Clean up memory connector data structures

Introduce TableId to represent the identity of a table
and separate it from the associated metadata, which is
now stored in TableInfo/ColumnInfo.

MemoryTableHandle is now use only in the interface between
engine and connector and is meant to represent the reference
to the entity over which the query will execute. Once we
add support for various types of pushdown, that information
will be encoded in the handle.

presto-memory/src/main/java/io/prestosql/plugin/memory/MemoryConnectorId.java → presto-memory/src/main/java/io/prestosql/plugin/memory/ColumnInfo.java

@@ -13,42 +13,43 @@
  */
 package io.prestosql.plugin.memory;
 
-import java.util.Objects;
+import io.prestosql.spi.connector.ColumnHandle;
+import io.prestosql.spi.connector.ColumnMetadata;
+import io.prestosql.spi.type.Type;
 
 import static java.util.Objects.requireNonNull;
 
-public final class MemoryConnectorId
+public class ColumnInfo
 {
-    private final String id;
+    private final ColumnHandle handle;
+    private final String name;
+    private final Type type;
 
-    public MemoryConnectorId(String id)
+    public ColumnInfo(ColumnHandle handle, String name, Type type)
     {
-        this.id = requireNonNull(id, "id is null");
+        this.handle = requireNonNull(handle, "handle is null");
+        this.name = requireNonNull(name, "name is null");
+        this.type = requireNonNull(type, "type is null");
     }
 
-    @Override
-    public String toString()
+    public ColumnHandle getHandle()
     {
-        return id;
+        return handle;
     }
 
-    @Override
-    public int hashCode()
+    public String getName()
     {
-        return Objects.hash(id);
+        return name;
+    }
+
+    public ColumnMetadata getMetadata()
+    {
+        return new ColumnMetadata(name, type);
     }
 
     @Override
-    public boolean equals(Object obj)
+    public String toString()
     {
-        if (this == obj) {
-            return true;
-        }
-        if ((obj == null) || (getClass() != obj.getClass())) {
-            return false;
-        }
-
-        MemoryConnectorId other = (MemoryConnectorId) obj;
-        return Objects.equals(this.id, other.id);
+        return name + "::" + type;
     }
 }

presto-memory/src/main/java/io/prestosql/plugin/memory/MemoryColumnHandle.java

@@ -15,67 +15,31 @@
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.google.common.collect.ImmutableList;
 import io.prestosql.spi.connector.ColumnHandle;
-import io.prestosql.spi.connector.ColumnMetadata;
-import io.prestosql.spi.type.Type;
 
-import java.util.List;
 import java.util.Objects;
 
-import static com.google.common.base.MoreObjects.toStringHelper;
-import static java.util.Objects.requireNonNull;
-
 public final class MemoryColumnHandle
         implements ColumnHandle
 {
-    private final String name;
-    private final Type columnType;
     private final int columnIndex;
 
-    public MemoryColumnHandle(ColumnMetadata columnMetadata, int columnIndex)
-    {
-        this(columnMetadata.getName(), columnMetadata.getType(), columnIndex);
-    }
-
     @JsonCreator
-    public MemoryColumnHandle(
-            @JsonProperty("name") String name,
-            @JsonProperty("columnType") Type columnType,
-            @JsonProperty("columnIndex") int columnIndex)
+    public MemoryColumnHandle(@JsonProperty("columnIndex") int columnIndex)
     {
-        this.name = requireNonNull(name, "name is null");
-        this.columnType = requireNonNull(columnType, "columnType is null");
         this.columnIndex = columnIndex;
     }
 
-    @JsonProperty
-    public String getName()
-    {
-        return name;
-    }
-
-    @JsonProperty
-    public Type getColumnType()
-    {
-        return columnType;
-    }
-
     @JsonProperty
     public int getColumnIndex()
     {
         return columnIndex;
     }
 
-    public ColumnMetadata toColumnMetadata()
-    {
-        return new ColumnMetadata(name, columnType);
-    }
-
     @Override
     public int hashCode()
     {
-        return Objects.hash(name, columnType);
+        return Objects.hash(columnIndex);
     }
 
     @Override
@@ -88,29 +52,12 @@ public boolean equals(Object obj)
             return false;
         }
         MemoryColumnHandle other = (MemoryColumnHandle) obj;
-        return Objects.equals(this.name, other.name) &&
-                Objects.equals(this.columnType, other.columnType) &&
-                Objects.equals(this.columnIndex, other.columnIndex);
-    }
-
-    public static List<MemoryColumnHandle> extractColumnHandles(List<ColumnMetadata> columns)
-    {
-        ImmutableList.Builder<MemoryColumnHandle> columnHandles = ImmutableList.builder();
-        int columnIndex = 0;
-        for (ColumnMetadata column : columns) {
-            columnHandles.add(new MemoryColumnHandle(column, columnIndex));
-            columnIndex++;
-        }
-        return columnHandles.build();
+        return Objects.equals(this.columnIndex, other.columnIndex);
     }
 
     @Override
     public String toString()
     {
-        return toStringHelper(this)
-                .add("name", name)
-                .add("columnType", columnType)
-                .add("columnIndex", columnIndex)
-                .toString();
+        return Integer.toString(columnIndex);
     }
 }

presto-memory/src/main/java/io/prestosql/plugin/memory/MemoryConnectorFactory.java

@@ -49,7 +49,7 @@ public Connector create(String catalogName, Map<String, String> requiredConfig,
             // A plugin is not required to use Guice; it is just very convenient
             Bootstrap app = new Bootstrap(
                     new JsonModule(),
-                    new MemoryModule(catalogName, context.getTypeManager(), context.getNodeManager()));
+                    new MemoryModule(context.getTypeManager(), context.getNodeManager()));
 
             Injector injector = app
                     .strictConfig()

presto-memory/src/main/java/io/prestosql/plugin/memory/MemoryInsertTableHandle.java

@@ -25,20 +25,20 @@
 public class MemoryInsertTableHandle
         implements ConnectorInsertTableHandle
 {
-    private final MemoryTableHandle table;
+    private final long table;
     private final Set<Long> activeTableIds;
 
     @JsonCreator
     public MemoryInsertTableHandle(
-            @JsonProperty("table") MemoryTableHandle table,
+            @JsonProperty("table") long table,
             @JsonProperty("activeTableIds") Set<Long> activeTableIds)
     {
         this.table = requireNonNull(table, "table is null");
         this.activeTableIds = requireNonNull(activeTableIds, "activeTableIds is null");
     }
 
     @JsonProperty
-    public MemoryTableHandle getTable()
+    public long getTable()
     {
         return table;
     }