1 files changed, 74 insertions, 40 deletions

diff --git a/src/tag/Tag.hxx b/src/tag/Tag.hxx
index 5846e7a9d..f1d3d5767 100644
--- a/src/tag/Tag.hxx
+++ b/src/tag/Tag.hxx
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -20,11 +20,13 @@
 #ifndef MPD_TAG_HXX
 #define MPD_TAG_HXX
 
-#include "TagType.h"
-#include "TagItem.hxx"
+#include "TagType.h" // IWYU pragma: export
+#include "TagItem.hxx" // IWYU pragma: export
+#include "Chrono.hxx"
 #include "Compiler.h"
 
 #include <algorithm>
+#include <iterator>
 
 #include <stddef.h>
 
@@ -34,12 +36,10 @@
  */
 struct Tag {
 	/**
-	 * The duration of the song (in seconds).  A value of zero
-	 * means that the length is unknown.  If the duration is
-	 * really between zero and one second, you should round up to
-	 * 1.
+	 * The duration of the song.  A negative value means that the
+	 * length is unknown.
 	 */
-	int time;
+	SignedSongTime duration;
 
 	/**
 	 * Does this file have an embedded playlist (e.g. embedded CUE
@@ -47,23 +47,23 @@ struct Tag {
 	 */
 	bool has_playlist;
 
+	/** the total number of tag items in the #items array */
+	unsigned short num_items;
+
 	/** an array of tag items */
 	TagItem **items;
 
-	/** the total number of tag items in the #items array */
-	unsigned num_items;
-
 	/**
 	 * Create an empty tag.
 	 */
-	Tag():time(-1), has_playlist(false),
-	      items(nullptr), num_items(0) {}
+	Tag():duration(SignedSongTime::Negative()), has_playlist(false),
+	      num_items(0), items(nullptr) {}
 
 	Tag(const Tag &other);
 
 	Tag(Tag &&other)
-		:time(other.time), has_playlist(other.has_playlist),
-		 items(other.items), num_items(other.num_items) {
+		:duration(other.duration), has_playlist(other.has_playlist),
+		 num_items(other.num_items), items(other.items) {
 		other.items = nullptr;
 		other.num_items = 0;
 	}
@@ -71,12 +71,14 @@ struct Tag {
 	/**
 	 * Free the tag object and all its items.
 	 */
-	~Tag();
+	~Tag() {
+		Clear();
+	}
 
 	Tag &operator=(const Tag &other) = delete;
 
 	Tag &operator=(Tag &&other) {
-		time = other.time;
+		duration = other.duration;
 		has_playlist = other.has_playlist;
 		std::swap(items, other.items);
 		std::swap(num_items, other.num_items);
@@ -84,8 +86,8 @@ struct Tag {
 	}
 
 	/**
-	 * Returns true if the tag contains no items.  This ignores the "time"
-	 * attribute.
+	 * Returns true if the tag contains no items.  This ignores
+	 * the "duration" attribute.
 	 */
 	bool IsEmpty() const {
 		return num_items == 0;
@@ -95,7 +97,7 @@ struct Tag {
 	 * Returns true if the tag contains any information.
 	 */
 	bool IsDefined() const {
-		return !IsEmpty() || time >= 0;
+		return !IsEmpty() || !duration.IsNegative();
 	}
 
 	/**
@@ -104,24 +106,6 @@ struct Tag {
 	void Clear();
 
 	/**
-	 * Appends a new tag item.
-	 *
-	 * @param type the type of the new tag item
-	 * @param value the value of the tag item (not null-terminated)
-	 * @param len the length of #value
-	 */
-	void AddItem(TagType type, const char *value, size_t len);
-
-	/**
-	 * Appends a new tag item.
-	 *
-	 * @param tag the #tag object
-	 * @param type the type of the new tag item
-	 * @param value the value of the tag item (null-terminated)
-	 */
-	void AddItem(TagType type, const char *value);
-
-	/**
 	 * Merges the data from two tags.  If both tags share data for the
 	 * same TagType, only data from "add" is used.
 	 *
@@ -153,8 +137,58 @@ struct Tag {
 	gcc_pure
 	bool HasType(TagType type) const;
 
-private:
-	void AddItemInternal(TagType type, const char *value, size_t len);
+	class const_iterator {
+		friend struct Tag;
+		const TagItem *const*cursor;
+
+		constexpr const_iterator(const TagItem *const*_cursor)
+			:cursor(_cursor) {}
+
+	public:
+		constexpr const TagItem &operator*() const {
+			return **cursor;
+		}
+
+		constexpr const TagItem *operator->() const {
+			return *cursor;
+		}
+
+		const_iterator &operator++() {
+			++cursor;
+			return *this;
+		}
+
+		const_iterator operator++(int) {
+			auto result = cursor++;
+			return const_iterator{result};
+		}
+
+		const_iterator &operator--() {
+			--cursor;
+			return *this;
+		}
+
+		const_iterator operator--(int) {
+			auto result = cursor--;
+			return const_iterator{result};
+		}
+
+		constexpr bool operator==(const_iterator other) const {
+			return cursor == other.cursor;
+		}
+
+		constexpr bool operator!=(const_iterator other) const {
+			return cursor != other.cursor;
+		}
+	};
+
+	const_iterator begin() const {
+		return const_iterator{items};
+	}
+
+	const_iterator end() const {
+		return const_iterator{items + num_items};
+	}
 };
 
 /**