diff options
Diffstat (limited to 'runtime/lua/vim/lsp/_changetracking.lua')
| -rw-r--r-- | runtime/lua/vim/lsp/_changetracking.lua | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/runtime/lua/vim/lsp/_changetracking.lua b/runtime/lua/vim/lsp/_changetracking.lua new file mode 100644 index 0000000000..b2be53269f --- /dev/null +++ b/runtime/lua/vim/lsp/_changetracking.lua @@ -0,0 +1,373 @@ +local protocol = require('vim.lsp.protocol') +local sync = require('vim.lsp.sync') +local util = require('vim.lsp.util') + +local api = vim.api +local uv = vim.uv + +local M = {} + +--- LSP has 3 different sync modes: +--- - None (Servers will read the files themselves when needed) +--- - Full (Client sends the full buffer content on updates) +--- - Incremental (Client sends only the changed parts) +--- +--- Changes are tracked per buffer. +--- A buffer can have multiple clients attached and each client needs to send the changes +--- To minimize the amount of changesets to compute, computation is grouped: +--- +--- None: One group for all clients +--- Full: One group for all clients +--- Incremental: One group per `offset_encoding` +--- +--- Sending changes can be debounced per buffer. To simplify the implementation the +--- smallest debounce interval is used and we don't group clients by different intervals. +--- +--- @class vim.lsp.CTGroup +--- @field sync_kind integer TextDocumentSyncKind, considers config.flags.allow_incremental_sync +--- @field offset_encoding "utf-8"|"utf-16"|"utf-32" +--- +--- @class vim.lsp.CTBufferState +--- @field name string name of the buffer +--- @field lines string[] snapshot of buffer lines from last didChange +--- @field lines_tmp string[] +--- @field pending_changes table[] List of debounced changes in incremental sync mode +--- @field timer uv.uv_timer_t? uv_timer +--- @field last_flush nil|number uv.hrtime of the last flush/didChange-notification +--- @field needs_flush boolean true if buffer updates haven't been sent to clients/servers yet +--- @field refs integer how many clients are using this group +--- +--- @class vim.lsp.CTGroupState +--- @field buffers table<integer,vim.lsp.CTBufferState> +--- @field debounce integer debounce duration in ms +--- @field clients table<integer, table> clients using this state. {client_id, client} + +---@param group vim.lsp.CTGroup +---@return string +local function group_key(group) + if group.sync_kind == protocol.TextDocumentSyncKind.Incremental then + return tostring(group.sync_kind) .. '\0' .. group.offset_encoding + end + return tostring(group.sync_kind) +end + +---@type table<vim.lsp.CTGroup,vim.lsp.CTGroupState> +local state_by_group = setmetatable({}, { + __index = function(tbl, k) + return rawget(tbl, group_key(k)) + end, + __newindex = function(tbl, k, v) + rawset(tbl, group_key(k), v) + end, +}) + +---@param client vim.lsp.Client +---@return vim.lsp.CTGroup +local function get_group(client) + local allow_inc_sync = vim.F.if_nil(client.flags.allow_incremental_sync, true) --- @type boolean + local change_capability = vim.tbl_get(client.server_capabilities, 'textDocumentSync', 'change') + local sync_kind = change_capability or protocol.TextDocumentSyncKind.None + if not allow_inc_sync and change_capability == protocol.TextDocumentSyncKind.Incremental then + sync_kind = protocol.TextDocumentSyncKind.Full --[[@as integer]] + end + return { + sync_kind = sync_kind, + offset_encoding = client.offset_encoding, + } +end + +---@param state vim.lsp.CTBufferState +---@param encoding string +---@param bufnr integer +---@param firstline integer +---@param lastline integer +---@param new_lastline integer +---@return lsp.TextDocumentContentChangeEvent +local function incremental_changes(state, encoding, bufnr, firstline, lastline, new_lastline) + local prev_lines = state.lines + local curr_lines = state.lines_tmp + + local changed_lines = api.nvim_buf_get_lines(bufnr, firstline, new_lastline, true) + for i = 1, firstline do + curr_lines[i] = prev_lines[i] + end + for i = firstline + 1, new_lastline do + curr_lines[i] = changed_lines[i - firstline] + end + for i = lastline + 1, #prev_lines do + curr_lines[i - lastline + new_lastline] = prev_lines[i] + end + if vim.tbl_isempty(curr_lines) then + -- Can happen when deleting the entire contents of a buffer, see https://github.com/neovim/neovim/issues/16259. + curr_lines[1] = '' + end + + local line_ending = vim.lsp._buf_get_line_ending(bufnr) + local incremental_change = sync.compute_diff( + state.lines, + curr_lines, + firstline, + lastline, + new_lastline, + encoding, + line_ending + ) + + -- Double-buffering of lines tables is used to reduce the load on the garbage collector. + -- At this point the prev_lines table is useless, but its internal storage has already been allocated, + -- so let's keep it around for the next didChange event, in which it will become the next + -- curr_lines table. Note that setting elements to nil doesn't actually deallocate slots in the + -- internal storage - it merely marks them as free, for the GC to deallocate them. + for i in ipairs(prev_lines) do + prev_lines[i] = nil + end + state.lines = curr_lines + state.lines_tmp = prev_lines + + return incremental_change +end + +---@param client vim.lsp.Client +---@param bufnr integer +function M.init(client, bufnr) + assert(client.offset_encoding, 'lsp client must have an offset_encoding') + local group = get_group(client) + local state = state_by_group[group] + if state then + state.debounce = math.min(state.debounce, client.flags.debounce_text_changes or 150) + state.clients[client.id] = client + else + state = { + buffers = {}, + debounce = client.flags.debounce_text_changes or 150, + clients = { + [client.id] = client, + }, + } + state_by_group[group] = state + end + local buf_state = state.buffers[bufnr] + if buf_state then + buf_state.refs = buf_state.refs + 1 + else + buf_state = { + name = api.nvim_buf_get_name(bufnr), + lines = {}, + lines_tmp = {}, + pending_changes = {}, + needs_flush = false, + refs = 1, + } + state.buffers[bufnr] = buf_state + if group.sync_kind == protocol.TextDocumentSyncKind.Incremental then + buf_state.lines = api.nvim_buf_get_lines(bufnr, 0, -1, true) + end + end +end + +--- @param client vim.lsp.Client +--- @param bufnr integer +--- @param name string +--- @return string +function M._get_and_set_name(client, bufnr, name) + local state = state_by_group[get_group(client)] or {} + local buf_state = (state.buffers or {})[bufnr] + local old_name = buf_state.name + buf_state.name = name + return old_name +end + +---@param buf_state vim.lsp.CTBufferState +local function reset_timer(buf_state) + local timer = buf_state.timer + if timer then + buf_state.timer = nil + if not timer:is_closing() then + timer:stop() + timer:close() + end + end +end + +--- @param client vim.lsp.Client +--- @param bufnr integer +function M.reset_buf(client, bufnr) + M.flush(client, bufnr) + local state = state_by_group[get_group(client)] + if not state then + return + end + assert(state.buffers, 'CTGroupState must have buffers') + local buf_state = state.buffers[bufnr] + buf_state.refs = buf_state.refs - 1 + assert(buf_state.refs >= 0, 'refcount on buffer state must not get negative') + if buf_state.refs == 0 then + state.buffers[bufnr] = nil + reset_timer(buf_state) + end +end + +--- @param client vim.lsp.Client +function M.reset(client) + local state = state_by_group[get_group(client)] + if not state then + return + end + state.clients[client.id] = nil + if vim.tbl_count(state.clients) == 0 then + for _, buf_state in pairs(state.buffers) do + reset_timer(buf_state) + end + state.buffers = {} + end +end + +-- 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 +-- +---@param debounce integer +---@param buf_state vim.lsp.CTBufferState +---@return number +local function next_debounce(debounce, buf_state) + if debounce == 0 then + return 0 + end + local ns_to_ms = 0.000001 + if not buf_state.last_flush then + return debounce + end + local now = uv.hrtime() + local ms_since_last_flush = (now - buf_state.last_flush) * ns_to_ms + return math.max(debounce - ms_since_last_flush, 0) +end + +---@param bufnr integer +---@param sync_kind integer protocol.TextDocumentSyncKind +---@param state vim.lsp.CTGroupState +---@param buf_state vim.lsp.CTBufferState +local function send_changes(bufnr, sync_kind, state, buf_state) + if not buf_state.needs_flush then + return + end + buf_state.last_flush = uv.hrtime() + buf_state.needs_flush = false + + if not api.nvim_buf_is_valid(bufnr) then + buf_state.pending_changes = {} + return + end + + local changes --- @type lsp.TextDocumentContentChangeEvent[] + if sync_kind == protocol.TextDocumentSyncKind.None then + return + elseif sync_kind == protocol.TextDocumentSyncKind.Incremental then + changes = buf_state.pending_changes + buf_state.pending_changes = {} + else + changes = { + { text = vim.lsp._buf_get_full_text(bufnr) }, + } + end + local uri = vim.uri_from_bufnr(bufnr) + for _, client in pairs(state.clients) do + if not client.is_stopped() and vim.lsp.buf_is_attached(bufnr, client.id) then + client.notify(protocol.Methods.textDocument_didChange, { + textDocument = { + uri = uri, + version = util.buf_versions[bufnr], + }, + contentChanges = changes, + }) + end + end +end + +--- @param bufnr integer +--- @param firstline integer +--- @param lastline integer +--- @param new_lastline integer +--- @param group vim.lsp.CTGroup +local function send_changes_for_group(bufnr, firstline, lastline, new_lastline, group) + local state = state_by_group[group] + if not state then + error( + string.format( + 'changetracking.init must have been called for all LSP clients. group=%s states=%s', + vim.inspect(group), + vim.inspect(vim.tbl_keys(state_by_group)) + ) + ) + end + local buf_state = state.buffers[bufnr] + buf_state.needs_flush = true + reset_timer(buf_state) + local debounce = next_debounce(state.debounce, buf_state) + if group.sync_kind == protocol.TextDocumentSyncKind.Incremental then + -- This must be done immediately and cannot be delayed + -- The contents would further change and startline/endline may no longer fit + local changes = incremental_changes( + buf_state, + group.offset_encoding, + bufnr, + firstline, + lastline, + new_lastline + ) + table.insert(buf_state.pending_changes, changes) + end + if debounce == 0 then + send_changes(bufnr, group.sync_kind, state, buf_state) + else + local timer = assert(uv.new_timer(), 'Must be able to create timer') + buf_state.timer = timer + timer:start( + debounce, + 0, + vim.schedule_wrap(function() + reset_timer(buf_state) + send_changes(bufnr, group.sync_kind, state, buf_state) + end) + ) + end +end + +--- @param bufnr integer +--- @param firstline integer +--- @param lastline integer +--- @param new_lastline integer +function M.send_changes(bufnr, firstline, lastline, new_lastline) + local groups = {} ---@type table<string,vim.lsp.CTGroup> + for _, client in pairs(vim.lsp.get_clients({ bufnr = bufnr })) do + local group = get_group(client) + groups[group_key(group)] = group + end + for _, group in pairs(groups) do + send_changes_for_group(bufnr, firstline, lastline, new_lastline, group) + end +end + +--- Flushes any outstanding change notification. +---@param client vim.lsp.Client +---@param bufnr? integer +function M.flush(client, bufnr) + local group = get_group(client) + local state = state_by_group[group] + if not state then + return + end + if bufnr then + local buf_state = state.buffers[bufnr] or {} + reset_timer(buf_state) + send_changes(bufnr, group.sync_kind, state, buf_state) + else + for buf, buf_state in pairs(state.buffers) do + reset_timer(buf_state) + send_changes(buf, group.sync_kind, state, buf_state) + end + end +end + +return M |