src/common/tag-list.h
changeset 4502 07d34c0d8d18
parent 4488 1faf35545dfd
child 4503 d70501bf2b14
--- a/src/common/tag-list.h	Tue Jun 02 19:46:01 2009 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,170 +0,0 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/*
- * Copyright (c) 2008 INRIA
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation;
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
- * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
- */
-#ifndef TAG_LIST_H
-#define TAG_LIST_H
-
-#include <stdint.h>
-#include "ns3/type-id.h"
-#include "tag-buffer.h"
-
-namespace ns3 {
-
-struct TagListData;
-
-/**
- * \ingroup packet
- *
- * \brief keep track of the tags stored in a packet.
- *
- * This class is mostly private to the Packet implementation and users
- * should never have to access it directly.
- *
- * \internal
- * The implementation of this class is a bit tricky so, there are a couple
- * of things to keep in mind here:
- *
- *   - it stores all tags in a single byte buffer: each tag is stored
- *     as 4 32bit integers (TypeId, tag data size, start, end) followed 
- *     by the tag data as generated by Tag::Serialize.
- *
- *   - the struct TagListData structure which contains the tag byte buffer
- *     is shared and, thus, reference-counted. This data structure is unshared
- *     as-needed to emulate COW semantics.
- *
- *   - each tag tags a unique set of bytes identified by the pair of offsets 
- *     (start,end). These offsets are provided by Buffer::GetCurrentStartOffset
- *     and Buffer::GetCurrentEndOffset which means that they are relative to 
- *     the start of the 'virtual byte buffer' as explained in the documentation
- *     for the ns3::Buffer class. Whenever the origin of the offset of the Buffer
- *     instance associated to this TagList instance changes, the Buffer class
- *     reports this to its container Packet class as a bool return value
- *     in Buffer::AddAtStart and Buffer::AddAtEnd. In both cases, when this happens
- *     the Packet class calls TagList::AddAtEnd and TagList::AddAtStart to update
- *     the byte offsets of each tag in the TagList.
- *
- *   - whenever bytes are removed from the packet byte buffer, the TagList offsets 
- *     are never updated because we rely on the fact that they will be updated in
- *     either the next call to Packet::AddHeader or Packet::AddTrailer or when
- *     the user iterates the tag list with Packet::GetTagIterator and 
- *     TagIterator::Next.
- */
-class TagList
-{
-public:
-
-  class Iterator
-  {
-  public:
-    struct Item 
-    {
-      TypeId tid;
-      uint32_t size;
-      int32_t start;
-      int32_t end;
-      TagBuffer buf;
-      Item (TagBuffer buf);
-    private:
-      friend class TagList;
-      friend class TagList::Iterator;
-    };
-    bool HasNext (void) const;
-    struct TagList::Iterator::Item Next (void);
-    uint32_t GetOffsetStart (void) const;
-  private:
-    friend class TagList;
-    Iterator (uint8_t *start, uint8_t *end, int32_t offsetStart, int32_t offsetEnd);
-    void PrepareForNext (void);
-    uint8_t *m_current;
-    uint8_t *m_end;
-    int32_t m_offsetStart;
-    int32_t m_offsetEnd;
-    uint32_t m_nextTid;
-    uint32_t m_nextSize;
-    int32_t m_nextStart;
-    int32_t m_nextEnd;
-  };
-
-  TagList ();
-  TagList (const TagList &o);
-  TagList &operator = (const TagList &o);
-  ~TagList ();
-
-  /**
-   * \param tid the typeid of the tag added
-   * \param bufferSize the size of the tag when its serialization will 
-   *        be completed. Typically, the return value of Tag::GetSerializedSize
-   * \param start offset which uniquely identifies the first byte tagged by this tag.
-   * \param end offset which uniquely identifies the last byte tagged by this tag.
-   * \returns a buffer which can be used to write the tag data.     
-   *
-   * 
-   */
-  TagBuffer Add (TypeId tid, uint32_t bufferSize, int32_t start, int32_t end);
-
-  /**
-   * \param o the other list of tags to aggregate.
-   *
-   * Aggregate the two lists of tags.
-   */
-  void Add (const TagList &o);
-
-  void RemoveAll (void);
-
-  /**
-   * \param offsetStart the offset which uniquely identifies the first data byte 
-   *        present in the byte buffer associated to this TagList.
-   * \param offsetEnd the offset which uniquely identifies the last data byte 
-   *        present in the byte buffer associated to this TagList.
-   * \returns an iterator
-   *
-   * The returned iterator will allow you to loop through the set of tags present
-   * in this list: the boundaries of each tag as reported by their start and
-   * end offsets will be included within the input offsetStart and offsetEnd.
-   */
-  TagList::Iterator Begin (int32_t offsetStart, int32_t offsetEnd) const;
-
-  /**
-   * Adjust the offsets stored internally by the adjustment delta and
-   * make sure that all offsets are smaller than appendOffset which represents
-   * the location where new bytes have been added to the byte buffer.
-   */
-  void AddAtEnd (int32_t adjustment, int32_t appendOffset);
-  /**
-   * Adjust the offsets stored internally by the adjustment delta and
-   * make sure that all offsets are bigger than prependOffset which represents
-   * the location where new bytes have been added to the byte buffer.
-   */
-  void AddAtStart (int32_t adjustment, int32_t prependOffset);
-
-private:
-  bool IsDirtyAtEnd (int32_t appendOffset);
-  bool IsDirtyAtStart (int32_t prependOffset);
-  TagList::Iterator BeginAll (void) const;
-
-  struct TagListData *Allocate (uint32_t size);
-  void Deallocate (struct TagListData *data);
-
-  uint16_t m_used;
-  struct TagListData *m_data;
-};
-
-} // namespace ns3
-
-#endif /* TAG_LIST_H */