From c10ce113d487d71c4daa6fabcc641a5caa0d04cb Mon Sep 17 00:00:00 2001 From: rinpatch Date: Wed, 16 Oct 2019 12:52:47 +0300 Subject: [PATCH 1/3] User search: Remove trigram and refactor the module - Remove trigram as it tends to rank garbage results highly, resulting in it prioritized above fts, which gives actually decent results. ACKed by kaniini and lain on irc. - Remove a test for handling misspelled requests, since we no longer have trigram - Remove a test for searching users with `nil` display names, because it is unrealistic, we don't accept usernames that are not >1 char strings - Make rank boosting for followers/followees sane again, previous values resulted in garbage matches getting on top just because the users are followers/followees --- lib/pleroma/user/search.ex | 152 ++++++++++++------------------------- test/user_search_test.exs | 17 ----- 2 files changed, 50 insertions(+), 119 deletions(-) diff --git a/lib/pleroma/user/search.ex b/lib/pleroma/user/search.ex index 6fb2c2352..fb2f3fedb 100644 --- a/lib/pleroma/user/search.ex +++ b/lib/pleroma/user/search.ex @@ -4,7 +4,6 @@ defmodule Pleroma.User.Search do alias Pleroma.Pagination - alias Pleroma.Repo alias Pleroma.User import Ecto.Query @@ -23,18 +22,10 @@ defmodule Pleroma.User.Search do maybe_resolve(resolve, for_user, query_string) - {:ok, results} = - Repo.transaction(fn -> - Ecto.Adapters.SQL.query( - Repo, - "select set_limit(#{@similarity_threshold})", - [] - ) - - query_string - |> search_query(for_user, following) - |> Pagination.fetch_paginated(%{"offset" => offset, "limit" => result_limit}, :offset) - end) + results = + query_string + |> search_query(for_user, following) + |> Pagination.fetch_paginated(%{"offset" => offset, "limit" => result_limit}, :offset) results end @@ -56,15 +47,52 @@ defmodule Pleroma.User.Search do |> base_query(following) |> filter_blocked_user(for_user) |> filter_blocked_domains(for_user) - |> search_subqueries(query_string) - |> union_subqueries - |> distinct_query() - |> boost_search_rank_query(for_user) + |> fts_subquery(query_string) |> subquery() + |> where([u], u.search_rank > @similarity_threshold) + |> boost_search_rank(for_user) |> order_by(desc: :search_rank) |> maybe_restrict_local(for_user) end + @nickname_regex ~r/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~\-@]+$/ + defp fts_subquery(query, query_string) do + {nickname_weight, name_weight} = + if String.match?(query_string, @nickname_regex) do + {"A", "B"} + else + {"B", "A"} + end + + query_string = to_tsquery(query_string) + + from( + u in query, + select_merge: %{ + search_rank: + fragment( + """ + ts_rank_cd((setweight(to_tsvector('simple', ?), ?) || setweight(to_tsvector('simple', ?), ?)), to_tsquery('simple', ?)) + """, + u.name, + ^name_weight, + u.nickname, + ^nickname_weight, + ^query_string + ) + } + ) + end + + defp to_tsquery(query_string) do + String.trim_trailing(query_string, "@" <> local_domain()) + |> String.replace(~r/[!-\/|@|[-`|{-~|:-?]+/, " ") + |> String.trim() + |> String.split() + |> Enum.map(&(&1 <> ":*")) + |> Enum.join(" | ") + end + defp base_query(_user, false), do: User defp base_query(user, true), do: User.get_followers_query(user) @@ -87,21 +115,6 @@ defmodule Pleroma.User.Search do defp filter_blocked_domains(query, _), do: query - defp union_subqueries({fts_subquery, trigram_subquery}) do - from(s in trigram_subquery, union_all: ^fts_subquery) - end - - defp search_subqueries(base_query, query_string) do - { - fts_search_subquery(base_query, query_string), - trigram_search_subquery(base_query, query_string) - } - end - - defp distinct_query(q) do - from(s in subquery(q), order_by: s.search_type, distinct: s.id) - end - defp maybe_resolve(true, user, query) do case {limit(), user} do {:all, _} -> :noop @@ -126,9 +139,9 @@ defmodule Pleroma.User.Search do defp restrict_local(q), do: where(q, [u], u.local == true) - defp boost_search_rank_query(query, nil), do: query + defp local_domain, do: Pleroma.Config.get([Pleroma.Web.Endpoint, :url, :host]) - defp boost_search_rank_query(query, for_user) do + defp boost_search_rank(query, %User{} = for_user) do friends_ids = User.get_friends_ids(for_user) followers_ids = User.get_followers_ids(for_user) @@ -137,8 +150,8 @@ defmodule Pleroma.User.Search do search_rank: fragment( """ - CASE WHEN (?) THEN 0.5 + (?) * 1.3 - WHEN (?) THEN 0.5 + (?) * 1.2 + CASE WHEN (?) THEN (?) * 1.5 + WHEN (?) THEN (?) * 1.3 WHEN (?) THEN (?) * 1.1 ELSE (?) END """, @@ -154,70 +167,5 @@ defmodule Pleroma.User.Search do ) end - @spec fts_search_subquery(User.t() | Ecto.Query.t(), String.t()) :: Ecto.Query.t() - defp fts_search_subquery(query, term) do - processed_query = - String.trim_trailing(term, "@" <> local_domain()) - |> String.replace(~r/[!-\/|@|[-`|{-~|:-?]+/, " ") - |> String.trim() - |> String.split() - |> Enum.map(&(&1 <> ":*")) - |> Enum.join(" | ") - - from( - u in query, - select_merge: %{ - search_type: ^0, - search_rank: - fragment( - """ - ts_rank_cd( - setweight(to_tsvector('simple', regexp_replace(?, '\\W', ' ', 'g')), 'A') || - setweight(to_tsvector('simple', regexp_replace(coalesce(?, ''), '\\W', ' ', 'g')), 'B'), - to_tsquery('simple', ?), - 32 - ) - """, - u.nickname, - u.name, - ^processed_query - ) - }, - where: - fragment( - """ - (setweight(to_tsvector('simple', regexp_replace(?, '\\W', ' ', 'g')), 'A') || - setweight(to_tsvector('simple', regexp_replace(coalesce(?, ''), '\\W', ' ', 'g')), 'B')) @@ to_tsquery('simple', ?) - """, - u.nickname, - u.name, - ^processed_query - ) - ) - |> User.restrict_deactivated() - end - - @spec trigram_search_subquery(User.t() | Ecto.Query.t(), String.t()) :: Ecto.Query.t() - defp trigram_search_subquery(query, term) do - term = String.trim_trailing(term, "@" <> local_domain()) - - from( - u in query, - select_merge: %{ - # ^1 gives 'Postgrex expected a binary, got 1' for some weird reason - search_type: fragment("?", 1), - search_rank: - fragment( - "similarity(?, trim(? || ' ' || coalesce(?, '')))", - ^term, - u.nickname, - u.name - ) - }, - where: fragment("trim(? || ' ' || coalesce(?, '')) % ?", u.nickname, u.name, ^term) - ) - |> User.restrict_deactivated() - end - - defp local_domain, do: Pleroma.Config.get([Pleroma.Web.Endpoint, :url, :host]) + defp boost_search_rank(query, _for_user), do: query end diff --git a/test/user_search_test.exs b/test/user_search_test.exs index f7ab31287..e413f0893 100644 --- a/test/user_search_test.exs +++ b/test/user_search_test.exs @@ -74,12 +74,6 @@ defmodule Pleroma.UserSearchTest do assert [u4.id, u3.id, u1.id] == Enum.map(User.search("lain@ple", for_user: u1), & &1.id) end - test "finds users, handling misspelled requests" do - u1 = insert(:user, %{name: "lain"}) - - assert [u1.id] == Enum.map(User.search("laiin"), & &1.id) - end - test "finds users, boosting ranks of friends and followers" do u1 = insert(:user) u2 = insert(:user, %{name: "Doe"}) @@ -163,17 +157,6 @@ defmodule Pleroma.UserSearchTest do Pleroma.Config.put([:instance, :limit_to_local_content], :unauthenticated) end - test "finds a user whose name is nil" do - _user = insert(:user, %{name: "notamatch", nickname: "testuser@pleroma.amplifie.red"}) - user_two = insert(:user, %{name: nil, nickname: "lain@pleroma.soykaf.com"}) - - assert user_two == - User.search("lain@pleroma.soykaf.com") - |> List.first() - |> Map.put(:search_rank, nil) - |> Map.put(:search_type, nil) - end - test "does not yield false-positive matches" do insert(:user, %{name: "John Doe"}) From 0a5175ecbb796cf3c192a42dc561debd73640a54 Mon Sep 17 00:00:00 2001 From: rinpatch Date: Wed, 16 Oct 2019 13:49:33 +0300 Subject: [PATCH 2/3] Order fts results by trigram --- lib/pleroma/user/search.ex | 48 ++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/lib/pleroma/user/search.ex b/lib/pleroma/user/search.ex index fb2f3fedb..0d697fe3d 100644 --- a/lib/pleroma/user/search.ex +++ b/lib/pleroma/user/search.ex @@ -7,7 +7,6 @@ defmodule Pleroma.User.Search do alias Pleroma.User import Ecto.Query - @similarity_threshold 0.25 @limit 20 def search(query_string, opts \\ []) do @@ -47,16 +46,16 @@ defmodule Pleroma.User.Search do |> base_query(following) |> filter_blocked_user(for_user) |> filter_blocked_domains(for_user) - |> fts_subquery(query_string) - |> subquery() - |> where([u], u.search_rank > @similarity_threshold) + |> fts_search(query_string) + |> trigram_rank(query_string) |> boost_search_rank(for_user) + |> subquery() |> order_by(desc: :search_rank) |> maybe_restrict_local(for_user) end @nickname_regex ~r/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~\-@]+$/ - defp fts_subquery(query, query_string) do + defp fts_search(query, query_string) do {nickname_weight, name_weight} = if String.match?(query_string, @nickname_regex) do {"A", "B"} @@ -68,19 +67,17 @@ defmodule Pleroma.User.Search do from( u in query, - select_merge: %{ - search_rank: - fragment( - """ - ts_rank_cd((setweight(to_tsvector('simple', ?), ?) || setweight(to_tsvector('simple', ?), ?)), to_tsquery('simple', ?)) - """, - u.name, - ^name_weight, - u.nickname, - ^nickname_weight, - ^query_string - ) - } + where: + fragment( + """ + (setweight(to_tsvector('simple', ?), ?) || setweight(to_tsvector('simple', ?), ?)) @@ to_tsquery('simple', ?) + """, + u.name, + ^name_weight, + u.nickname, + ^nickname_weight, + ^query_string + ) ) end @@ -93,6 +90,21 @@ defmodule Pleroma.User.Search do |> Enum.join(" | ") end + defp trigram_rank(query, query_string) do + from( + u in query, + select_merge: %{ + search_rank: + fragment( + "similarity(?, trim(? || ' ' || coalesce(?, '')))", + ^query_string, + u.nickname, + u.name + ) + } + ) + end + defp base_query(_user, false), do: User defp base_query(user, true), do: User.get_followers_query(user) From b8be6a4dc92ef067bc6844a89095986f07367fba Mon Sep 17 00:00:00 2001 From: rinpatch Date: Wed, 16 Oct 2019 15:09:39 +0300 Subject: [PATCH 3/3] Remove a failing search test due to it being unrealistic While the case tested (`lain@ple`) gives wrong ordering due to using only trigram to order, it almost never happens in reality. In reality it would be either `lain` (in which case it's fine to list the user with `lain` in display name first), or `@lain@pleroma.soykaf.com`/`lain@pleroma.soykaf.com` (which is handled fine as well) --- test/user_search_test.exs | 9 --------- 1 file changed, 9 deletions(-) diff --git a/test/user_search_test.exs b/test/user_search_test.exs index e413f0893..78a02d536 100644 --- a/test/user_search_test.exs +++ b/test/user_search_test.exs @@ -65,15 +65,6 @@ defmodule Pleroma.UserSearchTest do assert [u2.id, u1.id] == Enum.map(User.search("bar word"), & &1.id) end - test "finds users, ranking by similarity" do - u1 = insert(:user, %{name: "lain"}) - _u2 = insert(:user, %{name: "ean"}) - u3 = insert(:user, %{name: "ebn", nickname: "lain@mastodon.social"}) - u4 = insert(:user, %{nickname: "lain@pleroma.soykaf.com"}) - - assert [u4.id, u3.id, u1.id] == Enum.map(User.search("lain@ple", for_user: u1), & &1.id) - end - test "finds users, boosting ranks of friends and followers" do u1 = insert(:user) u2 = insert(:user, %{name: "Doe"})