Update readme

1. eglot
2. build instruction
3. better lsp-mode code (handle non-native-json version)

README.md

@@ -1,13 +1,13 @@
-# Emacs lsp-mode performance booster
+# Emacs LSP performance booster
 
-Improve performance of [lsp-mode](https://github.com/emacs-lsp/lsp-mode) using a wrapper executable.
+Improve performance of [lsp-mode](https://github.com/emacs-lsp/lsp-mode) or [eglot](https://github.com/joaotavora/eglot) using a wrapper executable.
 
 ## Background & Prior work
 
 (Huge thanks to @yyoncho for both maintaining lsp-mode and giving me the inspiration of this project).
 
 According to [yyoncho](https://www.reddit.com/r/emacs/comments/ymrkyn/comment/iv90q4i/?utm_source=share&utm_medium=web2x&context=3),
-the are several performance issues related to lsp-mode:
+the are several performance issues related to lsp-mode (mostly the same for elot):
 
 1. Json parsing in Emacs is slow
 2. The server may block on sending data to emacs when the buffer is full, because Emacs may consume the data too slo
@@ -17,6 +17,7 @@ the are several performance issues related to lsp-mode:
 The result is very good regarding performance. However it requires modifications in Emacs source code and it seems unlikely that those changes would be merged into upstream.
 Also, frankly I doubt that this would be well-maintained in the future since it also requires seperated code path in lsp-mode (I myself encountered some [issues](https://github.com/emacs-lsp/emacs/issues/12)).
 
+
 ## How this project work
 
 This project provides an wrapper executable around lsp servers to work around above-mentioned issues:
@@ -34,32 +35,51 @@ Overall, this achieves similar result as the native async non-blocking jsonrpc a
 
 ## How to use
 
-Prerequisite:
+Generally, what you need to do is:
+
+1. Wrap your lsp server command with this `emacs-lsp-booster` executable.
+   For example, if the original lsp server command is `pyright-langserver --stdio`, configure lsp-mode or eglot to run `emacs-lsp-booster pyright-langserver --stdio` instead.
+2. Advise the json parsing function in lsp-mode or eglot to try to parse the input as bytecode instead of json.
+
+See more detailed steps below.
+
+### Obtain or build `emacs-lsp-booster`
+
+For linux users, you may download the prebuilt binary from [release](https://github.com/blahgeek/emacs-lsp-booster/releases).
+*(The macOS binary in the release page lacks proper code signing for now.)*
 
-1. Emacs 28 or newer (NOT the [native-jsonrpc custom version](https://github.com/emacs-lsp/emacs)), recent version of lsp-mode
-2. **Use [plist for deserialization](https://emacs-lsp.github.io/lsp-mode/page/performance/#use-plists-for-deserialization) for lsp-mode**
+Or alternatively, you may build the target locally:
 
-Steps:
+1. Setup [Rust toolchain](https://rustup.rs/)
+2. Run `cargo build --release`
+3. Find the built binary in `target/release/emacs-lsp-booster`
 
-1. Build the target or download it from [release](https://github.com/blahgeek/emacs-lsp-booster/releases), put the executable `emacs-lsp-booster` in $PATH (e.g. `~/.local/bin`)
-2. Add the following code to your `init.el`:
+Then, put the `emacs-lsp-booster` binary in your $PATH (e.g. `~/.local/bin`).
 
-> NOTE: if your emacs does not have json support (aka, `(fboundp 'json-parse-buffer)` is nil),
-> replace `json-parse-buffer` with `json-read` in the first line!
+### Configure `lsp-mode`
 
-> **For eglot users**: see https://github.com/blahgeek/emacs-lsp-booster/issues/1
+(Make sure NOT to use the [native-jsonrpc custom version](https://github.com/emacs-lsp/emacs))
+
+1. **Use [plist for deserialization](https://emacs-lsp.github.io/lsp-mode/page/performance/#use-plists-for-deserialization) for lsp-mode**
+3. Add the following code to your `init.el`:
 
 ```elisp
-(define-advice json-parse-buffer (:around (old-fn &rest args) lsp-booster-parse-bytecode)
+(defun lsp-booster--advice-json-parse (old-fn &rest args)
   "Try to parse bytecode instead of json."
   (or
    (when (equal (following-char) ?#)
      (let ((bytecode (read (current-buffer))))
        (when (byte-code-function-p bytecode)
          (funcall bytecode))))
    (apply old-fn args)))
-
-(define-advice lsp-resolve-final-command (:around (old-fn cmd &optional test?) add-lsp-server-booster)
+(advice-add (if (progn (require 'json)
+                       (fboundp 'json-parse-buffer))
+                'json-parse-buffer
+              'json-read)
+            :around
+            #'lsp-booster--advice-json-parse)
+
+(defun lsp-booster--advice-final-command (old-fn cmd &optional test?)
   "Prepend emacs-lsp-booster command to lsp CMD."
   (let ((orig-result (funcall old-fn cmd test?)))
     (if (and (not test?)                             ;; for check lsp-server-present?
@@ -71,8 +91,16 @@ Steps:
           (message "Using emacs-lsp-booster for %s!" orig-result)
           (cons "emacs-lsp-booster" orig-result))
       orig-result)))
+(advice-add 'lsp-resolve-final-command :around #'lsp-booster--advice-final-command)
 ```
 
 Done! Now try to use lsp-mode as usual.
 
-You can verify that it works by checking that `emacs-lsp-booster` is running along with lsp servers and lsp-mode related functions works as expected.
+### Configure `eglot`
+
+Please see https://github.com/blahgeek/emacs-lsp-booster/issues/1 . Huge thanks to @jdtsmith
+
+### How to verify it's working
+
+1. Check that `emacs-lsp-booster` process is running
+2. Check the stderr buffer (e.g. for lsp-mode, `*pyright::stderr*` buffer), it should contain `emacs_lsp_booster` related log.