Replace flattenTrie by callback

Signed-off-by: Anthony Fieroni <bvbfan@abv.bg>

Use interruption point instead of boolean condition
Signed-off-by: Anthony Fieroni <bvbfan@abv.bg>

Add ability to earlier exit in rpc methods getclaimtrie and getclaimsintrie
Signed-off-by: Anthony Fieroni <bvbfan@abv.bg>

simplified early exit handling


ran formatter

src/claimtrie.cpp

@@ -403,28 +403,6 @@ CAmount CClaimTrie::getTotalValueOfClaimsRecursive(const CClaimTrieNode* current
      return value_in_subtrie;
 }
 
-bool CClaimTrie::recursiveFlattenTrie(const std::string& name, const CClaimTrieNode* current, std::vector<namedNodeType>& nodes) const
-{
-    namedNodeType node(name, *current);
-    nodes.push_back(node);
-    for (nodeMapType::const_iterator it = current->children.begin(); it != current->children.end(); ++it)
-    {
-        std::stringstream ss;
-        ss << name << it->first;
-        if (!recursiveFlattenTrie(ss.str(), it->second, nodes))
-            return false;
-    }
-    return true;
-}
-
-std::vector<namedNodeType> CClaimTrie::flattenTrie() const
-{
-    std::vector<namedNodeType> nodes;
-    if (!recursiveFlattenTrie("", &root, nodes))
-        LogPrintf("%s: Something went wrong flattening the trie", __func__);
-    return nodes;
-}
-
 const CClaimTrieNode* CClaimTrie::getNodeForName(const std::string& name) const
 {
     const CClaimTrieNode* current = &root;
@@ -2548,25 +2526,32 @@ uint256 CClaimTrieCache::getLeafHashForProof(const std::string& currentPosition,
     }
 }
 
-void CClaimTrieCache::recursiveFlattenTrie(const std::string& name, const CClaimTrieNode* current, std::vector<namedNodeType>& nodes) const
+void CClaimTrieCache::recursiveIterateTrie(std::string& name, const CClaimTrieNode* current, CNodeCallback& callback) const
 {
-    nodes.push_back(std::make_pair(name, *current));
+    callback.visit(name, current);
+
     nodeCacheType::const_iterator cachedNode;
     for (nodeMapType::const_iterator it = current->children.begin(); it != current->children.end(); ++it) {
-        const std::string str = name + char(it->first);
-        cachedNode = cache.find(str);
+        name.push_back(it->first);
+        cachedNode = cache.find(name);
         if (cachedNode != cache.end())
-            recursiveFlattenTrie(str, cachedNode->second, nodes);
+            recursiveIterateTrie(name, cachedNode->second, callback);
         else
-            recursiveFlattenTrie(str, it->second, nodes);
+            recursiveIterateTrie(name, it->second, callback);
+        name.erase(name.end() - 1);
     }
 }
 
-std::vector<namedNodeType> CClaimTrieCache::flattenTrie() const
+bool CClaimTrieCache::iterateTrie(CNodeCallback& callback) const
 {
-    std::vector<namedNodeType> nodes;
-    recursiveFlattenTrie("", getRoot(), nodes);
-    return nodes;
+    try {
+        std::string name;
+        recursiveIterateTrie(name, getRoot(), callback);
+        assert(name.empty());
+    } catch (const CNodeCallback::CRecursionInterruptionException& ex) {
+        return ex.success;
+    }
+    return true;
 }
 
 claimsForNameType CClaimTrieCache::getClaimsForName(const std::string& name) const

src/claimtrie.h

@@ -132,8 +132,6 @@ typedef std::vector<CSupportValue> supportMapEntryType;
 
 typedef std::map<unsigned char, CClaimTrieNode*> nodeMapType;
 
-typedef std::pair<std::string, CClaimTrieNode> namedNodeType;
-
 class CClaimTrieNode
 {
 public:
@@ -317,7 +315,6 @@ public:
     bool WriteToDisk();
     bool ReadFromDisk(bool check = false);
 
-    std::vector<namedNodeType> flattenTrie() const;
     bool getInfoForName(const std::string& name, CClaimValue& claim) const;
     bool getLastTakeoverForName(const std::string& name, int& lastTakeoverHeight) const;
 
@@ -392,9 +389,6 @@ private:
     unsigned int getTotalClaimsRecursive(const CClaimTrieNode* current) const;
     CAmount getTotalValueOfClaimsRecursive(const CClaimTrieNode* current,
                                            bool fControllingOnly) const;
-    bool recursiveFlattenTrie(const std::string& name,
-                              const CClaimTrieNode* current,
-                              std::vector<namedNodeType>& nodes) const;
 
     void markNodeDirty(const std::string& name, CClaimTrieNode* node);
     void updateQueueRow(int nHeight, claimQueueRowType& row);
@@ -459,6 +453,27 @@ public:
     int nHeightOfLastTakeover;
 };
 
+struct CNodeCallback {
+    struct CRecursionInterruptionException : public std::exception {
+        const bool success;
+        explicit CRecursionInterruptionException(bool success) : success(success) {}
+    };
+
+    virtual ~CNodeCallback()
+    {
+    }
+
+    /**
+     * Callback to be called on every trie node
+     * @param[in] name      full name of the node
+     * @param[in] node      pointer to node itself
+     *
+     * To breakout early throw an exception.
+     * Throwing CRecursionInterruptionException will allow you to set the return value of iterateTrie.
+     */
+    virtual void visit(const std::string& name, const CClaimTrieNode* node) = 0;
+};
+
 class CClaimTrieCache
 {
 public:
@@ -533,7 +548,7 @@ public:
 
     bool forkForExpirationChange(bool increment) const;
 
-    std::vector<namedNodeType> flattenTrie() const;
+    bool iterateTrie(CNodeCallback& callback) const;
 
     claimsForNameType getClaimsForName(const std::string& name) const;
 
@@ -635,7 +650,7 @@ protected:
 
     int getNumBlocksOfContinuousOwnership(const std::string& name) const;
 
-    void recursiveFlattenTrie(const std::string& name, const CClaimTrieNode* current, std::vector<namedNodeType>& nodes) const;
+    void recursiveIterateTrie(std::string& name, const CClaimTrieNode* current, CNodeCallback& callback) const;
 
     const CClaimTrieNode* getNodeForName(const std::string& name) const;
 };

src/rpc/claimtrie.cpp

@@ -112,44 +112,65 @@ UniValue getclaimsintrie(const UniValue& params, bool fHelp)
         RollBackTo(blockIndex, coinsCache, trieCache);
     }
 
-    UniValue ret(UniValue::VARR);
-    std::vector<namedNodeType> nodes = trieCache.flattenTrie();
-    for (std::vector<namedNodeType>::iterator it = nodes.begin(); it != nodes.end(); ++it) {
-        if (it->second.claims.empty()) continue;
-
-        UniValue claims(UniValue::VARR);
-        for (std::vector<CClaimValue>::iterator itClaims = it->second.claims.begin(); itClaims != it->second.claims.end(); ++itClaims) {
-            UniValue claim(UniValue::VOBJ);
-            claim.push_back(Pair("claimId", itClaims->claimId.GetHex()));
-            claim.push_back(Pair("txid", itClaims->outPoint.hash.GetHex()));
-            claim.push_back(Pair("n", (int)itClaims->outPoint.n));
-            claim.push_back(Pair("amount", ValueFromAmount(itClaims->nAmount)));
-            claim.push_back(Pair("height", itClaims->nHeight));
-            const CCoins* coin = coinsCache.AccessCoins(itClaims->outPoint.hash);
-            if (!coin) {
-                LogPrintf("%s: %s does not exist in the coins view, despite being associated with a name\n",
-                    __func__, itClaims->outPoint.hash.GetHex());
-                claim.push_back(Pair("error", "No value found for claim"));
-            } else if (!coin->IsAvailable(itClaims->outPoint.n)) {
-                LogPrintf("%s: the specified txout of %s appears to have been spent\n", __func__, itClaims->outPoint.hash.GetHex());
-                claim.push_back(Pair("error", "Txout spent"));
-            } else {
-                int op;
-                std::vector<std::vector<unsigned char> > vvchParams;
-                if (!DecodeClaimScript(coin->vout[itClaims->outPoint.n].scriptPubKey, op, vvchParams)) {
-                    LogPrintf("%s: the specified txout of %s does not have an claim command\n", __func__, itClaims->outPoint.hash.GetHex());
+    class CClaimsCallback : public CNodeCallback
+    {
+    public:
+        CClaimsCallback(UniValue& ret, const CCoinsViewCache& coinsCache) : nodes(ret), coinsCache(coinsCache)
+        {
+        }
+
+        void visit(const std::string& name, const CClaimTrieNode* node)
+        {
+            if (ShutdownRequested())
+                throw JSONRPCError(RPC_INTERNAL_ERROR, "Shutdown requested");
+
+            boost::this_thread::interruption_point();
+
+            if (node->claims.empty())
+                return;
+
+            UniValue claims(UniValue::VARR);
+            for (std::vector<CClaimValue>::const_iterator itClaims = node->claims.begin(); itClaims != node->claims.end(); ++itClaims) {
+                UniValue claim(UniValue::VOBJ);
+                claim.push_back(Pair("claimId", itClaims->claimId.GetHex()));
+                claim.push_back(Pair("txid", itClaims->outPoint.hash.GetHex()));
+                claim.push_back(Pair("n", (int)itClaims->outPoint.n));
+                claim.push_back(Pair("amount", ::ValueFromAmount(itClaims->nAmount)));
+                claim.push_back(Pair("height", itClaims->nHeight));
+                const CCoins* coin = coinsCache.AccessCoins(itClaims->outPoint.hash);
+                if (!coin) {
+                    LogPrintf("%s: %s does not exist in the coins view, despite being associated with a name\n",
+                        __func__, itClaims->outPoint.hash.GetHex());
+                    claim.push_back(Pair("error", "No value found for claim"));
+                } else if (!coin->IsAvailable(itClaims->outPoint.n)) {
+                    LogPrintf("%s: the specified txout of %s appears to have been spent\n", __func__, itClaims->outPoint.hash.GetHex());
+                    claim.push_back(Pair("error", "Txout spent"));
+                } else {
+                    int op;
+                    std::vector<std::vector<unsigned char> > vvchParams;
+                    if (!DecodeClaimScript(coin->vout[itClaims->outPoint.n].scriptPubKey, op, vvchParams)) {
+                        LogPrintf("%s: the specified txout of %s does not have an claim command\n", __func__, itClaims->outPoint.hash.GetHex());
+                    }
+                    std::string sValue(vvchParams[1].begin(), vvchParams[1].end());
+                    claim.push_back(Pair("value", sValue));
                 }
-                std::string sValue(vvchParams[1].begin(), vvchParams[1].end());
-                claim.push_back(Pair("value", sValue));
+                claims.push_back(claim);
             }
-            claims.push_back(claim);
+
+            UniValue nodeObj(UniValue::VOBJ);
+            nodeObj.push_back(Pair("name", name));
+            nodeObj.push_back(Pair("claims", claims));
+            nodes.push_back(nodeObj);
         }
 
-        UniValue node(UniValue::VOBJ);
-        node.push_back(Pair("name", it->first));
-        node.push_back(Pair("claims", claims));
-        ret.push_back(node);
-    }
+    private:
+        UniValue& nodes;
+        const CCoinsViewCache& coinsCache;
+    };
+
+    UniValue ret(UniValue::VARR);
+    CClaimsCallback claimsCallback(ret, coinsCache);
+    trieCache.iterateTrie(claimsCallback);
     return ret;
 }
 
@@ -188,23 +209,40 @@ UniValue getclaimtrie(const UniValue& params, bool fHelp)
         RollBackTo(blockIndex, coinsCache, trieCache);
     }
 
-    UniValue ret(UniValue::VARR);
-    std::vector<namedNodeType> nodes = trieCache.flattenTrie();
-    for (std::vector<namedNodeType>::iterator it = nodes.begin(); it != nodes.end(); ++it)
+    class CClaimCallback : public CNodeCallback
     {
-        UniValue node(UniValue::VOBJ);
-        node.push_back(Pair("name", it->first));
-        node.push_back(Pair("hash", it->second.hash.GetHex()));
-        CClaimValue claim;
-        if (it->second.getBestClaim(claim))
+    public:
+        CClaimCallback(UniValue& ret) : nodes(ret)
         {
-            node.push_back(Pair("txid", claim.outPoint.hash.GetHex()));
-            node.push_back(Pair("n", (int)claim.outPoint.n));
-            node.push_back(Pair("value", ValueFromAmount(claim.nAmount)));
-            node.push_back(Pair("height", claim.nHeight));
         }
-        ret.push_back(node);
-    }
+
+        void visit(const std::string& name, const CClaimTrieNode* node)
+        {
+            if (ShutdownRequested())
+                throw JSONRPCError(RPC_INTERNAL_ERROR, "Shutdown requested");
+
+            boost::this_thread::interruption_point();
+
+            UniValue nodeObj(UniValue::VOBJ);
+            nodeObj.push_back(Pair("name", name));
+            nodeObj.push_back(Pair("hash", node->hash.GetHex()));
+            CClaimValue claim;
+            if (node->getBestClaim(claim)) {
+                nodeObj.push_back(Pair("txid", claim.outPoint.hash.GetHex()));
+                nodeObj.push_back(Pair("n", (int)claim.outPoint.n));
+                nodeObj.push_back(Pair("value", ::ValueFromAmount(claim.nAmount)));
+                nodeObj.push_back(Pair("height", claim.nHeight));
+            }
+            nodes.push_back(nodeObj);
+        }
+
+    private:
+        UniValue& nodes;
+    };
+
+    UniValue ret(UniValue::VARR);
+    CClaimCallback claimCallback(ret);
+    trieCache.iterateTrie(claimCallback);
     return ret;
 }
 

src/test/claimtriecache_tests.cpp

@@ -274,5 +274,58 @@ BOOST_AUTO_TEST_CASE(recursive_prune_test)
     BOOST_CHECK_EQUAL(0, it->second->children.size());
 }
 
+BOOST_AUTO_TEST_CASE(iteratetrie_test)
+{
+    BOOST_CHECK(pclaimTrie->empty());
+    CClaimTrieCacheTest ctc(pclaimTrie);
+
+    uint256 hash0(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
+    CMutableTransaction tx1 = BuildTransaction(hash0);
+
+    const uint256 txhash = tx1.GetHash();
+    CClaimValue claimVal(COutPoint(txhash, 0), ClaimIdHash(txhash, 0), CAmount(10), 0, 0);
+    ctc.insertClaimIntoTrie("test", claimVal);
+
+
+    int count = 0;
+
+    struct TestCallBack : public CNodeCallback {
+        TestCallBack(int& count) : count(count)
+        {
+        }
+
+        void visit(const std::string& name, const CClaimTrieNode* node)
+        {
+            count++;
+            if (name == "test") {
+                BOOST_CHECK(node->claims.size() == 1);
+            }
+        }
+
+        int& count;
+    } testCallback(count);
+
+    BOOST_CHECK(ctc.iterateTrie(testCallback));
+    BOOST_CHECK(count == 5);
+
+    count = 3;
+
+    struct TestCallBack2 : public CNodeCallback {
+        TestCallBack2(int& count) : count(count)
+        {
+        }
+
+        void visit(const std::string& name, const CClaimTrieNode* node)
+        {
+            if (--count <= 0)
+                throw CRecursionInterruptionException(false);
+        }
+
+        int& count;
+    } testCallback2(count);
+
+    BOOST_CHECK(!ctc.iterateTrie(testCallback2));
+    BOOST_CHECK(count == 0);
+}
 
 BOOST_AUTO_TEST_SUITE_END()