feat(java): add builder-style scalar index params

java/src/main/java/org/lance/index/scalar/BTreeIndexParams.java

@@ -0,0 +1,87 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.lance.index.scalar;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/** Builder-style configuration for B-Tree scalar index parameters. */
+public final class BTreeIndexParams {
+
+  private static final String INDEX_TYPE = "btree";
+
+  private BTreeIndexParams() {}
+
+  /**
+   * Create a new builder for B-Tree index parameters.
+   *
+   * @return a new {@link Builder}
+   */
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  public static final class Builder {
+    private Long zoneSize;
+    private Integer rangeId;
+
+    /**
+     * Configure the number of rows per zone.
+     *
+     * @param zoneSize number of rows per zone, must be positive
+     * @return this builder
+     * @throws IllegalArgumentException
+     */
+    public Builder zoneSize(long zoneSize) {
+      if (zoneSize <= 0) {
+        throw new IllegalArgumentException("zoneSize must be positive");
+      }
+      this.zoneSize = zoneSize;
+      return this;
+    }
+
+    /**
+     * Configure the ordinal ID of a data partition for building a large, distributed BTree index.
+     *
+     * @param rangeId non-negative range identifier
+     * @return this builder
+     * @throws IllegalArgumentException
+     */
+    public Builder rangeId(int rangeId) {
+      if (rangeId < 0) {
+        throw new IllegalArgumentException("rangeId must be non-negative");
+      }
+      this.rangeId = rangeId;
+      return this;
+    }
+
+    /** Build a {@link ScalarIndexParams} instance for a B-Tree index. */
+    public ScalarIndexParams build() {
+      Map<String, Object> params = new LinkedHashMap<>();
+      if (zoneSize != null) {
+        params.put("zone_size", zoneSize);
+      }
+      if (rangeId != null) {
+        params.put("range_id", rangeId);
+      }
+
+      if (params.isEmpty()) {
+        return ScalarIndexParams.create(INDEX_TYPE);
+      }
+
+      String json = JsonUtils.toJson(params);
+      return ScalarIndexParams.create(INDEX_TYPE, json);
+    }
+  }
+}

java/src/main/java/org/lance/index/scalar/BitmapIndexParams.java

@@ -0,0 +1,33 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.lance.index.scalar;
+
+/** Builder-style configuration for Bitmap scalar index parameters. */
+public final class BitmapIndexParams {
+  private static final String INDEX_TYPE = "bitmap";
+
+  private BitmapIndexParams() {}
+
+  /** Create a new builder for Bitmap index parameters. */
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  public static final class Builder {
+    /** Build a {@link ScalarIndexParams} instance for a Bitmap index. */
+    public ScalarIndexParams build() {
+      return ScalarIndexParams.create(INDEX_TYPE);
+    }
+  }
+}