resolved: cache stringified transaction key once per transaction

We end up needing the stringified transaction key in many log messages,
hence let's simplify the logic and cache it inside of the transaction:
generate it the first time we need it, and reuse it afterwards. Free it
when the transaction goes away.

This also updated a couple of log messages to make use of this.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h
index 1f35a4dd8f..ee5b780644 100644
--- a/src/resolve/resolved-dns-transaction.h
+++ b/src/resolve/resolved-dns-transaction.h
@@ -62,6 +62,7 @@ struct DnsTransaction {
         DnsScope *scope;
 
         DnsResourceKey *key;
+        char *key_string;
 
         DnsTransactionState state;
         DnssecResult dnssec_result;
@@ -136,6 +137,8 @@ void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source);
 int dns_transaction_validate_dnssec(DnsTransaction *t);
 int dns_transaction_request_dnssec_keys(DnsTransaction *t);
 
+const char *dns_transaction_key_string(DnsTransaction *t);
+
 const char* dns_transaction_state_to_string(DnsTransactionState p) _const_;
 DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_;