refactor(api): use hashy hash for looking up api method and event names

This avoids generating khash tables at runtime, and is consistent with
how evalfuncs lookup work.

src/nvim/api/private/dispatch.c

@@ -32,37 +32,22 @@
 #include "nvim/api/window.h"
 #include "nvim/ui_client.h"
 
-static Map(String, MsgpackRpcRequestHandler) methods = MAP_INIT;
-
-static void msgpack_rpc_add_method_handler(String method, MsgpackRpcRequestHandler handler)
-{
-  map_put(String, MsgpackRpcRequestHandler)(&methods, method, handler);
-}
-
-void msgpack_rpc_add_redraw(void)
-{
-  msgpack_rpc_add_method_handler(STATIC_CSTR_AS_STRING("redraw"),
-                                 (MsgpackRpcRequestHandler) { .fn = ui_client_handle_redraw,
-                                                              .fast = true });
-}
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "api/private/dispatch_wrappers.generated.h"
+#endif
 
 /// @param name API method name
 /// @param name_len name size (includes terminating NUL)
 MsgpackRpcRequestHandler msgpack_rpc_get_handler_for(const char *name, size_t name_len,
                                                      Error *error)
 {
-  String m = { .data = (char *)name, .size = name_len };
-  MsgpackRpcRequestHandler rv =
-    map_get(String, MsgpackRpcRequestHandler)(&methods, m);
+  int hash = msgpack_rpc_get_handler_for_hash(name, name_len);
 
-  if (!rv.fn) {
+  if (hash < 0) {
     api_set_error(error, kErrorTypeException, "Invalid method: %.*s",
-                  m.size > 0 ? (int)m.size : (int)sizeof("<empty>"),
-                  m.size > 0 ? m.data : "<empty>");
+                  name_len > 0 ? (int)name_len : (int)sizeof("<empty>"),
+                  name_len > 0 ? name : "<empty>");
+    return (MsgpackRpcRequestHandler){ 0 };
   }
-  return rv;
+  return method_handlers[hash];
 }
-
-#ifdef INCLUDE_GENERATED_DECLARATIONS
-# include "api/private/dispatch_wrappers.generated.h"
-#endif

src/nvim/api/private/dispatch.h

@@ -10,6 +10,7 @@ typedef Object (*ApiDispatchWrapper)(uint64_t channel_id,
 /// The rpc_method_handlers table, used in msgpack_rpc_dispatch(), stores
 /// functions of this type.
 typedef struct {
+  const char *name;
   ApiDispatchWrapper fn;
   bool fast;  // Function is safe to be executed immediately while running the
               // uv loop (the loop is run very frequently due to breakcheck).

src/nvim/generators/gen_api_dispatch.lua

@@ -16,6 +16,10 @@ local functions = {}
 local nvimdir = arg[1]
 package.path = nvimdir .. '/?.lua;' .. package.path
 
+_G.vim = loadfile(nvimdir..'/../../runtime/lua/vim/shared.lua')()
+
+local hashy = require'generators.hashy'
+
 -- names of all headers relative to the source root (for inclusion in the
 -- generated file)
 local headers = {}
@@ -339,24 +343,27 @@ for i = 1, #functions do
   end
 end
 
--- Generate a function that initializes method names with handler functions
-output:write([[
-void msgpack_rpc_init_method_table(void)
-{
-]])
-
-for i = 1, #functions do
-  local fn = functions[i]
+local remote_fns = {}
+for _,fn in ipairs(functions) do
   if fn.remote then
-      output:write('  msgpack_rpc_add_method_handler('..
-                   '(String) {.data = "'..fn.name..'", '..
-                   '.size = sizeof("'..fn.name..'") - 1}, '..
-                   '(MsgpackRpcRequestHandler) {.fn = handle_'..  (fn.impl_name or fn.name)..
-                   ', .fast = '..tostring(fn.fast)..'});\n')
+    remote_fns[fn.name] = fn
   end
 end
+remote_fns.redraw = {impl_name="ui_client_redraw", fast=true}
+
+local hashorder, hashfun = hashy.hashy_hash("msgpack_rpc_get_handler_for", vim.tbl_keys(remote_fns), function (idx)
+  return "method_handlers["..idx.."].name"
+end)
+
+output:write("static const MsgpackRpcRequestHandler method_handlers[] = {\n")
+for _, name in ipairs(hashorder) do
+  local fn = remote_fns[name]
+  output:write('  { .name = "'..name..'", .fn = handle_'..  (fn.impl_name or fn.name)..
+               ', .fast = '..tostring(fn.fast)..'},\n')
+end
+output:write("};\n\n")
+output:write(hashfun)
 
-output:write('\n}\n\n')
 output:close()
 
 local mpack_output = io.open(mpack_outputf, 'wb')

src/nvim/generators/gen_api_ui_events.lua

@@ -15,6 +15,9 @@ local client_output = io.open(arg[8], 'wb')
 local c_grammar = require('generators.c_grammar')
 local events = c_grammar.grammar:match(input:read('*all'))
 
+_G.vim = loadfile(nvimdir..'/../../runtime/lua/vim/shared.lua')()
+local hashy = require'generators.hashy'
+
 local function write_signature(output, ev, prefix, notype)
   output:write('('..prefix)
   if prefix == "" and #ev.parameters == 0 then
@@ -213,24 +216,25 @@ for i = 1, #events do
   end
 end
 
--- Generate the map_init method for client handlers
-client_output:write([[
-void ui_client_methods_table_init(void)
-{
-
-]])
-
-for i = 1, #events do
-  local fn = events[i]
-  if (not fn.noexport) and ((not fn.remote_only) or fn.client_impl) then
-    client_output:write('  add_ui_client_event_handler('..
-                '(String) {.data = "'..fn.name..'", '..
-                '.size = sizeof("'..fn.name..'") - 1}, '..
-                '(UIClientHandler) ui_client_event_'..fn.name..');\n')
+local client_events = {}
+for _,ev in ipairs(events) do
+  if (not ev.noexport) and ((not ev.remote_only) or ev.client_impl) then
+    client_events[ev.name] = ev
   end
 end
 
-client_output:write('\n}\n\n')
+local hashorder, hashfun = hashy.hashy_hash("ui_client_handler", vim.tbl_keys(client_events), function (idx)
+  return "event_handlers["..idx.."].name"
+end)
+
+client_output:write("static const UIClientHandler event_handlers[] = {\n")
+
+for _, name in ipairs(hashorder) do
+  client_output:write('  { .name = "'..name..'", .fn = ui_client_event_'..name..'},\n')
+end
+
+client_output:write('\n};\n\n')
+client_output:write(hashfun)
 
 proto_output:close()
 call_output:close()

src/nvim/main.c

@@ -121,7 +121,6 @@ void event_init(void)
   resize_events = multiqueue_new_child(main_loop.events);
 
   // early msgpack-rpc initialization
-  msgpack_rpc_init_method_table();
   msgpack_rpc_helpers_init();
   input_init();
   signal_init();

src/nvim/map.c

@@ -14,7 +14,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "nvim/api/private/dispatch.h"
 #include "nvim/lib/khash.h"
 #include "nvim/map.h"
 #include "nvim/map_defs.h"
@@ -171,13 +170,10 @@ MAP_IMPL(uint64_t, ssize_t, SSIZE_INITIALIZER)
 MAP_IMPL(uint64_t, uint64_t, DEFAULT_INITIALIZER)
 MAP_IMPL(uint32_t, uint32_t, DEFAULT_INITIALIZER)
 MAP_IMPL(handle_T, ptr_t, DEFAULT_INITIALIZER)
-#define MSGPACK_HANDLER_INITIALIZER { .fn = NULL, .fast = false }
-MAP_IMPL(String, MsgpackRpcRequestHandler, MSGPACK_HANDLER_INITIALIZER)
 MAP_IMPL(HlEntry, int, DEFAULT_INITIALIZER)
 MAP_IMPL(String, handle_T, 0)
 MAP_IMPL(String, int, DEFAULT_INITIALIZER)
 MAP_IMPL(int, String, DEFAULT_INITIALIZER)
-MAP_IMPL(String, UIClientHandler, NULL)
 
 MAP_IMPL(ColorKey, ColorItem, COLOR_ITEM_INITIALIZER)
 

src/nvim/map.h

@@ -4,7 +4,6 @@
 #include <stdbool.h>
 
 #include "nvim/api/private/defs.h"
-#include "nvim/api/private/dispatch.h"
 #include "nvim/extmark_defs.h"
 #include "nvim/highlight_defs.h"
 #include "nvim/map_defs.h"
@@ -44,12 +43,10 @@ MAP_DECLS(uint64_t, uint64_t)
 MAP_DECLS(uint32_t, uint32_t)
 
 MAP_DECLS(handle_T, ptr_t)
-MAP_DECLS(String, MsgpackRpcRequestHandler)
 MAP_DECLS(HlEntry, int)
 MAP_DECLS(String, handle_T)
 MAP_DECLS(String, int)
 MAP_DECLS(int, String)
-MAP_DECLS(String, UIClientHandler)
 
 MAP_DECLS(ColorKey, ColorItem)
 

src/nvim/msgpack_rpc/channel_defs.h

@@ -6,6 +6,7 @@
 #include <uv.h>
 
 #include "nvim/api/private/defs.h"
+#include "nvim/api/private/dispatch.h"
 #include "nvim/event/process.h"
 #include "nvim/event/socket.h"
 #include "nvim/vim.h"

src/nvim/ui_client.c

@@ -16,18 +16,17 @@
 #include "nvim/ui_client.h"
 #include "nvim/vim.h"
 
-static Map(String, UIClientHandler) ui_client_handlers = MAP_INIT;
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "ui_client.c.generated.h"
+
+# include "ui_events_client.generated.h"
+#endif
 
 // Temporary buffer for converting a single grid_line event
 static size_t buf_size = 0;
 static schar_T *buf_char = NULL;
 static sattr_T *buf_attr = NULL;
 
-static void add_ui_client_event_handler(String method, UIClientHandler handler)
-{
-  map_put(String, UIClientHandler)(&ui_client_handlers, method, handler);
-}
-
 void ui_client_init(uint64_t chan)
 {
   Array args = ARRAY_DICT_INIT;
@@ -44,9 +43,6 @@ void ui_client_init(uint64_t chan)
   ADD(args, DICTIONARY_OBJ(opts));
 
   rpc_send_event(chan, "nvim_ui_attach", args);
-  msgpack_rpc_add_redraw();  // GAME!
-  // TODO(bfredl): use a keyset instead
-  ui_client_methods_table_init();
   ui_client_channel_id = chan;
 }
 
@@ -61,22 +57,23 @@ void ui_client_init(uint64_t chan)
 /// @param channel_id: The id of the rpc channel
 /// @param uidata: The dense array containing the ui_events sent by the server
 /// @param[out] err Error details, if any
-Object ui_client_handle_redraw(uint64_t channel_id, Array args, Error *error)
+Object handle_ui_client_redraw(uint64_t channel_id, Array args, Error *error)
 {
   for (size_t i = 0; i < args.size; i++) {
     Array call = args.items[i].data.array;
     String name = call.items[0].data.string;
 
-    UIClientHandler handler = map_get(String, UIClientHandler)(&ui_client_handlers, name);
-    if (!handler) {
+    int hash = ui_client_handler_hash(name.data, name.size);
+    if (hash < 0) {
       ELOG("No ui client handler for %s", name.size ? name.data : "<empty>");
       continue;
     }
+    UIClientHandler handler = event_handlers[hash];
 
     // fprintf(stderr, "%s: %zu\n", name.data, call.size-1);
     DLOG("Invoke ui client handler for %s", name.data);
     for (size_t j = 1; j < call.size; j++) {
-      handler(call.items[j].data.array);
+      handler.fn(call.items[j].data.array);
     }
   }
 
@@ -108,10 +105,6 @@ static HlAttrs ui_client_dict2hlattrs(Dictionary d, bool rgb)
   return dict2hlattrs(&dict, true, NULL, &err);
 }
 
-#ifdef INCLUDE_GENERATED_DECLARATIONS
-# include "ui_events_client.generated.h"
-#endif
-
 void ui_client_event_grid_resize(Array args)
 {
   if (args.size < 3

src/nvim/ui_client.h

@@ -3,7 +3,10 @@
 
 #include "nvim/api/private/defs.h"
 
-typedef void (*UIClientHandler)(Array args);
+typedef struct {
+  const char *name;
+  void (*fn)(Array args);
+} UIClientHandler;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "ui_client.h.generated.h"