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refactor: move terminal history code to TerminalHistory struct
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@dxrcy
dxrcy committed Dec 19, 2024
1 parent e8389d7 commit 15030d2
Showing 1 changed file with 77 additions and 63 deletions.
140 changes: 77 additions & 63 deletions src/debugger/source.rs
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
use std::fmt;
use std::fs::{self, File};
use std::io::{self, BufRead, BufReader, IsTerminal, Read, Write};
use std::path::PathBuf;

use console::Key;

Expand Down Expand Up @@ -47,14 +48,21 @@ struct Terminal {
/// Byte index
cursor: usize,

history: Vec<String>,
/// Focused item in history, or new entry if index==length
history_index: usize,
/// Visible line cursor in terminal
visible_cursor: usize,

history: TerminalHistory,
}

#[derive(Debug)]
struct TerminalHistory {
list: Vec<String>,
/// Focused item in history, or new entry if index==length
index: usize,
/// `None` indicates failure to open file
history_file: Option<File>,
file: Option<File>,
// /// `None` indicates failure to retrieve file path
// path: PathBuf,
}

fn echo_command_prompt(command: Option<&str>) {
Expand Down Expand Up @@ -201,30 +209,21 @@ impl SourceReader for Stdin {

impl Terminal {
pub fn new() -> Self {
let mut history_file = Self::get_history_file();

let history = Self::read_history_file(history_file.as_mut());
let history_index = history.len();

Self {
term: console::Term::stdout(),
buffer: String::new(),
cursor: 0,
history,
history_index,
visible_cursor: 0,
history_file,
history: TerminalHistory::new(),
}
}

const FILE_NAME: &str = "lace-debugger-history";

fn is_next(&self) -> bool {
debug_assert!(
self.history_index <= self.history.len(),
self.history.index <= self.history.list.len(),
"index went past history"
);
self.history_index >= self.history.len()
self.history.index >= self.history.list.len()
}

/// Run before modifying `next`
Expand All @@ -235,18 +234,22 @@ impl Terminal {
}
self.buffer = self
.history
.get(self.history_index)
.list
.get(self.history.index)
.expect("checked above")
.clone();
self.history_index = self.history.len();
self.history.index = self.history.list.len();
}

/// Get next or historic command, from index
fn get_current(&self) -> &str {
if self.is_next() {
&self.buffer
} else {
self.history.get(self.history_index).expect("checked above")
self.history
.list
.get(self.history.index)
.expect("checked above")
}
}

Expand All @@ -267,7 +270,10 @@ impl Terminal {
let current = if self.is_next() {
&self.buffer
} else {
self.history.get(self.history_index).expect("checked above")
self.history
.list
.get(self.history.index)
.expect("checked above")
};
write!(self.term, "{}", current).unwrap();

Expand Down Expand Up @@ -339,14 +345,14 @@ impl Terminal {

// Back/forth through history
Key::ArrowUp => {
if self.history_index > 0 {
self.history_index -= 1;
if self.history.index > 0 {
self.history.index -= 1;
self.visible_cursor = self.get_current().len();
}
}
Key::ArrowDown => {
if self.history_index < self.history.len() {
self.history_index += 1;
if self.history.index < self.history.list.len() {
self.history.index += 1;
self.visible_cursor = self.get_current().len();
}
}
Expand Down Expand Up @@ -378,13 +384,14 @@ impl Terminal {
// Push to history if different to last command
if !self
.history
.list
.last()
.is_some_and(|previous| previous == &self.buffer)
{
self.push_history();
self.history.push(self.buffer.clone());
}
// Always reset index to next command
self.history_index = self.history.len();
self.history.index = self.history.list.len();
}

/// Returns next command from line buffer
Expand All @@ -405,40 +412,45 @@ impl Terminal {
}
}
}
}

fn push_history(&mut self) {
self.history.push(self.buffer.clone());
if let Some(file) = &mut self.history_file {
if writeln!(file, "{}", self.buffer).is_err() {
Self::report_history_error("Failed to write to file");
}
impl SourceReader for Terminal {
fn read(&mut self) -> Option<&str> {
// Reached end of line buffer: read new line
if self.cursor == 0 {
self.read_line();
}
Some(self.get_next_command())
}
}

fn read_history_file(file: Option<&mut File>) -> Vec<String> {
let Some(file) = file else {
return Vec::new();
};
let mut history = Vec::new();
for line in BufReader::new(file).lines() {
let Ok(line) = line else {
Self::report_history_error("Failed to read from file");
break;
};
history.push(line);
impl TerminalHistory {
const FILE_NAME: &str = "lace-debugger-history";

pub fn new() -> Self {
let mut file = Self::get_file();
let list = Self::read_file(file.as_mut());
let index = list.len();
Self { list, index, file }
}

pub fn push(&mut self, command: String) {
if let Some(file) = &mut self.file {
if writeln!(file, "{}", command).is_err() {
Self::report_error("Failed to write to file");
}
}
return history;
}

fn get_history_file() -> Option<File> {
fn get_file() -> Option<File> {
let Some(parent_dir) = dirs_next::cache_dir() else {
Self::report_history_error(format_args!(
Self::report_error(format_args!(
"Cannot retrieve user cache directory. Eg. $XDG_CACHE_HOME"
));
return None;
};
if !parent_dir.is_dir() {
Self::report_history_error(format_args!(
Self::report_error(format_args!(
"Parent directory is not a directory: {}",
parent_dir.display(),
));
Expand All @@ -447,7 +459,7 @@ impl Terminal {

let file_path = parent_dir.join(Self::FILE_NAME);
if file_path.exists() && !file_path.is_file() {
Self::report_history_error(format_args!(
Self::report_error(format_args!(
"File exists but is not a file: {}",
file_path.display(),
));
Expand All @@ -462,16 +474,28 @@ impl Terminal {
{
Ok(file) => Some(file),
Err(_error) => {
Self::report_history_error(format_args!(
"Failed to open file: {}",
file_path.display(),
));
Self::report_error(format_args!("Failed to open file: {}", file_path.display(),));
None
}
}
}

fn report_history_error(message: impl fmt::Display) {
fn read_file(file: Option<&mut File>) -> Vec<String> {
let Some(file) = file else {
return Vec::new();
};
let mut history = Vec::new();
for line in BufReader::new(file).lines() {
let Ok(line) = line else {
Self::report_error("Failed to read from file");
break;
};
history.push(line);
}
return history;
}

fn report_error(message: impl fmt::Display) {
dprintln!(
Always,
Error,
Expand All @@ -480,13 +504,3 @@ impl Terminal {
);
}
}

impl SourceReader for Terminal {
fn read(&mut self) -> Option<&str> {
// Reached end of line buffer: read new line
if self.cursor == 0 {
self.read_line();
}
Some(self.get_next_command())
}
}

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