From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Tue, 4 Feb 2020 15:20:15 +0000 (+0200)
Subject: imap: Add imap_search_seqset_iter_*() API for batched iteration of a seqset
X-Git-Tag: 2.3.10~39
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2ed8d08c65d8d6011e16f1dd60d5c49809b30c90;p=thirdparty%2Fdovecot%2Fcore.git

imap: Add imap_search_seqset_iter_*() API for batched iteration of a seqset
---

diff --git a/src/imap/imap-search-args.c b/src/imap/imap-search-args.c
index 59d332b003..eb506d904a 100644
--- a/src/imap/imap-search-args.c
+++ b/src/imap/imap-search-args.c
@@ -224,3 +224,85 @@ void imap_search_add_changed_since(struct mail_search_args *search_args,
 	search_arg->next = search_args->args->next;
 	search_args->args->next = search_arg;
 }
+
+struct imap_search_seqset_iter {
+	struct mail_search_args *search_args;
+	ARRAY_TYPE(seq_range) seqset_left;
+	unsigned int batch_size;
+};
+
+static void imap_search_seqset_next_batch(struct imap_search_seqset_iter *iter)
+{
+	array_clear(&iter->search_args->args->value.seqset);
+	seq_range_array_merge_n(&iter->search_args->args->value.seqset,
+				&iter->seqset_left, iter->batch_size);
+}
+
+struct imap_search_seqset_iter *
+imap_search_seqset_iter_init(struct mail_search_args *search_args,
+			     uint32_t messages_count, unsigned int batch_size)
+{
+	struct imap_search_seqset_iter *iter;
+
+	i_assert(search_args->args->next == NULL);
+
+	iter = i_new(struct imap_search_seqset_iter, 1);
+	iter->search_args = search_args;
+	iter->batch_size = batch_size;
+	mail_search_args_ref(iter->search_args);
+
+	/* Assume that the search query is always a seqset or SEARCH_ALL. */
+	switch (search_args->args->type) {
+	case SEARCH_SEQSET:
+		break;
+	case SEARCH_ALL:
+		if (search_args->args->match_not) {
+			/* $ used before search result was saved */
+			return iter;
+		}
+		/* 1:* - convert to seqset */
+		search_args->args->type = SEARCH_SEQSET;
+		p_array_init(&search_args->args->value.seqset,
+			     search_args->pool, 1);
+		seq_range_array_add_range(&search_args->args->value.seqset,
+					  1, messages_count);
+		break;
+	default:
+		i_panic("Unexpected search_args type %d",
+			search_args->args->type);
+	}
+
+	i_assert(search_args->args->type == SEARCH_SEQSET);
+
+	i_array_init(&iter->seqset_left,
+		     array_count(&search_args->args->value.seqset));
+	array_append_array(&iter->seqset_left, &search_args->args->value.seqset);
+	imap_search_seqset_next_batch(iter);
+	return iter;
+}
+
+void imap_search_seqset_iter_deinit(struct imap_search_seqset_iter **_iter)
+{
+	struct imap_search_seqset_iter *iter = *_iter;
+
+	if (iter == NULL)
+		return;
+
+	mail_search_args_unref(&iter->search_args);
+	array_free(&iter->seqset_left);
+	i_free(iter);
+}
+
+bool imap_search_seqset_iter_next(struct imap_search_seqset_iter *iter)
+{
+	if (!array_is_created(&iter->seqset_left))
+		return FALSE;
+
+	/* remove the last batch of searched mails from seqset_left */
+	seq_range_array_invert(&iter->search_args->args->value.seqset,
+			       1, UINT32_MAX);
+	seq_range_array_intersect(&iter->seqset_left,
+				  &iter->search_args->args->value.seqset);
+	imap_search_seqset_next_batch(iter);
+	return array_count(&iter->search_args->args->value.seqset) > 0;
+}
diff --git a/src/imap/imap-search-args.h b/src/imap/imap-search-args.h
index abcc87bc31..32c95c49ca 100644
--- a/src/imap/imap-search-args.h
+++ b/src/imap/imap-search-args.h
@@ -28,4 +28,16 @@ int imap_search_get_seqset(struct client_command_context *cmd,
 void imap_search_add_changed_since(struct mail_search_args *search_args,
 				   uint64_t modseq);
 
+/* Iterate search_args in batches of messages. The search_args itself is
+   modified each time imap_search_seqset_iter_next() is called. Note that
+   search_args is expected to come from imap_search_get_anyset(), i.e. it
+   must contain only SEARCH_SEQSET or SEARCH_ALL arg. */
+struct imap_search_seqset_iter *
+imap_search_seqset_iter_init(struct mail_search_args *search_args,
+			     uint32_t messages_count, unsigned int batch_size);
+/* Iterate the next batch. Returns TRUE if the batch was updated, FALSE if
+   all the batches have been iterated. */
+bool imap_search_seqset_iter_next(struct imap_search_seqset_iter *iter);
+void imap_search_seqset_iter_deinit(struct imap_search_seqset_iter **iter);
+
 #endif