pub(crate)ify the multipart facade

src/multipart.rs

@@ -1,2 +1,420 @@
-//! # multipart/form-data
-pub use ::multipart_::{Form, Part};
+//! multipart/form-data
+use std::borrow::Cow;
+use std::fmt;
+use std::fs::File;
+use std::io::{self, Cursor, Read};
+use std::path::Path;
+
+use mime_guess::{self, Mime};
+use url::percent_encoding;
+use uuid::Uuid;
+
+use {Body};
+
+/// A multipart/form-data request.
+pub struct Form {
+    boundary: String,
+    fields: Vec<(Cow<'static, str>, Part)>,
+    headers: Vec<String>,
+}
+
+impl Form {
+    /// Creates a new Form without any content.
+    pub fn new() -> Form {
+        Form {
+            boundary: format!("{}", Uuid::new_v4().simple()),
+            fields: Vec::new(),
+            headers: Vec::new(),
+        }
+    }
+
+    /// Get the boundary that this form will use.
+    #[inline]
+    pub fn boundary(&self) -> &str {
+        &self.boundary
+    }
+
+    /// Add a data field with supplied name and value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let form = reqwest::multipart::Form::new()
+    ///     .text("username", "seanmonstar")
+    ///     .text("password", "secret");
+    /// ```
+    pub fn text<T, U>(self, name: T, value: U) -> Form
+    where T: Into<Cow<'static, str>>,
+          U: Into<Cow<'static, str>>,
+    {
+        self.part(name, Part::text(value))
+    }
+
+    /// Adds a file field.
+    ///
+    /// The path will be used to try to guess the filename and mime.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # fn run() -> ::std::io::Result<()> {
+    /// let files = reqwest::multipart::Form::new()
+    ///     .file("key", "/path/to/file")?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// # Errors
+    ///
+    /// Errors when the file cannot be opened.
+    pub fn file<T, U>(self, name: T, path: U) -> io::Result<Form>
+    where T: Into<Cow<'static, str>>,
+          U: AsRef<Path>
+    {
+        Ok(self.part(name, Part::file(path)?))
+    }
+
+    /// Adds a customized Part.
+    pub fn part<T>(mut self, name: T, part: Part) -> Form
+    where T: Into<Cow<'static, str>>,
+    {
+        self.fields.push((name.into(), part));
+        self
+    }
+
+    pub(crate) fn reader(self) -> Reader {
+        Reader::new(self)
+    }
+
+    // If predictable, computes the length the request will have
+    // The length should be preditable if only String and file fields have been added,
+    // but not if a generic reader has been added;
+    pub(crate) fn compute_length(&mut self) -> Option<u64> {
+        let mut length = 0u64;
+        for &(ref name, ref field) in self.fields.iter() {
+            match ::body::len(&field.value) {
+                Some(value_length) => {
+                    // We are constructing the header just to get its length. To not have to
+                    // construct it again when the request is sent we cache these headers.
+                    let header = header(name, field);
+                    let header_length = header.len();
+                    self.headers.push(header);
+                    // The additions mimick the format string out of which the field is constructed
+                    // in Reader. Not the cleanest solution because if that format string is
+                    // ever changed then this formula needs to be changed too which is not an
+                    // obvious dependency in the code.
+                    length += 2 + self.boundary.len() as u64 + 2 + header_length as u64 + 4 + value_length + 2
+                }
+                _ => return None,
+            }
+        }
+        // If there is a at least one field there is a special boundary for the very last field.
+        if self.fields.len() != 0 {
+            length += 2 + self.boundary.len() as u64 + 4
+        }
+        Some(length)
+    }
+}
+
+impl fmt::Debug for Form {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("Form")
+            .field("boundary", &self.boundary)
+            .field("parts", &self.fields)
+            .finish()
+    }
+}
+
+
+/// A field in a multipart form.
+pub struct Part {
+    value: Body,
+    mime: Option<Mime>,
+    file_name: Option<Cow<'static, str>>,
+}
+
+impl Part {
+    /// Makes a text parameter.
+    pub fn text<T>(value: T) -> Part
+    where T: Into<Cow<'static, str>>,
+    {
+        let body = match value.into() {
+            Cow::Borrowed(slice) => Body::from(slice),
+            Cow::Owned(string) => Body::from(string),
+        };
+        Part::new(body)
+    }
+
+    /// Adds a generic reader.
+    ///
+    /// Does not set filename or mime.
+    pub fn reader<T: Read + Send + 'static>(value: T) -> Part {
+        Part::new(Body::new(value))
+    }
+
+    /// Adds a generic reader with known length.
+    ///
+    /// Does not set filename or mime.
+    pub fn reader_with_length<T: Read + Send + 'static>(value: T, length: u64) -> Part {
+        Part::new(Body::sized(value, length))
+    }
+
+    /// Makes a file parameter.
+    ///
+    /// # Errors
+    ///
+    /// Errors when the file cannot be opened.
+    pub fn file<T: AsRef<Path>>(path: T) -> io::Result<Part> {
+        let path = path.as_ref();
+        let file_name = path.file_name().and_then(|filename| {
+            Some(Cow::from(filename.to_string_lossy().into_owned()))
+        });
+        let ext = path.extension()
+            .and_then(|ext| ext.to_str())
+            .unwrap_or("");
+        let mime = mime_guess::get_mime_type(ext);
+        let file = File::open(path)?;
+        let mut field = Part::new(Body::from(file));
+        field.mime = Some(mime);
+        field.file_name = file_name;
+        Ok(field)
+    }
+
+    fn new(value: Body) -> Part {
+        Part {
+            value: value,
+            mime: None,
+            file_name: None,
+        }
+    }
+
+    /// Sets the mime, builder style.
+    pub fn mime(mut self, mime: Mime) -> Part {
+        self.mime = Some(mime);
+        self
+    }
+
+    /// Sets the filename, builder style.
+    pub fn file_name<T: Into<Cow<'static, str>>>(mut self, filename: T) -> Part {
+        self.file_name = Some(filename.into());
+        self
+    }
+}
+
+impl fmt::Debug for Part {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("Part")
+            .field("value", &self.value)
+            .field("mime", &self.mime)
+            .field("file_name", &self.file_name)
+            .finish()
+    }
+}
+
+pub(crate) struct Reader {
+    form: Form,
+    active_reader: Option<Box<Read + Send>>,
+}
+
+impl fmt::Debug for Reader {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("Reader")
+            .field("form", &self.form)
+            .finish()
+    }
+}
+
+impl Reader {
+    fn new(form: Form) -> Reader {
+        let mut reader = Reader {
+            form: form,
+            active_reader: None,
+        };
+        reader.next_reader();
+        reader
+    }
+
+    fn next_reader(&mut self) {
+        self.active_reader = if self.form.fields.len() != 0 {
+            // We need to move out of the vector here because we are consuming the field's reader
+            let (name, field) = self.form.fields.remove(0);
+            let reader = Cursor::new(format!(
+                "--{}\r\n{}\r\n\r\n",
+                self.form.boundary,
+                // Try to use cached headers created by compute_length
+                if self.form.headers.len() > 0 {
+                    self.form.headers.remove(0)
+                } else {
+                    header(&name, &field)
+                }
+            )).chain(::body::reader(field.value))
+                .chain(Cursor::new("\r\n"));
+            // According to https://tools.ietf.org/html/rfc2046#section-5.1.1
+            // the very last field has a special boundary
+            if self.form.fields.len() != 0 {
+                Some(Box::new(reader))
+            } else {
+                Some(Box::new(reader.chain(Cursor::new(
+                    format!("--{}--\r\n", self.form.boundary),
+                ))))
+            }
+        } else {
+            None
+        }
+    }
+}
+
+impl Read for Reader {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let mut total_bytes_read = 0usize;
+        let mut last_read_bytes;
+        loop {
+            match self.active_reader {
+                Some(ref mut reader) => {
+                    last_read_bytes = reader.read(&mut buf[total_bytes_read..])?;
+                    total_bytes_read += last_read_bytes;
+                    if total_bytes_read == buf.len() {
+                        return Ok(total_bytes_read);
+                    }
+                }
+                None => return Ok(total_bytes_read),
+            };
+            if last_read_bytes == 0 && buf.len() != 0 {
+                self.next_reader();
+            }
+        }
+    }
+}
+
+
+fn header(name: &str, field: &Part) -> String {
+    format!(
+        "Content-Disposition: form-data; {}{}{}",
+        format_parameter("name", name),
+        match field.file_name {
+            Some(ref file_name) => format!("; {}", format_parameter("filename", file_name)),
+            None => String::new(),
+        },
+        match field.mime {
+            Some(ref mime) => format!("\r\nContent-Type: {}", mime),
+            None => "".to_string(),
+        }
+    )
+}
+
+fn format_parameter(name: &str, value: &str) -> String {
+    let legal_value =
+        percent_encoding::utf8_percent_encode(value, percent_encoding::PATH_SEGMENT_ENCODE_SET)
+            .to_string();
+    if value.len() == legal_value.len() {
+        // nothing has been percent encoded
+        format!("{}=\"{}\"", name, value)
+    } else {
+        // something has been percent encoded
+        format!("{}*=utf-8''{}", name, legal_value)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn form_empty() {
+        let mut output = Vec::new();
+        let mut form = Form::new();
+        let length = form.compute_length();
+        form.reader().read_to_end(&mut output).unwrap();
+        assert_eq!(output, b"");
+        assert_eq!(length.unwrap(), 0);
+    }
+
+    #[test]
+    fn read_to_end() {
+        let mut output = Vec::new();
+        let mut form = Form::new()
+            .part("reader1", Part::reader(::std::io::empty()))
+            .part("key1", Part::text("value1"))
+            .part(
+                "key2",
+                Part::text("value2").mime(::mime::IMAGE_BMP),
+            )
+            .part("reader2", Part::reader(::std::io::empty()))
+            .part(
+                "key3",
+                Part::text("value3").file_name("filename"),
+            );
+        form.boundary = "boundary".to_string();
+        let length = form.compute_length();
+        let expected = "--boundary\r\n\
+                        Content-Disposition: form-data; name=\"reader1\"\r\n\r\n\
+                        \r\n\
+                        --boundary\r\n\
+                        Content-Disposition: form-data; name=\"key1\"\r\n\r\n\
+                        value1\r\n\
+                        --boundary\r\n\
+                        Content-Disposition: form-data; name=\"key2\"\r\n\
+                        Content-Type: image/bmp\r\n\r\n\
+                        value2\r\n\
+                        --boundary\r\n\
+                        Content-Disposition: form-data; name=\"reader2\"\r\n\r\n\
+                        \r\n\
+                        --boundary\r\n\
+                        Content-Disposition: form-data; name=\"key3\"; filename=\"filename\"\r\n\r\n\
+                        value3\r\n--boundary--\r\n";
+        form.reader().read_to_end(&mut output).unwrap();
+        // These prints are for debug purposes in case the test fails
+        println!(
+            "START REAL\n{}\nEND REAL",
+            ::std::str::from_utf8(&output).unwrap()
+        );
+        println!("START EXPECTED\n{}\nEND EXPECTED", expected);
+        assert_eq!(::std::str::from_utf8(&output).unwrap(), expected);
+        assert!(length.is_none());
+    }
+
+    #[test]
+    fn read_to_end_with_length() {
+        let mut output = Vec::new();
+        let mut form = Form::new()
+            .text("key1", "value1")
+            .part(
+                "key2",
+                Part::text("value2").mime(::mime::IMAGE_BMP),
+            )
+            .part(
+                "key3",
+                Part::text("value3").file_name("filename"),
+            );
+        form.boundary = "boundary".to_string();
+        let length = form.compute_length();
+        let expected = "--boundary\r\n\
+                        Content-Disposition: form-data; name=\"key1\"\r\n\r\n\
+                        value1\r\n\
+                        --boundary\r\n\
+                        Content-Disposition: form-data; name=\"key2\"\r\n\
+                        Content-Type: image/bmp\r\n\r\n\
+                        value2\r\n\
+                        --boundary\r\n\
+                        Content-Disposition: form-data; name=\"key3\"; filename=\"filename\"\r\n\r\n\
+                        value3\r\n--boundary--\r\n";
+        form.reader().read_to_end(&mut output).unwrap();
+        // These prints are for debug purposes in case the test fails
+        println!(
+            "START REAL\n{}\nEND REAL",
+            ::std::str::from_utf8(&output).unwrap()
+        );
+        println!("START EXPECTED\n{}\nEND EXPECTED", expected);
+        assert_eq!(::std::str::from_utf8(&output).unwrap(), expected);
+        assert_eq!(length.unwrap(), expected.len() as u64);
+    }
+
+    #[test]
+    fn header_percent_encoding() {
+        let name = "start%'\"\r\nßend";
+        let field = Part::text("");
+        let expected = "Content-Disposition: form-data; name*=utf-8''start%25\'%22%0D%0A%C3%9Fend";
+
+        assert_eq!(header(name, &field), expected);
+    }
+}