net/curvecp/sent_block_list.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_CURVECP_SENT_BLOCK_LIST_H_
   6 #define NET_CURVECP_SENT_BLOCK_LIST_H_
   7 #pragma once
   8
   9 #include <vector>
  10
  11 #include "base/memory/ref_counted.h"
  12 #include "base/time.h"
  13
  14 namespace net {
  15
  16 class IOBufferWithSize;
  17
  18 // A SentBlockList manages everything needed to track a set of of blocks
  19 // which have been sent.  It can assign new ids to new blocks, find pending
  20 // blocks by id, or discard blocks after they have been acknowledged by the
  21 // remote.
  22 class SentBlockList {
  23  public:
  24   SentBlockList();
  25   ~SentBlockList();
  26
  27   // Creates a new block to be tracked.
  28   // On success, returns the unique position of this buffer within the stream,
  29   // which can be used to lookup this block later.
  30   // Returns -1 if the blocklist is already full.
  31   int64 CreateBlock(IOBufferWithSize* buffer);
  32
  33   // Tracks that a block has been sent.
  34   // |position| is the identifier of the block being sent.
  35   // |message_id| is the id of the message sent containing the block.
  36   // Returns false if no block for |position| exists.
  37   bool MarkBlockSent(int64 position, int64 message_id);
  38
  39   // Acknowledges ranges from |begin_range| to |end_range|.
  40   // Partial acknowledgements (e.g. where the ack range spans a partial
  41   // block) are not supported.
  42   // Removes blocks covered by these ranges from tracking.
  43   void AcknowledgeBlocks(int64 begin_range, int64 end_range);
  44
  45   // Returns a new, unique message id.
  46   int64 GetNewMessageId();
  47
  48   // Find a block based on its |position|.
  49   // Returns the block, if found, or NULL otherwise.
  50   IOBufferWithSize* FindBlockByPosition(int64 position) const;
  51
  52   // Find the last send time of a block, based the id of the last
  53   // message to send it.
  54   base::TimeTicks FindLastSendTime(int64 last_message_id) const;
  55
  56   // Returns the position of the oldest sent block.
  57   int64 FindPositionOfOldestSentBlock() const;
  58
  59   // Returns the number of blocks in the list.
  60   size_t size() const { return list_.size(); }
  61
  62   // Returns true if the list is full and cannot take new blocks.
  63   bool is_full() const;
  64
  65  private:
  66   // An UnackedBlock is a block of application data which has been sent in a
  67   // message, but not acknowledged by the other side yet.  We track this
  68   // because we may need to retransmit.
  69   typedef struct {
  70     int64 position;                  // Offset of this block in the stream.
  71     int64 length;                    // Number of bytes in this block.
  72     int64 transmissions;             // Count of transmissions of this block.
  73     int64 last_message_id;           // ID of last message sending this block.
  74     base::TimeTicks last_sent_time;  // Time of last message sending this block.
  75     scoped_refptr<IOBufferWithSize> data;
  76   } Block;
  77
  78   typedef std::vector<Block> BlockList;
  79
  80   // Finds a block by position and returns it index within |list_|.
  81   int FindBlock(int64 position) const;
  82
  83   // Debugging: Writes the entire blocklist to the log.
  84   void LogBlockList() const;
  85
  86   int64 current_message_id_;    // The current message id.
  87   int64 send_sequence_number_;  // The sending sequence number.
  88   BlockList list_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(SentBlockList);
  91 };
  92
  93 }  // namespace net
  94
  95 #endif  // NET_CURVECP_SENT_BLOCK_LIST_H_