libcody/client.cc

   1 // CODYlib              -*- mode:c++ -*-
   2 // Copyright (C) 2020 Nathan Sidwell, nathan@acm.org
   3 // License: Apache v2.0
   4
   5 // Cody
   6 #include "internal.hh"
   7 // C
   8 #include <cerrno>
   9 #include <cstdlib>
  10 #include <cstring>
  11
  12 // Client code
  13
  14 namespace Cody {
  15
  16 // These do not need to be members
  17 static Packet ConnectResponse (std::vector<std::string> &words);
  18 static Packet PathnameResponse (std::vector<std::string> &words);
  19 static Packet OKResponse (std::vector<std::string> &words);
  20 static Packet IncludeTranslateResponse (std::vector<std::string> &words);
  21
  22 // Must be consistently ordered with the RequestCode enum
  23 static Packet (*const responseTable[Detail::RC_HWM])
  24   (std::vector<std::string> &) =
  25   {
  26     &ConnectResponse,
  27     &PathnameResponse,
  28     &PathnameResponse,
  29     &PathnameResponse,
  30     &OKResponse,
  31     &IncludeTranslateResponse,
  32   };
  33
  34 Client::Client ()
  35 {
  36   fd.from = fd.to = -1;
  37 }
  38
  39 Client::Client (Client &&src)
  40   : write (std::move (src.write)),
  41     read (std::move (src.read)),
  42     corked (std::move (src.corked)),
  43     is_direct (src.is_direct),
  44     is_connected (src.is_connected)
  45 {
  46   if (is_direct)
  47     server = src.server;
  48   else
  49     {
  50       fd.from = src.fd.from;
  51       fd.to = src.fd.to;
  52     }
  53 }
  54
  55 Client::~Client ()
  56 {
  57 }
  58
  59 Client &Client::operator= (Client &&src)
  60 {
  61   write = std::move (src.write);
  62   read = std::move (src.read);
  63   corked = std::move (src.corked);
  64   is_direct = src.is_direct;
  65   is_connected = src.is_connected;
  66   if (is_direct)
  67     server = src.server;
  68   else
  69     {
  70       fd.from = src.fd.from;
  71       fd.to = src.fd.to;
  72     }
  73
  74   return *this;
  75 }
  76
  77 int Client::CommunicateWithServer ()
  78 {
  79   write.PrepareToWrite ();
  80   read.PrepareToRead ();
  81   if (IsDirect ())
  82     server->DirectProcess (write, read);
  83   else
  84     {
  85       // Write the write buffer
  86       while (int e = write.Write (fd.to))
  87         if (e != EAGAIN && e != EINTR)
  88           return e;
  89       // Read the read buffer
  90       while (int e = read.Read (fd.from))
  91         if (e != EAGAIN && e != EINTR)
  92           return e;
  93     }
  94
  95   return 0;
  96 }
  97
  98 static Packet CommunicationError (int err)
  99 {
 100   std::string e {u8"communication error:"};
 101   e.append (strerror (err));
 102
 103   return Packet (Client::PC_ERROR, std::move (e));
 104 }
 105
 106 Packet Client::ProcessResponse (std::vector<std::string> &words,
 107                                unsigned code, bool isLast)
 108 {
 109   if (int e = read.Lex (words))
 110     {
 111       if (e == EINVAL)
 112         {
 113           std::string msg (u8"malformed string '");
 114           msg.append (words[0]);
 115           msg.append (u8"'");
 116           return Packet (Client::PC_ERROR, std::move (msg));
 117         }
 118       else
 119         return Packet (Client::PC_ERROR, u8"missing response");
 120     }
 121
 122   Assert (!words.empty ());
 123   if (words[0] == u8"ERROR")
 124     return Packet (Client::PC_ERROR,
 125                    words.size () == 2 ? words[1]: u8"malformed error response");
 126
 127   if (isLast && !read.IsAtEnd ())
 128     return Packet (Client::PC_ERROR,
 129                    std::string (u8"unexpected extra response"));
 130
 131   Assert (code < Detail::RC_HWM);
 132   Packet result (responseTable[code] (words));
 133   result.SetRequest (code);
 134   if (result.GetCode () == Client::PC_ERROR && result.GetString ().empty ())
 135     {
 136       std::string msg {u8"malformed response '"};
 137
 138       read.LexedLine (msg);
 139       msg.append (u8"'");
 140       result.GetString () = std::move (msg);
 141     }
 142   else if (result.GetCode () == Client::PC_CONNECT)
 143     is_connected = true;
 144
 145   return result;
 146 }
 147
 148 Packet Client::MaybeRequest (unsigned code)
 149 {
 150   if (IsCorked ())
 151     {
 152       corked.push_back (code);
 153       return Packet (PC_CORKED);
 154     }
 155
 156   if (int err = CommunicateWithServer ())
 157     return CommunicationError (err);
 158
 159   std::vector<std::string> words;
 160   return ProcessResponse(words, code, true);
 161 }
 162
 163 void Client::Cork ()
 164 {
 165   if (corked.empty ())
 166     corked.push_back (-1);
 167 }
 168
 169 std::vector<Packet> Client::Uncork ()
 170 {
 171   std::vector<Packet> result;
 172
 173   if (corked.size () > 1)
 174     {
 175       if (int err = CommunicateWithServer ())
 176         result.emplace_back (CommunicationError (err));
 177       else
 178         {
 179           std::vector<std::string> words;
 180           for (auto iter = corked.begin () + 1; iter != corked.end ();)
 181             {
 182               char code = *iter;
 183               ++iter;
 184               result.emplace_back (ProcessResponse (words, code,
 185                                                     iter == corked.end ()));
 186             }
 187         }
 188     }
 189
 190   corked.clear ();
 191
 192   return result;
 193 }
 194
 195 // Now the individual message handlers
 196
 197 // HELLO $vernum $agent $ident
 198 Packet Client::Connect (char const *agent, char const *ident,
 199                           size_t alen, size_t ilen)
 200 {
 201   write.BeginLine ();
 202   write.AppendWord (u8"HELLO");
 203   write.AppendInteger (Version);
 204   write.AppendWord (agent, true, alen);
 205   write.AppendWord (ident, true, ilen);
 206   write.EndLine ();
 207
 208   return MaybeRequest (Detail::RC_CONNECT);
 209 }
 210
 211 // HELLO $version $agent [$flags]
 212 Packet ConnectResponse (std::vector<std::string> &words)
 213 {
 214   if (words[0] == u8"HELLO" && (words.size () == 3 || words.size () == 4))
 215     {
 216       char *eptr;
 217       unsigned long val = strtoul (words[1].c_str (), &eptr, 10);
 218
 219       unsigned version = unsigned (val);
 220       if (*eptr || version != val || version < Version)
 221         return Packet (Client::PC_ERROR, u8"incompatible version");
 222       else
 223         {
 224           unsigned flags = 0;
 225           if (words.size () == 4)
 226             {
 227               val = strtoul (words[3].c_str (), &eptr, 10);
 228               flags = unsigned (val);
 229             }
 230           return Packet (Client::PC_CONNECT, flags);
 231         }
 232     }
 233
 234   return Packet (Client::PC_ERROR, u8"");
 235 }
 236
 237 // MODULE-REPO
 238 Packet Client::ModuleRepo ()
 239 {
 240   write.BeginLine ();
 241   write.AppendWord (u8"MODULE-REPO");
 242   write.EndLine ();
 243
 244   return MaybeRequest (Detail::RC_MODULE_REPO);
 245 }
 246
 247 // PATHNAME $dir | ERROR
 248 Packet PathnameResponse (std::vector<std::string> &words)
 249 {
 250   if (words[0] == u8"PATHNAME" && words.size () == 2)
 251     return Packet (Client::PC_PATHNAME, std::move (words[1]));
 252
 253   return Packet (Client::PC_ERROR, u8"");
 254 }
 255
 256 // OK or ERROR
 257 Packet OKResponse (std::vector<std::string> &words)
 258 {
 259   if (words[0] == u8"OK")
 260     return Packet (Client::PC_OK);
 261   else
 262     return Packet (Client::PC_ERROR,
 263                    words.size () == 2 ? std::move (words[1]) : "");
 264 }
 265
 266 // MODULE-EXPORT $modulename [$flags]
 267 Packet Client::ModuleExport (char const *module, Flags flags, size_t mlen)
 268 {
 269   write.BeginLine ();
 270   write.AppendWord (u8"MODULE-EXPORT");
 271   write.AppendWord (module, true, mlen);
 272   if (flags != Flags::None)
 273     write.AppendInteger (unsigned (flags));
 274   write.EndLine ();
 275
 276   return MaybeRequest (Detail::RC_MODULE_EXPORT);
 277 }
 278
 279 // MODULE-IMPORT $modulename [$flags]
 280 Packet Client::ModuleImport (char const *module, Flags flags, size_t mlen)
 281 {
 282   write.BeginLine ();
 283   write.AppendWord (u8"MODULE-IMPORT");
 284   write.AppendWord (module, true, mlen);
 285   if (flags != Flags::None)
 286     write.AppendInteger (unsigned (flags));
 287   write.EndLine ();
 288
 289   return MaybeRequest (Detail::RC_MODULE_IMPORT);
 290 }
 291
 292 // MODULE-COMPILED $modulename [$flags]
 293 Packet Client::ModuleCompiled (char const *module, Flags flags, size_t mlen)
 294 {
 295   write.BeginLine ();
 296   write.AppendWord (u8"MODULE-COMPILED");
 297   write.AppendWord (module, true, mlen);
 298   if (flags != Flags::None)
 299     write.AppendInteger (unsigned (flags));
 300   write.EndLine ();
 301
 302   return MaybeRequest (Detail::RC_MODULE_COMPILED);
 303 }
 304
 305 // INCLUDE-TRANSLATE $includename [$flags]
 306 Packet Client::IncludeTranslate (char const *include, Flags flags, size_t ilen)
 307 {
 308   write.BeginLine ();
 309   write.AppendWord (u8"INCLUDE-TRANSLATE");
 310   write.AppendWord (include, true, ilen);
 311   if (flags != Flags::None)
 312     write.AppendInteger (unsigned (flags));
 313   write.EndLine ();
 314
 315   return MaybeRequest (Detail::RC_INCLUDE_TRANSLATE);
 316 }
 317
 318 // BOOL $knowntextualness
 319 // PATHNAME $cmifile
 320 Packet IncludeTranslateResponse (std::vector<std::string> &words)
 321 {
 322   if (words[0] == u8"BOOL" && words.size () == 2)
 323     {
 324       if (words[1] == u8"FALSE")
 325         return Packet (Client::PC_BOOL, 0);
 326       else if (words[1] == u8"TRUE")
 327         return Packet (Client::PC_BOOL, 1);
 328       else
 329         return Packet (Client::PC_ERROR, u8"");
 330     }
 331   else
 332     return PathnameResponse (words);
 333 }
 334
 335 }
 336