From f06346fbf03900c278e1d59717e1387bffc03f39 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 13 Nov 2020 20:26:30 +0300
Subject: [PATCH] Allow precompute size of serialized tags.

---
 ui/text/text_entity.cpp | 14 ++++++++++++++
 ui/text/text_entity.h   | 11 +++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/ui/text/text_entity.cpp b/ui/text/text_entity.cpp
index fe43783..9bdfc43 100644
--- a/ui/text/text_entity.cpp
+++ b/ui/text/text_entity.cpp
@@ -1950,6 +1950,20 @@ void Trim(TextWithEntities &result) {
 	}
 }
 
+int SerializeTagsSize(const TextWithTags::Tags &tags) {
+	auto result = qint32(0);
+	if (tags.isEmpty()) {
+		return result;
+	}
+	result += sizeof(qint32);
+	for (const auto &tag : tags) {
+		result += 2 * sizeof(qint32) // offset, length
+			+ sizeof(quint32) // id.size
+			+ tag.id.size() * sizeof(ushort);
+	}
+	return result;
+}
+
 QByteArray SerializeTags(const TextWithTags::Tags &tags) {
 	if (tags.isEmpty()) {
 		return QByteArray();
diff --git a/ui/text/text_entity.h b/ui/text/text_entity.h
index 83f4384..aa04175 100644
--- a/ui/text/text_entity.h
+++ b/ui/text/text_entity.h
@@ -344,10 +344,13 @@ inline QString PrepareForSending(const QString &text, PrepareTextOption option =
 // Replace bad symbols with space and remove '\r'.
 void ApplyServerCleaning(TextWithEntities &result);
 
-QByteArray SerializeTags(const TextWithTags::Tags &tags);
-TextWithTags::Tags DeserializeTags(QByteArray data, int textLength);
-QString TagsMimeType();
-QString TagsTextMimeType();
+[[nodiscard]] int SerializeTagsSize(const TextWithTags::Tags &tags);
+[[nodiscard]] QByteArray SerializeTags(const TextWithTags::Tags &tags);
+[[nodiscard]] TextWithTags::Tags DeserializeTags(
+	QByteArray data,
+	int textLength);
+[[nodiscard]] QString TagsMimeType();
+[[nodiscard]] QString TagsTextMimeType();
 
 inline const auto kMentionTagStart = qstr("mention://user.");