Merge #2454

2454: Unify the pagination of the index and documents route behind a common type r=curquiza a=irevoire

`@MarinPostma` wdyt of keeping the `auto_paginate_sized` until we implement the pagination on every route that needs it just to see if it could be useful to something else

Co-authored-by: Tamo <tamo@meilisearch.com>

meilisearch-http/src/routes/indexes/documents.rs

@@ -14,7 +14,7 @@ use mime::Mime;
 use once_cell::sync::Lazy;
 use serde::Deserialize;
 use serde_cs::vec::CS;
-use serde_json::{json, Value};
+use serde_json::Value;
 use tokio::sync::mpsc;
 
 use crate::analytics::Analytics;
@@ -22,7 +22,7 @@ use crate::error::MeilisearchHttpError;
 use crate::extractors::authentication::{policies::*, GuardedData};
 use crate::extractors::payload::Payload;
 use crate::extractors::sequential_extractor::SeqHandler;
-use crate::routes::{fold_star_or, StarOr};
+use crate::routes::{fold_star_or, PaginationView, StarOr};
 use crate::task::SummarizedTaskView;
 
 static ACCEPTED_CONTENT_TYPE: Lazy<Vec<String>> = Lazy::new(|| {
@@ -122,14 +122,12 @@ pub async fn delete_document(
     Ok(HttpResponse::Accepted().json(task))
 }
 
-const PAGINATION_DEFAULT_LIMIT: fn() -> usize = || 20;
-
 #[derive(Deserialize, Debug)]
 #[serde(rename_all = "camelCase", deny_unknown_fields)]
 pub struct BrowseQuery {
     #[serde(default)]
     offset: usize,
-    #[serde(default = "PAGINATION_DEFAULT_LIMIT")]
+    #[serde(default = "crate::routes::PAGINATION_DEFAULT_LIMIT")]
     limit: usize,
     fields: Option<CS<StarOr<String>>>,
 }
@@ -141,8 +139,8 @@ pub async fn get_all_documents(
 ) -> Result<HttpResponse, ResponseError> {
     debug!("called with params: {:?}", params);
     let BrowseQuery {
-        offset,
         limit,
+        offset,
         fields,
     } = params.into_inner();
     let attributes_to_retrieve = fields.map(CS::into_inner).and_then(fold_star_or);
@@ -151,10 +149,10 @@ pub async fn get_all_documents(
         .documents(path.into_inner(), offset, limit, attributes_to_retrieve)
         .await?;
 
-    debug!("returns: {:?}", documents);
-    Ok(HttpResponse::Ok().json(json!(
-        { "limit": limit, "offset": offset, "total": total, "results": documents }
-    )))
+    let ret = PaginationView::new(offset, limit, total as usize, documents);
+
+    debug!("returns: {:?}", ret);
+    Ok(HttpResponse::Ok().json(ret))
 }
 
 #[derive(Deserialize, Debug)]

meilisearch-http/src/routes/indexes/mod.rs

@@ -12,6 +12,8 @@ use crate::extractors::authentication::{policies::*, GuardedData};
 use crate::extractors::sequential_extractor::SeqHandler;
 use crate::task::SummarizedTaskView;
 
+use super::Pagination;
+
 pub mod documents;
 pub mod search;
 pub mod settings;
@@ -37,38 +39,22 @@ pub fn configure(cfg: &mut web::ServiceConfig) {
     );
 }
 
-const PAGINATION_DEFAULT_LIMIT: fn() -> usize = || 20;
-
-#[derive(Deserialize, Debug)]
-#[serde(rename_all = "camelCase", deny_unknown_fields)]
-pub struct Paginate {
-    #[serde(default)]
-    offset: usize,
-    #[serde(default = "PAGINATION_DEFAULT_LIMIT")]
-    limit: usize,
-}
-
 pub async fn list_indexes(
     data: GuardedData<ActionPolicy<{ actions::INDEXES_GET }>, MeiliSearch>,
-    paginate: web::Query<Paginate>,
+    paginate: web::Query<Pagination>,
 ) -> Result<HttpResponse, ResponseError> {
     let search_rules = &data.filters().search_rules;
     let indexes: Vec<_> = data.list_indexes().await?;
     let nb_indexes = indexes.len();
-    let indexes: Vec<_> = indexes
+    let iter = indexes
         .into_iter()
-        .filter(|i| search_rules.is_index_authorized(&i.uid))
-        .skip(paginate.offset)
-        .take(paginate.limit)
-        .collect();
+        .filter(|i| search_rules.is_index_authorized(&i.uid));
+    let ret = paginate
+        .into_inner()
+        .auto_paginate_unsized(nb_indexes, iter);
 
-    debug!("returns: {:?}", indexes);
-    Ok(HttpResponse::Ok().json(json!({
-        "results": indexes,
-        "offset": paginate.offset,
-        "limit": paginate.limit,
-        "total": nb_indexes,
-    })))
+    debug!("returns: {:?}", ret);
+    Ok(HttpResponse::Ok().json(ret))
 }
 
 #[derive(Debug, Deserialize)]

meilisearch-http/src/routes/mod.rs

@@ -3,6 +3,7 @@ use std::str::FromStr;
 use actix_web::{web, HttpResponse};
 use log::debug;
 use serde::{Deserialize, Serialize};
+
 use time::OffsetDateTime;
 
 use meilisearch_error::ResponseError;
@@ -58,6 +59,86 @@ pub fn fold_star_or<T>(content: impl IntoIterator<Item = StarOr<T>>) -> Option<V
         .collect()
 }
 
+const PAGINATION_DEFAULT_LIMIT: fn() -> usize = || 20;
+
+#[derive(Debug, Clone, Copy, Deserialize)]
+#[serde(rename_all = "camelCase", deny_unknown_fields)]
+pub struct Pagination {
+    #[serde(default)]
+    pub offset: usize,
+    #[serde(default = "PAGINATION_DEFAULT_LIMIT")]
+    pub limit: usize,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct PaginationView<T> {
+    pub results: Vec<T>,
+    pub offset: usize,
+    pub limit: usize,
+    pub total: usize,
+}
+
+impl Pagination {
+    /// Given the full data to paginate, returns the selected section.
+    pub fn auto_paginate_sized<T>(
+        self,
+        content: impl IntoIterator<Item = T> + ExactSizeIterator,
+    ) -> PaginationView<T>
+    where
+        T: Serialize,
+    {
+        let total = content.len();
+        let content: Vec<_> = content
+            .into_iter()
+            .skip(self.offset)
+            .take(self.limit)
+            .collect();
+        self.format_with(total, content)
+    }
+
+    /// Given an iterator and the total number of elements, returns the selected section.
+    pub fn auto_paginate_unsized<T>(
+        self,
+        total: usize,
+        content: impl IntoIterator<Item = T>,
+    ) -> PaginationView<T>
+    where
+        T: Serialize,
+    {
+        let content: Vec<_> = content
+            .into_iter()
+            .skip(self.offset)
+            .take(self.limit)
+            .collect();
+        self.format_with(total, content)
+    }
+
+    /// Given the data already paginated + the total number of elements, it stores
+    /// everything in a [PaginationResult].
+    pub fn format_with<T>(self, total: usize, results: Vec<T>) -> PaginationView<T>
+    where
+        T: Serialize,
+    {
+        PaginationView {
+            results,
+            offset: self.offset,
+            limit: self.limit,
+            total,
+        }
+    }
+}
+
+impl<T> PaginationView<T> {
+    pub fn new(offset: usize, limit: usize, total: usize, results: Vec<T>) -> Self {
+        Self {
+            offset,
+            limit,
+            results,
+            total,
+        }
+    }
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[allow(clippy::large_enum_variant)]
 #[serde(tag = "name")]

meilisearch-http/tests/documents/add_documents.rs

@@ -827,7 +827,7 @@ async fn add_larger_dataset() {
             ..Default::default()
         })
         .await;
-    assert_eq!(code, 200);
+    assert_eq!(code, 200, "failed with `{}`", response);
     assert_eq!(response["results"].as_array().unwrap().len(), 77);
 }