Language filtering in streaming API (#3339)

streaming/index.js

@@ -168,7 +168,7 @@ if (cluster.isMaster) {
         return;
       }
 
-      client.query('SELECT oauth_access_tokens.resource_owner_id, users.account_id FROM oauth_access_tokens INNER JOIN users ON oauth_access_tokens.resource_owner_id = users.id WHERE oauth_access_tokens.token = $1 LIMIT 1', [token], (err, result) => {
+      client.query('SELECT oauth_access_tokens.resource_owner_id, users.account_id, users.filtered_languages FROM oauth_access_tokens INNER JOIN users ON oauth_access_tokens.resource_owner_id = users.id WHERE oauth_access_tokens.token = $1 LIMIT 1', [token], (err, result) => {
         done();
 
         if (err) {
@@ -185,6 +185,7 @@ if (cluster.isMaster) {
         }
 
         req.accountId = result.rows[0].account_id;
+        req.filteredLanguages = result.rows[0].filtered_languages;
 
         next();
       });
@@ -248,6 +249,11 @@ if (cluster.isMaster) {
           const targetAccountIds = [unpackedPayload.account.id].concat(unpackedPayload.mentions.map(item => item.id)).concat(unpackedPayload.reblog ? [unpackedPayload.reblog.account.id] : []);
           const accountDomain    = unpackedPayload.account.acct.split('@')[1];
 
+          if (req.filteredLanguages.indexOf(unpackedPayload.language) !== -1) {
+            log.silly(req.requestId, `Message ${unpackedPayload.id} filtered by language (${unpackedPayload.language})`);
+            return;
+          }
+
           const queries = [
             client.query(`SELECT 1 FROM blocks WHERE account_id = $1 AND target_account_id IN (${placeholders(targetAccountIds, 1)}) UNION SELECT 1 FROM mutes WHERE account_id = $1 AND target_account_id IN (${placeholders(targetAccountIds, 1)})`, [req.accountId].concat(targetAccountIds)),
           ];