magmalake flare_mlake

flare_mlake · API · http

flare.http.fs

FileServer — serve files from a directory with HEAD + Range support.

Reads files synchronously via libc open(2) / read(2); suitable for sub-100 MB static directories. For larger trees (or concurrent reactor pressure) the reactor's Pool[T] blocking escape hatch is the follow-up.

Features:

  • GET and HEAD.
  • Single-range Range: bytes=<start>-<end> support, RFC 9110 paragraph 14.2 / 14.4. Multi-range responses are out of scope — servers may reject them per spec.
  • Path safety: rejects any URL whose normalised path escapes the base directory (.. components, absolute paths, NUL bytes).
  • Content-Type from a small built-in extension table (covers the common web shapes: HTML/CSS/JS/JSON/PNG/JPG/SVG/WOFF/TXT).
  • Sets Last-Modified from the file's mtime so caches / conditional GET (If-Modified-Since) work correctly.

The handler is a plain Handler so it composes with the rest of flare's middleware. Configure via FileServer.new(root).

Structs

ByteRange

struct ByteRange

One Range: bytes=start-end request.

Fields are 0-indexed inclusive, matching RFC 9110 paragraph 14.1.2's wire format. Negative start (suffix range) is resolved into an absolute [start, end] against the file size by parse_range.

Implements Copyable, Defaultable, Movable

Fields
start: Int
end: Int

__init__

def __init__(out self)

FileServer

struct FileServer

Serve files from root under the request URL path.

Construction: mojo var fs = FileServer.new("./public") var srv = HttpServer.bind(addr) srv.serve(fs^, num_workers=4)

Returns 404 for any path that escapes root, doesn't exist, or is not a regular file. HEAD returns the response with an empty body. Range: bytes=... returns 206 with the requested slice; other methods return 405.

Implements Copyable, Defaultable, Handler, Movable

Fields
root: String
index_file: String
comptime BodyType = InlineBody

The Body impl this handler authors its response with.

__init__

def __init__(out self)

new

def new(root: String, index_file: String = "index.html") -> Self

serve

def serve(self, req: Request) -> Response

Functions

parse_range

def parse_range(value: String, file_size: Int) -> Optional[ByteRange]

Parse a single-range Range header value.

Returns None if the header is missing/blank. Returns Some(ByteRange{start, end}) on success. Raises Error on:

  • Multi-range requests (,-separated).
  • Out-of-range / negative-end / inverted ranges.
  • Non-bytes= units.