src/helper.h

   1 /*
   2  * DEBUG: section 84    Helper process maintenance
   3  * AUTHOR: Harvest Derived?
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #ifndef SQUID_HELPER_H
  34 #define SQUID_HELPER_H
  35
  36 #include "base/AsyncCall.h"
  37 #include "cbdata.h"
  38 #include "comm/forward.h"
  39 #include "dlink.h"
  40 #include "HelperChildConfig.h"
  41 #include "HelperReply.h"
  42 #include "ip/Address.h"
  43
  44 class helper_request;
  45
  46 typedef void HLPCB(void *, const HelperReply &reply);
  47
  48 class helper
  49 {
  50 public:
  51     inline helper(const char *name) :
  52             cmdline(NULL),
  53             id_name(name),
  54             ipc_type(0),
  55             last_queue_warn(0),
  56             last_restart(0),
  57             eom('\n') {
  58         memset(&stats, 0, sizeof(stats));
  59     }
  60     ~helper();
  61
  62 public:
  63     wordlist *cmdline;
  64     dlink_list servers;
  65     dlink_list queue;
  66     const char *id_name;
  67     HelperChildConfig childs;    ///< Configuration settings for number running.
  68     int ipc_type;
  69     Ip::Address addr;
  70     time_t last_queue_warn;
  71     time_t last_restart;
  72     char eom;   ///< The char which marks the end of (response) message, normally '\n'
  73
  74     struct _stats {
  75         int requests;
  76         int replies;
  77         int queue_size;
  78         int avg_svc_time;
  79     } stats;
  80
  81 private:
  82     CBDATA_CLASS2(helper);
  83 };
  84
  85 class statefulhelper : public helper
  86 {
  87 public:
  88     inline statefulhelper(const char *name) : helper(name), datapool(NULL), IsAvailable(NULL), OnEmptyQueue(NULL) {};
  89     inline ~statefulhelper() {};
  90
  91 public:
  92     MemAllocator *datapool;
  93     HLPSAVAIL *IsAvailable;
  94     HLPSONEQ *OnEmptyQueue;
  95
  96 private:
  97     CBDATA_CLASS2(statefulhelper);
  98 };
  99
 100 /**
 101  * Fields shared between stateless and stateful helper servers.
 102  */
 103 class HelperServerBase
 104 {
 105 public:
 106     /** Closes pipes to the helper safely.
 107      * Handles the case where the read and write pipes are the same FD.
 108      */
 109     void closePipesSafely();
 110
 111     /** Closes the reading pipe.
 112      * If the read and write sockets are the same the write pipe will
 113      * also be closed. Otherwise its left open for later handling.
 114      */
 115     void closeWritePipeSafely();
 116
 117 public:
 118     int index;
 119     int pid;
 120     Ip::Address addr;
 121     Comm::ConnectionPointer readPipe;
 122     Comm::ConnectionPointer writePipe;
 123     void *hIpc;
 124
 125     char *rbuf;
 126     size_t rbuf_sz;
 127     size_t roffset;
 128
 129     struct timeval dispatch_time;
 130     struct timeval answer_time;
 131
 132     dlink_node link;
 133
 134     struct _helper_flags {
 135         bool busy;
 136         bool writing;
 137         bool closing;
 138         bool shutdown;
 139         bool reserved;
 140     } flags;
 141
 142     struct {
 143         uint64_t uses;     //< requests sent to this helper
 144         uint64_t replies;  //< replies received from this helper
 145         uint64_t pending;  //< queued lookups waiting to be sent to this helper
 146         uint64_t releases; //< times release() has been called on this helper (if stateful)
 147     } stats;
 148     void initStats();
 149 };
 150
 151 class MemBuf;
 152
 153 class helper_server : public HelperServerBase
 154 {
 155 public:
 156     MemBuf *wqueue;
 157     MemBuf *writebuf;
 158
 159     helper *parent;
 160     helper_request **requests;
 161
 162 private:
 163     CBDATA_CLASS2(helper_server);
 164 };
 165
 166 class helper_stateful_request;
 167
 168 class helper_stateful_server : public HelperServerBase
 169 {
 170 public:
 171     /* MemBuf wqueue; */
 172     /* MemBuf writebuf; */
 173
 174     statefulhelper *parent;
 175     helper_stateful_request *request;
 176
 177     void *data;                 /* State data used by the calling routines */
 178
 179 private:
 180     CBDATA_CLASS2(helper_stateful_server);
 181 };
 182
 183 class helper_request
 184 {
 185
 186 public:
 187     MEMPROXY_CLASS(helper_request);
 188     char *buf;
 189     HLPCB *callback;
 190     void *data;
 191
 192     struct timeval dispatch_time;
 193 };
 194
 195 MEMPROXY_CLASS_INLINE(helper_request);
 196
 197 class helper_stateful_request
 198 {
 199
 200 public:
 201     MEMPROXY_CLASS(helper_stateful_request);
 202     char *buf;
 203     HLPCB *callback;
 204     int placeholder;            /* if 1, this is a dummy request waiting for a stateful helper to become available */
 205     void *data;
 206 };
 207
 208 MEMPROXY_CLASS_INLINE(helper_stateful_request);
 209
 210 /* helper.c */
 211 void helperOpenServers(helper * hlp);
 212 void helperStatefulOpenServers(statefulhelper * hlp);
 213 void helperSubmit(helper * hlp, const char *buf, HLPCB * callback, void *data);
 214 void helperStatefulSubmit(statefulhelper * hlp, const char *buf, HLPCB * callback, void *data, helper_stateful_server * lastserver);
 215 void helperStats(StoreEntry * sentry, helper * hlp, const char *label = NULL);
 216 void helperStatefulStats(StoreEntry * sentry, statefulhelper * hlp, const char *label = NULL);
 217 void helperShutdown(helper * hlp);
 218 void helperStatefulShutdown(statefulhelper * hlp);
 219 void helperStatefulReleaseServer(helper_stateful_server * srv);
 220 void *helperStatefulServerGetData(helper_stateful_server * srv);
 221
 222 #endif /* SQUID_HELPER_H */