Defines Path and Session

partiql-planner/src/main/kotlin/org/partiql/planner/PartiQLPlanner.kt

@@ -4,8 +4,7 @@ import org.partiql.ast.Statement
 import org.partiql.errors.Problem
 import org.partiql.errors.ProblemCallback
 import org.partiql.plan.PartiQLPlan
-import org.partiql.spi.connector.ConnectorMetadata
-import java.time.Instant
+import org.partiql.planner.catalog.Session
 
 /**
  * PartiQLPlanner is responsible for transforming an AST into PartiQL's logical query plan.
@@ -32,24 +31,6 @@ public interface PartiQLPlanner {
         public val problems: List<Problem>,
     )
 
-    /**
-     * From [org.partiql.lang.planner.transforms]
-     *
-     * @property queryId
-     * @property userId
-     * @property currentCatalog
-     * @property currentDirectory
-     * @property catalogs
-     * @property instant
-     */
-    public class Session(
-        public val queryId: String,
-        public val userId: String,
-        public val currentCatalog: String,
-        public val currentDirectory: List<String> = emptyList(),
-        public val catalogs: Map<String, ConnectorMetadata> = emptyMap(),
-        public val instant: Instant = Instant.now(),
-    )
     public companion object {
 
         @JvmStatic

partiql-planner/src/main/kotlin/org/partiql/planner/catalog/Catalog.kt

@@ -25,7 +25,7 @@ public interface Catalog {
     /**
      * List top-level tables.
      */
-    public fun listTables(): Collection<Name> = listTables(Namespace.empty())
+    public fun listTables(): Collection<Name> = listTables(Namespace.root())
 
     /**
      * List all tables under this namespace.
@@ -37,7 +37,7 @@ public interface Catalog {
     /**
      * List top-level namespaces from the catalog.
      */
-    public fun listNamespaces(): Collection<Namespace> = listNamespaces(Namespace.empty())
+    public fun listNamespaces(): Collection<Namespace> = listNamespaces(Namespace.root())
 
     /**
      * List all child namespaces from the namespace.

partiql-planner/src/main/kotlin/org/partiql/planner/catalog/Namespace.kt

@@ -63,22 +63,22 @@ public class Namespace private constructor(
 
     public companion object {
 
-        private val EMPTY = Namespace(emptyArray())
+        private val ROOT = Namespace(emptyArray())
 
-        public fun empty(): Namespace = EMPTY
+        public fun root(): Namespace = ROOT
 
         @JvmStatic
         public fun of(vararg levels: String): Namespace {
             if (levels.isEmpty()) {
-                return empty()
+                return root()
             }
             return Namespace(arrayOf(*levels))
         }
 
         @JvmStatic
         public fun of(levels: Collection<String>): Namespace {
             if (levels.isEmpty()) {
-                return empty()
+                return root()
             }
             return Namespace(levels.toTypedArray())
         }

partiql-planner/src/main/kotlin/org/partiql/planner/catalog/Path.kt

@@ -0,0 +1,44 @@
+package org.partiql.planner.catalog
+
+import java.util.Spliterator
+import java.util.function.Consumer
+
+/**
+ * The routine resolution path, accessible via PATH.
+ */
+public class Path private constructor(
+    private val namespaces: List<Namespace>,
+) : Iterable<Namespace> {
+
+    public companion object {
+
+        @JvmStatic
+        public fun of(vararg namespaces: Namespace): Path = Path(namespaces.toList())
+    }
+
+    public fun getLength(): Int {
+        return namespaces.size
+    }
+
+    public fun isEmpty(): Boolean {
+        return namespaces.isEmpty()
+    }
+
+    public operator fun get(index: Int): Namespace {
+        return namespaces[index]
+    }
+
+    override fun forEach(action: Consumer<in Namespace>?) {
+        namespaces.forEach(action)
+    }
+
+    override fun iterator(): Iterator<Namespace> {
+        return namespaces.iterator()
+    }
+
+    override fun spliterator(): Spliterator<Namespace> {
+        return namespaces.spliterator()
+    }
+
+    override fun toString(): String = "PATH: (${namespaces.joinToString()})"
+}

partiql-planner/src/main/kotlin/org/partiql/planner/catalog/Session.kt

@@ -0,0 +1,64 @@
+package org.partiql.planner.catalog
+
+/**
+ * Session is used for authorization and name resolution.
+ */
+public interface Session {
+
+    public companion object {
+
+        private val EMPTY = object : Session {
+            override fun getIdentity(): String = "unknown"
+            override fun getNamespace(): Namespace = Namespace.root()
+        }
+
+        @JvmStatic
+        public fun empty(): Session = EMPTY
+
+        @JvmStatic
+        public fun builder(): Builder = Builder()
+    }
+
+    /**
+     * Returns the caller identity as a string; accessible via CURRENT_USER.
+     */
+    public fun getIdentity(): String
+
+    /**
+     * Returns the current [Namespace]; accessible via the NAMESPACE session variable.
+     */
+    public fun getNamespace(): Namespace
+
+    /**
+     * Returns the current [Path]; accessible via the PATH and CURRENT_PATH session variables.
+     *
+     * Default implementation returns the current namespace.
+     */
+    public fun getPath(): Path = Path.of(getNamespace())
+
+    /**
+     * Arbitrary session properties that may be used in planning or custom plan passes.
+     */
+    public fun getProperties(): Map<String, String> = emptyMap()
+
+    /**
+     * Java-style session builder.
+     */
+    public class Builder {
+
+        private var identity: String = "unknown"
+        private var namespace: Namespace = Namespace.root()
+        private var properties: MutableMap<String, String> = mutableMapOf()
+
+        public fun identity(identity: String): Builder = this.apply { this.identity = identity }
+
+        public fun namespace(namespace: Namespace): Builder = this.apply { this.namespace = namespace }
+
+        public fun property(name: String, value: String): Builder = this.apply { this.properties[name] = value }
+
+        public fun build(): Session = object : Session {
+            override fun getIdentity(): String = identity
+            override fun getNamespace(): Namespace = namespace
+        }
+    }
+}