[couchdb] 05/06: Support `GET /_dbs_info` endpoint

[da...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

davisp pushed a commit to branch prototype/fdb-layer-get-dbs-info
in repository https://gitbox.apache.org/repos/asf/couchdb.git

commit 5bfad0557c3aa3ab950afdb60376cd3a084134f5
Author: Paul J. Davis <pa...@gmail.com>
AuthorDate: Tue Dec 3 13:44:35 2019 -0600

    Support `GET /_dbs_info` endpoint
    
    Previously only `POST` with a list of keys was supported. The new `GET`
    support just dumps all database info blobs in a single ordered response.
---
 src/chttpd/src/chttpd_misc.erl | 52 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/src/chttpd/src/chttpd_misc.erl b/src/chttpd/src/chttpd_misc.erl
index 186ec9f..21a4fef 100644
--- a/src/chttpd/src/chttpd_misc.erl
+++ b/src/chttpd/src/chttpd_misc.erl
@@ -157,6 +157,40 @@ all_dbs_callback({error, Reason}, #vacc{resp=Resp0}=Acc) ->
     {ok, Resp1} = chttpd:send_delayed_error(Resp0, Reason),
     {ok, Acc#vacc{resp=Resp1}}.
 
+handle_dbs_info_req(#httpd{method = 'GET'} = Req) ->
+    ok = chttpd:verify_is_server_admin(Req),
+
+    #mrargs{
+        start_key = StartKey,
+        end_key = EndKey,
+        direction = Dir,
+        limit = Limit,
+        skip = Skip
+    } = couch_mrview_http:parse_params(Req, undefined),
+
+    Options = [
+        {start_key, StartKey},
+        {end_key, EndKey},
+        {dir, Dir},
+        {limit, Limit},
+        {skip, Skip}
+    ],
+
+    % Eventually the Etag for this request will be derived
+    % from the \xFFmetadataVersion key in fdb
+    Etag = <<"foo">>,
+
+    {ok, Resp} = chttpd:etag_respond(Req, Etag, fun() ->
+        Headers = [{"ETag", Etag}],
+        {ok, Resp} = chttpd:start_delayed_json_response(Req, 200, Headers),
+        Callback = fun dbs_info_callback/2,
+        Acc = #vacc{req = Req, resp = Resp},
+        fabric2_db:list_dbs_info(Callback, Acc, Options)
+    end),
+    case is_record(Resp, vacc) of
+        true -> {ok, Resp#vacc.resp};
+        _ -> {ok, Resp}
+    end;
 handle_dbs_info_req(#httpd{method='POST', user_ctx=UserCtx}=Req) ->
     chttpd:validate_ctype(Req, "application/json"),
     Props = chttpd:json_body_obj(Req),
@@ -188,7 +222,23 @@ handle_dbs_info_req(#httpd{method='POST', user_ctx=UserCtx}=Req) ->
     send_chunk(Resp, "]"),
     chttpd:end_json_response(Resp);
 handle_dbs_info_req(Req) ->
-    send_method_not_allowed(Req, "POST").
+    send_method_not_allowed(Req, "GET,HEAD,POST").
+
+dbs_info_callback({meta, _Meta}, #vacc{resp = Resp0} = Acc) ->
+    {ok, Resp1} = chttpd:send_delayed_chunk(Resp0, "["),
+    {ok, Acc#vacc{resp = Resp1}};
+dbs_info_callback({row, Props}, #vacc{resp = Resp0} = Acc) ->
+    Prepend = couch_mrview_http:prepend_val(Acc),
+    Chunk = [Prepend, ?JSON_ENCODE({Props})],
+    {ok, Resp1} = chttpd:send_delayed_chunk(Resp0, Chunk),
+    {ok, Acc#vacc{prepend = ",", resp = Resp1}};
+dbs_info_callback(complete, #vacc{resp = Resp0} = Acc) ->
+    {ok, Resp1} = chttpd:send_delayed_chunk(Resp0, "]"),
+    {ok, Resp2} = chttpd:end_delayed_json_response(Resp1),
+    {ok, Acc#vacc{resp = Resp2}};
+dbs_info_callback({error, Reason}, #vacc{resp = Resp0} = Acc) ->
+    {ok, Resp1} = chttpd:send_delayed_error(Resp0, Reason),
+    {ok, Acc#vacc{resp = Resp1}}.
 
 handle_task_status_req(#httpd{method='GET'}=Req) ->
     ok = chttpd:verify_is_server_admin(Req),