1 files changed, 39 insertions, 5 deletions

diff --git a/runtime/lua/vim/lsp.lua b/runtime/lua/vim/lsp.lua
index 7df0064b6b..fc9c991c05 100644
--- a/runtime/lua/vim/lsp.lua
+++ b/runtime/lua/vim/lsp.lua
@@ -306,7 +306,6 @@ local function once(fn)
   end
 end
 
-
 local changetracking = {}
 do
   --@private
@@ -327,6 +326,7 @@ do
     if not state then
       state = {
         pending_changes = {};
+        last_flush = {};
         use_incremental_sync = (
           if_nil(client.config.flags.allow_incremental_sync, true)
           and client.resolved_capabilities.text_document_did_change == protocol.TextDocumentSyncKind.Incremental
@@ -347,8 +347,11 @@ do
   function changetracking.reset_buf(client, bufnr)
     changetracking.flush(client)
     local state = state_by_client[client.id]
-    if state and state.buffers then
-      state.buffers[bufnr] = nil
+    if state then
+      if state.buffers then
+        state.buffers[bufnr] = nil
+      end
+      state.last_flush = {}
     end
   end
 
@@ -362,6 +365,33 @@ do
   end
 
   ---@private
+  --
+  -- Adjust debounce time by taking time of last didChange notification into
+  -- consideration. If the last didChange happened more than `debounce` time ago,
+  -- debounce can be skipped and otherwise maybe reduced.
+  --
+  -- This turns the debounce into a kind of client rate limiting
+  local function next_debounce(debounce, state, bufnr)
+    if debounce == 0 then
+      return 0
+    end
+    local ns_to_ms = 0.000001
+    local last_flush = state.last_flush[bufnr]
+    if not last_flush then
+      return debounce
+    end
+    local now = uv.hrtime()
+    local ms_since_last_flush = (now - last_flush) * ns_to_ms
+    local remaining_debounce = debounce - ms_since_last_flush
+    if remaining_debounce > 0 then
+      return remaining_debounce
+    else
+      state.last_flush[bufnr] = now
+      return 0
+    end
+  end
+
+  ---@private
   function changetracking.prepare(bufnr, firstline, lastline, new_lastline)
     local incremental_changes = function(client)
       local cached_buffers = state_by_client[client.id].buffers
@@ -383,8 +413,12 @@ do
         return
       end
       local state = state_by_client[client.id]
-      local debounce = client.config.flags.debounce_text_changes or 150
+      changetracking._reset_timer(state)
+      local debounce = next_debounce(client.config.flags.debounce_text_changes or 150, state, bufnr)
       if debounce == 0 then
+        if state.pending_change then
+          state.pending_change()
+        end
         local changes = state.use_incremental_sync and incremental_changes(client) or full_changes()
         client.notify("textDocument/didChange", {
           textDocument = {
@@ -395,7 +429,6 @@ do
         })
         return
       end
-      changetracking._reset_timer(state)
       if state.use_incremental_sync then
         -- This must be done immediately and cannot be delayed
         -- The contents would further change and startline/endline may no longer fit
@@ -406,6 +439,7 @@ do
       end
       state.pending_change = function()
         state.pending_change = nil
+        state.last_flush[bufnr] = uv.hrtime()
         if client.is_stopped() or not vim.api.nvim_buf_is_valid(bufnr) then
           return
         end