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 #include "HelperReply.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) : cmdline(NULL), id_name(name), eom('\n'), url_quoting(false) {}
  52     ~helper();
  53
  54 public:
  55     wordlist *cmdline;
  56     dlink_list servers;
  57     dlink_list queue;
  58     const char *id_name;
  59     HelperChildConfig childs;    ///< Configuration settings for number running.
  60     int ipc_type;
  61     Ip::Address addr;
  62     time_t last_queue_warn;
  63     time_t last_restart;
  64     char eom;   ///< The char which marks the end of (response) message, normally '\n'
  65     bool url_quoting;
  66
  67     struct _stats {
  68         int requests;
  69         int replies;
  70         int queue_size;
  71         int avg_svc_time;
  72     } stats;
  73
  74 private:
  75     CBDATA_CLASS2(helper);
  76 };
  77
  78 class statefulhelper : public helper
  79 {
  80 public:
  81     inline statefulhelper(const char *name) : helper(name) {};
  82     inline ~statefulhelper() {};
  83
  84 public:
  85     MemAllocator *datapool;
  86     HLPSAVAIL *IsAvailable;
  87     HLPSONEQ *OnEmptyQueue;
  88
  89 private:
  90     CBDATA_CLASS2(statefulhelper);
  91 };
  92
  93 /**
  94  * Fields shared between stateless and stateful helper servers.
  95  */
  96 class HelperServerBase
  97 {
  98 public:
  99     /** Closes pipes to the helper safely.
 100      * Handles the case where the read and write pipes are the same FD.
 101      */
 102     void closePipesSafely();
 103
 104     /** Closes the reading pipe.
 105      * If the read and write sockets are the same the write pipe will
 106      * also be closed. Otherwise its left open for later handling.
 107      */
 108     void closeWritePipeSafely();
 109
 110 public:
 111     int index;
 112     int pid;
 113     Ip::Address addr;
 114     Comm::ConnectionPointer readPipe;
 115     Comm::ConnectionPointer writePipe;
 116     void *hIpc;
 117
 118     char *rbuf;
 119     size_t rbuf_sz;
 120     size_t roffset;
 121
 122     struct timeval dispatch_time;
 123     struct timeval answer_time;
 124
 125     dlink_node link;
 126
 127     struct _helper_flags {
 128         unsigned int busy:1;
 129         unsigned int writing:1;
 130         unsigned int closing:1;
 131         unsigned int shutdown:1;
 132         unsigned int reserved:1;
 133     } flags;
 134
 135     struct {
 136         uint64_t uses;     //< requests sent to this helper
 137         uint64_t replies;  //< replies received from this helper
 138         uint64_t pending;  //< queued lookups waiting to be sent to this helper
 139         uint64_t releases; //< times release() has been called on this helper (if stateful)
 140     } stats;
 141     void initStats();
 142 };
 143
 144 class MemBuf;
 145
 146 class helper_server : public HelperServerBase
 147 {
 148 public:
 149     MemBuf *wqueue;
 150     MemBuf *writebuf;
 151
 152     helper *parent;
 153     helper_request **requests;
 154
 155 private:
 156     CBDATA_CLASS2(helper_server);
 157 };
 158
 159 class helper_stateful_request;
 160
 161 class helper_stateful_server : public HelperServerBase
 162 {
 163 public:
 164     /* MemBuf wqueue; */
 165     /* MemBuf writebuf; */
 166
 167     statefulhelper *parent;
 168     helper_stateful_request *request;
 169
 170     void *data;                 /* State data used by the calling routines */
 171
 172 private:
 173     CBDATA_CLASS2(helper_stateful_server);
 174 };
 175
 176 class helper_request
 177 {
 178
 179 public:
 180     MEMPROXY_CLASS(helper_request);
 181     char *buf;
 182     HLPCB *callback;
 183     void *data;
 184
 185     struct timeval dispatch_time;
 186 };
 187
 188 MEMPROXY_CLASS_INLINE(helper_request);
 189
 190 class helper_stateful_request
 191 {
 192
 193 public:
 194     MEMPROXY_CLASS(helper_stateful_request);
 195     char *buf;
 196     HLPCB *callback;
 197     int placeholder;            /* if 1, this is a dummy request waiting for a stateful helper to become available */
 198     void *data;
 199 };
 200
 201 MEMPROXY_CLASS_INLINE(helper_stateful_request);
 202
 203 /* helper.c */
 204 void helperOpenServers(helper * hlp);
 205 void helperStatefulOpenServers(statefulhelper * hlp);
 206 void helperSubmit(helper * hlp, const char *buf, HLPCB * callback, void *data);
 207 void helperStatefulSubmit(statefulhelper * hlp, const char *buf, HLPCB * callback, void *data, helper_stateful_server * lastserver);
 208 void helperStats(StoreEntry * sentry, helper * hlp, const char *label = NULL);
 209 void helperStatefulStats(StoreEntry * sentry, statefulhelper * hlp, const char *label = NULL);
 210 void helperShutdown(helper * hlp);
 211 void helperStatefulShutdown(statefulhelper * hlp);
 212 void helperStatefulReleaseServer(helper_stateful_server * srv);
 213 void *helperStatefulServerGetData(helper_stateful_server * srv);
 214
 215 #endif /* SQUID_HELPER_H */