paginate versions api

Author: Marco Napetti

src/controllers/krate/metadata.rs

@@ -8,7 +8,8 @@ use std::cmp::Reverse;
 use std::str::FromStr;
 
 use crate::controllers::frontend_prelude::*;
-use crate::controllers::helpers::pagination::PaginationOptions;
+use crate::controllers::helpers::pagination::{Paginated, PaginationOptions};
+use crate::controllers::helpers::Paginate;
 
 use crate::models::{
     Category, Crate, CrateCategory, CrateKeyword, CrateVersions, Keyword, RecentCrateDownloads,
@@ -325,15 +326,20 @@ pub fn readme(req: &mut dyn RequestExt) -> EndpointResult {
 // FIXME: Not sure why this is necessary since /crates/:crate_id returns
 // this information already, but ember is definitely requesting it
 pub fn versions(req: &mut dyn RequestExt) -> EndpointResult {
+    let pagination_options = PaginationOptions::builder().gather(req)?;
     let crate_name = &req.params()["crate_id"];
     let conn = req.db_read()?;
     let krate: Crate = Crate::by_name(crate_name).first(&*conn)?;
-    let mut versions_and_publishers: Vec<(Version, Option<User>)> = krate
+    let data: Paginated<(Version, Option<User>)> = krate
         .all_versions()
         .left_outer_join(users::table)
         .select((versions::all_columns, users::all_columns.nullable()))
+        .order(versions::created_at.desc())
+        .pages_pagination(pagination_options)
         .load(&*conn)?;
+    let more = data.next_page_params().is_some();
 
+    let mut versions_and_publishers = data.into_iter().collect::<Vec<_>>();
     versions_and_publishers
         .sort_by_cached_key(|(version, _)| Reverse(semver::Version::parse(&version.num).ok()));
 
@@ -348,7 +354,10 @@ pub fn versions(req: &mut dyn RequestExt) -> EndpointResult {
         .map(|((v, pb), aas)| EncodableVersion::from(v, crate_name, pb, aas))
         .collect::<Vec<_>>();
 
-    Ok(req.json(&json!({ "versions": versions })))
+    Ok(req.json(&json!({
+        "versions": versions,
+        "meta": { "more": more },
+    })))
 }
 
 /// Handles the `GET /crates/:crate_id/reverse_dependencies` route.