apt-pkg/contrib/error.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4
   5    Global Error Class - Global error mechanism
   6
   7    We use a simple STL vector to store each error record. A PendingFlag
   8    is kept which indicates when the vector contains a Sever error.
   9
  10    This source is placed in the Public Domain, do with it what you will
  11    It was originally written by Jason Gunthorpe.
  12
  13    ##################################################################### */
  14                                                                         /*}}}*/
  15 // Include Files                                                        /*{{{*/
  16 #include <config.h>
  17
  18 #include <apt-pkg/error.h>
  19
  20 #include <stdarg.h>
  21 #include <stddef.h>
  22 #include <list>
  23 #include <iostream>
  24 #include <errno.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <string>
  29 #include <cstring>
  30 #include <algorithm>
  31
  32                                                                         /*}}}*/
  33
  34 // Global Error Object                                                  /*{{{*/
  35 /* If the implementation supports posix threads then the accessor function
  36    is compiled to be thread safe otherwise a non-safe version is used. A
  37    Per-Thread error object is maintained in much the same manner as libc
  38    manages errno */
  39 #if defined(_POSIX_THREADS) && defined(HAVE_PTHREAD)
  40         #include <pthread.h>
  41
  42         static pthread_key_t ErrorKey;
  43         static void ErrorDestroy(void *Obj) {delete (GlobalError *)Obj;};
  44         static void KeyAlloc() {pthread_key_create(&ErrorKey,ErrorDestroy);};
  45
  46         GlobalError *_GetErrorObj() {
  47                 static pthread_once_t Once = PTHREAD_ONCE_INIT;
  48                 pthread_once(&Once,KeyAlloc);
  49
  50                 void *Res = pthread_getspecific(ErrorKey);
  51                 if (Res == 0)
  52                         pthread_setspecific(ErrorKey,Res = new GlobalError);
  53                 return (GlobalError *)Res;
  54         }
  55 #else
  56         GlobalError *_GetErrorObj() {
  57                 static GlobalError *Obj = new GlobalError;
  58                 return Obj;
  59         }
  60 #endif
  61                                                                         /*}}}*/
  62 // GlobalError::GlobalError - Constructor                               /*{{{*/
  63 GlobalError::GlobalError() : PendingFlag(false) {}
  64                                                                         /*}}}*/
  65 // GlobalError::FatalE, Errno, WarningE, NoticeE and DebugE - Add to the list/*{{{*/
  66 #define GEMessage(NAME, TYPE) \
  67 bool GlobalError::NAME (const char *Function, const char *Description,...) { \
  68         va_list args; \
  69         size_t msgSize = 400; \
  70         int const errsv = errno; \
  71         bool retry; \
  72         do { \
  73                 va_start(args,Description); \
  74                 retry = InsertErrno(TYPE, Function, Description, args, errsv, msgSize); \
  75                 va_end(args); \
  76         } while (retry); \
  77         return false; \
  78 }
  79 GEMessage(FatalE, FATAL)
  80 GEMessage(Errno, ERROR)
  81 GEMessage(WarningE, WARNING)
  82 GEMessage(NoticeE, NOTICE)
  83 GEMessage(DebugE, DEBUG)
  84 #undef GEMessage
  85                                                                         /*}}}*/
  86 // GlobalError::InsertErrno - Get part of the errortype string from errno/*{{{*/
  87 bool GlobalError::InsertErrno(MsgType const &type, const char *Function,
  88                                 const char *Description,...) {
  89         va_list args;
  90         size_t msgSize = 400;
  91         int const errsv = errno;
  92         bool retry;
  93         do {
  94                 va_start(args,Description);
  95                 retry = InsertErrno(type, Function, Description, args, errsv, msgSize);
  96                 va_end(args);
  97         } while (retry);
  98         return false;
  99 }
 100                                                                         /*}}}*/
 101 // GlobalError::InsertErrno - formats an error message with the errno   /*{{{*/
 102 bool GlobalError::InsertErrno(MsgType type, const char* Function,
 103                               const char* Description, va_list &args,
 104                               int const errsv, size_t &msgSize) {
 105         char* S = (char*) malloc(msgSize);
 106         int const n = snprintf(S, msgSize, "%s - %s (%i: %s)", Description,
 107                                Function, errsv, strerror(errsv));
 108         if (n > -1 && ((unsigned int) n) < msgSize);
 109         else {
 110                 if (n > -1)
 111                         msgSize = n + 1;
 112                 else
 113                         msgSize *= 2;
 114                 free(S);
 115                 return true;
 116         }
 117
 118         bool const geins = Insert(type, S, args, msgSize);
 119         free(S);
 120         return geins;
 121 }
 122                                                                         /*}}}*/
 123 // GlobalError::Fatal, Error, Warning, Notice and Debug - Add to the list/*{{{*/
 124 #define GEMessage(NAME, TYPE) \
 125 bool GlobalError::NAME (const char *Description,...) { \
 126         va_list args; \
 127         size_t msgSize = 400; \
 128         bool retry; \
 129         do { \
 130                 va_start(args,Description); \
 131                 retry = Insert(TYPE, Description, args, msgSize); \
 132                 va_end(args); \
 133         } while (retry); \
 134         return false; \
 135 }
 136 GEMessage(Fatal, FATAL)
 137 GEMessage(Error, ERROR)
 138 GEMessage(Warning, WARNING)
 139 GEMessage(Notice, NOTICE)
 140 GEMessage(Debug, DEBUG)
 141 #undef GEMessage
 142                                                                         /*}}}*/
 143 // GlobalError::Insert - Add a errotype message to the list             /*{{{*/
 144 bool GlobalError::Insert(MsgType const &type, const char *Description,...)
 145 {
 146         va_list args;
 147         size_t msgSize = 400;
 148         bool retry;
 149         do {
 150                 va_start(args,Description);
 151                 retry = Insert(type, Description, args, msgSize);
 152                 va_end(args);
 153         } while (retry);
 154         return false;
 155 }
 156                                                                         /*}}}*/
 157 // GlobalError::Insert - Insert a new item at the end                   /*{{{*/
 158 bool GlobalError::Insert(MsgType type, const char* Description,
 159                          va_list &args, size_t &msgSize) {
 160         char* S = (char*) malloc(msgSize);
 161         int const n = vsnprintf(S, msgSize, Description, args);
 162         if (n > -1 && ((unsigned int) n) < msgSize);
 163         else {
 164                 if (n > -1)
 165                         msgSize = n + 1;
 166                 else
 167                         msgSize *= 2;
 168                 free(S);
 169                 return true;
 170         }
 171
 172         Item const m(S, type);
 173         Messages.push_back(m);
 174
 175         if (type == ERROR || type == FATAL)
 176                 PendingFlag = true;
 177
 178         if (type == FATAL || type == DEBUG)
 179                 std::clog << m << std::endl;
 180
 181         free(S);
 182         return false;
 183 }
 184                                                                         /*}}}*/
 185 // GlobalError::PopMessage - Pulls a single message out                 /*{{{*/
 186 bool GlobalError::PopMessage(std::string &Text) {
 187         if (Messages.empty() == true)
 188                 return false;
 189
 190         Item const msg = Messages.front();
 191         Messages.pop_front();
 192
 193         bool const Ret = (msg.Type == ERROR || msg.Type == FATAL);
 194         Text = msg.Text;
 195         if (PendingFlag == false || Ret == false)
 196                 return Ret;
 197
 198         // check if another error message is pending
 199         for (std::list<Item>::const_iterator m = Messages.begin();
 200              m != Messages.end(); ++m)
 201                 if (m->Type == ERROR || m->Type == FATAL)
 202                         return Ret;
 203
 204         PendingFlag = false;
 205         return Ret;
 206 }
 207                                                                         /*}}}*/
 208 // GlobalError::DumpErrors - Dump all of the errors/warns to cerr       /*{{{*/
 209 void GlobalError::DumpErrors(std::ostream &out, MsgType const &threshold,
 210                              bool const &mergeStack) {
 211         if (mergeStack == true)
 212                 for (std::list<MsgStack>::const_reverse_iterator s = Stacks.rbegin();
 213                      s != Stacks.rend(); ++s)
 214                         std::copy(s->Messages.begin(), s->Messages.end(), std::front_inserter(Messages));
 215
 216         std::for_each(Messages.begin(), Messages.end(), [&threshold, &out](Item const &m) {
 217                 if (m.Type >= threshold)
 218                         out << m << std::endl;
 219         });
 220
 221         Discard();
 222 }
 223                                                                         /*}}}*/
 224 // GlobalError::Discard - Discard                                       /*{{{*/
 225 void GlobalError::Discard() {
 226         Messages.clear();
 227         PendingFlag = false;
 228 }
 229                                                                         /*}}}*/
 230 // GlobalError::ReturnError - convert a stored error to a return code           /*{{{*/
 231 bool GlobalError::ReturnError() {
 232         for (auto &message : Messages)
 233                 if (message.Type == ERROR)
 234                         message.Type = WARNING;
 235         PendingFlag = false;
 236         return false;
 237 }
 238                                                                         /*}}}*/
 239 // GlobalError::empty - does our error list include anything?           /*{{{*/
 240 bool GlobalError::empty(MsgType const &threshold) const {
 241         if (PendingFlag == true)
 242                 return false;
 243
 244         if (Messages.empty() == true)
 245                 return true;
 246
 247         return std::find_if(Messages.begin(), Messages.end(), [&threshold](Item const &m) {
 248                 return m.Type >= threshold;
 249         }) == Messages.end();
 250 }
 251                                                                         /*}}}*/
 252 // GlobalError::PushToStack                                             /*{{{*/
 253 void GlobalError::PushToStack() {
 254         Stacks.emplace_back(Messages, PendingFlag);
 255         Discard();
 256 }
 257                                                                         /*}}}*/
 258 // GlobalError::RevertToStack                                           /*{{{*/
 259 void GlobalError::RevertToStack() {
 260         Discard();
 261         MsgStack pack = Stacks.back();
 262         Messages = pack.Messages;
 263         PendingFlag = pack.PendingFlag;
 264         Stacks.pop_back();
 265 }
 266                                                                         /*}}}*/
 267 // GlobalError::MergeWithStack                                          /*{{{*/
 268 void GlobalError::MergeWithStack() {
 269         MsgStack pack = Stacks.back();
 270         Messages.splice(Messages.begin(), pack.Messages);
 271         PendingFlag = PendingFlag || pack.PendingFlag;
 272         Stacks.pop_back();
 273 }
 274                                                                         /*}}}*/