Fix data race and leak

src/Coordination/KeeperSnapshotManager.cpp

@@ -82,7 +82,7 @@ namespace
         writeBinary(node.czxid, out);
         writeBinary(node.mzxid, out);
         writeBinary(node.ctime(), out);
-        writeBinary(node.mtime(), out);
+        writeBinary(node.mtime, out);
         writeBinary(node.version, out);
         writeBinary(node.cversion, out);
         writeBinary(node.aversion, out);
@@ -143,9 +143,7 @@ namespace
         int64_t ctime;
         readBinary(ctime, in);
         node.setCtime(ctime);
-        int64_t mtime;
-        readBinary(mtime, in);
-        node.setMtime(mtime);
+        readBinary(node.mtime, in);
         readBinary(node.version, in);
         readBinary(node.cversion, in);
         readBinary(node.aversion, in);

src/Coordination/KeeperStorage.cpp

@@ -175,13 +175,13 @@ uint64_t calculateDigest(std::string_view path, const KeeperStorage::Node & node
     if (node.data_size != 0)
     {
         chassert(node.data != nullptr);
-        hash.update(node.data, node.data_size);
+        hash.update(node.getData());
     }
 
     hash.update(node.czxid);
     hash.update(node.mzxid);
     hash.update(node.ctime());
-    hash.update(node.mtime());
+    hash.update(node.mtime);
     hash.update(node.version);
     hash.update(node.cversion);
     hash.update(node.aversion);
@@ -189,17 +189,17 @@ uint64_t calculateDigest(std::string_view path, const KeeperStorage::Node & node
     hash.update(node.numChildren());
     hash.update(node.pzxid);
 
+    auto digest = hash.get64();
+
+    /// 0 means no cached digest
+    if (digest == 0)
+        return 1;
+
     return hash.get64();
 }
 
 }
 
-KeeperStorage::Node::~Node()
-{
-    if (data_size)
-        delete[] data;
-}
-
 KeeperStorage::Node & KeeperStorage::Node::operator=(const Node & other)
 {
     if (this == &other)
@@ -209,8 +209,8 @@ KeeperStorage::Node & KeeperStorage::Node::operator=(const Node & other)
     mzxid = other.mzxid;
     pzxid = other.pzxid;
     acl_id = other.acl_id;
-    has_cached_digest_and_ctime = other.has_cached_digest_and_ctime;
-    is_ephemeral_and_mtime = other.is_ephemeral_and_mtime;
+    mtime = other.mtime;
+    is_ephemeral_and_ctime = other.is_ephemeral_and_ctime;
     ephemeral_or_children_data = other.ephemeral_or_children_data;
     data_size = other.data_size;
     version = other.version;
@@ -219,8 +219,8 @@ KeeperStorage::Node & KeeperStorage::Node::operator=(const Node & other)
 
     if (data_size != 0)
     {
-        data = new char[data_size];
-        memcpy(data, other.data, data_size);
+        data = std::unique_ptr<char[]>(new char[data_size]);
+        memcpy(data.get(), other.data.get(), data_size);
     }
 
     children = other.children;
@@ -244,8 +244,8 @@ void KeeperStorage::Node::copyStats(const Coordination::Stat & stat)
     mzxid = stat.mzxid;
     pzxid = stat.pzxid;
 
+    mtime = stat.mtime;
     setCtime(stat.ctime);
-    setMtime(stat.mtime);
 
     version = stat.version;
     cversion = stat.cversion;
@@ -253,7 +253,7 @@ void KeeperStorage::Node::copyStats(const Coordination::Stat & stat)
 
     if (stat.ephemeralOwner == 0)
     {
-        is_ephemeral_and_mtime.is_ephemeral = false;
+        is_ephemeral_and_ctime.is_ephemeral = false;
         setNumChildren(stat.numChildren);
     }
     else
@@ -267,7 +267,7 @@ void KeeperStorage::Node::setResponseStat(Coordination::Stat & response_stat) co
     response_stat.czxid = czxid;
     response_stat.mzxid = mzxid;
     response_stat.ctime = ctime();
-    response_stat.mtime = mtime();
+    response_stat.mtime = mtime;
     response_stat.version = version;
     response_stat.cversion = cversion;
     response_stat.aversion = aversion;
@@ -288,8 +288,8 @@ void KeeperStorage::Node::setData(const String & new_data)
     data_size = static_cast<uint32_t>(new_data.size());
     if (data_size != 0)
     {
-        data = new char[new_data.size()];
-        memcpy(data, new_data.data(), data_size);
+        data = std::unique_ptr<char[]>(new char[new_data.size()]);
+        memcpy(data.get(), new_data.data(), data_size);
     }
 }
 
@@ -305,16 +305,13 @@ void KeeperStorage::Node::removeChild(StringRef child_path)
 
 void KeeperStorage::Node::invalidateDigestCache() const
 {
-    has_cached_digest_and_ctime.has_cached_digest = false;
+    cached_digest = 0;
 }
 
 UInt64 KeeperStorage::Node::getDigest(const std::string_view path) const
 {
-    if (!has_cached_digest_and_ctime.has_cached_digest)
-    {
+    if (cached_digest == 0)
         cached_digest = calculateDigest(path, *this);
-        has_cached_digest_and_ctime.has_cached_digest = true;
-    }
 
     return cached_digest;
 };
@@ -326,17 +323,17 @@ void KeeperStorage::Node::shallowCopy(const KeeperStorage::Node & other)
     pzxid = other.pzxid;
     acl_id = other.acl_id; /// 0 -- no ACL by default
 
-    has_cached_digest_and_ctime = other.has_cached_digest_and_ctime;
+    mtime = other.mtime;
 
-    is_ephemeral_and_mtime = other.is_ephemeral_and_mtime;
+    is_ephemeral_and_ctime = other.is_ephemeral_and_ctime;
 
     ephemeral_or_children_data = other.ephemeral_or_children_data;
 
     data_size = other.data_size;
     if (data_size != 0)
     {
-        data = new char[data_size];
-        memcpy(data, other.data, data_size);
+        data = std::unique_ptr<char[]>(new char[data_size]);
+        memcpy(data.get(), other.data.get(), data_size);
     }
 
     version = other.version;
@@ -1448,7 +1445,7 @@ struct KeeperStorageSetRequestProcessor final : public KeeperStorageRequestProce
                 {
                     value.version++;
                     value.mzxid = zxid;
-                    value.setMtime(time);
+                    value.mtime = time;
                     value.setData(data);
                 },
                 request.version});

src/Coordination/KeeperStorage.h

@@ -38,17 +38,13 @@ public:
         int64_t pzxid{0};
         uint64_t acl_id = 0; /// 0 -- no ACL by default
 
-        mutable struct
-        {
-            bool has_cached_digest : 1;
-            int64_t ctime : 63;
-        } has_cached_digest_and_ctime{false, 0};
+        int64_t mtime;
 
         struct
         {
             bool is_ephemeral : 1;
-            int64_t mtime : 63;
-        } is_ephemeral_and_mtime{false, 0};
+            int64_t ctime : 63;
+        } is_ephemeral_and_ctime{false, 0};
 
         union
         {
@@ -60,19 +56,15 @@ public:
             } children_info;
         } ephemeral_or_children_data{0};
 
-        char * data{nullptr};
+        std::unique_ptr<char[]> data{nullptr};
         uint32_t data_size{0};
 
         int32_t version{0};
         int32_t cversion{0};
         int32_t aversion{0};
 
-        /// we cannot use `std::optional<uint64_t> because we want to
-        /// pack the boolean with seq_num above
         mutable uint64_t cached_digest = 0;
 
-        ~Node();
-
         Node() = default;
 
         Node & operator=(const Node & other);
@@ -83,7 +75,7 @@ public:
 
         bool isEphemeral() const
         {
-            return is_ephemeral_and_mtime.is_ephemeral;
+            return is_ephemeral_and_ctime.is_ephemeral;
         }
 
         int64_t ephemeralOwner() const
@@ -96,7 +88,7 @@ public:
 
         void setEphemeralOwner(int64_t ephemeral_owner)
         {
-            is_ephemeral_and_mtime.is_ephemeral = ephemeral_owner != 0;
+            is_ephemeral_and_ctime.is_ephemeral = ephemeral_owner != 0;
             ephemeral_or_children_data.ephemeral_owner = ephemeral_owner;
         }
 
@@ -146,22 +138,12 @@ public:
 
         int64_t ctime() const
         {
-            return has_cached_digest_and_ctime.ctime;
+            return is_ephemeral_and_ctime.ctime;
         }
 
         void setCtime(uint64_t ctime)
         {
-            has_cached_digest_and_ctime.ctime = ctime;
-        }
-
-        int64_t mtime() const
-        {
-            return is_ephemeral_and_mtime.mtime;
-        }
-
-        void setMtime(uint64_t mtime)
-        {
-            is_ephemeral_and_mtime.mtime = mtime;
+            is_ephemeral_and_ctime.ctime = ctime;
         }
 
         void copyStats(const Coordination::Stat & stat);
@@ -173,7 +155,7 @@ public:
 
         void setData(const String & new_data);
 
-        StringRef getData() const noexcept { return {data, data_size}; }
+        StringRef getData() const noexcept { return {data.get(), data_size}; }
 
         void addChild(StringRef child_path);
 
@@ -205,10 +187,11 @@ public:
         NO_DIGEST = 0,
         V1 = 1,
         V2 = 2, // added system nodes that modify the digest on startup so digest from V0 is invalid
-        V3 = 3  // fixed bug with casting, removed duplicate czxid usage
+        V3 = 3, // fixed bug with casting, removed duplicate czxid usage
+        V4 = 4  // 0 is not a valid digest value
     };
 
-    static constexpr auto CURRENT_DIGEST_VERSION = DigestVersion::V3;
+    static constexpr auto CURRENT_DIGEST_VERSION = DigestVersion::V4;
 
     struct ResponseForSession
     {

src/Coordination/ZooKeeperDataReader.cpp

@@ -114,9 +114,7 @@ int64_t deserializeStorageData(KeeperStorage & storage, ReadBuffer & in, LoggerP
         int64_t ctime;
         Coordination::read(ctime, in);
         node.setCtime(ctime);
-        int64_t mtime;
-        Coordination::read(mtime, in);
-        node.setMtime(mtime);
+        Coordination::read(node.mtime, in);
         Coordination::read(node.version, in);
         Coordination::read(node.cversion, in);
         Coordination::read(node.aversion, in);