import from khatru.

postgresql/init.go

@@ -0,0 +1,71 @@
+package postgresql
+
+import (
+	"github.com/jmoiron/sqlx"
+	"github.com/jmoiron/sqlx/reflectx"
+	_ "github.com/lib/pq"
+)
+
+const (
+	queryLimit        = 100
+	queryIDsLimit     = 500
+	queryAuthorsLimit = 500
+	queryKindsLimit   = 10
+	queryTagsLimit    = 10
+)
+
+func (b *PostgresBackend) Init() error {
+	db, err := sqlx.Connect("postgres", b.DatabaseURL)
+	if err != nil {
+		return err
+	}
+
+	// sqlx default is 0 (unlimited), while postgresql by default accepts up to 100 connections
+	db.SetMaxOpenConns(80)
+
+	db.Mapper = reflectx.NewMapperFunc("json", sqlx.NameMapper)
+	b.DB = db
+
+	_, err = b.DB.Exec(`
+CREATE OR REPLACE FUNCTION tags_to_tagvalues(jsonb) RETURNS text[]
+    AS 'SELECT array_agg(t->>1) FROM (SELECT jsonb_array_elements($1) AS t)s WHERE length(t->>0) = 1;'
+    LANGUAGE SQL
+    IMMUTABLE
+    RETURNS NULL ON NULL INPUT;
+
+CREATE TABLE IF NOT EXISTS event (
+  id text NOT NULL,
+  pubkey text NOT NULL,
+  created_at integer NOT NULL,
+  kind integer NOT NULL,
+  tags jsonb NOT NULL,
+  content text NOT NULL,
+  sig text NOT NULL,
+
+  tagvalues text[] GENERATED ALWAYS AS (tags_to_tagvalues(tags)) STORED
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS ididx ON event USING btree (id text_pattern_ops);
+CREATE INDEX IF NOT EXISTS pubkeyprefix ON event USING btree (pubkey text_pattern_ops);
+CREATE INDEX IF NOT EXISTS timeidx ON event (created_at DESC);
+CREATE INDEX IF NOT EXISTS kindidx ON event (kind);
+CREATE INDEX IF NOT EXISTS arbitrarytagvalues ON event USING gin (tagvalues);
+    `)
+
+	if b.QueryLimit == 0 {
+		b.QueryLimit = queryLimit
+	}
+	if b.QueryIDsLimit == 0 {
+		b.QueryIDsLimit = queryIDsLimit
+	}
+	if b.QueryAuthorsLimit == 0 {
+		b.QueryAuthorsLimit = queryAuthorsLimit
+	}
+	if b.QueryKindsLimit == 0 {
+		b.QueryKindsLimit = queryKindsLimit
+	}
+	if b.QueryTagsLimit == 0 {
+		b.QueryTagsLimit = queryTagsLimit
+	}
+	return err
+}