feat: add branch/tag metadata maps and tag timestamps

docs/src/format/table/branch_tag.md

@@ -38,10 +38,11 @@ Each branch metadata file is a JSON file with the following fields:
 
 | JSON Key         | Type   | Optional | Description                                                                    |
 |------------------|--------|----------|--------------------------------------------------------------------------------|
-| `parent_branch`  | string | Yes      | Name of the branch this was created from. `null` indicates branched from main. |
-| `parent_version` | number |          | Version number of the parent branch at the time this branch was created.       |
-| `create_at`      | number |          | Unix timestamp (seconds since epoch) when the branch was created.              |
-| `manifest_size`  | number |          | Size of the initial manifest file in bytes.                                    |
+| `parentBranch`   | string | Yes      | Name of the branch this was created from. `null` indicates branched from main. |
+| `parentVersion`  | number |          | Version number of the parent branch at the time this branch was created.       |
+| `createAt`       | number |          | Unix timestamp (seconds since epoch) when the branch was created.              |
+| `manifestSize`   | number |          | Size of the initial manifest file in bytes.                                    |
+| `metadata`       | object | Yes      | String key/value metadata map. If absent, it is treated as an empty object.    |
 
 ### Branch Dataset Layout
 
@@ -118,4 +119,7 @@ Each tag file is a JSON file with the following fields:
 |-----------------|--------|----------|--------------------------------------------------------------------------|
 | `branch`        | string | Yes      | Branch name being tagged. `null` or absent indicates main branch.        |
 | `version`       | number |          | Version number being tagged within that branch.                          |
-| `manifest_size` | number |          | Size of the manifest file in bytes. Used for efficient manifest loading. |
+| `createdAt`     | string | Yes      | RFC 3339 timestamp for when the tag was first created.                  |
+| `updatedAt`     | string | Yes      | RFC 3339 timestamp for the latest tag reference update.                 |
+| `manifestSize`  | number |          | Size of the manifest file in bytes. Used for efficient manifest loading. |
+| `metadata`      | object | Yes      | String key/value metadata map. If absent, it is treated as an empty object. |

docs/src/guide/tags_and_branches.md

@@ -36,21 +36,21 @@ print(ds.tags.list())
 # {}
 ds.tags.create("v1-prod", (None, 1))
 print(ds.tags.list())
-# {'v1-prod': {'version': 1, 'manifest_size': ...}}
+# {'v1-prod': {'version': 1, 'created_at': ..., 'updated_at': ..., 'manifest_size': ...}}
 ds.tags.update("v1-prod", (None, 2))
 print(ds.tags.list())
-# {'v1-prod': {'version': 2, 'manifest_size': ...}}
+# {'v1-prod': {'version': 2, 'created_at': ..., 'updated_at': ..., 'manifest_size': ...}}
 ds.tags.delete("v1-prod")
 print(ds.tags.list())
 # {}
 print(ds.tags.list_ordered())
 # []
 ds.tags.create("v1-prod", (None, 1))
 print(ds.tags.list_ordered())
-# [('v1-prod', {'version': 1, 'manifest_size': ...})]
+# [('v1-prod', {'version': 1, 'created_at': ..., 'updated_at': ..., 'manifest_size': ...})]
 ds.tags.update("v1-prod", (None, 2))
 print(ds.tags.list_ordered())
-# [('v1-prod', {'version': 2, 'manifest_size': ...})]
+# [('v1-prod', {'version': 2, 'created_at': ..., 'updated_at': ..., 'manifest_size': ...})]
 ds.tags.delete("v1-prod")
 print(ds.tags.list_ordered())
 # []
@@ -122,4 +122,4 @@ print(ds.branches.list_ordered(order="desc"))
 
     Branches hold references to data files. Lance ensures that cleanup does not delete files still referenced by any branch.
 
-    Delete unused branches to allow their referenced files to be cleaned up by `cleanup_old_versions()`.
+    Delete unused branches to allow their referenced files to be cleaned up by `cleanup_old_versions()`.

java/lance-jni/src/blocking_dataset.rs

@@ -11,7 +11,7 @@ use crate::storage_options::JavaStorageOptionsProvider;
 use crate::traits::{FromJObjectWithEnv, FromJString, export_vec, import_vec, import_vec_to_rust};
 use crate::utils::{
     build_compaction_options, extract_storage_options, extract_write_params,
-    get_scalar_index_params, get_vector_index_params, to_rust_map,
+    get_scalar_index_params, get_vector_index_params, to_java_map, to_rust_map,
 };
 use crate::{RT, traits::IntoJava};
 use arrow::array::RecordBatchReader;
@@ -314,6 +314,24 @@ impl BlockingDataset {
         Ok(())
     }
 
+    pub fn replace_tag_metadata(
+        &mut self,
+        tag: &str,
+        metadata: HashMap<String, String>,
+    ) -> Result<()> {
+        RT.block_on(self.inner.tags().replace_metadata(tag, metadata))?;
+        Ok(())
+    }
+
+    pub fn replace_branch_metadata(
+        &mut self,
+        branch: &str,
+        metadata: HashMap<String, String>,
+    ) -> Result<()> {
+        RT.block_on(self.inner.branches().replace_metadata(branch, metadata))?;
+        Ok(())
+    }
+
     pub fn get_version(&self, tag: &str) -> Result<u64> {
         let version = RT.block_on(self.inner.tags().get_version(tag))?;
         Ok(version)
@@ -2261,6 +2279,26 @@ fn inner_add_columns_by_schema(
 //////////////////////////////
 // Tag operation Methods    //
 //////////////////////////////
+fn optional_datetime_to_java_instant<'local>(
+    env: &mut JNIEnv<'local>,
+    timestamp: Option<&DateTime<Utc>>,
+) -> Result<JObject<'local>> {
+    if let Some(timestamp) = timestamp {
+        let seconds = timestamp.timestamp();
+        let nanos = timestamp.timestamp_subsec_nanos() as i64;
+        Ok(env
+            .call_static_method(
+                "java/time/Instant",
+                "ofEpochSecond",
+                "(JJ)Ljava/time/Instant;",
+                &[JValue::Long(seconds), JValue::Long(nanos)],
+            )?
+            .l()?)
+    } else {
+        Ok(JObject::null())
+    }
+}
+
 #[unsafe(no_mangle)]
 pub extern "system" fn Java_org_lance_Dataset_nativeListTags<'local>(
     mut env: JNIEnv<'local>,
@@ -2273,27 +2311,34 @@ fn inner_list_tags<'local>(
     env: &mut JNIEnv<'local>,
     java_dataset: JObject,
 ) -> Result<JObject<'local>> {
-    let tag_map = {
+    let mut tags: Vec<_> = {
         let dataset_guard =
             unsafe { env.get_rust_field::<_, _, BlockingDataset>(java_dataset, NATIVE_DATASET) }?;
-        dataset_guard.list_tags()?
+        dataset_guard.list_tags()?.into_iter().collect()
     };
+    tags.sort_unstable_by(|(left_name, _), (right_name, _)| left_name.cmp(right_name));
     let array_list = env.new_object("java/util/ArrayList", "()V", &[])?;
 
-    for (tag_name, tag_contents) in tag_map {
+    for (tag_name, tag_contents) in tags {
         let branch_name: JObject = if let Some(branch_name) = tag_contents.branch.as_ref() {
             env.new_string(branch_name)?.into()
         } else {
             JObject::null()
         };
+        let created_at = optional_datetime_to_java_instant(env, tag_contents.created_at.as_ref())?;
+        let updated_at = optional_datetime_to_java_instant(env, tag_contents.updated_at.as_ref())?;
+        let java_metadata = to_java_map(env, &tag_contents.metadata)?;
         let java_tag = env.new_object(
             "org/lance/Tag",
-            "(Ljava/lang/String;Ljava/lang/String;JI)V",
+            "(Ljava/lang/String;Ljava/lang/String;JILjava/time/Instant;Ljava/time/Instant;Ljava/util/Map;)V",
             &[
                 JValue::Object(&env.new_string(tag_name)?.into()),
                 JValue::Object(&branch_name),
                 JValue::Long(tag_contents.version as i64),
                 JValue::Int(tag_contents.manifest_size as i32),
+                JValue::Object(&created_at),
+                JValue::Object(&updated_at),
+                JValue::Object(&java_metadata),
             ],
         )?;
         env.call_method(
@@ -2375,6 +2420,32 @@ fn inner_update_tag(
     dataset_guard.update_tag(tag.as_str(), reference)
 }
 
+#[unsafe(no_mangle)]
+pub extern "system" fn Java_org_lance_Dataset_nativeReplaceTagMetadata(
+    mut env: JNIEnv,
+    java_dataset: JObject,
+    jtag_name: JString,
+    jmetadata: JObject,
+) {
+    ok_or_throw_without_return!(
+        env,
+        inner_replace_tag_metadata(&mut env, java_dataset, jtag_name, jmetadata)
+    )
+}
+
+fn inner_replace_tag_metadata(
+    env: &mut JNIEnv,
+    java_dataset: JObject,
+    jtag_name: JString,
+    jmetadata: JObject,
+) -> Result<()> {
+    let tag = jtag_name.extract(env)?;
+    let metadata = extract_metadata_map(env, &jmetadata)?;
+    let mut dataset_guard =
+        { unsafe { env.get_rust_field::<_, _, BlockingDataset>(java_dataset, NATIVE_DATASET) }? };
+    dataset_guard.replace_tag_metadata(tag.as_str(), metadata)
+}
+
 #[unsafe(no_mangle)]
 pub extern "system" fn Java_org_lance_Dataset_nativeGetVersionByTag(
     mut env: JNIEnv,
@@ -2414,11 +2485,12 @@ fn inner_list_branches<'local>(
     env: &mut JNIEnv<'local>,
     java_dataset: JObject,
 ) -> Result<JObject<'local>> {
-    let branches = {
+    let mut branches: Vec<_> = {
         let dataset_guard =
             unsafe { env.get_rust_field::<_, _, BlockingDataset>(java_dataset, NATIVE_DATASET) }?;
-        dataset_guard.list_branches()?
+        dataset_guard.list_branches()?.into_iter().collect()
     };
+    branches.sort_unstable_by(|(left_name, _), (right_name, _)| left_name.cmp(right_name));
     let array_list = env.new_object("java/util/ArrayList", "()V", &[])?;
 
     for (name, contents) in branches {
@@ -2447,16 +2519,18 @@ fn inner_list_branches<'local>(
                 &[JValue::Object(&jmapping)],
             )?;
         }
+        let java_metadata = to_java_map(env, &contents.metadata)?;
         let jbranch = env.new_object(
             "org/lance/Branch",
-            "(Ljava/lang/String;Ljava/lang/String;Ljava/util/List;JJI)V",
+            "(Ljava/lang/String;Ljava/lang/String;Ljava/util/List;JJILjava/util/Map;)V",
             &[
                 JValue::Object(&jname),
                 JValue::Object(&jparent),
                 JValue::Object(&jbranch_identifier),
                 JValue::Long(contents.parent_version as i64),
                 JValue::Long(contents.create_at as i64),
                 JValue::Int(contents.manifest_size as i32),
+                JValue::Object(&java_metadata),
             ],
         )?;
         env.call_method(
@@ -2507,6 +2581,37 @@ fn inner_create_branch<'local>(
     new_blocking_dataset.into_java(env)
 }
 
+#[unsafe(no_mangle)]
+pub extern "system" fn Java_org_lance_Dataset_nativeReplaceBranchMetadata(
+    mut env: JNIEnv,
+    java_dataset: JObject,
+    jbranch: JString,
+    jmetadata: JObject,
+) {
+    ok_or_throw_without_return!(
+        env,
+        inner_replace_branch_metadata(&mut env, java_dataset, jbranch, jmetadata)
+    )
+}
+
+fn inner_replace_branch_metadata(
+    env: &mut JNIEnv,
+    java_dataset: JObject,
+    jbranch: JString,
+    jmetadata: JObject,
+) -> Result<()> {
+    let branch: String = jbranch.extract(env)?;
+    let metadata = extract_metadata_map(env, &jmetadata)?;
+    let mut dataset_guard =
+        unsafe { env.get_rust_field::<_, _, BlockingDataset>(java_dataset, NATIVE_DATASET) }?;
+    dataset_guard.replace_branch_metadata(&branch, metadata)
+}
+
+fn extract_metadata_map(env: &mut JNIEnv, jmetadata: &JObject) -> Result<HashMap<String, String>> {
+    let jmap = JMap::from_env(env, jmetadata)?;
+    to_rust_map(env, &jmap)
+}
+
 fn transform_jref_to_ref(jref: JObject, env: &mut JNIEnv) -> Result<Ref> {
     let source_tag_name = env.get_optional_string_from_method(&jref, "getTagName")?;
     let source_version_number = env.get_optional_u64_from_method(&jref, "getVersionNumber")?;

java/lance-jni/src/traits.rs

@@ -262,6 +262,15 @@ impl IntoJava for JLance<Option<usize>> {
     }
 }
 
+impl IntoJava for JLance<Option<&str>> {
+    fn into_java<'a>(self, env: &mut JNIEnv<'a>) -> Result<JObject<'a>> {
+        Ok(match self.0 {
+            Some(value) => env.new_string(value)?.into(),
+            None => JObject::null(),
+        })
+    }
+}
+
 impl FromJObjectWithEnv<Option<i64>> for JObject<'_> {
     fn extract_object(&self, env: &mut JNIEnv<'_>) -> Result<Option<i64>> {
         let ret = if self.is_null() {

java/src/main/java/org/lance/Branch.java

@@ -16,7 +16,10 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableList;
 
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 
@@ -70,10 +73,18 @@ public int hashCode() {
   private final long parentVersion;
   private final long createAt;
   private final int manifestSize;
+  private final Map<String, String> metadata;
 
   public Branch(
       String name, String parentBranch, long parentVersion, long createAt, int manifestSize) {
-    this(name, parentBranch, ImmutableList.of(), parentVersion, createAt, manifestSize);
+    this(
+        name,
+        parentBranch,
+        ImmutableList.of(),
+        parentVersion,
+        createAt,
+        manifestSize,
+        Collections.emptyMap());
   }
 
   public Branch(
@@ -82,13 +93,15 @@ public Branch(
       List<BranchVersionMapping> branchIdentifier,
       long parentVersion,
       long createAt,
-      int manifestSize) {
+      int manifestSize,
+      Map<String, String> metadata) {
     this.name = name;
     this.parentBranch = Optional.ofNullable(parentBranch);
     this.branchIdentifier = ImmutableList.copyOf(Objects.requireNonNull(branchIdentifier));
     this.parentVersion = parentVersion;
     this.createAt = createAt;
     this.manifestSize = manifestSize;
+    this.metadata = Collections.unmodifiableMap(new HashMap<>(metadata));
   }
 
   public String getName() {
@@ -115,6 +128,10 @@ public int getManifestSize() {
     return manifestSize;
   }
 
+  public Map<String, String> getMetadata() {
+    return metadata;
+  }
+
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
@@ -124,6 +141,7 @@ public String toString() {
         .add("parentVersion", parentVersion)
         .add("createAt", createAt)
         .add("manifestSize", manifestSize)
+        .add("metadata", metadata)
         .toString();
   }
 
@@ -137,12 +155,13 @@ public boolean equals(Object o) {
         && manifestSize == branch.manifestSize
         && Objects.equals(name, branch.name)
         && Objects.equals(parentBranch, branch.parentBranch)
-        && Objects.equals(branchIdentifier, branch.branchIdentifier);
+        && Objects.equals(branchIdentifier, branch.branchIdentifier)
+        && Objects.equals(metadata, branch.metadata);
   }
 
   @Override
   public int hashCode() {
     return Objects.hash(
-        name, parentBranch, branchIdentifier, parentVersion, createAt, manifestSize);
+        name, parentBranch, branchIdentifier, parentVersion, createAt, manifestSize, metadata);
   }
 }