1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133

use crate::http::GQLRequest;
use crate::{ParseRequestError, Request};
use bytes::Bytes;
use futures::io::AsyncRead;
use futures::stream::{self, Stream};
use multer::{Constraints, Multipart, SizeLimit};
use std::collections::HashMap;
use std::io::{self, Seek, SeekFrom, Write};
use std::pin::Pin;
use std::task::Poll;

/// Options for `receive_multipart`.
#[derive(Default, Clone)]
pub struct MultipartOptions {
    max_file_size: Option<usize>,
    max_num_files: Option<usize>,
}

impl MultipartOptions {
    /// Set maximum file size.
    pub fn max_file_size(self, size: usize) -> Self {
        MultipartOptions {
            max_file_size: Some(size),
            ..self
        }
    }

    /// Set maximum number of files.
    pub fn max_num_files(self, n: usize) -> Self {
        MultipartOptions {
            max_num_files: Some(n),
            ..self
        }
    }
}

/// Receive a multipart request.
pub async fn receive_multipart(
    body: impl AsyncRead + Send + 'static,
    boundary: impl Into<String>,
    opts: MultipartOptions,
) -> Result<Request, ParseRequestError> {
    let mut multipart = Multipart::new_with_constraints(
        reader_stream(body),
        boundary,
        Constraints::new().size_limit({
            let mut limit = SizeLimit::new();
            if let (Some(max_file_size), Some(max_num_files)) =
                (opts.max_file_size, opts.max_file_size)
            {
                limit = limit.whole_stream((max_file_size * max_num_files) as u64);
            }
            if let Some(max_file_size) = opts.max_file_size {
                limit = limit.per_field(max_file_size as u64);
            }
            limit
        }),
    );

    let mut request = None;
    let mut map = None;
    let mut files = Vec::new();

    while let Some(mut field) = multipart.next_field().await? {
        match field.name() {
            Some("operations") => {
                let request_str = field.text().await?;
                request = Some(
                    serde_json::from_str::<GQLRequest>(&request_str)
                        .map_err(ParseRequestError::InvalidRequest)?
                        .into(),
                );
            }
            Some("map") => {
                let map_str = field.text().await?;
                map = Some(
                    serde_json::from_str::<HashMap<String, Vec<String>>>(&map_str)
                        .map_err(ParseRequestError::InvalidFilesMap)?,
                );
            }
            _ => {
                if let Some(name) = field.name().map(ToString::to_string) {
                    if let Some(filename) = field.file_name().map(ToString::to_string) {
                        let content_type = field.content_type().map(|mime| mime.to_string());
                        let mut file = tempfile::tempfile().map_err(ParseRequestError::Io)?;
                        while let Some(chunk) = field.chunk().await.unwrap() {
                            file.write(&chunk).map_err(ParseRequestError::Io)?;
                        }
                        file.seek(SeekFrom::Start(0))?;
                        files.push((name, filename, content_type, file));
                    }
                }
            }
        }
    }

    let mut request: Request = request.ok_or(ParseRequestError::MissingOperatorsPart)?;
    let map = map.as_mut().ok_or(ParseRequestError::MissingMapPart)?;

    for (name, filename, content_type, file) in files {
        if let Some(var_paths) = map.remove(&name) {
            for var_path in var_paths {
                request.set_upload(
                    &var_path,
                    filename.clone(),
                    content_type.clone(),
                    file.try_clone().unwrap(),
                );
            }
        }
    }

    if !map.is_empty() {
        return Err(ParseRequestError::MissingFiles);
    }

    Ok(request)
}

fn reader_stream(
    reader: impl AsyncRead + Send + 'static,
) -> impl Stream<Item = io::Result<Bytes>> + Send + 'static {
    let mut buf = [0u8; 2048];
    let mut reader = Box::pin(reader);
    stream::poll_fn(move |cx| {
        Poll::Ready(
            match futures::ready!(Pin::new(&mut reader).poll_read(cx, &mut buf)?) {
                0 => None,
                size => Some(Ok(Bytes::copy_from_slice(&buf[..size]))),
            },
        )
    })
}