1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
# Pleroma: A lightweight social networking server
# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.User.Search do
alias Pleroma.Repo
alias Pleroma.User
import Ecto.Query
@similarity_threshold 0.25
@limit 20
def search(query_string, opts \\ []) do
resolve = Keyword.get(opts, :resolve, false)
following = Keyword.get(opts, :following, false)
result_limit = Keyword.get(opts, :limit, @limit)
offset = Keyword.get(opts, :offset, 0)
for_user = Keyword.get(opts, :for_user)
# Strip the beginning @ off if there is a query
query_string = String.trim_leading(query_string, "@")
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)
|> paginate(result_limit, offset)
|> Repo.all()
end)
results
end
defp search_query(query_string, for_user, following) do
for_user
|> base_query(following)
|> search_subqueries(query_string)
|> union_subqueries
|> distinct_query()
|> boost_search_rank_query(for_user)
|> subquery()
|> order_by(desc: :search_rank)
|> maybe_restrict_local(for_user)
end
defp base_query(_user, false), do: User
defp base_query(user, true), do: User.get_followers_query(user)
defp paginate(query, limit, offset) do
from(q in query, limit: ^limit, offset: ^offset)
end
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
{:unauthenticated, %User{}} -> User.get_or_fetch(query)
{:unauthenticated, _} -> :noop
{false, _} -> User.get_or_fetch(query)
end
end
defp maybe_resolve(_, _, _), do: :noop
defp maybe_restrict_local(q, user) do
case {limit(), user} do
{:all, _} -> restrict_local(q)
{:unauthenticated, %User{}} -> q
{:unauthenticated, _} -> restrict_local(q)
{false, _} -> q
end
end
defp limit, do: Pleroma.Config.get([:instance, :limit_to_local_content], :unauthenticated)
defp restrict_local(q), do: where(q, [u], u.local == true)
defp boost_search_rank_query(query, nil), do: query
defp boost_search_rank_query(query, for_user) do
friends_ids = User.get_friends_ids(for_user)
followers_ids = User.get_followers_ids(for_user)
from(u in subquery(query),
select_merge: %{
search_rank:
fragment(
"""
CASE WHEN (?) THEN 0.5 + (?) * 1.3
WHEN (?) THEN 0.5 + (?) * 1.2
WHEN (?) THEN (?) * 1.1
ELSE (?) END
""",
u.id in ^friends_ids and u.id in ^followers_ids,
u.search_rank,
u.id in ^friends_ids,
u.search_rank,
u.id in ^followers_ids,
u.search_rank,
u.search_rank
)
}
)
end
@spec fts_search_subquery(User.t() | Ecto.Query.t(), String.t()) :: Ecto.Query.t()
defp fts_search_subquery(query, term) do
processed_query =
term
|> String.replace(~r/\W+/, " ")
|> 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
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
end
|
