use std::io::Cursor;
 
     #[test]
     fn it_encodes() {
@@ -87,6 +115,15 @@ mod tests {
         assert_eq!(encoded, String::from("uwu uwu owo uwu uwu OmO"))
     }
 
+    #[test]
+    fn it_stream_encodes() {
+        let data = vec![0u8, 16u8, 12u8];
+        let mut output_buf = Vec::new();
+        encode_stream(&mut data.as_slice(), &mut output_buf).unwrap();
+        let encoded = String::from_utf8(output_buf).unwrap();
+        assert_eq!(encoded, String::from("uwu uwu owo uwu uwu OmO"))
+    }
+
     #[test]
     fn it_decodes() {
         let encoded_data = String::from("uwu uwu owo uwu uwu OmO");
@@ -94,6 +131,14 @@ mod tests {
         assert_eq!(decoded, vec![0u8, 16u8, 12u8])
     }
 
+    #[test]
+    fn it_stream_decodes() {
+        let mut data = Cursor::new(String::from("uwu uwu owo uwu uwu OmO"));
+        let mut output_buf = Vec::new();
+        decode_stream(&mut data, &mut output_buf).unwrap();
+        assert_eq!(output_buf, vec![0u8, 16u8, 12u8])
+    }
+
     #[test]
     fn it_encodes_100000() {
         let data = vec![0u8, 16u8, 12u8];