#830 Implement a socket wrapper API for use with LSP connections

3 files changed, 166 insertions, 25 deletions

diff --git a/autoload/ale/job.vim b/autoload/ale/job.vim
index 6ffc2a06..e0266cba 100644
--- a/autoload/ale/job.vim
+++ b/autoload/ale/job.vim
@@ -26,34 +26,11 @@ function! s:KillHandler(timer) abort
     call job_stop(l:job, 'kill')
 endfunction
 
-" Note that jobs and IDs are the same thing on NeoVim.
-function! ale#job#JoinNeovimOutput(job, last_line, data, mode, callback) abort
-    if a:mode is# 'raw'
-        call a:callback(a:job, join(a:data, "\n"))
-        return ''
-    endif
-
-    let l:lines = a:data[:-2]
-
-    if len(a:data) > 1
-        let l:lines[0] = a:last_line . l:lines[0]
-        let l:new_last_line = a:data[-1]
-    else
-        let l:new_last_line = a:last_line . get(a:data, 0, '')
-    endif
-
-    for l:line in l:lines
-        call a:callback(a:job, l:line)
-    endfor
-
-    return l:new_last_line
-endfunction
-
 function! s:NeoVimCallback(job, data, event) abort
     let l:info = s:job_map[a:job]
 
     if a:event is# 'stdout'
-        let l:info.out_cb_line = ale#job#JoinNeovimOutput(
+        let l:info.out_cb_line = ale#util#JoinNeovimOutput(
         \   a:job,
         \   l:info.out_cb_line,
         \   a:data,
@@ -61,7 +38,7 @@ function! s:NeoVimCallback(job, data, event) abort
         \   ale#util#GetFunction(l:info.out_cb),
         \)
     elseif a:event is# 'stderr'
-        let l:info.err_cb_line = ale#job#JoinNeovimOutput(
+        let l:info.err_cb_line = ale#util#JoinNeovimOutput(
         \   a:job,
         \   l:info.err_cb_line,
         \   a:data,
diff --git a/autoload/ale/socket.vim b/autoload/ale/socket.vim
new file mode 100644
index 00000000..78eba737
--- /dev/null
+++ b/autoload/ale/socket.vim
@@ -0,0 +1,137 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: APIs for working with asynchronous sockets, with an API
+" normalised between Vim 8 and NeoVim. Socket connections only work in NeoVim
+" 0.3+, and silently do nothing in earlier NeoVim versions.
+"
+" Important functions are described below. They are:
+"
+"   ale#socket#Open(address, options) -> channel_id (>= 0 if successful)
+"   ale#socket#IsOpen(channel_id) -> 1 if open, 0 otherwise
+"   ale#socket#Close(channel_id)
+"   ale#socket#Send(channel_id, data)
+
+let s:channel_map = get(s:, 'channel_map', {})
+
+function! s:VimOutputCallback(channel, data) abort
+    let l:channel_id = ch_info(a:channel).id
+
+    " Only call the callbacks for jobs which are valid.
+    if l:channel_id >= 0 && has_key(s:channel_map, l:channel_id)
+        call ale#util#GetFunction(s:channel_map[l:channel_id].callback)(l:channel_id, a:data)
+    endif
+endfunction
+
+function! s:NeoVimOutputCallback(channel_id, data, event) abort
+    let l:info = s:channel_map[a:channel_id]
+
+    if a:event is# 'data'
+        let l:info.last_line = ale#util#JoinNeovimOutput(
+        \   a:channel_id,
+        \   l:info.last_line,
+        \   a:data,
+        \   l:info.mode,
+        \   ale#util#GetFunction(l:info.callback),
+        \)
+    endif
+endfunction
+
+" Open a socket for a given address. The following options are accepted:
+"
+" callback - A callback for receiving input. (required)
+"
+" A non-negative number representing a channel ID will be returned is the
+" connection was successful. 0 is a valid channel ID in Vim, so test if the
+" connection ID is >= 0.
+function! ale#socket#Open(address, options) abort
+    let l:mode = get(a:options, 'mode', 'raw')
+    let l:Callback = a:options.callback
+
+    let l:channel_info = {
+    \   'mode': l:mode,
+    \   'callback': a:options.callback,
+    \}
+
+    if !has('nvim')
+        " Vim
+        let l:channel_info.channel = ch_open(a:address, {
+        \   'mode': l:mode,
+        \   'waittime': 0,
+        \   'callback': function('s:VimOutputCallback'),
+        \})
+        let l:vim_info = ch_info(l:channel_info.channel)
+        let l:channel_id = !empty(l:vim_info) ? l:vim_info.id : -1
+    elseif exists('*chansend') && exists('*sockconnect')
+        " NeoVim 0.3+
+        try
+            let l:channel_id = sockconnect('tcp', a:address, {
+            \   'on_data': function('s:NeoVimOutputCallback'),
+            \})
+            let l:channel_info.last_line = ''
+        catch /connection failed/
+            let l:channel_id = -1
+        endtry
+
+        " 0 means the connection failed some times in NeoVim, so make the ID
+        " invalid to match Vim.
+        if l:channel_id is 0
+            let l:channel_id = -1
+        endif
+
+        let l:channel_info.channel = l:channel_id
+    else
+        " Other Vim versions.
+        let l:channel_id = -1
+    endif
+
+    if l:channel_id >= 0
+        let s:channel_map[l:channel_id] = l:channel_info
+    endif
+
+    return l:channel_id
+endfunction
+
+" Return 1 is a channel is open, 0 otherwise.
+function! ale#socket#IsOpen(channel_id) abort
+    if !has_key(s:channel_map, a:channel_id)
+        return 0
+    endif
+
+    if has('nvim')
+        " In NeoVim, we have to check if this channel is in the global list.
+        return index(map(nvim_list_chans(), 'v:val.id'), a:channel_id) >= 0
+    endif
+
+    let l:channel = s:channel_map[a:channel_id].channel
+    return ch_status(l:channel) is# 'open'
+endfunction
+
+" Close a socket, if it's still open.
+function! ale#socket#Close(channel_id) abort
+    " IsRunning isn't called here, so we don't check nvim_list_chans()
+    if !has_key(s:channel_map, a:channel_id)
+        return 0
+    endif
+
+    let l:channel = remove(s:channel_map, a:channel_id).channel
+
+    if has('nvim')
+        silent! call chanclose(l:channel)
+    elseif ch_status(l:channel) is# 'open'
+        call ch_close(l:channel)
+    endif
+endfunction
+
+" Send some data to a socket.
+function! ale#socket#Send(channel_id, data) abort
+    if !has_key(s:channel_map, a:channel_id)
+        return
+    endif
+
+    let l:channel = s:channel_map[a:channel_id].channel
+
+    if has('nvim')
+        call chansend(l:channel, a:data)
+    else
+        call ch_sendraw(l:channel, a:data)
+    endif
+endfunction
diff --git a/autoload/ale/util.vim b/autoload/ale/util.vim
index 28ab8231..d7b6904c 100644
--- a/autoload/ale/util.vim
+++ b/autoload/ale/util.vim
@@ -46,6 +46,33 @@ if !exists('g:ale#util#nul_file')
     endif
 endif
 
+" Given a job, a buffered line of data, a list of parts of lines, a mode data
+" is being read in, and a callback, join the lines of output for a NeoVim job
+" or socket together, and call the callback with the joined output.
+"
+" Note that jobs and IDs are the same thing on NeoVim.
+function! ale#util#JoinNeovimOutput(job, last_line, data, mode, callback) abort
+    if a:mode is# 'raw'
+        call a:callback(a:job, join(a:data, "\n"))
+        return ''
+    endif
+
+    let l:lines = a:data[:-2]
+
+    if len(a:data) > 1
+        let l:lines[0] = a:last_line . l:lines[0]
+        let l:new_last_line = a:data[-1]
+    else
+        let l:new_last_line = a:last_line . get(a:data, 0, '')
+    endif
+
+    for l:line in l:lines
+        call a:callback(a:job, l:line)
+    endfor
+
+    return l:new_last_line
+endfunction
+
 " Return the number of lines for a given buffer.
 function! ale#util#GetLineCount(buffer) abort
     return len(getbufline(a:buffer, 1, '$'))