1 files changed, 218 insertions, 0 deletions
diff --git a/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts b/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts
new file mode 100644
index 000000000..089d04659
--- /dev/null
+++ b/packages/utils/src/abi_encoder/abstract_data_types/types/set.ts
@@ -0,0 +1,218 @@
+import { DataItem } from 'ethereum-types';
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
+
+import { BigNumber } from '../../../configured_bignumber';
+import { SetCalldataBlock } from '../../calldata/blocks/set';
+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, MemberIndexByName } from '../interfaces';
+
+import { AbstractPointerDataType } from './pointer';
+
+export abstract class AbstractSetDataType extends DataType {
+    protected readonly _arrayLength: number | undefined;
+    protected readonly _arrayElementType: string | undefined;
+    private readonly _memberIndexByName: MemberIndexByName;
+    private readonly _members: DataType[];
+    private readonly _isArray: boolean;
+
+    public constructor(
+        dataItem: DataItem,
+        factory: DataTypeFactory,
+        isArray: boolean = false,
+        arrayLength?: number,
+        arrayElementType?: string,
+    ) {
+        super(dataItem, factory);
+        this._memberIndexByName = {};
+        this._members = [];
+        this._isArray = isArray;
+        this._arrayLength = arrayLength;
+        this._arrayElementType = arrayElementType;
+        if (isArray && !_.isUndefined(arrayLength)) {
+            [this._members, this._memberIndexByName] = this._createMembersWithLength(dataItem, arrayLength);
+        } else if (!isArray) {
+            [this._members, this._memberIndexByName] = this._createMembersWithKeys(dataItem);
+        }
+    }
+
+    public generateCalldataBlock(value: any[] | object, parentBlock?: CalldataBlock): SetCalldataBlock {
+        const block =
+            value instanceof Array
+                ? this._generateCalldataBlockFromArray(value, parentBlock)
+                : this._generateCalldataBlockFromObject(value, parentBlock);
+        return block;
+    }
+
+    public generateValue(calldata: RawCalldata, rules: DecodingRules): any[] | object {
+        let members = this._members;
+        // Case 1: This is an array of undefined length, which means that `this._members` was not
+        //         populated in the constructor. So we must construct the set of members now.
+        if (this._isArray && _.isUndefined(this._arrayLength)) {
+            const arrayLengthBuf = calldata.popWord();
+            const arrayLengthHex = ethUtil.bufferToHex(arrayLengthBuf);
+            const arrayLength = new BigNumber(arrayLengthHex, constants.HEX_BASE);
+            [members] = this._createMembersWithLength(this.getDataItem(), arrayLength.toNumber());
+        }
+        // Create a new scope in the calldata, before descending into the members of this set.
+        calldata.startScope();
+        let value: any[] | object;
+        if (rules.structsAsObjects && !this._isArray) {
+            // Construct an object with values for each member of the set.
+            value = {};
+            _.each(this._memberIndexByName, (idx: number, key: string) => {
+                const member = this._members[idx];
+                const memberValue = member.generateValue(calldata, rules);
+                (value as { [key: string]: any })[key] = memberValue;
+            });
+        } else {
+            // Construct an array with values for each member of the set.
+            value = [];
+            _.each(members, (member: DataType, idx: number) => {
+                const memberValue = member.generateValue(calldata, rules);
+                (value as any[]).push(memberValue);
+            });
+        }
+        // Close this scope and return tetheh value.
+        calldata.endScope();
+        return value;
+    }
+
+    public isStatic(): boolean {
+        // An array with an undefined length is never static.
+        if (this._isArray && _.isUndefined(this._arrayLength)) {
+            return false;
+        }
+        // If any member of the set is a pointer then the set is not static.
+        const dependentMember = _.find(this._members, (member: DataType) => {
+            return member instanceof AbstractPointerDataType;
+        });
+        const isStatic = _.isUndefined(dependentMember);
+        return isStatic;
+    }
+
+    protected _generateCalldataBlockFromArray(value: any[], parentBlock?: CalldataBlock): SetCalldataBlock {
+        // Sanity check: if the set has a defined length then `value` must have the same length.
+        if (!_.isUndefined(this._arrayLength) && value.length !== this._arrayLength) {
+            throw new Error(
+                `Expected array of ${JSON.stringify(
+                    this._arrayLength,
+                )} elements, but got array of length ${JSON.stringify(value.length)}`,
+            );
+        }
+        // Create a new calldata block for this set.
+        const parentName = _.isUndefined(parentBlock) ? '' : parentBlock.getName();
+        const block = new SetCalldataBlock(this.getDataItem().name, this.getSignature(), parentName);
+        // If this set has an undefined length then set its header to be the number of elements.
+        let members = this._members;
+        if (this._isArray && _.isUndefined(this._arrayLength)) {
+            [members] = this._createMembersWithLength(this.getDataItem(), value.length);
+            const lenBuf = ethUtil.setLengthLeft(
+                ethUtil.toBuffer(`0x${value.length.toString(constants.HEX_BASE)}`),
+                constants.EVM_WORD_WIDTH_IN_BYTES,
+            );
+            block.setHeader(lenBuf);
+        }
+        // Create blocks for members of set.
+        const memberCalldataBlocks: CalldataBlock[] = [];
+        _.each(members, (member: DataType, idx: number) => {
+            const memberBlock = member.generateCalldataBlock(value[idx], block);
+            memberCalldataBlocks.push(memberBlock);
+        });
+        block.setMembers(memberCalldataBlocks);
+        return block;
+    }
+
+    protected _generateCalldataBlockFromObject(obj: object, parentBlock?: CalldataBlock): SetCalldataBlock {
+        // Create a new calldata block for this set.
+        const parentName = _.isUndefined(parentBlock) ? '' : parentBlock.getName();
+        const block = new SetCalldataBlock(this.getDataItem().name, this.getSignature(), parentName);
+        // Create blocks for members of set.
+        const memberCalldataBlocks: CalldataBlock[] = [];
+        const childMap = _.cloneDeep(this._memberIndexByName);
+        _.forOwn(obj, (value: any, key: string) => {
+            if (!(key in childMap)) {
+                throw new Error(
+                    `Could not assign tuple to object: unrecognized key '${key}' in object ${this.getDataItem().name}`,
+                );
+            }
+            const memberBlock = this._members[this._memberIndexByName[key]].generateCalldataBlock(value, block);
+            memberCalldataBlocks.push(memberBlock);
+            delete childMap[key];
+        });
+        // Sanity check that all members have been included.
+        if (Object.keys(childMap).length !== 0) {
+            throw new Error(`Could not assign tuple to object: missing keys ${Object.keys(childMap)}`);
+        }
+        // Associate member blocks with Set block.
+        block.setMembers(memberCalldataBlocks);
+        return block;
+    }
+
+    protected _computeSignatureOfMembers(): string {
+        // Compute signature of members
+        let signature = `(`;
+        _.each(this._members, (member: DataType, i: number) => {
+            signature += member.getSignature();
+            if (i < this._members.length - 1) {
+                signature += ',';
+            }
+        });
+        signature += ')';
+        return signature;
+    }
+
+    private _createMembersWithKeys(dataItem: DataItem): [DataType[], MemberIndexByName] {
+        // Sanity check
+        if (_.isUndefined(dataItem.components)) {
+            throw new Error(
+                `Tried to create a set using key/value pairs, but no components were defined by the input DataItem '${
+                    dataItem.name
+                }'.`,
+            );
+        }
+        // Create one member for each component of `dataItem`
+        const members: DataType[] = [];
+        const memberIndexByName: MemberIndexByName = {};
+        _.each(dataItem.components, (memberItem: DataItem) => {
+            const childDataItem: DataItem = {
+                type: memberItem.type,
+                name: `${dataItem.name}.${memberItem.name}`,
+            };
+            const components = memberItem.components;
+            if (!_.isUndefined(components)) {
+                childDataItem.components = components;
+            }
+            const child = this.getFactory().create(childDataItem, this);
+            memberIndexByName[memberItem.name] = members.length;
+            members.push(child);
+        });
+        return [members, memberIndexByName];
+    }
+
+    private _createMembersWithLength(dataItem: DataItem, length: number): [DataType[], MemberIndexByName] {
+        // Create `length` members, deriving the type from `dataItem`
+        const members: DataType[] = [];
+        const memberIndexByName: MemberIndexByName = {};
+        const range = _.range(length);
+        _.each(range, (idx: number) => {
+            const memberDataItem: DataItem = {
+                type: _.isUndefined(this._arrayElementType) ? '' : this._arrayElementType,
+                name: `${dataItem.name}[${idx.toString(constants.DEC_BASE)}]`,
+            };
+            const components = dataItem.components;
+            if (!_.isUndefined(components)) {
+                memberDataItem.components = components;
+            }
+            const memberType = this.getFactory().create(memberDataItem, this);
+            memberIndexByName[idx.toString(constants.DEC_BASE)] = members.length;
+            members.push(memberType);
+        });
+        return [members, memberIndexByName];
+    }
+}