Make ByteSpan a GraphQL scalar

This helps shrink GraphQL search responses a bit, makes queries less
repetitive (no need to specify `start end` all the time), generally
saves processing time (fewer JSON objects) and avoids having to use
signed integers. In an example request, it shrank the response size
from 210 to 190KB. Not a ton but still 10%.

backend/src/api/model/search/event.rs

@@ -112,7 +112,7 @@ impl SearchEvent {
                 .iter()
                 .filter_map(|m| {
                     m.indices.as_ref().and_then(|v| v.get(0)).map(|index| ArrayMatch {
-                        span: ByteSpan { start: m.start as i32, len: m.length as i32 },
+                        span: ByteSpan { start: m.start as u32, len: m.length as u32 },
                         index: *index as i32,
                     })
                 })

backend/src/api/model/search/mod.rs

@@ -1,5 +1,5 @@
 use chrono::{DateTime, Utc};
-use juniper::GraphQLObject;
+use juniper::{GraphQLObject, GraphQLScalar, InputValue, ScalarValue};
 use meilisearch_sdk::search::{FederationOptions, MatchRange, QueryFederationOptions};
 use once_cell::sync::Lazy;
 use regex::Regex;
@@ -81,11 +81,22 @@ make_search_results_object!("EventSearchResults", SearchEvent);
 make_search_results_object!("SeriesSearchResults", SearchSeries);
 make_search_results_object!("PlaylistSearchResults", search::Playlist);
 
-
-#[derive(Debug, GraphQLObject)]
+/// A byte range, encoded as two hex numbers separated by `-`.
+#[derive(Debug, Clone, Copy, GraphQLScalar)]
+#[graphql(parse_token(String))]
 pub struct ByteSpan {
-    pub start: i32,
-    pub len: i32,
+    pub start: u32,
+    pub len: u32,
+}
+
+impl ByteSpan {
+    fn to_output<S: ScalarValue>(&self) -> juniper::Value<S> {
+        juniper::Value::scalar(format!("{:x}-{:x}", self.start, self.len))
+    }
+
+    fn from_input<S: ScalarValue>(_input: &InputValue<S>) -> Result<Self, String> {
+        unimplemented!("not used right now")
+    }
 }
 
 #[derive(Debug, Clone, Copy, juniper::GraphQLEnum)]
@@ -579,7 +590,7 @@ fn field_matches_for(
     field: &str,
 ) -> Vec<ByteSpan> {
     match_ranges_for(match_positions, field).iter()
-        .map(|m| ByteSpan { start: m.start as i32, len: m.length as i32 })
+        .map(|m| ByteSpan { start: m.start as u32, len: m.length as u32 })
         .take(8) // The frontend can only show a limited number anyway
         .collect()
 }

backend/src/search/event.rs

@@ -451,8 +451,8 @@ impl TextSearchIndex {
 
             let highlights = matches.iter().map(|m| {
                 ByteSpan {
-                    start: (m.start - range_with_context.start) as i32,
-                    len: m.length as i32,
+                    start: (m.start - range_with_context.start) as u32,
+                    len: m.length as u32,
                 }
             }).collect();
 

frontend/relay.config.js

@@ -10,6 +10,7 @@ module.exports = {
     customScalarTypes: {
         "DateTime": "string",
         "Cursor": "string",
+        "ByteSpan": "string",
         "ExtraMetadata": "Record<string, Record<string, string[]>>",
         "TranslatedString": "Record<string, string>",
     },

frontend/src/routes/Search.tsx

@@ -177,13 +177,13 @@ const query = graphql`
                             duration
                             text
                             ty
-                            highlights { start len }
+                            highlights
                         }
                         matches {
-                            title { start len }
-                            description { start len }
-                            seriesTitle { start len }
-                            creators { index span { start len }}
+                            title
+                            description
+                            seriesTitle
+                            creators { index span }
                         }
                     }
                     ... on SearchSeries {
@@ -192,19 +192,14 @@ const query = graphql`
                         description
                         thumbnails { thumbnail isLive audioOnly }
                         hostRealms { path ancestorNames }
-                        matches {
-                            title { start len }
-                            description { start len }
-                        }
+                        matches { title description }
                     }
                     ... on SearchRealm {
                         id
                         name
                         path
                         ancestorNames
-                        matches {
-                            name { start len }
-                        }
+                        matches { name }
                     }
                 }
                 totalHits
@@ -1226,13 +1221,16 @@ const byteSlice = (s: string, start: number, len: number): readonly [string, str
  */
 const highlightText = (
     s: string,
-    spans: readonly { start: number; len: number }[],
+    spans: readonly string[],
     maxUnmarkedSectionLen = Infinity,
 ) => {
     const textParts = [];
     let remainingText = s;
     let offset = 0;
-    for (const span of spans) {
+    for (const encodedSpan of spans) {
+        const [start, len] = encodedSpan.split("-").map(v => parseInt(v, 16));
+        const span = { start, len };
+
         const highlightStart = span.start - offset;
         const [prefix_, middle, rest]
             = byteSlice(remainingText, highlightStart, span.len);

frontend/src/schema.graphql

@@ -188,6 +188,9 @@ interface Node {
   id: ID!
 }
 
+"A byte range, encoded as two hex numbers separated by `-`."
+scalar ByteSpan
+
 "An opaque cursor used for pagination"
 scalar Cursor
 
@@ -291,11 +294,6 @@ type AuthorizedPlaylist implements Node {
   entries: [VideoListEntry!]!
 }
 
-type ByteSpan {
-  start: Int!
-  len: Int!
-}
-
 type Caption {
   uri: String!
   lang: String