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 "ip/Address.h"
  41 #include "HelperChildConfig.h"
  42
  43 class helper_request;
  44
  45 typedef void HLPSCB(void *, void *lastserver, char *buf);
  46
  47 class helper
  48 {
  49 public:
  50     inline helper(const char *name) : cmdline(NULL), id_name(name), eom('\n') {}
  51     ~helper();
  52
  53 public:
  54     wordlist *cmdline;
  55     dlink_list servers;
  56     dlink_list queue;
  57     const char *id_name;
  58     HelperChildConfig childs;    ///< Configuration settings for number running.
  59     int ipc_type;
  60     Ip::Address addr;
  61     time_t last_queue_warn;
  62     time_t last_restart;
  63     char eom;   ///< The char which marks the end of (response) message, normally '\n'
  64
  65     struct _stats {
  66         int requests;
  67         int replies;
  68         int queue_size;
  69         int avg_svc_time;
  70     } stats;
  71
  72 private:
  73     CBDATA_CLASS2(helper);
  74 };
  75
  76 class statefulhelper : public helper
  77 {
  78 public:
  79     inline statefulhelper(const char *name) : helper(name) {};
  80     inline ~statefulhelper() {};
  81
  82 public:
  83     MemAllocator *datapool;
  84     HLPSAVAIL *IsAvailable;
  85     HLPSONEQ *OnEmptyQueue;
  86
  87 private:
  88     CBDATA_CLASS2(statefulhelper);
  89 };
  90
  91 /*
  92  * Fields shared between stateless and stateful helper servers.
  93  */
  94 class HelperServerBase
  95 {
  96 public:
  97     /** Closes pipes to the helper safely.
  98      * Handles the case where the read and write pipes are the same FD.
  99      */
 100     void closePipesSafely();
 101
 102     /** Closes the reading pipe.
 103      * If the read and write sockets are the same the write pipe will
 104      * also be closed. Otherwise its left open for later handling.
 105      */
 106     void closeWritePipeSafely();
 107
 108 public:
 109     int index;
 110     int pid;
 111     Ip::Address addr;
 112     Comm::ConnectionPointer readPipe;
 113     Comm::ConnectionPointer writePipe;
 114     void *hIpc;
 115
 116     char *rbuf;
 117     size_t rbuf_sz;
 118     size_t roffset;
 119
 120     struct timeval dispatch_time;
 121     struct timeval answer_time;
 122
 123     dlink_node link;
 124
 125     struct _helper_flags {
 126         unsigned int busy:1;
 127         unsigned int writing:1;
 128         unsigned int closing:1;
 129         unsigned int shutdown:1;
 130         unsigned int reserved:1;
 131     } flags;
 132
 133 };
 134
 135 class MemBuf;
 136
 137 class helper_server : public HelperServerBase
 138 {
 139 public:
 140     MemBuf *wqueue;
 141     MemBuf *writebuf;
 142
 143     helper *parent;
 144     helper_request **requests;
 145
 146     struct {
 147         int uses;
 148         unsigned int pending;
 149     } stats;
 150
 151 private:
 152     CBDATA_CLASS2(helper_server);
 153 };
 154
 155 class helper_stateful_request;
 156
 157 class helper_stateful_server : public HelperServerBase
 158 {
 159 public:
 160     /* MemBuf wqueue; */
 161     /* MemBuf writebuf; */
 162
 163     statefulhelper *parent;
 164     helper_stateful_request *request;
 165
 166     struct {
 167         int uses;
 168         int submits;
 169         int releases;
 170     } stats;
 171     void *data;                 /* State data used by the calling routines */
 172
 173 private:
 174     CBDATA_CLASS2(helper_stateful_server);
 175 };
 176
 177 class helper_request
 178 {
 179
 180 public:
 181     MEMPROXY_CLASS(helper_request);
 182     char *buf;
 183     HLPCB *callback;
 184     void *data;
 185
 186     struct timeval dispatch_time;
 187 };
 188
 189 MEMPROXY_CLASS_INLINE(helper_request);
 190
 191 class helper_stateful_request
 192 {
 193
 194 public:
 195     MEMPROXY_CLASS(helper_stateful_request);
 196     char *buf;
 197     HLPSCB *callback;
 198     int placeholder;            /* if 1, this is a dummy request waiting for a stateful helper to become available */
 199     void *data;
 200 };
 201
 202 MEMPROXY_CLASS_INLINE(helper_stateful_request);
 203
 204 /* helper.c */
 205 SQUIDCEXTERN void helperOpenServers(helper * hlp);
 206 SQUIDCEXTERN void helperStatefulOpenServers(statefulhelper * hlp);
 207 SQUIDCEXTERN void helperSubmit(helper * hlp, const char *buf, HLPCB * callback, void *data);
 208 SQUIDCEXTERN void helperStatefulSubmit(statefulhelper * hlp, const char *buf, HLPSCB * callback, void *data, helper_stateful_server * lastserver);
 209 SQUIDCEXTERN void helperStats(StoreEntry * sentry, helper * hlp, const char *label = NULL);
 210 SQUIDCEXTERN void helperStatefulStats(StoreEntry * sentry, statefulhelper * hlp, const char *label = NULL);
 211 SQUIDCEXTERN void helperShutdown(helper * hlp);
 212 SQUIDCEXTERN void helperStatefulShutdown(statefulhelper * hlp);
 213 SQUIDCEXTERN void helperStatefulReleaseServer(helper_stateful_server * srv);
 214 SQUIDCEXTERN void *helperStatefulServerGetData(helper_stateful_server * srv);
 215
 216 #endif /* SQUID_HELPER_H */