feat(server): JSON family using JSON type (#561)

feat(server): json family using json type

Signed-off-by: Boaz Sade <boaz@dragonflydb.io>

Signed-off-by: Boaz Sade <boaz@dragonflydb.io>

src/server/generic_family.cc

@@ -665,7 +665,7 @@ void GenericFamily::Exists(CmdArgList args, ConnectionContext* cntx) {
   OpStatus status = transaction->ScheduleSingleHop(std::move(cb));
   CHECK_EQ(OpStatus::OK, status);
 
-  return (*cntx)->SendLong(result.load(memory_order_release));
+  return (*cntx)->SendLong(result.load(memory_order_acquire));
 }
 
 void GenericFamily::Persist(CmdArgList args, ConnectionContext* cntx) {

src/server/json_family.cc

@@ -17,6 +17,7 @@ extern "C" {
 #include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
 
 #include "base/logging.h"
+#include "core/json_object.h"
 #include "server/command_registry.h"
 #include "server/error.h"
 #include "server/journal/journal.h"
@@ -28,30 +29,19 @@ namespace dfly {
 using namespace std;
 using namespace jsoncons;
 
-using JsonExpression = jsonpath::jsonpath_expression<json>;
+using JsonExpression = jsonpath::jsonpath_expression<JsonType>;
 using OptBool = optional<bool>;
 using OptLong = optional<long>;
 using OptSizeT = optional<size_t>;
 using OptString = optional<string>;
-using JsonReplaceCb = function<void(const string&, json&)>;
+using JsonReplaceCb = function<void(const string&, JsonType&)>;
+using JsonReplaceVerify = std::function<OpStatus()>;
 using CI = CommandId;
 
 namespace {
 
-string GetString(EngineShard* shard, const PrimeValue& pv) {
+inline OpStatus JsonReplaceVerifyNoOp() {
-  string res;
+  return OpStatus::OK;
-  if (pv.IsExternal()) {
-    auto* tiered = shard->tiered_storage();
-    auto [offset, size] = pv.GetExternalPtr();
-    res.resize(size);
-
-    error_code ec = tiered->Read(offset, size, res.data());
-    CHECK(!ec) << "TBD: " << ec;
-  } else {
-    pv.GetString(&res);
-  }
-
-  return res;
 }
 
 inline void RecordJournal(const OpArgs& op_args, string_view key, const PrimeKey& pvalue) {
@@ -61,34 +51,36 @@ inline void RecordJournal(const OpArgs& op_args, string_view key, const PrimeKey
   }
 }
 
-void SetString(const OpArgs& op_args, string_view key, const string& value) {
+void SetJson(const OpArgs& op_args, string_view key, JsonType&& value) {
   auto& db_slice = op_args.shard->db_slice();
   DbIndex db_index = op_args.db_cntx.db_index;
   auto [it_output, added] = db_slice.AddOrFind(op_args.db_cntx, key);
   db_slice.PreUpdate(db_index, it_output);
-  it_output->second.SetString(value);
+  it_output->second.SetJson(std::move(value));
   db_slice.PostUpdate(db_index, it_output, key);
   RecordJournal(op_args, key, it_output->second);
 }
 
-string JsonType(const json& val) {
+string JsonTypeToName(const JsonType& val) {
+  using namespace std::string_literals;
+
   if (val.is_null()) {
-    return "null";
+    return "null"s;
   } else if (val.is_bool()) {
-    return "boolean";
+    return "boolean"s;
   } else if (val.is_string()) {
-    return "string";
+    return "string"s;
   } else if (val.is_int64() || val.is_uint64()) {
-    return "integer";
+    return "integer"s;
   } else if (val.is_number()) {
-    return "number";
+    return "number"s;
   } else if (val.is_object()) {
-    return "object";
+    return "object"s;
   } else if (val.is_array()) {
-    return "array";
+    return "array"s;
   }
 
-  return "";
+  return std::string{};
 }
 
 template <typename T>
@@ -112,13 +104,13 @@ void PrintOptVec(ConnectionContext* cntx, const OpResult<vector<optional<T>>>& r
   }
 }
 
-error_code JsonReplace(json& instance, string_view& path, JsonReplaceCb callback) {
+error_code JsonReplace(JsonType& instance, string_view path, JsonReplaceCb callback) {
-  using evaluator_t = jsoncons::jsonpath::detail::jsonpath_evaluator<json, json&>;
+  using evaluator_t = jsoncons::jsonpath::detail::jsonpath_evaluator<JsonType, JsonType&>;
   using value_type = evaluator_t::value_type;
   using reference = evaluator_t::reference;
   using json_selector_t = evaluator_t::path_expression_type;
   using json_location_type = evaluator_t::json_location_type;
-  jsonpath::custom_functions<json> funcs = jsonpath::custom_functions<json>();
+  jsonpath::custom_functions<JsonType> funcs = jsonpath::custom_functions<JsonType>();
 
   error_code ec;
   jsoncons::jsonpath::detail::static_resources<value_type, reference> static_resources(funcs);
@@ -138,40 +130,47 @@ error_code JsonReplace(json& instance, string_view& path, JsonReplaceCb callback
   return ec;
 }
 
-bool JsonErrorHandler(json_errc ec, const ser_context&) {
+OpStatus UpdateEntry(const OpArgs& op_args, std::string_view key, std::string_view path,
-  VLOG(1) << "Error while decode JSON: " << make_error_code(ec).message();
+                     JsonReplaceCb callback, JsonReplaceVerify verify_op = JsonReplaceVerifyNoOp) {
-  return false;
+  OpResult<PrimeIterator> it_res = op_args.shard->db_slice().Find(op_args.db_cntx, key, OBJ_JSON);
-}
+  if (!it_res.ok()) {
-
+    return it_res.status();
-optional<json> ConstructJsonFromString(string_view val) {
-  error_code ec;
-  json_decoder<json> decoder;
-  basic_json_parser<char> parser(basic_json_decode_options<char>{}, &JsonErrorHandler);
-
-  parser.update(val);
-  parser.finish_parse(decoder, ec);
-
-  if (!decoder.is_valid()) {
-    return nullopt;
   }
 
-  return decoder.get_result();
+  PrimeIterator entry_it = it_res.value();
-}
+  auto& db_slice = op_args.shard->db_slice();
+  auto db_index = op_args.db_cntx.db_index;
+  JsonType* json_val = entry_it->second.GetJson();
+  DCHECK(json_val) << "should have a valid JSON object for key '" << key << "' the type for it is '"
+                   << entry_it->second.ObjType() << "'";
+  JsonType& json_entry = *json_val;
+  db_slice.PreUpdate(db_index, entry_it);
 
-OpResult<json> GetJson(const OpArgs& op_args, string_view key) {
+  // Run the update operation on this entry
-  OpResult<PrimeIterator> it_res = op_args.shard->db_slice().Find(op_args.db_cntx, key, OBJ_STRING);
+  error_code ec = JsonReplace(json_entry, path, callback);
-  if (!it_res.ok())
+  if (ec) {
-    return it_res.status();
+    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-
-  const PrimeValue& pv = it_res.value()->second;
-
-  string val = GetString(op_args.shard, pv);
-  optional<json> j = ConstructJsonFromString(val);
-  if (!j) {
     return OpStatus::SYNTAX_ERR;
   }
 
-  return *j;
+  // Make sure that we don't have other internal issue with the operation
+  OpStatus res = verify_op();
+  if (res == OpStatus::OK) {
+    db_slice.PostUpdate(db_index, entry_it, key);
+  }
+
+  return res;
+}
+
+OpResult<JsonType*> GetJson(const OpArgs& op_args, string_view key) {
+  OpResult<PrimeIterator> it_res = op_args.shard->db_slice().Find(op_args.db_cntx, key, OBJ_JSON);
+  if (!it_res.ok())
+    return it_res.status();
+
+  JsonType* json_val = it_res.value()->second.GetJson();
+  DCHECK(json_val) << "should have a valid JSON object for key " << key;
+
+  return json_val;
 }
 
 // Returns the index of the next right bracket
@@ -287,7 +286,7 @@ string ConvertToJsonPointer(string_view json_path) {
   return result;
 }
 
-size_t CountJsonFields(const json& j) {
+size_t CountJsonFields(const JsonType& j) {
   size_t res = 0;
   json_type type = j.type();
   if (type == json_type::array_value) {
@@ -314,7 +313,7 @@ size_t CountJsonFields(const json& j) {
   return res;
 }
 
-void SendJsonValue(ConnectionContext* cntx, const json& j) {
+void SendJsonValue(ConnectionContext* cntx, const JsonType& j) {
   if (j.is_double()) {
     (*cntx)->SendDouble(j.as_double());
   } else if (j.is_number()) {
@@ -344,19 +343,25 @@ void SendJsonValue(ConnectionContext* cntx, const json& j) {
 
 OpResult<string> OpGet(const OpArgs& op_args, string_view key,
                        vector<pair<string_view, JsonExpression>> expressions) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
+  const JsonType& json_entry = *(result.value());
+  if (expressions.empty()) {
+    // this implicitly means that we're using $ which
+    // means we just brings all values
+    return json_entry.to_string();
+  }
   if (expressions.size() == 1) {
-    json out = expressions[0].second.evaluate(*result);
+    json out = expressions[0].second.evaluate(json_entry);
     return out.as<string>();
   }
 
   json out;
   for (auto& expr : expressions) {
-    json eval = expr.second.evaluate(*result);
+    json eval = expr.second.evaluate(json_entry);
     out[expr.first] = eval;
   }
 
@@ -364,27 +369,30 @@ OpResult<string> OpGet(const OpArgs& op_args, string_view key,
 }
 
 OpResult<vector<string>> OpType(const OpArgs& op_args, string_view key, JsonExpression expression) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
+  const JsonType& json_entry = *(result.value());
   vector<string> vec;
-  auto cb = [&vec](const string_view& path, const json& val) { vec.emplace_back(JsonType(val)); };
+  auto cb = [&vec](const string_view& path, const JsonType& val) {
+    vec.emplace_back(JsonTypeToName(val));
+  };
 
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 OpResult<vector<OptSizeT>> OpStrLen(const OpArgs& op_args, string_view key,
                                     JsonExpression expression) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
-
+  const JsonType& json_entry = *(result.value());
   vector<OptSizeT> vec;
-  auto cb = [&vec](const string_view& path, const json& val) {
+  auto cb = [&vec](const string_view& path, const JsonType& val) {
     if (val.is_string()) {
       vec.emplace_back(val.as_string_view().size());
     } else {
@@ -392,19 +400,20 @@ OpResult<vector<OptSizeT>> OpStrLen(const OpArgs& op_args, string_view key,
     }
   };
 
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 OpResult<vector<OptSizeT>> OpObjLen(const OpArgs& op_args, string_view key,
                                     JsonExpression expression) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
+  const JsonType& json_entry = *(result.value());
   vector<OptSizeT> vec;
-  auto cb = [&vec](const string_view& path, const json& val) {
+  auto cb = [&vec](const string_view& path, const JsonType& val) {
     if (val.is_object()) {
       vec.emplace_back(val.object_value().size());
     } else {
@@ -412,19 +421,20 @@ OpResult<vector<OptSizeT>> OpObjLen(const OpArgs& op_args, string_view key,
     }
   };
 
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 OpResult<vector<OptSizeT>> OpArrLen(const OpArgs& op_args, string_view key,
                                     JsonExpression expression) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
+  const JsonType& json_entry = *(result.value());
   vector<OptSizeT> vec;
-  auto cb = [&vec](const string_view& path, const json& val) {
+  auto cb = [&vec](const string_view& path, const JsonType& val) {
     if (val.is_array()) {
       vec.emplace_back(val.array_value().size());
     } else {
@@ -432,18 +442,13 @@ OpResult<vector<OptSizeT>> OpArrLen(const OpArgs& op_args, string_view key,
     }
   };
 
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 OpResult<vector<OptBool>> OpToggle(const OpArgs& op_args, string_view key, string_view path) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   vector<OptBool> vec;
-  auto cb = [&vec](const string& path, json& val) {
+  auto cb = [&vec](const string& path, JsonType& val) {
     if (val.is_bool()) {
       bool current_val = val.as_bool() ^ true;
       val = current_val;
@@ -453,31 +458,23 @@ OpResult<vector<OptBool>> OpToggle(const OpArgs& op_args, string_view key, strin
     }
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
 
-  SetString(op_args, key, j.as_string());
   return vec;
 }
 
 template <typename Op>
 OpResult<string> OpDoubleArithmetic(const OpArgs& op_args, string_view key, string_view path,
                                     double num, Op arithmetic_op) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   bool is_result_overflow = false;
   double int_part;
   bool has_fractional_part = (modf(num, &int_part) != 0);
   json output(json_array_arg);
 
-  auto cb = [&](const string& path, json& val) {
+  auto cb = [&](const string& path, JsonType& val) {
     if (val.is_number()) {
       double result = arithmetic_op(val.as<double>(), num);
       if (isinf(result)) {
@@ -496,18 +493,18 @@ OpResult<string> OpDoubleArithmetic(const OpArgs& op_args, string_view key, stri
     }
   };
 
-  json j = move(result.value());
+  auto verifier = [&is_result_overflow]() {
-  error_code ec = JsonReplace(j, path, cb);
-  if (ec) {
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
-  }
-
     if (is_result_overflow) {
       return OpStatus::INVALID_NUMERIC_RESULT;
     }
+    return OpStatus::OK;
+  };
+
+  OpStatus status = UpdateEntry(op_args, key, path, cb, verifier);
+  if (status != OpStatus::OK) {
+    return status;
+  }
 
-  SetString(op_args, key, j.as_string());
   return output.as_string();
 }
 
@@ -520,18 +517,19 @@ OpResult<long> OpDel(const OpArgs& op_args, string_view key, string_view path) {
     return total_deletions;
   }
 
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return total_deletions;
   }
 
   vector<string> deletion_items;
-  auto cb = [&](const string& path, json& val) { deletion_items.emplace_back(path); };
+  auto cb = [&](const string& path, JsonType& val) { deletion_items.emplace_back(path); };
 
-  json j = move(result.value());
+  // json j = move(result.value());
-  error_code ec = JsonReplace(j, path, cb);
+  JsonType& json_entry = *(result.value());
+  error_code ec = JsonReplace(json_entry, path, cb);
   if (ec) {
-    VLOG(1) << "Failed to evaulate expression on json with error: " << ec.message();
+    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
     return total_deletions;
   }
 
@@ -548,13 +546,13 @@ OpResult<long> OpDel(const OpArgs& op_args, string_view key, string_view path) {
     patch.emplace_back(patch_item);
   }
 
-  jsonpatch::apply_patch(j, patch, ec);
+  jsonpatch::apply_patch(json_entry, patch, ec);
   if (ec) {
     VLOG(1) << "Failed to apply patch on json with error: " << ec.message();
     return 0;
   }
 
-  SetString(op_args, key, j.as_string());
+  // SetString(op_args, key, j.as_string());
   return total_deletions;
 }
 
@@ -562,13 +560,13 @@ OpResult<long> OpDel(const OpArgs& op_args, string_view key, string_view path) {
 // keys within the same object are stored in the same string vector.
 OpResult<vector<StringVec>> OpObjKeys(const OpArgs& op_args, string_view key,
                                       JsonExpression expression) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
   vector<StringVec> vec;
-  auto cb = [&vec](const string_view& path, const json& val) {
+  auto cb = [&vec](const string_view& path, const JsonType& val) {
     // Aligned with ElastiCache flavor.
     if (!val.is_object()) {
       vec.emplace_back();
@@ -580,21 +578,17 @@ OpResult<vector<StringVec>> OpObjKeys(const OpArgs& op_args, string_view key,
       current_object.emplace_back(member.key());
     }
   };
+  JsonType& json_entry = *(result.value());
 
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 // Retruns array of string lengths after a successful operation.
 OpResult<vector<OptSizeT>> OpStrAppend(const OpArgs& op_args, string_view key, string_view path,
                                        const vector<string_view>& strs) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   vector<OptSizeT> vec;
-  auto cb = [&](const string& path, json& val) {
+  auto cb = [&](const string& path, JsonType& val) {
     if (val.is_string()) {
       string new_val = val.as_string();
       for (auto& str : strs) {
@@ -608,27 +602,19 @@ OpResult<vector<OptSizeT>> OpStrAppend(const OpArgs& op_args, string_view key, s
     }
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
 
-  SetString(op_args, key, j.as_string());
   return vec;
 }
 
 // Returns the numbers of values cleared.
 // Clears containers(arrays or objects) and zeroing numbers.
 OpResult<long> OpClear(const OpArgs& op_args, string_view key, string_view path) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   long clear_items = 0;
-  auto cb = [&clear_items](const string& path, json& val) {
+  auto cb = [&clear_items](const string& path, JsonType& val) {
     if (!(val.is_object() || val.is_array() || val.is_number())) {
       return;
     }
@@ -644,27 +630,18 @@ OpResult<long> OpClear(const OpArgs& op_args, string_view key, string_view path)
     clear_items += 1;
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
-
-  SetString(op_args, key, j.as_string());
   return clear_items;
 }
 
 // Returns string vector that represents the pop out values.
 OpResult<vector<OptString>> OpArrPop(const OpArgs& op_args, string_view key, string_view path,
                                      int index) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   vector<OptString> vec;
-  auto cb = [&](const string& path, json& val) {
+  auto cb = [&](const string& path, JsonType& val) {
     if (!val.is_array() || val.empty()) {
       vec.emplace_back(nullopt);
       return;
@@ -695,27 +672,19 @@ OpResult<vector<OptString>> OpArrPop(const OpArgs& op_args, string_view key, str
     val.erase(it);
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
 
-  SetString(op_args, key, j.as_string());
   return vec;
 }
 
 // Returns numeric vector that represents the new length of the array at each path.
 OpResult<vector<OptSizeT>> OpArrTrim(const OpArgs& op_args, string_view key, string_view path,
                                      int start_index, int stop_index) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   vector<OptSizeT> vec;
-  auto cb = [&](const string& path, json& val) {
+  auto cb = [&](const string& path, JsonType& val) {
     if (!val.is_array() || val.empty()) {
       vec.emplace_back(nullopt);
       return;
@@ -753,31 +722,22 @@ OpResult<vector<OptSizeT>> OpArrTrim(const OpArgs& op_args, string_view key, str
     vec.emplace_back(val.size());
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
-
-  SetString(op_args, key, j.as_string());
   return vec;
 }
 
 // Returns numeric vector that represents the new length of the array at each path.
 OpResult<vector<OptSizeT>> OpArrInsert(const OpArgs& op_args, string_view key, string_view path,
-                                       int index, const vector<json>& new_values) {
+                                       int index, const vector<JsonType>& new_values) {
-  OpResult<json> result = GetJson(op_args, key);
-  if (!result) {
-    return result.status();
-  }
-
   bool out_of_boundaries_encountered = false;
   vector<OptSizeT> vec;
   // Insert user-supplied value into the supplied index that should be valid.
   // If at least one index isn't valid within an array in the json doc, the operation is discarded.
   // Negative indexes start from the end of the array.
-  auto cb = [&](const string& path, json& val) {
+  auto cb = [&](const string& path, JsonType& val) {
     if (out_of_boundaries_encountered) {
       return;
     }
@@ -819,33 +779,30 @@ OpResult<vector<OptSizeT>> OpArrInsert(const OpArgs& op_args, string_view key, s
     vec.emplace_back(val.size());
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
 
   if (out_of_boundaries_encountered) {
     return OpStatus::OUT_OF_RANGE;
   }
 
-  SetString(op_args, key, j.as_string());
   return vec;
 }
 
 // Returns numeric vector that represents the new length of the array at each path, or Null reply
 // if the matching JSON value is not an array.
 OpResult<vector<OptSizeT>> OpArrAppend(const OpArgs& op_args, string_view key, string_view path,
-                                       const vector<json>& append_values) {
+                                       const vector<JsonType>& append_values) {
   vector<OptSizeT> vec;
 
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
-  auto cb = [&](const string& path, json& val) {
+  auto cb = [&](const string& path, JsonType& val) {
     if (!val.is_array()) {
       vec.emplace_back(nullopt);
       return;
@@ -856,14 +813,11 @@ OpResult<vector<OptSizeT>> OpArrAppend(const OpArgs& op_args, string_view key, s
     vec.emplace_back(val.size());
   };
 
-  json j = move(result.value());
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  error_code ec = JsonReplace(j, path, cb);
+  if (status != OpStatus::OK) {
-  if (ec) {
+    return status;
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
-    return OpStatus::SYNTAX_ERR;
   }
 
-  SetString(op_args, key, j.as_string());
   return vec;
 }
 
@@ -871,15 +825,15 @@ OpResult<vector<OptSizeT>> OpArrAppend(const OpArgs& op_args, string_view key, s
 // An index value of -1 represents unfound in the array.
 // JSON scalar has types of string, boolean, null, and number.
 OpResult<vector<OptLong>> OpArrIndex(const OpArgs& op_args, string_view key,
-                                     JsonExpression expression, const json& search_val,
+                                     JsonExpression expression, const JsonType& search_val,
                                      int start_index, int end_index) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
   vector<OptLong> vec;
-  auto cb = [&](const string_view& path, const json& val) {
+  auto cb = [&](const string_view& path, const JsonType& val) {
     if (!val.is_array()) {
       vec.emplace_back(nullopt);
       return;
@@ -927,8 +881,8 @@ OpResult<vector<OptLong>> OpArrIndex(const OpArgs& op_args, string_view key,
 
     vec.emplace_back(pos);
   };
-
+  JsonType& json_entry = *(result.value());
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
@@ -937,13 +891,14 @@ OpResult<vector<OptString>> OpMGet(const OpArgs& op_args, const vector<string_vi
                                    JsonExpression expression) {
   vector<OptString> vec;
   for (auto& it : keys) {
-    OpResult<json> result = GetJson(op_args, it);
+    // OpResult<JsonType> result = GetJson(op_args, it);
+    OpResult<JsonType*> result = GetJson(op_args, it);
     if (!result) {
       vec.emplace_back();
       continue;
     }
 
-    auto cb = [&vec](const string_view& path, const json& val) {
+    auto cb = [&vec](const string_view& path, const JsonType& val) {
       string str;
       error_code ec;
       val.dump(str, {}, ec);
@@ -954,8 +909,8 @@ OpResult<vector<OptString>> OpMGet(const OpArgs& op_args, const vector<string_vi
 
       vec.push_back(move(str));
     };
-
+    const JsonType& json_entry = *(result.value());
-    expression.evaluate(*result, cb);
+    expression.evaluate(json_entry, cb);
   }
 
   return vec;
@@ -964,74 +919,70 @@ OpResult<vector<OptString>> OpMGet(const OpArgs& op_args, const vector<string_vi
 // Returns numeric vector that represents the number of fields of JSON value at each path.
 OpResult<vector<OptSizeT>> OpFields(const OpArgs& op_args, string_view key,
                                     JsonExpression expression) {
-  OpResult<json> result = GetJson(op_args, key);
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
   vector<OptSizeT> vec;
-  auto cb = [&vec](const string_view& path, const json& val) {
+  auto cb = [&vec](const string_view& path, const JsonType& val) {
     vec.emplace_back(CountJsonFields(val));
   };
-
+  const JsonType& json_entry = *(result.value());
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 // Returns json vector that represents the result of the json query.
-OpResult<vector<json>> OpResp(const OpArgs& op_args, string_view key, JsonExpression expression) {
+OpResult<vector<JsonType>> OpResp(const OpArgs& op_args, string_view key,
-  OpResult<json> result = GetJson(op_args, key);
+                                  JsonExpression expression) {
+  OpResult<JsonType*> result = GetJson(op_args, key);
   if (!result) {
     return result.status();
   }
 
-  vector<json> vec;
+  vector<JsonType> vec;
-  auto cb = [&vec](const string_view& path, const json& val) { vec.emplace_back(val); };
+  auto cb = [&vec](const string_view& path, const JsonType& val) { vec.emplace_back(val); };
-
+  const JsonType& json_entry = *(result.value());
-  expression.evaluate(*result, cb);
+  expression.evaluate(json_entry, cb);
   return vec;
 }
 
 // Returns boolean that represents the result of the operation.
 OpResult<bool> OpSet(const OpArgs& op_args, string_view key, string_view path,
-                     string_view json_str) {
+                     std::string_view json_str) {
-  // Check if the supplied JSON is valid.
+  std::optional<JsonType> parsed_json = JsonFromString(json_str);
-  optional<json> j = ConstructJsonFromString(json_str);
+  if (!parsed_json) {
-  if (!j) {
+    LOG(WARNING) << "got invalid JSON string '" << json_str << "' cannot be saved";
     return OpStatus::SYNTAX_ERR;
   }
 
   // The whole key should be replaced.
+  // NOTE: unlike in Redis, we are overriding the value when the path is "$"
+  // this is regardless of the current key type. In redis if the key exists
+  // and its not JSON, it would return an error.
   if (path == "." || path == "$") {
-    SetString(op_args, key, j->as_string());
+    SetJson(op_args, key, std::move(parsed_json.value()));
     return true;
   }
 
-  // Update the existing JSON.
+  // Note that this operation would use copy and not move!
-  OpResult<json> result = GetJson(op_args, key);
+  // The reason being, that we are applying this multiple times
-  if (!result) {
+  // For each match we found. So for example if we have
-    return result.status();
+  // an array that this expression will match each entry in it
-  }
+  // then the assign here is called N times, where N == array.size().
-
-  json existing_json = move(result.value());
   bool path_exists = false;
-  auto cb = [&](const string& path, json& val) {
+  const JsonType& new_json = parsed_json.value();
+  auto cb = [&](const string& path, JsonType& val) {
     path_exists = true;
-    val = *j;
+    val = new_json;
   };
 
-  error_code ec = JsonReplace(existing_json, path, cb);
+  OpStatus status = UpdateEntry(op_args, key, path, cb);
-  if (ec) {
+  if (status != OpStatus::OK) {
-    VLOG(1) << "Failed to evaluate expression on json with error: " << ec.message();
+    return status;
-    return OpStatus::SYNTAX_ERR;
   }
-
+  return path_exists;
-  if (!path_exists) {
-    return false;
-  }
-
-  SetString(op_args, key, existing_json.as_string());
-  return true;
 }
 
 }  // namespace
@@ -1064,7 +1015,7 @@ void JsonFamily::Resp(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1077,7 +1028,7 @@ void JsonFamily::Resp(CmdArgList args, ConnectionContext* cntx) {
   };
 
   Transaction* trans = cntx->transaction;
-  OpResult<vector<json>> result = trans->ScheduleSingleHopT(move(cb));
+  OpResult<vector<JsonType>> result = trans->ScheduleSingleHopT(move(cb));
 
   if (result) {
     (*cntx)->StartArray(result->size());
@@ -1117,7 +1068,7 @@ void JsonFamily::Debug(CmdArgList args, ConnectionContext* cntx) {
   error_code ec;
   string_view key = ArgS(args, 2);
   string_view path = ArgS(args, 3);
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1142,7 +1093,7 @@ void JsonFamily::Debug(CmdArgList args, ConnectionContext* cntx) {
 void JsonFamily::MGet(CmdArgList args, ConnectionContext* cntx) {
   error_code ec;
   string_view path = ArgS(args, args.size() - 1);
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1181,7 +1132,7 @@ void JsonFamily::ArrIndex(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1189,7 +1140,7 @@ void JsonFamily::ArrIndex(CmdArgList args, ConnectionContext* cntx) {
     return;
   }
 
-  optional<json> search_value = ConstructJsonFromString(ArgS(args, 3));
+  optional<JsonType> search_value = JsonFromString(ArgS(args, 3));
   if (!search_value) {
     (*cntx)->SendError(kSyntaxErr);
     return;
@@ -1244,9 +1195,9 @@ void JsonFamily::ArrInsert(CmdArgList args, ConnectionContext* cntx) {
     return;
   }
 
-  vector<json> new_values;
+  vector<JsonType> new_values;
   for (size_t i = 4; i < args.size(); i++) {
-    optional<json> val = ConstructJsonFromString(ArgS(args, i));
+    optional<JsonType> val = JsonFromString(ArgS(args, i));
     if (!val) {
       (*cntx)->SendError(kSyntaxErr);
       return;
@@ -1271,9 +1222,9 @@ void JsonFamily::ArrInsert(CmdArgList args, ConnectionContext* cntx) {
 void JsonFamily::ArrAppend(CmdArgList args, ConnectionContext* cntx) {
   string_view key = ArgS(args, 1);
   string_view path = ArgS(args, 2);
-  vector<json> append_values;
+  vector<JsonType> append_values;
   for (size_t i = 3; i < args.size(); ++i) {
-    optional<json> converted_val = ConstructJsonFromString(ArgS(args, i));
+    optional<JsonType> converted_val = JsonFromString(ArgS(args, i));
     if (!converted_val) {
       (*cntx)->SendError(kSyntaxErr);
       return;
@@ -1349,7 +1300,7 @@ void JsonFamily::ArrPop(CmdArgList args, ConnectionContext* cntx) {
   }
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1423,7 +1374,7 @@ void JsonFamily::ObjKeys(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1541,7 +1492,7 @@ void JsonFamily::Type(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1577,7 +1528,7 @@ void JsonFamily::ArrLen(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1604,7 +1555,7 @@ void JsonFamily::ObjLen(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1631,7 +1582,7 @@ void JsonFamily::StrLen(CmdArgList args, ConnectionContext* cntx) {
   string_view path = ArgS(args, 2);
 
   error_code ec;
-  JsonExpression expression = jsonpath::make_expression<json>(path, ec);
+  JsonExpression expression = jsonpath::make_expression<JsonType>(path, ec);
 
   if (ec) {
     VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
@@ -1654,22 +1605,20 @@ void JsonFamily::StrLen(CmdArgList args, ConnectionContext* cntx) {
 }
 
 void JsonFamily::Get(CmdArgList args, ConnectionContext* cntx) {
-  DCHECK_GE(args.size(), 3U);
+  DCHECK_GE(args.size(), 2U);
   string_view key = ArgS(args, 1);
 
   vector<pair<string_view, JsonExpression>> expressions;
+
   for (size_t i = 2; i < args.size(); ++i) {
     string_view path = ArgS(args, i);
-
     error_code ec;
-    JsonExpression expr = jsonpath::make_expression<json>(path, ec);
+    JsonExpression expr = jsonpath::make_expression<JsonType>(path, ec);
 
     if (ec) {
-      VLOG(1) << "Invalid JSONPath syntax: " << ec.message();
+      LOG(WARNING) << "path '" << path << "': Invalid JSONPath syntax: " << ec.message();
-      (*cntx)->SendError(kSyntaxErr);
+      return (*cntx)->SendError(kSyntaxErr);
-      return;
     }
-
     expressions.emplace_back(path, move(expr));
   }
 
@@ -1682,15 +1631,20 @@ void JsonFamily::Get(CmdArgList args, ConnectionContext* cntx) {
 
   if (result) {
     (*cntx)->SendBulkString(*result);
+  } else {
+    if (result == facade::OpStatus::KEY_NOTFOUND) {
+      // Match what Redis returning
+      (*cntx)->SendNull();
     } else {
       (*cntx)->SendError(result.status());
     }
+  }
 }
 
 #define HFUNC(x) SetHandler(&JsonFamily::x)
 
 void JsonFamily::Register(CommandRegistry* registry) {
-  *registry << CI{"JSON.GET", CO::READONLY | CO::FAST, -3, 1, 1, 1}.HFUNC(Get);
+  *registry << CI{"JSON.GET", CO::READONLY | CO::FAST, -2, 1, 1, 1}.HFUNC(Get);
   *registry << CI{"JSON.MGET", CO::READONLY | CO::FAST, -3, 1, 1, 1}.HFUNC(MGet);
   *registry << CI{"JSON.TYPE", CO::READONLY | CO::FAST, 3, 1, 1, 1}.HFUNC(Type);
   *registry << CI{"JSON.STRLEN", CO::READONLY | CO::FAST, 3, 1, 1, 1}.HFUNC(StrLen);

src/server/json_family_test.cc

@@ -467,25 +467,26 @@ TEST_F(JsonFamilyTest, Del) {
   resp = Run({"JSON.DEL", "json", "$.d.*"});
   EXPECT_THAT(resp, IntArg(3));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":{},"b":{"a":1},"c":{"a":1,"b":2},"d":{},"e":[1,2,3,4,5]})");
 
   resp = Run({"JSON.DEL", "json", "$.e[*]"});
   EXPECT_THAT(resp, IntArg(5));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":{},"b":{"a":1},"c":{"a":1,"b":2},"d":{},"e":[]})");
 
   resp = Run({"JSON.DEL", "json", "$..*"});
   EXPECT_THAT(resp, IntArg(8));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({})");
 
   resp = Run({"JSON.DEL", "json"});
   EXPECT_THAT(resp, IntArg(1));
-
+  resp = Run({"GET", "json"});  // This is legal since the key was removed
-  resp = Run({"GET", "json"});
+  EXPECT_THAT(resp, ArgType(RespExpr::NIL));
+  resp = Run({"JSON.GET", "json"});
   EXPECT_THAT(resp, ArgType(RespExpr::NIL));
 
   json = R"(
@@ -498,19 +499,21 @@ TEST_F(JsonFamilyTest, Del) {
   resp = Run({"JSON.DEL", "json", "$.a[0].b[0]"});
   EXPECT_THAT(resp, IntArg(1));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"GET", "json"});  // not a legal type
+  EXPECT_THAT(resp, ErrArg("Operation against a key holding the wrong kind of value"));
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":[{"b":[2,3]}],"b":[{"c":2}],"c']":[1,2,3]})");
 
   resp = Run({"JSON.DEL", "json", "$.b[0].c"});
   EXPECT_THAT(resp, IntArg(1));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":[{"b":[2,3]}],"b":[{}],"c']":[1,2,3]})");
 
   resp = Run({"JSON.DEL", "json", "$.*"});
   EXPECT_THAT(resp, IntArg(3));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({})");
 }
 
@@ -582,7 +585,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   resp = Run({"JSON.STRAPPEND", "json", "$.a.a", "a", "b"});
   EXPECT_THAT(resp, IntArg(3));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(
       resp,
       R"({"a":{"a":"aab"},"b":{"a":"a","b":1},"c":{"a":"a","b":"bb"},"d":{"a":1,"b":"b","c":3}})");
@@ -590,7 +593,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   resp = Run({"JSON.STRAPPEND", "json", "$.a.*", "a"});
   EXPECT_THAT(resp, IntArg(4));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(
       resp,
       R"({"a":{"a":"aaba"},"b":{"a":"a","b":1},"c":{"a":"a","b":"bb"},"d":{"a":1,"b":"b","c":3}})");
@@ -599,7 +602,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(2), ArgType(RespExpr::NIL)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(
       resp,
       R"({"a":{"a":"aaba"},"b":{"a":"aa","b":1},"c":{"a":"a","b":"bb"},"d":{"a":1,"b":"b","c":3}})");
@@ -608,7 +611,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(2), IntArg(3)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(
       resp,
       R"({"a":{"a":"aaba"},"b":{"a":"aa","b":1},"c":{"a":"aa","b":"bba"},"d":{"a":1,"b":"b","c":3}})");
@@ -616,7 +619,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   resp = Run({"JSON.STRAPPEND", "json", "$.c.b", "a"});
   EXPECT_THAT(resp, IntArg(4));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(
       resp,
       R"({"a":{"a":"aaba"},"b":{"a":"aa","b":1},"c":{"a":"aa","b":"bbaa"},"d":{"a":1,"b":"b","c":3}})");
@@ -626,7 +629,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   EXPECT_THAT(resp.GetVec(),
               ElementsAre(ArgType(RespExpr::NIL), IntArg(2), ArgType(RespExpr::NIL)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(
       resp,
       R"({"a":{"a":"aaba"},"b":{"a":"aa","b":1},"c":{"a":"aa","b":"bbaa"},"d":{"a":1,"b":"ba","c":3}})");
@@ -642,7 +645,7 @@ TEST_F(JsonFamilyTest, StrAppend) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(6), IntArg(6), ArgType(RespExpr::NIL)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":"foobar","inner":{"a":"byebar"},"inner1":{"a":7}})");
 }
 
@@ -657,13 +660,13 @@ TEST_F(JsonFamilyTest, Clear) {
   resp = Run({"JSON.CLEAR", "json", "$[*]"});
   EXPECT_THAT(resp, IntArg(5));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([[],[],[],[],0,true,null,"d"])");
 
   resp = Run({"JSON.CLEAR", "json", "$"});
   EXPECT_THAT(resp, IntArg(1));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([])");
 
   json = R"(
@@ -676,13 +679,13 @@ TEST_F(JsonFamilyTest, Clear) {
   resp = Run({"JSON.CLEAR", "json", "$.children"});
   EXPECT_THAT(resp, IntArg(1));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"children":[]})");
 
   resp = Run({"JSON.CLEAR", "json", "$"});
   EXPECT_THAT(resp, IntArg(1));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({})");
 }
 
@@ -698,7 +701,7 @@ TEST_F(JsonFamilyTest, ArrPop) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre("1", "2", "3"));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([[6,6],[7,7],[8,8]])");
 }
 
@@ -714,7 +717,7 @@ TEST_F(JsonFamilyTest, ArrTrim) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(ArgType(RespExpr::NIL), IntArg(0), IntArg(1), IntArg(2)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([[],[],["b"],["b","c"]])");
 
   json = R"(
@@ -728,7 +731,7 @@ TEST_F(JsonFamilyTest, ArrTrim) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(ArgType(RespExpr::NIL), IntArg(1)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":[],"nested":{"a":[4]}})");
 
   json = R"(
@@ -742,7 +745,7 @@ TEST_F(JsonFamilyTest, ArrTrim) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(3), ArgType(RespExpr::NIL)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":[1,3,2],"nested":{"a":false}})");
 }
 
@@ -758,21 +761,21 @@ TEST_F(JsonFamilyTest, ArrInsert) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(1), IntArg(2), IntArg(3)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([["a"],["a","a"],["a","a","b"]])");
 
   resp = Run({"JSON.ARRINSERT", "json", "$[*]", "-1", R"("b")"});
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(2), IntArg(3), IntArg(4)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([["b","a"],["a","b","a"],["a","a","b","b"]])");
 
   resp = Run({"JSON.ARRINSERT", "json", "$[*]", "1", R"("c")"});
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(3), IntArg(4), IntArg(5)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"([["b","c","a"],["a","c","b","a"],["a","c","a","b","b"]])");
 }
 
@@ -802,7 +805,7 @@ TEST_F(JsonFamilyTest, ArrAppend) {
   ASSERT_EQ(RespExpr::ARRAY, resp.type);
   EXPECT_THAT(resp.GetVec(), ElementsAre(IntArg(2), IntArg(3), ArgType(RespExpr::NIL)));
 
-  resp = Run({"GET", "json"});
+  resp = Run({"JSON.GET", "json"});
   EXPECT_EQ(resp, R"({"a":[1,3],"nested":{"a":[1,2,3],"nested2":{"a":42}}})");
 }
 

tests/dragonfly/json_test.py

@@ -0,0 +1,102 @@
+import pytest
+from redis.commands.json.path import Path
+from .utility import *
+
+jane = {
+    'name': "Jane",
+    'Age': 33,
+    'Location': "Chawton"
+}
+
+json_num = {
+    "a": {"a": 1, "b": 2, "c": 3}
+}
+
+
+def get_type(connection, key):
+    return connection.execute_command("type", key)
+
+
+def get_set_json(connection, key, value, path="$"):
+
+    try:
+        connection.json().set(key, path, value)
+
+        result = connection.json().get(key, path)
+        return result
+    except redis.exceptions.ResponseError as re:
+        return str(re)
+    except Exception as e:
+        return None
+
+
+def get_str(connect, key):
+    try:
+        return connect.get(key)
+    except redis.exceptions.ResponseError as re:
+        return str(re)
+    except Exception as e:
+        return None
+
+
+def test_basic_json_get_set(client):
+    key_name = "test-json-key"
+    result = get_set_json(connection=client, key=key_name, value=jane)
+    assert result is not None, "failed to set JSON value"
+    the_type = get_type(connection=client, key=key_name)
+    assert the_type == "ReJSON-RL"
+    assert len(result) == 1
+    assert result[0]['name'] == 'Jane'
+    assert result[0]['Age'] == 33
+
+
+def test_access_json_value_as_string(client):
+    key_name = "test-json-key"
+    result = get_set_json(connection=client, key=key_name, value=jane)
+    assert result is not None, "failed to set JSON value"
+    # make sure that we have valid JSON here
+    the_type = get_type(connection=client, key=key_name)
+    assert the_type == "ReJSON-RL"
+    # you cannot access this key as string
+    result = get_str(connect=client, key=key_name)
+    assert result is not None
+    assert result == "WRONGTYPE Operation against a key holding the wrong kind of value"
+
+
+def test_reset_key_to_string(client):
+    key_name = "test-json-key"
+    result = get_set_json(connection=client, key=key_name, value=jane)
+    assert result is not None, "failed to set JSON value"
+    # make sure that we have valid JSON here
+    the_type = get_type(connection=client, key=key_name)
+    assert the_type == "ReJSON-RL"
+    # set the key to be string - this is legal
+    assert client.set(
+        key_name, "some random value"), "we should be able to set type to string"
+    result = get_str(connect=client, key=key_name)
+    assert result == "some random value"
+    # For JSON set the update the root path, we are allowing
+    # to change the type to JSON and override it
+    result = get_set_json(connection=client, key=key_name, value=jane)
+    the_type = get_type(connection=client, key=key_name)
+    assert the_type == "ReJSON-RL"
+
+
+def test_update_value(client):
+    key_name = "test-json-key"
+    result = get_set_json(connection=client, key=key_name, value=json_num)
+    assert result is not None, "failed to set JSON value"
+    # make sure that we have valid JSON here
+    the_type = get_type(connection=client, key=key_name)
+    assert the_type == "ReJSON-RL"
+    result = get_set_json(connection=client, value="0",
+                          key=key_name, path="$.a.*")
+    assert len(result) == 3
+    # make sure that all the values under 'a' where set to 0
+    assert result == ['0', '0', '0']
+    # Ensure that after we're changing this into STRING type, it will no longer work
+    assert client.set(key_name, "some random value")
+    assert get_type(connection=client, key=key_name) == "string"
+    assert get_set_json(connection=client, value="0", key=key_name,
+                        path="$.a.*") == "WRONGTYPE Operation against a key holding the wrong kind of value"
+    assert get_type(connection=client, key=key_name) == "string"

tools/json_benchmark.py

@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+
+import multiprocessing
+import time
+import redis
+import sys
+import argparse
+from urllib.parse import urlparse
+import os
+from collections import defaultdict
+import math
+
+'''
+Run JSON benchmark for 3 commands:
+    JSON.SET
+    JSON.GET
+    JSON.TYPE
+We want to the overall time it takes
+to save and access keys that contains
+JSON values with this benchmark.
+This also verify that the basic functionalities
+for using JSON types work correctly
+'''
+
+def ping(r):
+    r.ping()
+
+def jsonset(r, i):
+    key = "json-{}".format(i)
+    r.execute_command('JSON.SET', key, '.', '{"a":123456, "b": "hello", "nested": {"abc": "ffffff", "bfb": null}}')
+
+
+def jsonget(r, i):
+    key = "json-{}".format(i)
+    r.execute_command('JSON.GET', key, '$.a', '$..abc')
+
+def jsontype(r, i):
+    key = "json-{}".format(i)
+    r.execute_command('JSON.TYPE', key, '$.a')
+
+def runWorker(ctx):
+    wpid = os.getpid()
+    print( '{} '.format(wpid))
+
+    rep = defaultdict(int)
+    r = redis.StrictRedis(host=ctx['host'], port=ctx['port'])
+    work = ctx['work']
+    if ctx['pipeline'] == 0:
+        total_count = int(ctx['count'])
+        for i in range(0, total_count):
+            s0 = time.time()
+            jsonset(r, i)
+            s1 = time.time() - s0
+            bin = int(math.floor(s1 * 1000)) + 1
+            rep[bin] += 1
+        for i in range(0, total_count):
+            s0 = time.time()
+            jsonget(r, i)
+            s1 = time.time() - s0
+            bin = int(math.floor(s1 * 1000)) + 1
+            rep[bin] += 1
+        for i in range(0, total_count):
+            s0 = time.time()
+            jsontype(r, i)
+            s1 = time.time() - s0
+            bin = int(math.floor(s1 * 1000)) + 1
+            rep[bin] += 1
+    else:
+        for i in range(0, ctx['count'], ctx['pipeline']):
+            p = r.pipeline()
+            s0 = time.time()
+            for j in range(0, ctx['pipeline']):
+                work(p)
+            p.execute()
+            s1 = time.time() - s0
+            bin = int(math.floor(s1 * 1000)) + 1
+            rep[bin] += ctx['pipeline']
+
+    return rep
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='ReJSON Benchmark', formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+    parser.add_argument('-c', '--count', type=int, default=100000, help='total number of operations')
+    parser.add_argument('-p', '--pipeline', type=int, default=0, help='pipeline size')
+    parser.add_argument('-w', '--workers', type=int, default=8, help='number of worker processes')
+    parser.add_argument('-u', '--uri', type=str, default='redis://localhost:6379', help='Redis server URI')
+    args = parser.parse_args()
+    uri = urlparse(args.uri)
+
+    r = redis.Redis(host=uri.hostname, port=uri.port)
+
+    pool = multiprocessing.Pool(args.workers)
+    s0 = time.time()
+    ctx = {
+        'count': args.count / args.workers,
+        'pipeline': args.pipeline,
+        'host': uri.hostname,
+        'port': uri.port,
+        'work': jsonset,
+    }
+
+    print ('Starting workers: ')
+    p = multiprocessing.Pool(args.workers)
+    results = p.map(runWorker, (ctx, ) * args.workers)
+    print("")
+    sys.stdout.flush()
+
+    s1 = time.time() - s0
+    agg = defaultdict(int)
+    for res in results:
+        for k, v in res.items():
+            agg[k] += v
+
+    print()
+    count = args.count * 3
+    print (f'Count: {args.count}, Workers: {args.workers}, Pipeline: {args.pipeline}')
+    print (f'Using hireds: {redis.utils.HIREDIS_AVAILABLE}')
+    print (f'Runtime: {round(s1, 2):,} seconds')
+    print (f'Throughput: {round(count/s1, 2):,} requests per second')
+    for k, v in sorted(agg.items()):
+        perc = 100.0 * v / count
+        print (f'{perc:.4f}% <= {k:,} milliseconds')