Struct FormFileBuilder 

pub struct FormFileBuilder { /* private fields */ }

Incrementally builds a FormFile while a multipart part streams in.

The builder buffers in memory up to memory_threshold bytes and spills to a temporary file beyond that, so peak memory per upload is bounded regardless of file size.

Implementations

impl FormFileBuilder

pub fn new( field_name: impl Into<String>, raw_file_name: impl Into<String>, content_type: Option<String>, ) -> FormFileBuilder

Start building a file for field_name.

raw_file_name is the client-supplied name; it is sanitised by sanitize_file_name when the file is finished.

pub fn memory_threshold(self, bytes: usize) -> FormFileBuilder

Bytes kept in memory before spilling to disk. Default: 1 MiB.

pub fn max_size(self, bytes: u64) -> FormFileBuilder

Maximum accepted size for this file. Default: 128 MiB.

Exceeding it fails the upload with Error::PayloadTooLarge.

pub fn spool_dir(self, dir: impl Into<PathBuf>) -> FormFileBuilder

Directory used for spooled files. Default: spool_root.

pub async fn write(&mut self, chunk: &[u8]) -> Result<(), Error>

Append a chunk of the current part.

Returns Error::PayloadTooLarge as soon as the file exceeds FormFileBuilder::max_size, so an oversized upload is rejected without buffering the whole body.

pub async fn finish(self) -> Result<FormFile, Error>

Finish the part and produce the FormFile.