fix comments

Author: songqing

src/types/redis_stream.cc

@@ -27,6 +27,7 @@
 #include <vector>
 
 #include "db_util.h"
+#include "string_util.h"
 #include "time_util.h"
 
 namespace redis {
@@ -751,6 +752,14 @@ rocksdb::Status Stream::DestroyGroup(engine::Context &ctx, const Slice &stream_n
     return rocksdb::Status::InvalidArgument(errXGroupSubcommandRequiresKeyExist);
   }
 
+  std::string group_key = internalKeyFromGroupName(ns_key, metadata, group_name);
+  std::string val;
+  s = storage_->Get(ctx, ctx.GetReadOptions(), stream_cf_handle_, group_key, &val);
+  if (s.IsNotFound()) {
+    return rocksdb::Status::OK();
+  }
+  if (!s.ok()) return s;
+
   auto batch = storage_->GetWriteBatchBase();
   WriteBatchLogData log_data(kRedisStream);
   s = batch->PutLogData(log_data.Encode());
@@ -764,43 +773,22 @@ rocksdb::Status Stream::DestroyGroup(engine::Context &ctx, const Slice &stream_n
     PutFixed64(&sub_key_prefix, group_name.size());
     sub_key_prefix += group_name;
 
-    std::string next_version_prefix_key =
-        InternalKey(ns_key, sub_key_prefix, metadata.version + 1, storage_->IsSlotIdEncoded()).Encode();
     std::string prefix_key =
         InternalKey(ns_key, sub_key_prefix, metadata.version, storage_->IsSlotIdEncoded()).Encode();
+    std::string end_key =
+        InternalKey(ns_key, util::StringNext(sub_key_prefix), metadata.version, storage_->IsSlotIdEncoded()).Encode();
 
-    rocksdb::ReadOptions read_options = ctx.DefaultScanOptions();
-    rocksdb::Slice upper_bound(next_version_prefix_key);
-    read_options.iterate_upper_bound = &upper_bound;
-    rocksdb::Slice lower_bound(prefix_key);
-    read_options.iterate_lower_bound = &lower_bound;
-
-    auto iter = util::UniqueIterator(ctx, read_options, stream_cf_handle_);
-    for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
-      if (identifySubkeyType(iter->key()) != type) {
-        continue;
-      }
-      if (groupNameFromInternalKey(iter->key()) != group_name) {
-        continue;
-      }
-      s = batch->Delete(stream_cf_handle_, iter->key());
-      if (!s.ok()) return s;
-      *delete_cnt += 1;
-    }
-
-    if (auto s = iter->status(); !s.ok()) {
-      return s;
-    }
-  }
-
-  if (*delete_cnt != 0) {
-    metadata.group_number -= 1;
-    std::string metadata_bytes;
-    metadata.Encode(&metadata_bytes);
-    s = batch->Put(metadata_cf_handle_, ns_key, metadata_bytes);
+    s = batch->DeleteRange(stream_cf_handle_, prefix_key, end_key);
     if (!s.ok()) return s;
   }
 
+  *delete_cnt = 1;
+  metadata.group_number -= 1;
+  std::string metadata_bytes;
+  metadata.Encode(&metadata_bytes);
+  s = batch->Put(metadata_cf_handle_, ns_key, metadata_bytes);
+  if (!s.ok()) return s;
+
   return storage_->Write(ctx, storage_->DefaultWriteOptions(), batch->GetWriteBatch());
 }