1 files changed, 15 insertions, 19 deletions

diff --git a/src/core/lib/channel/channelz_registry.cc b/src/core/lib/channel/channelz_registry.cc
index e90a9e1f7f..1fe2fad3e1 100644
--- a/src/core/lib/channel/channelz_registry.cc
+++ b/src/core/lib/channel/channelz_registry.cc
@@ -79,12 +79,13 @@ void ChannelzRegistry::MaybePerformCompactionLocked() {
   }
 }
 
-int ChannelzRegistry::FindByUuidLocked(intptr_t target_uuid) {
-  size_t left = 0;
-  size_t right = entities_.size() - 1;
+int ChannelzRegistry::FindByUuidLocked(intptr_t target_uuid,
+                                       bool direct_hit_needed) {
+  int left = 0;
+  int right = int(entities_.size() - 1);
   while (left <= right) {
-    size_t true_middle = left + (right - left) / 2;
-    size_t first_non_null = true_middle;
+    int true_middle = left + (right - left) / 2;
+    int first_non_null = true_middle;
     while (first_non_null < right && entities_[first_non_null] == nullptr) {
       first_non_null++;
     }
@@ -102,14 +103,14 @@ int ChannelzRegistry::FindByUuidLocked(intptr_t target_uuid) {
       right = true_middle - 1;
     }
   }
-  return -1;
+  return direct_hit_needed ? -1 : left;
 }
 
 void ChannelzRegistry::InternalUnregister(intptr_t uuid) {
   GPR_ASSERT(uuid >= 1);
   MutexLock lock(&mu_);
   GPR_ASSERT(uuid <= uuid_generator_);
-  int idx = FindByUuidLocked(uuid);
+  int idx = FindByUuidLocked(uuid, true);
   GPR_ASSERT(idx >= 0);
   entities_[idx] = nullptr;
   num_empty_slots_++;
@@ -121,7 +122,7 @@ BaseNode* ChannelzRegistry::InternalGet(intptr_t uuid) {
   if (uuid < 1 || uuid > uuid_generator_) {
     return nullptr;
   }
-  int idx = FindByUuidLocked(uuid);
+  int idx = FindByUuidLocked(uuid, true);
   return idx < 0 ? nullptr : entities_[idx];
 }
 
@@ -131,16 +132,13 @@ char* ChannelzRegistry::InternalGetTopChannels(intptr_t start_channel_id) {
   grpc_json* json = top_level_json;
   grpc_json* json_iterator = nullptr;
   InlinedVector<BaseNode*, 10> top_level_channels;
-  // uuids index into entities one-off (idx 0 is really uuid 1, since 0 is
-  // reserved). However, we want to support requests coming in with
-  // start_channel_id=0, which signifies "give me everything." Hence this
-  // funky looking line below.
-  size_t start_idx = start_channel_id == 0 ? 0 : start_channel_id - 1;
   bool reached_pagination_limit = false;
+  int start_idx = GPR_MAX(FindByUuidLocked(start_channel_id, false), 0);
   for (size_t i = start_idx; i < entities_.size(); ++i) {
     if (entities_[i] != nullptr &&
         entities_[i]->type() ==
-            grpc_core::channelz::BaseNode::EntityType::kTopLevelChannel) {
+            grpc_core::channelz::BaseNode::EntityType::kTopLevelChannel &&
+        entities_[i]->uuid() >= start_channel_id) {
       // check if we are over pagination limit to determine if we need to set
       // the "end" element. If we don't go through this block, we know that
       // when the loop terminates, we have <= to kPaginationLimit.
@@ -176,15 +174,13 @@ char* ChannelzRegistry::InternalGetServers(intptr_t start_server_id) {
   grpc_json* json = top_level_json;
   grpc_json* json_iterator = nullptr;
   InlinedVector<BaseNode*, 10> servers;
-  // uuids index into entities one-off (idx 0 is really uuid 1, since 0 is
-  // reserved). However, we want to support requests coming in with
-  // start_server_id=0, which signifies "give me everything."
-  size_t start_idx = start_server_id == 0 ? 0 : start_server_id - 1;
   bool reached_pagination_limit = false;
+  int start_idx = GPR_MAX(FindByUuidLocked(start_server_id, false), 0);
   for (size_t i = start_idx; i < entities_.size(); ++i) {
     if (entities_[i] != nullptr &&
         entities_[i]->type() ==
-            grpc_core::channelz::BaseNode::EntityType::kServer) {
+            grpc_core::channelz::BaseNode::EntityType::kServer &&
+        entities_[i]->uuid() >= start_server_id) {
       // check if we are over pagination limit to determine if we need to set
       // the "end" element. If we don't go through this block, we know that
       // when the loop terminates, we have <= to kPaginationLimit.