1 files changed, 54 insertions, 0 deletions
diff --git a/packages/utils/src/abi_encoder/abstract_data_types/types/pointer.ts b/packages/utils/src/abi_encoder/abstract_data_types/types/pointer.ts
new file mode 100644
index 000000000..0f3c55280
--- /dev/null
+++ b/packages/utils/src/abi_encoder/abstract_data_types/types/pointer.ts
@@ -0,0 +1,54 @@
+import { DataItem } from 'ethereum-types';
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
+
+import { PointerCalldataBlock } from '../../calldata/blocks/pointer';
+import { CalldataBlock } from '../../calldata/calldata_block';
+import { RawCalldata } from '../../calldata/raw_calldata';
+import { constants } from '../../utils/constants';
+import { DecodingRules } from '../../utils/rules';
+
+import { DataType } from '../data_type';
+import { DataTypeFactory } from '../interfaces';
+
+export abstract class AbstractPointerDataType extends DataType {
+    protected _destination: DataType;
+    protected _parent: DataType;
+
+    public constructor(dataItem: DataItem, factory: DataTypeFactory, destination: DataType, parent: DataType) {
+        super(dataItem, factory);
+        this._destination = destination;
+        this._parent = parent;
+    }
+
+    public generateCalldataBlock(value: any, parentBlock?: CalldataBlock): PointerCalldataBlock {
+        if (_.isUndefined(parentBlock)) {
+            throw new Error(`DependentDataType requires a parent block to generate its block`);
+        }
+        const destinationBlock = this._destination.generateCalldataBlock(value, parentBlock);
+        const name = this.getDataItem().name;
+        const signature = this.getSignature();
+        const parentName = parentBlock.getName();
+        const block = new PointerCalldataBlock(name, signature, parentName, destinationBlock, parentBlock);
+        return block;
+    }
+
+    public generateValue(calldata: RawCalldata, rules: DecodingRules): any {
+        const destinationOffsetBuf = calldata.popWord();
+        const destinationOffsetHex = ethUtil.bufferToHex(destinationOffsetBuf);
+        const destinationOffsetRelative = parseInt(destinationOffsetHex, constants.HEX_BASE);
+        const destinationOffsetAbsolute = calldata.toAbsoluteOffset(destinationOffsetRelative);
+        const currentOffset = calldata.getOffset();
+        calldata.setOffset(destinationOffsetAbsolute);
+        const value = this._destination.generateValue(calldata, rules);
+        calldata.setOffset(currentOffset);
+        return value;
+    }
+
+    // Disable prefer-function-over-method for inherited abstract method.
+    /* tslint:disable prefer-function-over-method */
+    public isStatic(): boolean {
+        return true;
+    }
+    /* tslint:enable prefer-function-over-method */
+}