review: parquet_file singular, proto doc link, fix metastore accessor

Author: g-talbot

quickwit/quickwit-metastore/src/metastore/file_backed/file_backed_index/mod.rs

@@ -981,7 +981,7 @@ fn metrics_split_matches_query(split: &StoredMetricsSplit, query: &ListMetricsSp
 
     // Filter by compaction scope
     if let Some(ws) = query.window_start
-        && split.metadata.window_start != Some(ws)
+        && split.metadata.window_start() != Some(ws)
     {
         return false;
     }

quickwit/quickwit-parquet-engine/src/split/metadata.rs

@@ -160,8 +160,8 @@ pub struct MetricsSplitMetadata {
     /// When this split was created.
     pub created_at: SystemTime,
 
-    /// Parquet file path(s) relative to storage root.
-    pub parquet_files: Vec<String>,
+    /// Parquet file path relative to storage root.
+    pub parquet_file: String,
 
     /// Time window as `[start, start + duration)` in epoch seconds.
     /// None for pre-Phase-31 splits (backward compat).
@@ -175,7 +175,8 @@ pub struct MetricsSplitMetadata {
     /// 0 for newly ingested splits.
     pub num_merge_ops: u32,
 
-    /// RowKeys (sort-key min/max boundaries) as proto bytes.
+    /// RowKeys (sort-key min/max boundaries) as serialized proto bytes
+    /// ([`sortschema::RowKeys`](../../quickwit-proto/protos/event_store_sortschema/event_store_sortschema.proto)).
     /// None for pre-Phase-31 splits or splits without sort schema.
     pub row_keys_proto: Option<Vec<u8>>,
 
@@ -198,7 +199,7 @@ struct MetricsSplitMetadataSerde {
     low_cardinality_tags: HashMap<String, HashSet<String>>,
     high_cardinality_tag_keys: HashSet<String>,
     created_at: SystemTime,
-    parquet_files: Vec<String>,
+    parquet_file: String,
 
     #[serde(default, skip_serializing_if = "Option::is_none")]
     window_start: Option<i64>,
@@ -235,7 +236,7 @@ impl From<MetricsSplitMetadataSerde> for MetricsSplitMetadata {
             low_cardinality_tags: s.low_cardinality_tags,
             high_cardinality_tag_keys: s.high_cardinality_tag_keys,
             created_at: s.created_at,
-            parquet_files: s.parquet_files,
+            parquet_file: s.parquet_file,
             window,
             sort_fields: s.sort_fields,
             num_merge_ops: s.num_merge_ops,
@@ -261,7 +262,7 @@ impl From<MetricsSplitMetadata> for MetricsSplitMetadataSerde {
             low_cardinality_tags: m.low_cardinality_tags,
             high_cardinality_tag_keys: m.high_cardinality_tag_keys,
             created_at: m.created_at,
-            parquet_files: m.parquet_files,
+            parquet_file: m.parquet_file,
             window_start,
             window_duration_secs,
             sort_fields: m.sort_fields,
@@ -351,7 +352,7 @@ pub struct MetricsSplitMetadataBuilder {
     metric_names: HashSet<String>,
     low_cardinality_tags: HashMap<String, HashSet<String>>,
     high_cardinality_tag_keys: HashSet<String>,
-    parquet_files: Vec<String>,
+    parquet_file: String,
     window_start: Option<i64>,
     window_duration_secs: u32,
     sort_fields: String,
@@ -425,8 +426,8 @@ impl MetricsSplitMetadataBuilder {
         self
     }
 
-    pub fn add_parquet_file(mut self, path: impl Into<String>) -> Self {
-        self.parquet_files.push(path.into());
+    pub fn parquet_file(mut self, path: impl Into<String>) -> Self {
+        self.parquet_file = path.into();
         self
     }
 
@@ -500,7 +501,7 @@ impl MetricsSplitMetadataBuilder {
             low_cardinality_tags: self.low_cardinality_tags,
             high_cardinality_tag_keys: self.high_cardinality_tag_keys,
             created_at: SystemTime::now(),
-            parquet_files: self.parquet_files,
+            parquet_file: self.parquet_file,
             window,
             sort_fields: self.sort_fields,
             num_merge_ops: self.num_merge_ops,
@@ -626,7 +627,7 @@ mod tests {
             "low_cardinality_tags": {},
             "high_cardinality_tag_keys": [],
             "created_at": {"secs_since_epoch": 1700000000, "nanos_since_epoch": 0},
-            "parquet_files": ["split1.parquet"]
+            "parquet_file": "split1.parquet"
         }"#;
 
         let metadata: MetricsSplitMetadata =

quickwit/quickwit-parquet-engine/src/storage/split_writer.rs

@@ -122,7 +122,7 @@ impl ParquetSplitWriter {
             .size_bytes(0)
             .sort_fields(self.writer.sort_fields_string())
             .window_duration_secs(window_duration)
-            .add_parquet_file(filename);
+            .parquet_file(filename);
 
         if let Some(ws) = window_start_secs {
             builder = builder.window_start_secs(ws);