storageResolver

src/storage/storageResolver.js

@@ -0,0 +1,161 @@
+'use strict'
+var traceHelper = require('../helpers/traceHelper')
+var helper = require('../helpers/util')
+var util = require('../helpers/global')
+
+class StorageResolver {
+  constructor (_debugger, _traceManager) {
+    this.debugger = _debugger
+    this.traceManager = _traceManager
+    this.clear()
+    _debugger.event.register('newTraceLoaded', () => {
+      this.clear()
+    })
+  }
+
+  /**
+    * return the storage for the current context (address and vm trace index)
+    * by default now returns the range 0 => 1000
+    *
+    * @param {Function} - callback - contains a map: [hashedKey] = {key, hashedKey, value}
+    */
+  storageRange (callback) {
+    storageRangeInternal(this, '0x0', 1000, callback)
+  }
+
+  /**
+    * return a slot value for the current context (address and vm trace index)
+    *
+    * @param {Function} - callback - {key, hashedKey, value} -
+    */
+  storageSlot (slot, callback) {
+    storageRangeInternal(this, slot, 100, function (error, storage) {
+      if (error) {
+        callback(error)
+      } else {
+        var hashed = helper.sha3(slot)
+        callback(null, storage[hashed] !== undefined ? storage[hashed] : null)
+      }
+    })
+  }
+
+  /**
+    * return True if the storage at @arg address is complete
+    *
+    * @param {String} address  - contract address
+    * @return {Bool} - return True if the storage at @arg address is complete
+    */
+  isComplete (address) {
+    return this.storageByAddress[address] && this.storageByAddress[address].complete
+  }
+
+  /**
+    * retrieve the storage from the cache. if @arg slot is defined, return only the desired slot, if not return the entire known storage
+    *
+    * @param {String} address  - contract address
+    * @param {String} slotKey  - key of the value to return
+    * @return {String} - either the entire known storage or a single value
+    */
+  fromCache (address, slotKey) {
+    if (!this.storageByAddress[address]) {
+      return null
+    }
+    return slotKey ? this.storageByAddress[address].storage[slotKey] : this.storageByAddress[address].storage
+  }
+
+  /**
+    * store the result of `storageRangeAtInternal`
+    *
+    * @param {String} address  - contract address
+    * @param {Object} storage  - result of `storageRangeAtInternal`, contains {key, hashedKey, value}
+    * @param {Bool} complete  - True if the storage is complete
+    */
+  toCache (address, storage, complete) {
+    if (!this.storageByAddress[address]) {
+      this.storageByAddress[address] = {}
+    }
+    this.storageByAddress[address].storage = Object.assign(this.storageByAddress[address].storage || {}, storage)
+    if (complete !== undefined) {
+      this.storageByAddress[address].complete = complete
+    }
+  }
+
+  /**
+    * clear the cache
+    *
+    */
+  clear () {
+    this.storageByAddress = {}
+  }
+
+  /**
+    * resolve the storage to the specified execution step @arg index. uses the traceManager.resolveStorage
+    *
+    * @param {Int} index  - execution step index
+    * @param {String} address  - contract address
+    * @param {Map} storage  - Map of the known storage
+    * @return {Map} - The storage resolved to the given exection point
+    */
+  resolveStorage (address, storage, callback) {
+    this.traceManager.resolveStorage(this.debugger.currentStepIndex, address, storage, callback)
+  }
+}
+
+function resolveAddress (self, callback) {
+  self.traceManager.getCurrentCalledAddressAt(self.debugger.currentStepIndex, (error, result) => {
+    if (error) {
+      callback(error)
+    } else {
+      callback(null, result)
+    }
+  })
+}
+
+function storageRangeAtInternal (tx, address, start, maxSize, callback) {
+  util.web3.debug.storageRangeAt(
+    tx.blockHash, tx.transactionIndex === undefined ? tx.hash : tx.transactionIndex,
+    address,
+    start,
+    maxSize,
+    (error, result) => {
+      if (error) {
+        callback(error)
+      } else if (result.storage) {
+        callback(null, result.storage, result.complete)
+      } else {
+        callback('the storage has not been provided')
+      }
+    })
+}
+
+function storageRangeInternal (self, start, maxSize, callback) {
+  resolveAddress(self, (error, address) => {
+    if (error) {
+      callback(error)
+    } else {
+      if (traceHelper.isContractCreation(address)) {
+        callback(null, {})
+      } else {
+        if (!util.web3.debug.storageRangeAt) {
+          callback('no storageRangeAt endpoint found')
+        } else {
+          if (self.isComplete(address)) {
+            var cached = self.fromCache(address)
+            self.resolveStorage(address, cached, callback)
+          } else {
+            storageRangeAtInternal(self.debugger.tx, address, start, maxSize, (error, storage, complete) => {
+              if (error) {
+                callback(error)
+              } else {
+                self.toCache(address, storage, complete)
+                self.resolveStorage(address, storage, callback)
+              }
+            })
+          }
+        }
+      }
+    }
+  })
+}
+
+module.exports = StorageResolver