[WIP] Refactor Hyperspace Index Configs to allow support for addition of new index

src/main/scala/com/microsoft/hyperspace/index/Config.scala

@@ -0,0 +1,137 @@
+/*
+ * Copyright (2020) The Hyperspace Project Authors.
+ *
+ * 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 com.microsoft.hyperspace.index
+
+import java.util.Locale
+
+/**
+ * IndexConfig specifies the configuration of an index.
+ * Associated Builder [[com.microsoft.hyperspace.index.configs.covering.IndexConfig.builder()]]
+ *
+ * @param indexName Index name.
+ * @param indexedColumns Columns from which an index is created.
+ * @param includedColumns Columns to be included in the index.
+ */
+case class IndexConfig(
+    indexName: String,
+    indexedColumns: Seq[String],
+    includedColumns: Seq[String] = Seq())
+    extends CoveringIndexConfigBase {
+  if (indexName.isEmpty || indexedColumns.isEmpty) {
+    throw new IllegalArgumentException("Empty index name or indexed columns are not allowed.")
+  }
+
+  val lowerCaseIndexedColumns: Seq[String] = toLowerCase(indexedColumns)
+  val lowerCaseIncludedColumns: Seq[String] = toLowerCase(includedColumns)
+  val lowerCaseIncludedColumnsSet: Set[String] = lowerCaseIncludedColumns.toSet
+
+  if (lowerCaseIndexedColumns.toSet.size < lowerCaseIndexedColumns.size) {
+    throw new IllegalArgumentException("Duplicate indexed column names are not allowed.")
+  }
+
+  if (lowerCaseIncludedColumnsSet.size < lowerCaseIncludedColumns.size) {
+    throw new IllegalArgumentException("Duplicate included column names are not allowed.")
+  }
+
+  for (indexedColumn <- lowerCaseIndexedColumns) {
+    if (lowerCaseIncludedColumns.contains(indexedColumn)) {
+      throw new IllegalArgumentException(
+        "Duplicate column names in indexed/included columns are not allowed.")
+    }
+  }
+
+  override def equals(that: Any): Boolean = {
+    that match {
+      case IndexConfig(thatIndexName, thatIndexedColumns, thatIncludedColumns) =>
+        indexName.equalsIgnoreCase(thatIndexName) &&
+          lowerCaseIndexedColumns.equals(toLowerCase(thatIndexedColumns)) &&
+          lowerCaseIncludedColumnsSet.equals(toLowerCase(thatIncludedColumns).toSet)
+      case _ => false
+    }
+  }
+
+  override def hashCode(): Int = {
+    lowerCaseIndexedColumns.hashCode + lowerCaseIncludedColumnsSet.hashCode
+  }
+
+  override def toString: String = {
+    val indexedColumnNames = lowerCaseIndexedColumns.mkString(", ")
+    val includedColumnNames = lowerCaseIncludedColumns.mkString(", ")
+    s"[indexName: $indexName; indexedColumns: $indexedColumnNames; " +
+      s"includedColumns: $includedColumnNames]"
+  }
+
+  private def toLowerCase(seq: Seq[String]): Seq[String] = seq.map(_.toLowerCase(Locale.ROOT))
+}
+
+case class BloomFilterIndexConfig(
+    indexName: String,
+    indexedColumn: String,
+    expectedNumItems: Long,
+    fpp: Double = -1,
+    numBits: Long = -1)
+    extends NonCoveringIndexConfigBase {
+  if (indexName.isEmpty || indexedColumn.isEmpty || expectedNumItems < 1) {
+    throw new IllegalArgumentException(
+      "Empty index name or indexed column or expected items less than 1 are not allowed.")
+  }
+
+  if (fpp != -1 && fpp < 0) {
+    throw new IllegalArgumentException("False positive probability cannot be negative.")
+  }
+
+  if (numBits != -1 && numBits < 0) {
+    throw new IllegalArgumentException("Bits given for ")
+  }
+
+  val lowerCaseIndexedColumn: String = indexedColumn.toLowerCase(Locale.ROOT)
+
+  override def equals(that: Any): Boolean = {
+    that match {
+      case BloomFilterIndexConfig(
+          thatIndexName,
+          thatIndexedColumn,
+          thatExpectedItems,
+          thatFpp,
+          thatBits) =>
+        indexName.equalsIgnoreCase(thatIndexName) &&
+          lowerCaseIndexedColumn.equals(thatIndexedColumn.toLowerCase(Locale.ROOT)) &&
+          expectedNumItems == thatExpectedItems &&
+          ((fpp == -1 && thatFpp == -1) || fpp == thatFpp) &&
+          ((numBits == -1 && thatBits == -1) || numBits == thatBits)
+      case _ => false
+    }
+  }
+
+  override def hashCode(): Int = {
+    (indexName.hashCode * (indexedColumn.hashCode + expectedNumItems
+      .hashCode())) % scala.Int.MaxValue
+  }
+
+  override def toString: String = {
+    s"[indexName: $indexName; indexedColumn: $indexedColumn; " +
+      s"ExpectedItems: $expectedNumItems; FPP: $fpp; NumBitsUsed: $numBits;]"
+  }
+}
+
+object Config {
+
+  // TODO - prints info table about all types of index supported by hyperspace
+  def printAllIndexConfigInfo(): String = {
+    s""
+  }
+}

src/main/scala/com/microsoft/hyperspace/index/ConfigBase.scala

@@ -0,0 +1,45 @@
+/*
+ * Copyright (2020) The Hyperspace Project Authors.
+ *
+ * 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 com.microsoft.hyperspace.index
+
+/**
+ * All index supported in Hyperspace whose user facing config needs to be defined needs
+ * to extend [[ConfigBase]] trait.
+ */
+sealed trait ConfigBase {
+  val indexName: String
+
+  def equals(obj: Any): Boolean
+
+  def hashCode(): Int
+
+  def toString: String
+}
+
+trait CoveringIndexConfigBase extends ConfigBase {
+  /*
+   * Columns from which index are created.
+   */
+  val indexedColumns: Seq[String]
+
+  /*
+   * Columns to be included with the indexed columns.
+   */
+  val includedColumns: Seq[String]
+}
+
+trait NonCoveringIndexConfigBase extends ConfigBase {}

src/main/scala/com/microsoft/hyperspace/index/IndexConfig.scala → src/main/scala/com/microsoft/hyperspace/index/configs/covering/IndexConfig.scala

@@ -14,67 +14,9 @@
  * limitations under the License.
  */
 
-package com.microsoft.hyperspace.index
+package com.microsoft.hyperspace.index.configs.covering
 
-import java.util.Locale
-
-/**
- * IndexConfig specifies the configuration of an index.
- *
- * @param indexName Index name.
- * @param indexedColumns Columns from which an index is created.
- * @param includedColumns Columns to be included in the index.
- */
-case class IndexConfig(
-    indexName: String,
-    indexedColumns: Seq[String],
-    includedColumns: Seq[String] = Seq()) {
-  if (indexName.isEmpty || indexedColumns.isEmpty) {
-    throw new IllegalArgumentException("Empty index name or indexed columns are not allowed.")
-  }
-
-  val lowerCaseIndexedColumns = toLowerCase(indexedColumns)
-  val lowerCaseIncludedColumns = toLowerCase(includedColumns)
-  val lowerCaseIncludedColumnsSet = lowerCaseIncludedColumns.toSet
-
-  if (lowerCaseIndexedColumns.toSet.size < lowerCaseIndexedColumns.size) {
-    throw new IllegalArgumentException("Duplicate indexed column names are not allowed.")
-  }
-
-  if (lowerCaseIncludedColumnsSet.size < lowerCaseIncludedColumns.size) {
-    throw new IllegalArgumentException("Duplicate included column names are not allowed.")
-  }
-
-  for (indexedColumn <- lowerCaseIndexedColumns) {
-    if (lowerCaseIncludedColumns.contains(indexedColumn)) {
-      throw new IllegalArgumentException(
-        "Duplicate column names in indexed/included columns are not allowed.")
-    }
-  }
-
-  override def equals(that: Any): Boolean = {
-    that match {
-      case IndexConfig(thatIndexName, thatIndexedColumns, thatIncludedColumns) =>
-        indexName.equalsIgnoreCase(thatIndexName) &&
-          lowerCaseIndexedColumns.equals(toLowerCase(thatIndexedColumns)) &&
-          lowerCaseIncludedColumnsSet.equals(toLowerCase(thatIncludedColumns).toSet)
-      case _ => false
-    }
-  }
-
-  override def hashCode(): Int = {
-    lowerCaseIndexedColumns.hashCode + lowerCaseIncludedColumnsSet.hashCode
-  }
-
-  override def toString: String = {
-    val indexedColumnNames = lowerCaseIndexedColumns.mkString(", ")
-    val includedColumnNames = lowerCaseIncludedColumns.mkString(", ")
-    s"[indexName: $indexName; indexedColumns: $indexedColumnNames; " +
-      s"includedColumns: $includedColumnNames]"
-  }
-
-  private def toLowerCase(seq: Seq[String]): Seq[String] = seq.map(_.toLowerCase(Locale.ROOT))
-}
+import com.microsoft.hyperspace.index.IndexConfig
 
 /**
  * Defines [[IndexConfig.Builder]] and relevant helper methods for enabling builder pattern for
@@ -98,7 +40,7 @@ object IndexConfig {
      * @return an [[IndexConfig.Builder]] object with updated index name.
      */
     def indexName(indexName: String): Builder = {
-      if (!this.indexName.isEmpty) {
+      if (this.indexName.nonEmpty) {
         throw new UnsupportedOperationException("Index name is already set.")
       }
 
@@ -152,8 +94,8 @@ object IndexConfig {
      *
      * @return an [[IndexConfig]] object.
      */
-    def create(): IndexConfig = {
-      IndexConfig(indexName, indexedColumns, includedColumns)
+    def build(): IndexConfig = {
+      new IndexConfig(indexName, indexedColumns, includedColumns)
     }
   }
 

src/main/scala/com/microsoft/hyperspace/index/configs/noncovering/BloomFilterIndexConfig.scala

@@ -0,0 +1,115 @@
+/*
+ * Copyright (2020) The Hyperspace Project Authors.
+ *
+ * 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 com.microsoft.hyperspace.index.configs.noncovering
+
+import com.microsoft.hyperspace.index.BloomFilterIndexConfig
+import com.microsoft.hyperspace.index.configs.covering.IndexConfig
+
+/**
+ * TODO Defines [[BloomFilterIndexConfig.Builder]] and relevant helper methods for enabling
+ *  builder pattern for [[BloomFilterIndexConfig]].
+ */
+object BloomFilterIndexConfig {
+
+  /**
+   * Builder for [[BloomFilterIndexConfig]].
+   */
+  private[index] class Builder {
+
+    private[this] var indexedColumn: String = ""
+    private[this] var indexName: String = ""
+    private[this] var fpp: Double = -1
+    private[this] var expectedItems: Long = -1
+    private[this] var numBits: Long = -1
+
+    /**
+     * Updates index name for [[IndexConfig]].
+     *
+     * @param indexName index name for the [[BloomFilterIndexConfig]].
+     * @return an [[BloomFilterIndexConfig.Builder]] object with updated index name.
+     */
+    def init(indexName: String, indexedColumn: String): Builder = {
+      if (this.indexName.nonEmpty || this.indexedColumn.nonEmpty) {
+        // TODO: Prevent creating index config if index already exists.
+        throw new UnsupportedOperationException(
+          "Bloom Filter index metadata already set can't override, " +
+            "maybe try creating a new config.")
+      }
+
+      if (indexName.isEmpty || indexedColumn.isEmpty) {
+        throw new IllegalArgumentException("Empty metadata names is not allowed.")
+      }
+
+      this.indexName = indexName
+      this.indexedColumn = indexedColumn
+      this
+    }
+
+    /**
+     *
+     * @param items
+     * @return
+     */
+    def expectedNumItems(items: Long): Builder = {
+      if (items < 1) {
+        throw new IllegalArgumentException("Can't support the items value provided.")
+      }
+
+      this.expectedItems = items
+      this
+    }
+
+    /**
+     *
+     * @param fpp
+     * @return
+     */
+    def fppToSupport(fpp: Double): Builder = {
+      if (fpp <= 0) {
+        throw new IllegalArgumentException("Can't support the fpp value.")
+      }
+
+      this.fpp = fpp
+      this
+    }
+
+    /**
+     *
+     * @param bits
+     * @return
+     */
+    def numBitsToDefineBloomFilter(bits: Long): Builder = {
+      if (bits < 1) {
+        throw new IllegalArgumentException("Can't allow bits for storage be less than 1")
+      }
+
+      this.numBits = bits
+      this
+    }
+
+    def build(): BloomFilterIndexConfig = {
+      new BloomFilterIndexConfig(indexName, indexedColumn, expectedItems, fpp, numBits)
+    }
+  }
+
+  /**
+   * Creates new [[BloomFilterIndexConfig.Builder]] for constructing an [[BloomFilterIndexConfig]].
+   *
+   * @return an [[BloomFilterIndexConfig.Builder]] object.
+   */
+  def builder(): Builder = new Builder
+}