Merge pull request #1900 from trufflesuite/star-decode

Move from promise-based decoder that makes web3 calls to generator-based decoder that makes requests to caller

Author: haltman-at

packages/truffle-debugger/lib/data/actions/index.js

@@ -43,14 +43,6 @@ export function mapPathAndAssign(
   };
 }
 
-export const MAP_KEY_DECODING = "MAP_KEY_DECODING";
-export function mapKeyDecoding(started) {
-  return {
-    type: MAP_KEY_DECODING,
-    started
-  };
-}
-
 export const RESET = "DATA_RESET";
 export function reset() {
   return { type: RESET };

packages/truffle-debugger/lib/data/reducers.js

@@ -156,7 +156,6 @@ function assignments(state = DEFAULT_ASSIGNMENTS, action) {
 }
 
 const DEFAULT_PATHS = {
-  decodingStarted: 0,
   byAddress: {}
 };
 
@@ -166,15 +165,6 @@ const DEFAULT_PATHS = {
 //which is fine, as that's all we need it for.
 function mappedPaths(state = DEFAULT_PATHS, action) {
   switch (action.type) {
-    case actions.MAP_KEY_DECODING:
-      debug(
-        "decoding started: %d",
-        state.decodingStarted + (action.started ? 1 : -1)
-      );
-      return {
-        ...state,
-        decodingStarted: state.decodingStarted + (action.started ? 1 : -1)
-      };
     case actions.MAP_PATH_AND_ASSIGN:
       let { address, slot, typeIdentifier, parentType } = action;
       //how this case works: first, we find the spot in our table (based on

packages/truffle-debugger/lib/data/sagas/index.js

@@ -1,7 +1,7 @@
 import debugModule from "debug";
 const debug = debugModule("debugger:data:sagas");
 
-import { put, takeEvery, select, call } from "redux-saga/effects";
+import { put, takeEvery, select } from "redux-saga/effects";
 
 import { prefixName, stableKeccak256, makeAssignment } from "lib/helpers";
 
@@ -19,7 +19,8 @@ import {
   getMemoryAllocations,
   getCalldataAllocations,
   readStack,
-  storageSize
+  storageSize,
+  forEvmState
 } from "truffle-decoder";
 import BN from "bn.js";
 
@@ -42,9 +43,48 @@ function* tickSaga() {
   yield* trace.signalTickSagaCompletion();
 }
 
+export function* decode(definition, ref) {
+  let referenceDeclarations = yield select(data.views.referenceDeclarations);
+  let state = yield select(data.current.state);
+  let mappingKeys = yield select(data.views.mappingKeys);
+  let allocations = yield select(data.info.allocations);
+
+  let ZERO_WORD = new Uint8Array(DecodeUtils.EVM.WORD_SIZE);
+  ZERO_WORD.fill(0);
+
+  let decoder = forEvmState(definition, ref, {
+    referenceDeclarations,
+    state,
+    mappingKeys,
+    storageAllocations: allocations.storage,
+    memoryAllocations: allocations.memory,
+    calldataAllocations: allocations.calldata
+  });
+
+  let result = decoder.next();
+  while (!result.done) {
+    let request = result.value;
+    let response;
+    switch (request.type) {
+      //yes, this is a little silly right now
+      case "storage":
+        //the debugger supplies all storage it knows at the beginning.
+        //any storage it does not know is presumed to be zero.
+        response = ZERO_WORD;
+        break;
+      default:
+        debug("unrecognized request type!");
+    }
+    result = decoder.next(response);
+  }
+  //at this point, result.value holds the final value
+  //note: we're still using the old decoder output format, so we need to clean
+  //containers before returning something the debugger can use
+  return DecodeUtils.Conversion.cleanContainers(result.value);
+}
+
 function* variablesAndMappingsSaga() {
   let node = yield select(data.current.node);
-  let decode = yield select(data.views.decoder);
   let scopes = yield select(data.views.scopes.inlined);
   let referenceDeclarations = yield select(data.views.referenceDeclarations);
   let allocations = yield select(data.info.allocations.storage);
@@ -267,7 +307,6 @@ function* variablesAndMappingsSaga() {
       //begin subsection: key decoding
       //(I tried factoring this out into its own saga but it didn't work when I
       //did :P )
-      yield put(actions.mapKeyDecoding(true));
 
       let indexValue;
       let indexDefinition = node.indexExpression;
@@ -291,7 +330,7 @@ function* variablesAndMappingsSaga() {
           //value will go on the stack *left*-padded instead of right-padded,
           //so looking for a prior assignment will read the wrong value.
           //so instead it's preferable to use the constant directly.
-          indexValue = yield call(decode, keyDefinition, {
+          indexValue = yield* decode(keyDefinition, {
             definition: indexDefinition
           });
         } else if (indexReference) {
@@ -311,7 +350,7 @@ function* variablesAndMappingsSaga() {
           } else {
             splicedDefinition = keyDefinition;
           }
-          indexValue = yield call(decode, splicedDefinition, indexReference);
+          indexValue = yield* decode(splicedDefinition, indexReference);
         } else if (
           indexDefinition.referencedDeclaration &&
           scopes[indexDefinition.referenceDeclaration]
@@ -333,7 +372,7 @@ function* variablesAndMappingsSaga() {
             if (
               DecodeUtils.Definition.isSimpleConstant(indexConstantDefinition)
             ) {
-              indexValue = yield call(decode, keyDefinition, {
+              indexValue = yield* decode(keyDefinition, {
                 definition: indexConstantDeclaration.value
               });
             }
@@ -362,7 +401,6 @@ function* variablesAndMappingsSaga() {
         //now, as mentioned, retry in the typeConversion case
       }
 
-      yield put(actions.mapKeyDecoding(false));
       //end subsection: key decoding
 
       debug("index value %O", indexValue);

packages/truffle-debugger/lib/data/selectors/index.js

@@ -10,7 +10,6 @@ import evm from "lib/evm/selectors";
 import solidity from "lib/solidity/selectors";
 
 import * as DecodeUtils from "truffle-decode-utils";
-import { forEvmState } from "truffle-decoder";
 
 /**
  * @private
@@ -120,33 +119,6 @@ const data = createSelectorTree({
       }
     },
 
-    /**
-     * data.views.decoder
-     *
-     * selector returns (ast node definition, data reference) => Promise<value>
-     */
-    decoder: createLeaf(
-      [
-        "/views/referenceDeclarations",
-        "/current/state",
-        "/views/mappingKeys",
-        "/info/allocations"
-      ],
-
-      (referenceDeclarations, state, mappingKeys, allocations) => (
-        definition,
-        ref
-      ) =>
-        forEvmState(definition, ref, {
-          referenceDeclarations,
-          state,
-          mappingKeys,
-          storageAllocations: allocations.storage,
-          memoryAllocations: allocations.memory,
-          calldataAllocations: allocations.calldata
-        })
-    ),
-
     /*
      * data.views.userDefinedTypes
      */
@@ -717,30 +689,6 @@ const data = createSelectorTree({
               }
             )
           )
-      ),
-
-      /**
-       * data.current.identifiers.decoded
-       *
-       * Returns an object with values as Promises
-       */
-      decoded: createLeaf(
-        ["/views/decoder", "./definitions", "./refs"],
-
-        async (decode, definitions, refs) => {
-          debug("setting up keyedPromises");
-          const keyedPromises = Object.entries(refs).map(
-            async ([identifier, ref]) => ({
-              [identifier]: await decode(definitions[identifier], ref)
-            })
-          );
-          debug("set up keyedPromises");
-          const keyedResults = await Promise.all(keyedPromises);
-          debug("got keyedResults");
-          return DecodeUtils.Conversion.cleanContainers(
-            Object.assign({}, ...keyedResults)
-          );
-        }
       )
     }
   },

packages/truffle-debugger/lib/session/index.js

@@ -6,6 +6,7 @@ import configureStore from "lib/store";
 import * as controller from "lib/controller/actions";
 import * as actions from "./actions";
 import data from "lib/data/selectors";
+import { decode } from "lib/data/sagas";
 import controllerSelector from "lib/controller/selectors";
 
 import rootSaga from "./sagas";
@@ -26,7 +27,9 @@ export default class Session {
     /**
      * @private
      */
-    this._store = configureStore(reducer, rootSaga);
+    let { store, sagaMiddleware } = configureStore(reducer, rootSaga);
+    this._store = store;
+    this._sagaMiddleware = sagaMiddleware;
 
     let { contexts, sources } = Session.normalize(contracts, files);
 
@@ -145,6 +148,16 @@ export default class Session {
     return true;
   }
 
+  /**
+   * @private
+   * Allows running any saga -- for internal use only!
+   * Using this could seriously screw up the debugger state if you
+   * don't know what you're doing!
+   */
+  async _runSaga(saga, ...args) {
+    return await this._sagaMiddleware.run(saga, ...args).toPromise();
+  }
+
   async interrupt() {
     return this.dispatch(controller.interrupt());
   }
@@ -219,49 +232,29 @@ export default class Session {
     return this.dispatch(controller.removeAllBreakpoints());
   }
 
+  //deprecated -- decode is now *always* ready!
   async decodeReady() {
-    return new Promise(resolve => {
-      let haveResolved = false;
-      const unsubscribe = this._store.subscribe(() => {
-        const subscriptionDecodingStarted = this.view(data.proc.decodingKeys);
-
-        debug("following decoding started: %d", subscriptionDecodingStarted);
-
-        if (subscriptionDecodingStarted <= 0 && !haveResolved) {
-          haveResolved = true;
-          unsubscribe();
-          resolve();
-        }
-      });
-
-      const decodingStarted = this.view(data.proc.decodingKeys);
-
-      debug("initial decoding started: %d", decodingStarted);
-
-      if (decodingStarted <= 0) {
-        haveResolved = true;
-        unsubscribe();
-        resolve();
-      }
-    });
+    return true;
   }
 
   async variable(name) {
-    await this.decodeReady();
-
     const definitions = this.view(data.current.identifiers.definitions);
     const refs = this.view(data.current.identifiers.refs);
 
-    const decode = this.view(data.views.decoder);
-    return await decode(definitions[name], refs[name]);
+    return await this._runSaga(decode, definitions[name], refs[name]);
   }
 
   async variables() {
-    debug("awaiting decodeReady");
-    await this.decodeReady();
-    debug("decode now ready");
-
-    return await this.view(data.current.identifiers.decoded);
-    debug("got variables");
+    let definitions = this.view(data.current.identifiers.definitions);
+    let refs = this.view(data.current.identifiers.refs);
+    let decoded = {};
+    for (let [identifier, ref] of Object.entries(refs)) {
+      decoded[identifier] = await this._runSaga(
+        decode,
+        definitions[identifier],
+        ref
+      );
+    }
+    return decoded;
   }
 }