Make parse memory configurable and raise HTML size limit

- Raise size limit from 5 MB to 50 MB
- Use DOCSRS_MAX_PARSE_MEMORY to configure the max memory, defaulting to
350 MB

Author: jyn514

src/config.rs

@@ -28,6 +28,8 @@ pub struct Config {
     // Max size of the files served by the docs.rs frontend
     pub(crate) max_file_size: usize,
     pub(crate) max_file_size_html: usize,
+    // The most memory that can be used to parse an HTML file
+    pub(crate) max_parse_memory: usize,
 }
 
 impl Config {
@@ -55,7 +57,8 @@ impl Config {
             github_accesstoken: maybe_env("CRATESFYI_GITHUB_ACCESSTOKEN")?,
 
             max_file_size: env("DOCSRS_MAX_FILE_SIZE", 50 * 1024 * 1024)?,
-            max_file_size_html: env("DOCSRS_MAX_FILE_SIZE_HTML", 5 * 1024 * 1024)?,
+            max_file_size_html: env("DOCSRS_MAX_FILE_SIZE_HTML", 50 * 1024 * 1024)?,
+            max_parse_memory: env("DOCSRS_MAX_PARSE_MEMORY", 350 * 1024 * 1024)?,
         })
     }
 

src/utils/html.rs

@@ -9,6 +9,7 @@ use tera::Context;
 /// The output is an HTML page which has not yet been UTF-8 validated.
 pub(crate) fn rewrite_lol(
     html: &[u8],
+    max_allowed_memory_usage: usize,
     ctx: Context,
     templates: &TemplateData,
 ) -> Result<Vec<u8>, RewritingError> {
@@ -67,7 +68,7 @@ pub(crate) fn rewrite_lol(
     let settings = Settings {
         element_content_handlers: vec![head, body],
         memory_settings: MemorySettings {
-            max_allowed_memory_usage: 1024 * 1024 * 350, // 350 MB, about 1.5x as large as our current largest file
+            max_allowed_memory_usage,
             ..MemorySettings::default()
         },
         ..Settings::default()

src/web/rustdoc.rs

@@ -192,7 +192,7 @@ struct RustdocPage {
 }
 
 impl RustdocPage {
-    fn into_response(self, rustdoc_html: &[u8], req: &mut Request) -> IronResult<Response> {
+    fn into_response(self, rustdoc_html: &[u8], max_parse_memory: usize, req: &mut Request) -> IronResult<Response> {
         use iron::{headers::ContentType, status::Status};
 
         let templates = req
@@ -203,7 +203,7 @@ impl RustdocPage {
         // Build the page of documentation
         let ctx = ctry!(req, tera::Context::from_serialize(self),);
         // Extract the head and body of the rustdoc file so that we can insert it into our own html
-        let html = ctry!(req, utils::rewrite_lol(rustdoc_html, ctx, templates));
+        let html = ctry!(req, utils::rewrite_lol(rustdoc_html, max_parse_memory, ctx, templates));
 
         let mut response = Response::with((Status::Ok, html));
         response.headers.set(ContentType::html());
@@ -382,7 +382,7 @@ pub fn rustdoc_html_server_handler(req: &mut Request) -> IronResult<Response> {
         is_latest_version,
         krate,
     }
-    .into_response(&file.0.content, req)
+    .into_response(&file.0.content, config.max_parse_memory, req)
 }
 
 /// Checks whether the given path exists.