feat: Implement parse_snapshot

src/types/in_memory.rs

@@ -656,6 +656,7 @@ pub enum DataFileFormat {
 }
 
 /// Snapshot of contains all data of a table at a point in time.
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub struct Snapshot {
     /// A unique long ID
     pub snapshot_id: i64,

src/types/on_disk/mod.rs

@@ -16,4 +16,7 @@ pub use sort_order::parse_sort_order;
 mod transform;
 pub use transform::parse_transform;
 
+mod snapshot;
+pub use snapshot::parse_snapshot;
+
 mod types;

src/types/on_disk/snapshot.rs

@@ -0,0 +1,103 @@
+use std::collections::HashMap;
+
+use serde::Deserialize;
+
+use crate::types;
+use anyhow::Result;
+
+/// Parse snapshot from json bytes.
+pub fn parse_snapshot(bs: &[u8]) -> Result<types::Snapshot> {
+    let v: Snapshot = serde_json::from_slice(bs)?;
+    v.try_into()
+}
+
+#[derive(Deserialize)]
+#[cfg_attr(test, derive(Debug, PartialEq, Eq))]
+#[serde(rename_all = "kebab-case")]
+struct Snapshot {
+    snapshot_id: i64,
+    parent_snapshot_id: Option<i64>,
+    #[serde(default)]
+    sequence_number: i64,
+    timestamp_ms: i64,
+    manifest_list: String,
+    summary: HashMap<String, String>,
+    schema_id: Option<i64>,
+}
+
+impl TryFrom<Snapshot> for types::Snapshot {
+    type Error = anyhow::Error;
+
+    fn try_from(v: Snapshot) -> Result<Self, Self::Error> {
+        Ok(types::Snapshot {
+            snapshot_id: v.snapshot_id,
+            parent_snapshot_id: v.parent_snapshot_id,
+            sequence_number: v.sequence_number,
+            timestamp_ms: v.timestamp_ms,
+            manifest_list: v.manifest_list,
+            summary: v.summary,
+            schema_id: v.schema_id,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_snapshot() {
+        let content = r#"
+{
+    "snapshot-id" : 1646658105718557341,
+    "timestamp-ms" : 1686911671713,
+    "summary" : {
+      "operation" : "append",
+      "spark.app.id" : "local-1686911651377",
+      "added-data-files" : "3",
+      "added-records" : "3",
+      "added-files-size" : "1929",
+      "changed-partition-count" : "1",
+      "total-records" : "3",
+      "total-files-size" : "1929",
+      "total-data-files" : "3",
+      "total-delete-files" : "0",
+      "total-position-deletes" : "0",
+      "total-equality-deletes" : "0"
+    },
+    "manifest-list" : "/opt/bitnami/spark/warehouse/db/table/metadata/snap-1646658105718557341-1-10d28031-9739-484c-92db-cdf2975cead4.avro",
+    "schema-id" : 0
+  }
+        "#;
+
+        let v = parse_snapshot(content.as_bytes()).unwrap();
+
+        assert_eq!(
+            v,
+            types::Snapshot {
+                snapshot_id: 1646658105718557341,
+                parent_snapshot_id: None,
+                sequence_number: 0,
+                timestamp_ms: 1686911671713,
+                manifest_list: "/opt/bitnami/spark/warehouse/db/table/metadata/snap-1646658105718557341-1-10d28031-9739-484c-92db-cdf2975cead4.avro".to_string(),
+                summary: {
+                    let mut m = HashMap::new();
+                    m.insert("operation", "append");
+                    m.insert("spark.app.id", "local-1686911651377");
+                    m.insert("added-data-files", "3");
+                    m.insert("added-records", "3");
+                    m.insert("added-files-size", "1929");
+                    m.insert("changed-partition-count", "1");
+                    m.insert("total-records", "3");
+                    m.insert("total-files-size", "1929");
+                    m.insert("total-data-files", "3");
+                    m.insert("total-delete-files", "0");
+                    m.insert("total-position-deletes", "0");
+                    m.insert("total-equality-deletes", "0");
+                    m.into_iter().map(|(k,v)|(k.to_string(), v.to_string())).collect()
+                },
+                schema_id: Some(0)
+            }
+        )
+    }
+}