From 968551d5f1a202e71808971022d720417ee8430d Mon Sep 17 00:00:00 2001
From: Twice <twice.mliu@gmail.com>
Date: Sat, 21 Oct 2023 15:49:59 +0900
Subject: [PATCH] Add method to read JSON from storage for simplifying code
 (#1843)

---
 kvrocks.conf            |  5 ++++
 src/types/redis_json.cc | 55 ++++++++++++++++++-----------------------
 src/types/redis_json.h  |  2 ++
 3 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/kvrocks.conf b/kvrocks.conf
index 7089cec89eb..be4332543d8 100644
--- a/kvrocks.conf
+++ b/kvrocks.conf
@@ -312,6 +312,11 @@ max-bitmap-to-string-mb 16
 # Default: no
 redis-cursor-compatible no
 
+# Maximum nesting depth allowed when parsing and serializing 
+# JSON documents while using JSON commands like JSON.SET.
+# Default: 1024
+json-max-nesting-depth 1024
+
 ################################## TLS ###################################
 
 # By default, TLS/SSL is disabled, i.e. `tls-port` is set to 0.
diff --git a/src/types/redis_json.cc b/src/types/redis_json.cc
index 291d14b591d..cc4fc7681fd 100644
--- a/src/types/redis_json.cc
+++ b/src/types/redis_json.cc
@@ -45,15 +45,31 @@ rocksdb::Status Json::write(Slice ns_key, JsonMetadata *metadata, const JsonValu
   return storage_->Write(storage_->DefaultWriteOptions(), batch->GetWriteBatch());
 }
 
+rocksdb::Status Json::read(const Slice &ns_key, JsonMetadata *metadata, JsonValue *value) {
+  std::string bytes;
+  Slice rest;
+
+  auto s = GetMetadata(kRedisJson, ns_key, &bytes, metadata, &rest);
+  if (!s.ok()) return s;
+
+  if (metadata->format != JsonStorageFormat::JSON)
+    return rocksdb::Status::NotSupported("JSON storage format not supported");
+
+  auto origin_res = JsonValue::FromString(rest.ToStringView());
+  if (!origin_res) return rocksdb::Status::Corruption(origin_res.Msg());
+  *value = *std::move(origin_res);
+
+  return rocksdb::Status::OK();
+}
+
 rocksdb::Status Json::Set(const std::string &user_key, const std::string &path, const std::string &value) {
   auto ns_key = AppendNamespacePrefix(user_key);
 
   LockGuard guard(storage_->GetLockManager(), ns_key);
 
-  std::string bytes;
   JsonMetadata metadata;
-  Slice rest;
-  auto s = GetMetadata(kRedisJson, ns_key, &bytes, &metadata, &rest);
+  JsonValue origin;
+  auto s = read(ns_key, &metadata, &origin);
 
   if (s.IsNotFound()) {
     if (path != "$") return rocksdb::Status::InvalidArgument("new objects must be created at the root");
@@ -67,17 +83,10 @@ rocksdb::Status Json::Set(const std::string &user_key, const std::string &path,
 
   if (!s.ok()) return s;
 
-  if (metadata.format != JsonStorageFormat::JSON)
-    return rocksdb::Status::NotSupported("JSON storage format not supported");
-
   auto new_res = JsonValue::FromString(value, storage_->GetConfig()->json_max_nesting_depth);
   if (!new_res) return rocksdb::Status::InvalidArgument(new_res.Msg());
   auto new_val = *std::move(new_res);
 
-  auto origin_res = JsonValue::FromString(rest.ToStringView());
-  if (!origin_res) return rocksdb::Status::Corruption(origin_res.Msg());
-  auto origin = *std::move(origin_res);
-
   auto set_res = origin.Set(path, std::move(new_val));
   if (!set_res) return rocksdb::Status::InvalidArgument(set_res.Msg());
 
@@ -87,19 +96,11 @@ rocksdb::Status Json::Set(const std::string &user_key, const std::string &path,
 rocksdb::Status Json::Get(const std::string &user_key, const std::vector<std::string> &paths, JsonValue *result) {
   auto ns_key = AppendNamespacePrefix(user_key);
 
-  std::string bytes;
   JsonMetadata metadata;
-  Slice rest;
-  auto s = GetMetadata(kRedisJson, ns_key, &bytes, &metadata, &rest);
+  JsonValue json_val;
+  auto s = read(ns_key, &metadata, &json_val);
   if (!s.ok()) return s;
 
-  if (metadata.format != JsonStorageFormat::JSON)
-    return rocksdb::Status::NotSupported("JSON storage format not supported");
-
-  auto json_res = JsonValue::FromString(rest.ToStringView());
-  if (!json_res) return rocksdb::Status::Corruption(json_res.Msg());
-  auto json_val = *std::move(json_res);
-
   JsonValue res;
 
   if (paths.empty()) {
@@ -127,7 +128,7 @@ rocksdb::Status Json::ArrAppend(const std::string &user_key, const std::string &
   std::vector<jsoncons::json> append_values;
   append_values.reserve(values.size());
   for (auto &v : values) {
-    auto value_res = JsonValue::FromString(v);
+    auto value_res = JsonValue::FromString(v, storage_->GetConfig()->json_max_nesting_depth);
     if (!value_res) return rocksdb::Status::InvalidArgument(value_res.Msg());
     auto value = *std::move(value_res);
     append_values.emplace_back(std::move(value.value));
@@ -135,19 +136,11 @@ rocksdb::Status Json::ArrAppend(const std::string &user_key, const std::string &
 
   LockGuard guard(storage_->GetLockManager(), ns_key);
 
-  std::string bytes;
   JsonMetadata metadata;
-  Slice rest;
-  auto s = GetMetadata(kRedisJson, ns_key, &bytes, &metadata, &rest);
+  JsonValue value;
+  auto s = read(ns_key, &metadata, &value);
   if (!s.ok()) return s;
 
-  if (metadata.format != JsonStorageFormat::JSON)
-    return rocksdb::Status::NotSupported("JSON storage format not supported");
-
-  auto value_res = JsonValue::FromString(rest.ToStringView());
-  if (!value_res) return rocksdb::Status::Corruption(value_res.Msg());
-  auto value = *std::move(value_res);
-
   auto append_res = value.ArrAppend(path, append_values, result_count);
   if (!append_res) return rocksdb::Status::InvalidArgument(append_res.Msg());
 
diff --git a/src/types/redis_json.h b/src/types/redis_json.h
index 33c2625a533..04895be5e47 100644
--- a/src/types/redis_json.h
+++ b/src/types/redis_json.h
@@ -25,6 +25,7 @@
 #include <string>
 
 #include "json.h"
+#include "storage/redis_metadata.h"
 
 namespace redis {
 
@@ -39,6 +40,7 @@ class Json : public Database {
 
  private:
   rocksdb::Status write(Slice ns_key, JsonMetadata *metadata, const JsonValue &json_val);
+  rocksdb::Status read(const Slice &ns_key, JsonMetadata *metadata, JsonValue *value);
 };
 
 }  // namespace redis