bat/src/input.rs
2020-05-29 22:13:10 +02:00

296 lines
7.8 KiB
Rust

use std::ffi::{OsStr, OsString};
use std::fs::File;
use std::io::{self, BufRead, BufReader, Read};
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.as_ref() {
Some(ref 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(OsString),
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<OsString>,
}
pub struct Input<'a> {
pub(crate) kind: InputKind<'a>,
pub(crate) metadata: InputMetadata,
pub(crate) description: InputDescription,
}
pub(crate) enum OpenedInputKind {
OrdinaryFile(OsString),
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<'a> Input<'a> {
pub fn ordinary_file(path: &OsStr) -> Self {
let kind = InputKind::OrdinaryFile(path.to_os_string());
Input {
description: kind.description(),
metadata: InputMetadata::default(),
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 {
if let InputKind::StdIn = self.kind {
true
} else {
false
}
}
pub fn with_name(mut self, provided_name: Option<&OsStr>) -> Self {
match provided_name {
Some(name) => self.description.name = name.to_string_lossy().to_string(),
None => {}
}
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) -> Result<OpenedInput<'a>> {
let description = self.description().clone();
match self.kind {
InputKind::StdIn => 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 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());
}
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> {
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() {
let res = self.inner.read_until(b'\n', buf).map(|size| size > 0)?;
if self.content_type == Some(ContentType::UTF_16LE) {
self.inner.read_until(0x00, buf).ok();
}
Ok(res)
} else {
buf.append(&mut self.first_line);
Ok(true)
}
}
}
#[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_eq!(true, res.unwrap());
assert_eq!(b"#!/bin/bash\n", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert_eq!(true, res.unwrap());
assert_eq!(b"echo hello", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert_eq!(false, 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_eq!(true, 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_eq!(true, res.unwrap());
assert_eq!(b"\x64\x00", &buffer[..]);
buffer.clear();
let res = reader.read_line(&mut buffer);
assert!(res.is_ok());
assert_eq!(false, res.unwrap());
assert!(buffer.is_empty());
}