From a4d0866716a314def5b55095cf3ba1a971e80783 Mon Sep 17 00:00:00 2001
From: Emmanuel Touzery <etouzery@gmail.com>
Date: Fri, 8 Dec 2023 22:31:59 +0100
Subject: [PATCH] introduce query rows limit to avoid OOM

---
 autoload/db.vim   | 9 +++++++--
 doc/dadbod.txt    | 8 ++++++++
 plugin/dadbod.vim | 2 ++
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/autoload/db.vim b/autoload/db.vim
index 026bf9e..e8326db 100644
--- a/autoload/db.vim
+++ b/autoload/db.vim
@@ -169,8 +169,13 @@ function! s:vim_job_close_cb(state, channel) abort
 endfunction
 
 function! s:nvim_job_callback(lines, job_id, data, event) dict abort
-  let a:lines[-1] .= a:data[0]
-  call extend(a:lines, a:data[1:])
+  if len(a:lines) < g:db_query_rows_limit
+    let a:lines[-1] .= a:data[0]
+    call extend(a:lines, a:data[1:])
+  else
+    call extend(a:lines, ['Query aborted: it exceeded the rows limit'])
+    call s:job_stop(a:job_id)
+  endif
 endfunction
 
 function! s:job_run(cmd, on_finish, in_file) abort
diff --git a/doc/dadbod.txt b/doc/dadbod.txt
index 3850138..8a4a799 100644
--- a/doc/dadbod.txt
+++ b/doc/dadbod.txt
@@ -214,5 +214,13 @@ the following variable to enable an experimental mode where dbext's
 configuration always mirrors Dadbod's default.
 >
   let g:dadbod_manage_dbext = 1
+<
+QUERY ROWS LIMIT                                *g:db_query_rows_limit*
+
+In order to avoid out of memory when querying vast amounts of data from the
+database, dadbod will cancel queries exceeding the maximum number of rows that
+you set up in this variable. The default is 10,000 rows.
+>
+  let g:db_query_rows_limit= 10000
 <
  vim:tw=78:et:ft=help:norl:
diff --git a/plugin/dadbod.vim b/plugin/dadbod.vim
index 1f45fd5..beadc05 100644
--- a/plugin/dadbod.vim
+++ b/plugin/dadbod.vim
@@ -8,6 +8,8 @@ if exists('g:loaded_dadbod') || &cp || v:version < 704
 endif
 let g:loaded_dadbod = 1
 
+let g:db_query_rows_limit = get(g:, 'db_query_rows_limit', 10000)
+
 call extend(g:, {'db_adapters': {}}, 'keep')
 
 call extend(g:db_adapters, {