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use crate::*;
use std::{
fmt::Debug,
sync::{atomic::AtomicBool, Arc},
};
pub struct RawStream {
pub stream: Box<dyn Iterator<Item = Result<Vec<u8>, ShellError>> + Send + 'static>,
pub leftover: Vec<u8>,
pub ctrlc: Option<Arc<AtomicBool>>,
pub is_binary: bool,
pub span: Span,
pub known_size: Option<u64>, // (bytes)
}
impl RawStream {
pub fn new(
stream: Box<dyn Iterator<Item = Result<Vec<u8>, ShellError>> + Send + 'static>,
ctrlc: Option<Arc<AtomicBool>>,
span: Span,
known_size: Option<u64>,
) -> Self {
Self {
stream,
leftover: vec![],
ctrlc,
is_binary: false,
span,
known_size,
}
}
pub fn into_bytes(self) -> Result<Spanned<Vec<u8>>, ShellError> {
let mut output = vec![];
for item in self.stream {
if nu_utils::ctrl_c::was_pressed(&self.ctrlc) {
break;
}
output.extend(item?);
}
Ok(Spanned {
item: output,
span: self.span,
})
}
pub fn into_string(self) -> Result<Spanned<String>, ShellError> {
let mut output = String::new();
let span = self.span;
let ctrlc = &self.ctrlc.clone();
for item in self {
if nu_utils::ctrl_c::was_pressed(ctrlc) {
break;
}
output.push_str(&item?.coerce_into_string()?);
}
Ok(Spanned { item: output, span })
}
pub fn chain(self, stream: RawStream) -> RawStream {
RawStream {
stream: Box::new(self.stream.chain(stream.stream)),
leftover: self.leftover.into_iter().chain(stream.leftover).collect(),
ctrlc: self.ctrlc,
is_binary: self.is_binary,
span: self.span,
known_size: self.known_size,
}
}
pub fn drain(self) -> Result<(), ShellError> {
for next in self {
match next {
Ok(val) => {
if let Value::Error { error, .. } = val {
return Err(*error);
}
}
Err(err) => return Err(err),
}
}
Ok(())
}
}
impl Debug for RawStream {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("RawStream").finish()
}
}
impl Iterator for RawStream {
type Item = Result<Value, ShellError>;
fn next(&mut self) -> Option<Self::Item> {
if nu_utils::ctrl_c::was_pressed(&self.ctrlc) {
return None;
}
// If we know we're already binary, just output that
if self.is_binary {
self.stream.next().map(|buffer| {
buffer.map(|mut v| {
if !self.leftover.is_empty() {
for b in self.leftover.drain(..).rev() {
v.insert(0, b);
}
}
Value::binary(v, self.span)
})
})
} else {
// We *may* be text. We're only going to try utf-8. Other decodings
// needs to be taken as binary first, then passed through `decode`.
if let Some(buffer) = self.stream.next() {
match buffer {
Ok(mut v) => {
if !self.leftover.is_empty() {
while let Some(b) = self.leftover.pop() {
v.insert(0, b);
}
}
match String::from_utf8(v.clone()) {
Ok(s) => {
// Great, we have a complete string, let's output it
Some(Ok(Value::string(s, self.span)))
}
Err(err) => {
// Okay, we *might* have a string but we've also got some errors
if v.is_empty() {
// We can just end here
None
} else if v.len() > 3
&& (v.len() - err.utf8_error().valid_up_to() > 3)
{
// As UTF-8 characters are max 4 bytes, if we have more than that in error we know
// that it's not just a character spanning two frames.
// We now know we are definitely binary, so switch to binary and stay there.
self.is_binary = true;
Some(Ok(Value::binary(v, self.span)))
} else {
// Okay, we have a tiny bit of error at the end of the buffer. This could very well be
// a character that spans two frames. Since this is the case, remove the error from
// the current frame an dput it in the leftover buffer.
self.leftover = v[err.utf8_error().valid_up_to()..].to_vec();
let buf = v[0..err.utf8_error().valid_up_to()].to_vec();
match String::from_utf8(buf) {
Ok(s) => Some(Ok(Value::string(s, self.span))),
Err(_) => {
// Something is definitely wrong. Switch to binary, and stay there
self.is_binary = true;
Some(Ok(Value::binary(v, self.span)))
}
}
}
}
}
}
Err(e) => Some(Err(e)),
}
} else if !self.leftover.is_empty() {
let output = Ok(Value::binary(self.leftover.clone(), self.span));
self.leftover.clear();
Some(output)
} else {
None
}
}
}
}
/// A potentially infinite stream of values, optionally with a mean to send a Ctrl-C signal to stop
/// the stream from continuing.
///
/// In practice, a "stream" here means anything which can be iterated and produce Values as it iterates.
/// Like other iterators in Rust, observing values from this stream will drain the items as you view them
/// and the stream cannot be replayed.
pub struct ListStream {
pub stream: Box<dyn Iterator<Item = Value> + Send + 'static>,
pub ctrlc: Option<Arc<AtomicBool>>,
first_guard: bool,
}
impl ListStream {
pub fn into_string(self, separator: &str, config: &Config) -> String {
self.map(|x: Value| x.to_expanded_string(", ", config))
.collect::<Vec<String>>()
.join(separator)
}
pub fn drain(self) -> Result<(), ShellError> {
for next in self {
if let Value::Error { error, .. } = next {
return Err(*error);
}
}
Ok(())
}
pub fn from_stream(
input: impl Iterator<Item = Value> + Send + 'static,
ctrlc: Option<Arc<AtomicBool>>,
) -> ListStream {
ListStream {
stream: Box::new(input),
ctrlc,
first_guard: true,
}
}
}
impl Debug for ListStream {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("ListStream").finish()
}
}
impl Iterator for ListStream {
type Item = Value;
fn next(&mut self) -> Option<Self::Item> {
// We need to check `first_guard` to guarantee that it always have something to return in
// underlying stream.
//
// A realworld example is running an external commands, which have an `exit_code`
// ListStream.
// When we press ctrl-c, the external command receives the signal too, if we don't have
// `first_guard`, the `exit_code` ListStream will return Nothing, which is not expected
if self.first_guard {
self.first_guard = false;
return self.stream.next();
}
if nu_utils::ctrl_c::was_pressed(&self.ctrlc) {
None
} else {
self.stream.next()
}
}
}