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use super::{FileBytesStream, FileBytesStreamMultiRange, FileBytesStreamRange};
use http::response::Builder as ResponseBuilder;
use http::{header, HeaderMap, Method, Request, Response, Result, StatusCode};
use http_range::HttpRange;
use http_range::HttpRangeParseError;
use hyper::Body;
use rand::prelude::{thread_rng, SliceRandom};
use std::fs::Metadata;
use std::time::{Duration, SystemTime, UNIX_EPOCH};
use tokio::fs::File;
const MIN_VALID_MTIME: Duration = Duration::from_secs(2);
const BOUNDARY_LENGTH: usize = 60;
const BOUNDARY_CHARS: &[u8] = b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
#[derive(Clone, Debug, Default)]
pub struct FileResponseBuilder {
pub cache_headers: Option<u32>,
pub is_head: bool,
pub if_modified_since: Option<SystemTime>,
pub range: Option<String>,
pub if_range: Option<String>,
}
impl FileResponseBuilder {
pub fn new() -> Self {
Self::default()
}
pub fn request<B>(&mut self, req: &Request<B>) -> &mut Self {
self.request_parts(req.method(), req.headers())
}
pub fn request_parts(&mut self, method: &Method, headers: &HeaderMap) -> &mut Self {
self.request_method(method);
self.request_headers(headers);
self
}
pub fn request_method(&mut self, method: &Method) -> &mut Self {
self.is_head = *method == Method::HEAD;
self
}
pub fn request_headers(&mut self, headers: &HeaderMap) -> &mut Self {
self.if_modified_since_header(headers.get(header::IF_MODIFIED_SINCE));
self.range_header(headers.get(header::RANGE));
self.if_range(headers.get(header::IF_RANGE));
self
}
pub fn cache_headers(&mut self, value: Option<u32>) -> &mut Self {
self.cache_headers = value;
self
}
pub fn is_head(&mut self, value: bool) -> &mut Self {
self.is_head = value;
self
}
pub fn if_modified_since(&mut self, value: Option<SystemTime>) -> &mut Self {
self.if_modified_since = value;
self
}
pub fn if_modified_since_header(&mut self, value: Option<&header::HeaderValue>) -> &mut Self {
self.if_modified_since = value
.and_then(|v| v.to_str().ok())
.and_then(|v| httpdate::parse_http_date(v).ok());
self
}
pub fn if_range(&mut self, value: Option<&header::HeaderValue>) -> &mut Self {
if let Some(s) = value.and_then(|s| s.to_str().ok()) {
self.if_range = Some(s.to_string());
}
self
}
pub fn range_header(&mut self, value: Option<&header::HeaderValue>) -> &mut Self {
self.range = value.and_then(|v| v.to_str().ok()).map(|v| v.to_string());
self
}
pub fn build(
&self,
file: File,
metadata: Metadata,
content_type: String,
) -> Result<Response<Body>> {
let mut res = ResponseBuilder::new();
let modified = metadata.modified().ok().filter(|v| {
v.duration_since(UNIX_EPOCH)
.ok()
.filter(|v| v >= &MIN_VALID_MTIME)
.is_some()
});
let mut range_cond_ok = self.if_range.is_none();
if let Some(modified) = modified {
if let Ok(modified_unix) = modified.duration_since(UNIX_EPOCH) {
if let Some(Ok(ims_unix)) =
self.if_modified_since.map(|v| v.duration_since(UNIX_EPOCH))
{
if modified_unix.as_secs() <= ims_unix.as_secs() {
return ResponseBuilder::new()
.status(StatusCode::NOT_MODIFIED)
.body(Body::empty());
}
}
let etag = format!(
"W/\"{0:x}-{1:x}.{2:x}\"",
metadata.len(),
modified_unix.as_secs(),
modified_unix.subsec_nanos()
);
if let Some(ref v) = self.if_range {
if *v == etag {
range_cond_ok = true;
}
}
res = res.header(header::ETAG, etag);
}
let last_modified_formatted = httpdate::fmt_http_date(modified);
if let Some(ref v) = self.if_range {
if *v == last_modified_formatted {
range_cond_ok = true;
}
}
res = res
.header(header::LAST_MODIFIED, last_modified_formatted)
.header(header::ACCEPT_RANGES, "bytes");
}
if let Some(seconds) = self.cache_headers {
res = res.header(
header::CACHE_CONTROL,
format!("public, max-age={}", seconds),
);
}
if self.is_head {
res = res.header(header::CONTENT_LENGTH, format!("{}", metadata.len()));
return res.status(StatusCode::OK).body(Body::empty());
}
let ranges = self.range.as_ref().filter(|_| range_cond_ok).and_then(|r| {
match HttpRange::parse(r, metadata.len()) {
Ok(r) => Some(Ok(r)),
Err(HttpRangeParseError::NoOverlap) => Some(Err(())),
Err(HttpRangeParseError::InvalidRange) => None,
}
});
if let Some(ranges) = ranges {
let ranges = match ranges {
Ok(r) => r,
Err(()) => {
return res
.status(StatusCode::RANGE_NOT_SATISFIABLE)
.body(Body::empty());
}
};
if ranges.len() == 1 {
let single_span = ranges[0];
res = res
.header(
header::CONTENT_RANGE,
content_range_header(&single_span, metadata.len()),
)
.header(header::CONTENT_LENGTH, format!("{}", single_span.length));
let body_stream = FileBytesStreamRange::new(file, single_span);
return res
.status(StatusCode::PARTIAL_CONTENT)
.body(body_stream.into_body());
} else if ranges.len() > 1 {
let mut boundary_tmp = [0u8; BOUNDARY_LENGTH];
let mut rng = thread_rng();
for v in boundary_tmp.iter_mut() {
*v = *BOUNDARY_CHARS.choose(&mut rng).unwrap();
}
let boundary = std::str::from_utf8(&boundary_tmp[..]).unwrap().to_string();
res = res.header(
hyper::header::CONTENT_TYPE,
format!("multipart/byteranges; boundary={}", boundary),
);
let mut body_stream =
FileBytesStreamMultiRange::new(file, ranges, boundary, metadata.len());
if !content_type.is_empty() {
body_stream.set_content_type(&content_type);
}
res = res.header(
hyper::header::CONTENT_LENGTH,
format!("{}", body_stream.compute_length()),
);
return res
.status(StatusCode::PARTIAL_CONTENT)
.body(body_stream.into_body());
}
}
res = res.header(header::CONTENT_LENGTH, format!("{}", metadata.len()));
if !content_type.is_empty() {
res = res.header(header::CONTENT_TYPE, content_type);
}
res.status(StatusCode::OK)
.body(FileBytesStream::new_with_limit(file, metadata.len()).into_body())
}
}
fn content_range_header(r: &HttpRange, total_length: u64) -> String {
format!(
"bytes {}-{}/{}",
r.start,
r.start + r.length - 1,
total_length
)
}