bat/src/input.rs
2023-09-02 08:48:26 +02:00

353 lines
10 KiB
Rust

use std::convert::TryFrom;
use std::fs;
use std::fs::File;
use std::io::{self, BufRead, BufReader, Read};
use std::path::{Path, PathBuf};
use clircle::{Clircle, Identifier};
use content_inspector::{self, ContentType};
use crate::error::*;
/// A description of an Input source.
/// This tells bat how to refer to the input.
#[derive(Clone)]
pub struct InputDescription {
pub(crate) name: String,
/// The input title.
/// This replaces the name if provided.
title: Option<String>,
/// The input kind.
kind: Option<String>,
/// A summary description of the input.
/// Defaults to "{kind} '{name}'"
summary: Option<String>,
}
impl InputDescription {
/// Creates a description for an input.
pub fn new(name: impl Into<String>) -> Self {
InputDescription {
name: name.into(),
title: None,
kind: None,
summary: None,
}
}
pub fn set_kind(&mut self, kind: Option<String>) {
self.kind = kind;
}
pub fn set_summary(&mut self, summary: Option<String>) {
self.summary = summary;
}
pub fn set_title(&mut self, title: Option<String>) {
self.title = title;
}
pub fn title(&self) -> &String {
match &self.title {
Some(title) => title,
None => &self.name,
}
}
pub fn kind(&self) -> Option<&String> {
self.kind.as_ref()
}
pub fn summary(&self) -> String {
self.summary.clone().unwrap_or_else(|| match &self.kind {
None => self.name.clone(),
Some(kind) => format!("{} '{}'", kind.to_lowercase(), self.name),
})
}
}
pub(crate) enum InputKind<'a> {
OrdinaryFile(PathBuf),
StdIn,
CustomReader(Box<dyn Read + 'a>),
}
impl<'a> InputKind<'a> {
pub fn description(&self) -> InputDescription {
match self {
InputKind::OrdinaryFile(ref path) => InputDescription::new(path.to_string_lossy()),
InputKind::StdIn => InputDescription::new("STDIN"),
InputKind::CustomReader(_) => InputDescription::new("READER"),
}
}
}
#[derive(Clone, Default)]
pub(crate) struct InputMetadata {
pub(crate) user_provided_name: Option<PathBuf>,
pub(crate) size: Option<u64>,
}
pub struct Input<'a> {
pub(crate) kind: InputKind<'a>,
pub(crate) metadata: InputMetadata,
pub(crate) description: InputDescription,
}
pub(crate) enum OpenedInputKind {
OrdinaryFile(PathBuf),
StdIn,
CustomReader,
}
pub(crate) struct OpenedInput<'a> {
pub(crate) kind: OpenedInputKind,
pub(crate) metadata: InputMetadata,
pub(crate) reader: InputReader<'a>,
pub(crate) description: InputDescription,
}
impl OpenedInput<'_> {
/// Get the path of the file:
/// If this was set by the metadata, that will take priority.
/// If it wasn't, it will use the real file path (if available).
pub(crate) fn path(&self) -> Option<&PathBuf> {
self.metadata
.user_provided_name
.as_ref()
.or(match self.kind {
OpenedInputKind::OrdinaryFile(ref path) => Some(path),
_ => None,
})
}
}
impl<'a> Input<'a> {
pub fn ordinary_file(path: impl AsRef<Path>) -> Self {
Self::_ordinary_file(path.as_ref())
}
fn _ordinary_file(path: &Path) -> Self {
let kind = InputKind::OrdinaryFile(path.to_path_buf());
let metadata = InputMetadata {
size: fs::metadata(path).map(|m| m.len()).ok(),
..InputMetadata::default()
};
Input {
description: kind.description(),
metadata,
kind,
}
}
pub fn stdin() -> Self {
let kind = InputKind::StdIn;
Input {
description: kind.description(),
metadata: InputMetadata::default(),
kind,
}
}
pub fn from_reader(reader: Box<dyn Read + 'a>) -> Self {
let kind = InputKind::CustomReader(reader);
Input {
description: kind.description(),
metadata: InputMetadata::default(),
kind,
}
}
pub fn is_stdin(&self) -> bool {
matches!(self.kind, InputKind::StdIn)
}
pub fn with_name(self, provided_name: Option<impl AsRef<Path>>) -> Self {
self._with_name(provided_name.as_ref().map(|it| it.as_ref()))
}
fn _with_name(mut self, provided_name: Option<&Path>) -> Self {
if let Some(name) = provided_name {
self.description.name = name.to_string_lossy().to_string()
}
self.metadata.user_provided_name = provided_name.map(|n| n.to_owned());
self
}
pub fn description(&self) -> &InputDescription {
&self.description
}
pub fn description_mut(&mut self) -> &mut InputDescription {
&mut self.description
}
pub(crate) fn open<R: BufRead + 'a>(
self,
stdin: R,
stdout_identifier: Option<&Identifier>,
) -> Result<OpenedInput<'a>> {
let description = self.description().clone();
match self.kind {
InputKind::StdIn => {
if let Some(stdout) = stdout_identifier {
let input_identifier = Identifier::try_from(clircle::Stdio::Stdin)
.map_err(|e| format!("Stdin: Error identifying file: {}", e))?;
if stdout.surely_conflicts_with(&input_identifier) {
return Err("IO circle detected. The input from stdin is also an output. Aborting to avoid infinite loop.".into());
}
}
Ok(OpenedInput {
kind: OpenedInputKind::StdIn,
description,
metadata: self.metadata,
reader: InputReader::new(stdin),
})
}
InputKind::OrdinaryFile(path) => Ok(OpenedInput {
kind: OpenedInputKind::OrdinaryFile(path.clone()),
description,
metadata: self.metadata,
reader: {
let mut file = File::open(&path)
.map_err(|e| format!("'{}': {}", path.to_string_lossy(), e))?;
if file.metadata()?.is_dir() {
return Err(format!("'{}' is a directory.", path.to_string_lossy()).into());
}
if let Some(stdout) = stdout_identifier {
let input_identifier = Identifier::try_from(file).map_err(|e| {
format!("{}: Error identifying file: {}", path.to_string_lossy(), e)
})?;
if stdout.surely_conflicts_with(&input_identifier) {
return Err(format!(
"IO circle detected. The input from '{}' is also an output. Aborting to avoid infinite loop.",
path.to_string_lossy()
)
.into());
}
file = input_identifier.into_inner().expect("The file was lost in the clircle::Identifier, this should not have happened...");
}
InputReader::new(BufReader::new(file))
},
}),
InputKind::CustomReader(reader) => Ok(OpenedInput {
description,
kind: OpenedInputKind::CustomReader,
metadata: self.metadata,
reader: InputReader::new(BufReader::new(reader)),
}),
}
}
}
pub(crate) struct InputReader<'a> {
inner: Box<dyn BufRead + 'a>,
pub(crate) first_line: Vec<u8>,
pub(crate) content_type: Option<ContentType>,
}
impl<'a> InputReader<'a> {
pub(crate) fn new<R: BufRead + 'a>(mut reader: R) -> InputReader<'a> {
let mut first_line = vec![];
reader.read_until(b'\n', &mut first_line).ok();
let content_type = if first_line.is_empty() {
None
} else {
Some(content_inspector::inspect(&first_line[..]))
};
if content_type == Some(ContentType::UTF_16LE) {
reader.read_until(0x00, &mut first_line).ok();
}
InputReader {
inner: Box::new(reader),
first_line,
content_type,
}
}
pub(crate) fn read_line(&mut self, buf: &mut Vec<u8>) -> io::Result<bool> {
if !self.first_line.is_empty() {
buf.append(&mut self.first_line);
return Ok(true);
}
let res = self.inner.read_until(b'\n', buf).map(|size| size > 0)?;
if self.content_type == Some(ContentType::UTF_16LE) {
let _ = self.inner.read_until(0x00, buf);
}
Ok(res)
}
}
#[test]
fn basic() {
let content = b"#!/bin/bash\necho hello";
let mut reader = InputReader::new(&content[..]);
assert_eq!(b"#!/bin/bash\n", &reader.first_line[..]);
let mut buffer = vec![];
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert!(res.unwrap());
assert_eq!(b"#!/bin/bash\n", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert!(res.unwrap());
assert_eq!(b"echo hello", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert!(!res.unwrap());
assert!(buffer.is_empty());
}
#[test]
fn utf16le() {
let content = b"\xFF\xFE\x73\x00\x0A\x00\x64\x00";
let mut reader = InputReader::new(&content[..]);
assert_eq!(b"\xFF\xFE\x73\x00\x0A\x00", &reader.first_line[..]);
let mut buffer = vec![];
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert!(res.unwrap());
assert_eq!(b"\xFF\xFE\x73\x00\x0A\x00", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert!(res.unwrap());
assert_eq!(b"\x64\x00", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert!(!res.unwrap());
assert!(buffer.is_empty());
}