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author | Leonid Logvinov <logvinov.leon@gmail.com> | 2019-01-09 19:02:25 +0800 |
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committer | Leonid Logvinov <logvinov.leon@gmail.com> | 2019-01-09 19:02:25 +0800 |
commit | ea14913b412e78ff458bdfba47182f7363e776e5 (patch) | |
tree | 3ee220bfbbd9923b5e1adc36ee51f9b5d39ad640 /packages/utils/src/abi_encoder/calldata/iterator.ts | |
parent | 5868c91cfb54cfa9177572b201d88d1168bf5b06 (diff) | |
parent | 5dd55491b86bf8577405e37d0f2d668aa1273b10 (diff) | |
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Merge development
Diffstat (limited to 'packages/utils/src/abi_encoder/calldata/iterator.ts')
-rw-r--r-- | packages/utils/src/abi_encoder/calldata/iterator.ts | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/packages/utils/src/abi_encoder/calldata/iterator.ts b/packages/utils/src/abi_encoder/calldata/iterator.ts new file mode 100644 index 000000000..333b32b4f --- /dev/null +++ b/packages/utils/src/abi_encoder/calldata/iterator.ts @@ -0,0 +1,114 @@ +/* tslint:disable max-classes-per-file */ +import * as _ from 'lodash'; + +import { Queue } from '../utils/queue'; + +import { BlobCalldataBlock } from './blocks/blob'; +import { PointerCalldataBlock } from './blocks/pointer'; +import { SetCalldataBlock } from './blocks/set'; +import { CalldataBlock } from './calldata_block'; + +/** + * Iterator class for Calldata Blocks. Blocks follows the order + * they should be put into calldata that is passed to he EVM. + * + * Example #1: + * Let root = Set { + * Blob{} A, + * Pointer { + * Blob{} a + * } B, + * Blob{} C + * } + * It will iterate as follows: [A, B, C, B.a] + * + * Example #2: + * Let root = Set { + * Blob{} A, + * Pointer { + * Blob{} a + * Pointer { + * Blob{} b + * } + * } B, + * Pointer { + * Blob{} c + * } C + * } + * It will iterate as follows: [A, B, C, B.a, B.b, C.c] + */ +abstract class BaseIterator implements Iterable<CalldataBlock> { + protected readonly _root: CalldataBlock; + protected readonly _queue: Queue<CalldataBlock>; + + private static _createQueue(block: CalldataBlock): Queue<CalldataBlock> { + const queue = new Queue<CalldataBlock>(); + // Base case + if (!(block instanceof SetCalldataBlock)) { + queue.pushBack(block); + return queue; + } + // This is a set; add members + const set = block; + _.eachRight(set.getMembers(), (member: CalldataBlock) => { + queue.mergeFront(BaseIterator._createQueue(member)); + }); + // Add children + _.each(set.getMembers(), (member: CalldataBlock) => { + // Traverse child if it is a unique pointer. + // A pointer that is an alias for another pointer is ignored. + if (member instanceof PointerCalldataBlock && _.isUndefined(member.getAlias())) { + const dependency = member.getDependency(); + queue.mergeBack(BaseIterator._createQueue(dependency)); + } + }); + // Put set block at the front of the queue + queue.pushFront(set); + return queue; + } + + public constructor(root: CalldataBlock) { + this._root = root; + this._queue = BaseIterator._createQueue(root); + } + + public [Symbol.iterator](): { next: () => IteratorResult<CalldataBlock> } { + return { + next: () => { + const nextBlock = this.nextBlock(); + if (!_.isUndefined(nextBlock)) { + return { + value: nextBlock, + done: false, + }; + } + return { + done: true, + value: new BlobCalldataBlock('', '', '', new Buffer('')), + }; + }, + }; + } + + public abstract nextBlock(): CalldataBlock | undefined; +} + +export class CalldataIterator extends BaseIterator { + public constructor(root: CalldataBlock) { + super(root); + } + + public nextBlock(): CalldataBlock | undefined { + return this._queue.popFront(); + } +} + +export class ReverseCalldataIterator extends BaseIterator { + public constructor(root: CalldataBlock) { + super(root); + } + + public nextBlock(): CalldataBlock | undefined { + return this._queue.popBack(); + } +} |