Merge pull request #178 from 0xProject/feature/getLogs

Add zeroEx.getLogsAsync

3 files changed, 107 insertions, 6 deletions

diff --git a/src/contract_wrappers/contract_wrapper.ts b/src/contract_wrappers/contract_wrapper.ts
index 2a55b53d9..743dfc9b2 100644
--- a/src/contract_wrappers/contract_wrapper.ts
+++ b/src/contract_wrappers/contract_wrapper.ts
@@ -1,13 +1,52 @@
 import * as _ from 'lodash';
 import * as Web3 from 'web3';
+import * as ethUtil from 'ethereumjs-util';
 import {Web3Wrapper} from '../web3_wrapper';
-import {ZeroExError, Artifact} from '../types';
+import {AbiDecoder} from '../utils/abi_decoder';
+import {
+    InternalZeroExError,
+    Artifact,
+    LogWithDecodedArgs,
+    RawLog,
+    ContractEvents,
+    SubscriptionOpts,
+    IndexedFilterValues,
+} from '../types';
 import {utils} from '../utils/utils';
 
+const TOPIC_LENGTH = 32;
+
 export class ContractWrapper {
     protected _web3Wrapper: Web3Wrapper;
-    constructor(web3Wrapper: Web3Wrapper) {
+    private _abiDecoder?: AbiDecoder;
+    constructor(web3Wrapper: Web3Wrapper, abiDecoder?: AbiDecoder) {
         this._web3Wrapper = web3Wrapper;
+        this._abiDecoder = abiDecoder;
+    }
+    protected async _getLogsAsync(address: string, eventName: ContractEvents, subscriptionOpts: SubscriptionOpts,
+                                  indexFilterValues: IndexedFilterValues,
+                                  abi: Web3.ContractAbi): Promise<LogWithDecodedArgs[]> {
+        const eventAbi = _.find(abi, {name: eventName}) as Web3.EventAbi;
+        const eventSignature = this._getEventSignatureFromAbiByName(eventAbi, eventName);
+        const topicForEventSignature = this._web3Wrapper.keccak256(eventSignature);
+        const topicsForIndexedArgs = this._getTopicsForIndexedArgs(eventAbi, indexFilterValues);
+        const topics = [topicForEventSignature, ...topicsForIndexedArgs];
+        const filter = {
+            fromBlock: subscriptionOpts.fromBlock,
+            toBlock: subscriptionOpts.toBlock,
+            address,
+            topics,
+        };
+        const logs = await this._web3Wrapper.getLogsAsync(filter);
+        const logsWithDecodedArguments = _.map(logs, this._tryToDecodeLogOrNoop.bind(this));
+        return logsWithDecodedArguments;
+    }
+    protected _tryToDecodeLogOrNoop(log: Web3.LogEntry): LogWithDecodedArgs|RawLog {
+        if (_.isUndefined(this._abiDecoder)) {
+            throw new Error(InternalZeroExError.NoAbiDecoder);
+        }
+        const logWithDecodedArgs = this._abiDecoder.tryToDecodeLogOrNoop(log);
+        return logWithDecodedArgs;
     }
     protected async _instantiateContractIfExistsAsync<A extends Web3.ContractInstance>(artifact: Artifact,
                                                                                        addressIfExists?: string,
@@ -16,4 +55,27 @@ export class ContractWrapper {
             await this._web3Wrapper.getContractInstanceFromArtifactAsync<A>(artifact, addressIfExists);
         return contractInstance;
     }
+    protected _getEventSignatureFromAbiByName(eventAbi: Web3.EventAbi, eventName: ContractEvents): string {
+        const types = _.map(eventAbi.inputs, 'type');
+        const signature = `${eventAbi.name}(${types.join(',')})`;
+        return signature;
+    }
+    private _getTopicsForIndexedArgs(abi: Web3.EventAbi, indexFilterValues: IndexedFilterValues): Array<string|null> {
+        const topics: Array<string|null> = [];
+        for (const eventInput of abi.inputs) {
+            if (!eventInput.indexed) {
+                continue;
+            }
+            if (_.isUndefined(indexFilterValues[eventInput.name])) {
+                topics.push(null);
+            } else {
+                const value = indexFilterValues[eventInput.name] as string;
+                const buffer = ethUtil.toBuffer(value);
+                const paddedBuffer = ethUtil.setLengthLeft(buffer, TOPIC_LENGTH);
+                const topic = ethUtil.bufferToHex(paddedBuffer);
+                topics.push(topic);
+            }
+        }
+        return topics;
+    }
 }
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index d02a6e642..b3a35d5bf 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -30,6 +30,7 @@ import {
     MethodOpts,
     ValidateOrderFillableOpts,
     OrderTransactionOpts,
+    RawLog,
 } from '../types';
 import {assert} from '../utils/assert';
 import {utils} from '../utils/utils';
@@ -39,6 +40,7 @@ import {ContractWrapper} from './contract_wrapper';
 import {constants} from '../utils/constants';
 import {TokenWrapper} from './token_wrapper';
 import {decorators} from '../utils/decorators';
+import {AbiDecoder} from '../utils/abi_decoder';
 import {artifacts} from '../artifacts';
 
 const SHOULD_VALIDATE_BY_DEFAULT = true;
@@ -79,8 +81,9 @@ export class ExchangeWrapper extends ContractWrapper {
         ];
         return [orderAddresses, orderValues];
     }
-    constructor(web3Wrapper: Web3Wrapper, tokenWrapper: TokenWrapper, contractAddressIfExists?: string) {
-        super(web3Wrapper);
+    constructor(web3Wrapper: Web3Wrapper, abiDecoder: AbiDecoder,
+                tokenWrapper: TokenWrapper, contractAddressIfExists?: string) {
+        super(web3Wrapper, abiDecoder);
         this._tokenWrapper = tokenWrapper;
         this._orderValidationUtils = new OrderValidationUtils(tokenWrapper, this);
         this._exchangeLogEventEmitters = [];
@@ -656,6 +659,22 @@ export class ExchangeWrapper extends ContractWrapper {
         return eventEmitter;
     }
     /**
+     * Gets historical logs without creating a subscription
+     * @param   eventName           The exchange contract event you would like to subscribe to.
+     * @param   subscriptionOpts    Subscriptions options that let you configure the subscription.
+     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
+     *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
+     * @return  Array of logs that match the parameters
+     */
+    public async getLogsAsync(eventName: ExchangeEvents, subscriptionOpts: SubscriptionOpts,
+                              indexFilterValues: IndexedFilterValues): Promise<LogWithDecodedArgs[]> {
+        const exchangeContractAddress = await this.getContractAddressAsync();
+        const logs = await this._getLogsAsync(
+            exchangeContractAddress, eventName, subscriptionOpts, indexFilterValues, artifacts.ExchangeArtifact.abi,
+        );
+        return logs;
+    }
+    /**
      * Stops watching for all exchange events
      */
     public async stopWatchingAllEventsAsync(): Promise<void> {
diff --git a/src/contract_wrappers/token_wrapper.ts b/src/contract_wrappers/token_wrapper.ts
index f7f0a0ce3..91af223e4 100644
--- a/src/contract_wrappers/token_wrapper.ts
+++ b/src/contract_wrappers/token_wrapper.ts
@@ -7,6 +7,7 @@ import {utils} from '../utils/utils';
 import {eventUtils} from '../utils/event_utils';
 import {constants} from '../utils/constants';
 import {ContractWrapper} from './contract_wrapper';
+import {AbiDecoder} from '../utils/abi_decoder';
 import {artifacts} from '../artifacts';
 import {
     TokenContract,
@@ -18,6 +19,8 @@ import {
     ContractEventEmitter,
     ContractEventObj,
     MethodOpts,
+    LogWithDecodedArgs,
+    RawLog,
 } from '../types';
 
 const ALLOWANCE_TO_ZERO_GAS_AMOUNT = 47155;
@@ -32,8 +35,9 @@ export class TokenWrapper extends ContractWrapper {
     private _tokenContractsByAddress: {[address: string]: TokenContract};
     private _tokenLogEventEmitters: ContractEventEmitter[];
     private _tokenTransferProxyContractAddressFetcher: () => Promise<string>;
-    constructor(web3Wrapper: Web3Wrapper, tokenTransferProxyContractAddressFetcher: () => Promise<string>) {
-        super(web3Wrapper);
+    constructor(web3Wrapper: Web3Wrapper, abiDecoder: AbiDecoder,
+                tokenTransferProxyContractAddressFetcher: () => Promise<string>) {
+        super(web3Wrapper, abiDecoder);
         this._tokenContractsByAddress = {};
         this._tokenLogEventEmitters = [];
         this._tokenTransferProxyContractAddressFetcher = tokenTransferProxyContractAddressFetcher;
@@ -277,6 +281,22 @@ export class TokenWrapper extends ContractWrapper {
         return eventEmitter;
     }
     /**
+     * Gets historical logs without creating a subscription
+     * @param   tokenAddress        An address of the token that emmited the logs.
+     * @param   eventName           The token contract event you would like to subscribe to.
+     * @param   subscriptionOpts    Subscriptions options that let you configure the subscription.
+     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
+     *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
+     * @return  Array of logs that match the parameters
+     */
+    public async getLogsAsync(tokenAddress: string, eventName: TokenEvents, subscriptionOpts: SubscriptionOpts,
+                              indexFilterValues: IndexedFilterValues): Promise<LogWithDecodedArgs[]> {
+        const logs = await this._getLogsAsync(
+            tokenAddress, eventName, subscriptionOpts, indexFilterValues, artifacts.TokenArtifact.abi,
+        );
+        return logs;
+    }
+    /**
      * Stops watching for all token events
      */
     public async stopWatchingAllEventsAsync(): Promise<void> {