src/MemObject.h

   1 /*
   2  *
   3  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   4  * ----------------------------------------------------------
   5  *
   6  *  Squid is the result of efforts by numerous individuals from
   7  *  the Internet community; see the CONTRIBUTORS file for full
   8  *  details.   Many organizations have provided support for Squid's
   9  *  development; see the SPONSORS file for full details.  Squid is
  10  *  Copyrighted (C) 2001 by the Regents of the University of
  11  *  California; see the COPYRIGHT file for full details.  Squid
  12  *  incorporates software developed and/or copyrighted by other
  13  *  sources; see the CREDITS file for full details.
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or
  18  *  (at your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program; if not, write to the Free Software
  27  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  28  *
  29  */
  30
  31 #ifndef SQUID_MEMOBJECT_H
  32 #define SQUID_MEMOBJECT_H
  33
  34 #include "StoreIOBuffer.h"
  35 #include "StoreIOState.h"
  36 #include "stmem.h"
  37 #include "CommRead.h"
  38 #include "RemovalPolicy.h"
  39 #include "HttpRequestMethod.h"
  40
  41 typedef void STMCB (void *data, StoreIOBuffer wroteBuffer);
  42
  43 class store_client;
  44 class HttpRequest;
  45 #if USE_DELAY_POOLS
  46 #include "DelayId.h"
  47 #endif
  48
  49 class MemObject
  50 {
  51
  52 public:
  53     static size_t inUseCount();
  54     MEMPROXY_CLASS(MemObject);
  55
  56     void dump() const;
  57     MemObject(char const *, char const *);
  58     ~MemObject();
  59
  60     /// replaces construction-time URLs with correct ones; see hidden_mem_obj
  61     void resetUrls(char const *aUrl, char const *aLog_url);
  62
  63     void write(StoreIOBuffer, STMCB *, void *);
  64     void unlinkRequest();
  65     HttpReply const *getReply() const;
  66     void replaceHttpReply(HttpReply *newrep);
  67     void stat (MemBuf * mb) const;
  68     int64_t endOffset () const;
  69     void markEndOfReplyHeaders(); ///< sets _reply->hdr_sz to endOffset()
  70     /// negative if unknown; otherwise, expected object_sz, expected endOffset
  71     /// maximum, and stored reply headers+body size (all three are the same)
  72     int64_t expectedReplySize() const;
  73     int64_t size() const;
  74     void reset();
  75     int64_t lowestMemReaderOffset() const;
  76     bool readAheadPolicyCanRead() const;
  77     void addClient(store_client *);
  78     /* XXX belongs in MemObject::swapout, once swaphdrsz is managed
  79      * better
  80      */
  81     int64_t objectBytesOnDisk() const;
  82     int64_t policyLowestOffsetToKeep(bool swap) const;
  83     int64_t availableForSwapOut() const; ///< buffered bytes we have not swapped out yet
  84     void trimSwappable();
  85     void trimUnSwappable();
  86     bool isContiguous() const;
  87     int mostBytesWanted(int max, bool ignoreDelayPools) const;
  88     void setNoDelay(bool const newValue);
  89 #if USE_DELAY_POOLS
  90     DelayId mostBytesAllowed() const;
  91 #endif
  92
  93 #if URL_CHECKSUM_DEBUG
  94
  95     void checkUrlChecksum() const;
  96 #endif
  97
  98     HttpRequestMethod method;
  99     char *url;
 100     mem_hdr data_hdr;
 101     int64_t inmem_lo;
 102     dlink_list clients;
 103
 104     /** \todo move into .cc or .cci */
 105     size_t clientCount() const {return nclients;}
 106
 107     bool clientIsFirst(void *sc) const {return (clients.head && sc == clients.head->data);}
 108
 109     int nclients;
 110
 111     class SwapOut
 112     {
 113
 114     public:
 115         int64_t queue_offset; ///< number of bytes sent to SwapDir for writing
 116         StoreIOState::Pointer sio;
 117
 118         /// Decision states for StoreEntry::swapoutPossible() and related code.
 119         typedef enum { swNeedsCheck = 0, swImpossible = -1, swPossible = +1 } Decision;
 120         Decision decision; ///< current decision state
 121     };
 122
 123     SwapOut swapout;
 124
 125     /* Read only - this reply must be preserved by store clients */
 126     /* The original reply. possibly with updated metadata. */
 127     HttpRequest *request;
 128
 129     struct timeval start_ping;
 130     IRCB *ping_reply_callback;
 131     void *ircb_data;
 132
 133     struct {
 134         STABH *callback;
 135         void *data;
 136     } abort;
 137     char *log_url;
 138     RemovalPolicyNode repl;
 139     int id;
 140     int64_t object_sz;
 141     size_t swap_hdr_sz;
 142 #if URL_CHECKSUM_DEBUG
 143
 144     unsigned int chksum;
 145 #endif
 146
 147     const char *vary_headers;
 148
 149     void delayRead(DeferredRead const &);
 150     void kickReads();
 151
 152 private:
 153     HttpReply *_reply;
 154
 155     DeferredReadManager deferredReads;
 156 };
 157
 158 MEMPROXY_CLASS_INLINE(MemObject);
 159
 160 /** global current memory removal policy */
 161 extern RemovalPolicy *mem_policy;
 162
 163 #endif /* SQUID_MEMOBJECT_H */