lib-dict: Add dict_transaction_set_timestamp()

src/lib-dict/dict-private.h

@@ -1,6 +1,7 @@
 #ifndef DICT_PRIVATE_H
 #define DICT_PRIVATE_H
 
+#include <time.h>
 #include "dict.h"
 
 struct dict_vfuncs {
@@ -40,6 +41,8 @@ struct dict_vfuncs {
 	void (*lookup_async)(struct dict *dict, const char *key,
 			     dict_lookup_callback_t *callback, void *context);
 	bool (*switch_ioloop)(struct dict *dict);
+	void (*set_timestamp)(struct dict_transaction_context *ctx,
+			      const struct timespec *ts);
 };
 
 struct dict {
@@ -62,6 +65,8 @@ struct dict_iterate_context {
 struct dict_transaction_context {
 	struct dict *dict;
 
+	struct timespec timestamp;
+
 	bool changed:1;
 	bool no_slowness_warning:1;
 };

src/lib-dict/dict.c

@@ -222,6 +222,22 @@ void dict_transaction_no_slowness_warning(struct dict_transaction_context *ctx)
 	ctx->no_slowness_warning = TRUE;
 }
 
+void dict_transaction_set_timestamp(struct dict_transaction_context *ctx,
+				    const struct timespec *ts)
+{
+	/* These asserts are mainly here to guarantee a possibility in future
+	   to change the API to support multiple timestamps within the same
+	   transaction, so this call would apply only to the following
+	   changes. */
+	i_assert(!ctx->changed);
+	i_assert(ctx->timestamp.tv_sec == 0);
+	i_assert(ts->tv_sec > 0);
+
+	ctx->timestamp = *ts;
+	if (ctx->dict->v.set_timestamp != NULL)
+		ctx->dict->v.set_timestamp(ctx, ts);
+}
+
 struct dict_commit_sync_result {
 	int ret;
 	char *error;

src/lib-dict/dict.h

@@ -129,6 +129,11 @@ struct dict_transaction_context *dict_transaction_begin(struct dict *dict);
    finish up anytime soon. Mainly useful for transactions which aren't
    especially important whether they finish or not. */
 void dict_transaction_no_slowness_warning(struct dict_transaction_context *ctx);
+/* Set write timestamp for the entire transaction. This must be set before
+   any changes are done and can't be changed afterwards. Currently only
+   dict-sql with Cassandra backend does anything with this. */
+void dict_transaction_set_timestamp(struct dict_transaction_context *ctx,
+				    const struct timespec *ts);
 /* Commit the transaction. Returns 1 if ok, 0 if dict_atomic_inc() was used
    on a nonexistent key, -1 if failed. */
 int dict_transaction_commit(struct dict_transaction_context **ctx,