granicus.if.org Git - imagemagick/blob - MagickCore/distribute-cache.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %    DDDD    IIIII   SSSSS  TTTTT  RRRR   IIIII  BBBB   U   U  TTTTT  EEEEE   %
   6 %    D   D     I     SS       T    R   R    I    B   B  U   U    T    E       %
   7 %    D   D     I      SSS     T    RRRR     I    BBBB   U   U    T    EEE     %
   8 %    D   D     I        SS    T    R R      I    B   B  U   U    T    E       %
   9 %    DDDDA   IIIII   SSSSS    T    R  R   IIIII  BBBB    UUU     T    EEEEE   %
  10 %                                                                             %
  11 %                      CCCC   AAA    CCCC  H   H  EEEEE                       %
  12 %                     C      A   A  C      H   H  E                           %
  13 %                     C      AAAAA  C      HHHHH  EEE                         %
  14 %                     C      A   A  C      H   H  E                           %
  15 %                      CCCC  A   A   CCCC  H   H  EEEEE                       %
  16 %                                                                             %
  17 %                                                                             %
  18 %                 MagickCore Distributed Pixel Cache Methods                  %
  19 %                                                                             %
  20 %                              Software Design                                %
  21 %                                John Cristy                                  %
  22 %                                January 2013                                 %
  23 %                                                                             %
  24 %                                                                             %
  25 %  Copyright 1999-2013 ImageMagick Studio LLC, a non-profit organization      %
  26 %  dedicated to making software imaging solutions freely available.           %
  27 %                                                                             %
  28 %  You may not use this file except in compliance with the License.  You may  %
  29 %  obtain a copy of the License at                                            %
  30 %                                                                             %
  31 %    http://www.imagemagick.org/script/license.php                            %
  32 %                                                                             %
  33 %  Unless required by applicable law or agreed to in writing, software        %
  34 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  35 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  36 %  See the License for the specific language governing permissions and        %
  37 %  limitations under the License.                                             %
  38 %                                                                             %
  39 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  40 %
  41 % A distributed pixel cache is an extension of the traditional pixel cache
  42 % available on a single host.  The distributed pixel cache may span multiple
  43 % servers so that it can grow in size and transactional capacity to support
  44 % very large images.  Start up the pixel cache server on one or more machines.
  45 % When you read or operate on an image and the local pixel cache resources are
  46 % exhausted, ImageMagick contacts one or more of these remote pixel servers to
  47 % store or retrieve pixels.
  48 %
  49 */
  50 \f
  51 /*
  52   Include declarations.
  53 */
  54 #include "MagickCore/studio.h"
  55 #include "MagickCore/cache.h"
  56 #include "MagickCore/cache-private.h"
  57 #include "MagickCore/distribute-cache.h"
  58 #include "MagickCore/distribute-cache-private.h"
  59 #include "MagickCore/exception.h"
  60 #include "MagickCore/exception-private.h"
  61 #include "MagickCore/geometry.h"
  62 #include "MagickCore/image.h"
  63 #include "MagickCore/list.h"
  64 #include "MagickCore/locale_.h"
  65 #include "MagickCore/memory_.h"
  66 #include "MagickCore/pixel.h"
  67 #include "MagickCore/policy.h"
  68 #include "MagickCore/random_.h"
  69 #include "MagickCore/registry.h"
  70 #include "MagickCore/splay-tree.h"
  71 #include "MagickCore/string_.h"
  72 #include "MagickCore/string-private.h"
  73 #include "MagickCore/version.h"
  74 #if defined(MAGICKCORE_HAVE_SOCKET)
  75 #include <netinet/in.h>
  76 #include <netdb.h>
  77 #include <sys/socket.h>
  78 #include <arpa/inet.h>
  79 #endif
  80 \f
  81 /*
  82   Define declarations.
  83 */
  84 #define DPCHostname  "127.0.0.1"
  85 #define DPCPendingConnections  10
  86 #define DPCPort  6668
  87 #define DPCSessionKeyLength  8
  88 \f
  89 /*
  90 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  91 %                                                                             %
  92 %                                                                             %
  93 %                                                                             %
  94 +   A c q u i r e D i s t r i b u t e C a c h e I n f o                       %
  95 %                                                                             %
  96 %                                                                             %
  97 %                                                                             %
  98 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  99 %
 100 %  AcquireDistributeCacheInfo() allocates the DistributeCacheInfo structure.
 101 %
 102 %  The format of the AcquireDistributeCacheInfo method is:
 103 %
 104 %      DistributeCacheInfo *AcquireDistributeCacheInfo(ExceptionInfo *exception)
 105 %
 106 %  A description of each parameter follows:
 107 %
 108 %    o exception: return any errors or warnings in this structure.
 109 %
 110 */
 111
 112 static MagickSizeType CRC64(const unsigned char *message,
 113   const MagickSizeType length)
 114 {
 115   MagickSizeType
 116     crc;
 117
 118   register MagickOffsetType
 119     i;
 120
 121   static MagickBooleanType
 122     crc_initial = MagickFalse;
 123
 124   static MagickSizeType
 125     crc_xor[256];
 126
 127   /*
 128     Generate a 64-bit cyclic redundancy check for the message.
 129   */
 130   if (crc_initial == MagickFalse)
 131     {
 132       MagickSizeType
 133         alpha;
 134
 135       for (i=0; i < 256; i++)
 136       {
 137         register MagickOffsetType
 138           j;
 139
 140         alpha=(MagickSizeType) i;
 141         for (j=0; j < 8; j++)
 142         {
 143           if ((alpha & 0x01) == 0)
 144             alpha>>=1;
 145           else
 146             alpha=(MagickSizeType) ((alpha >> 1) ^
 147               MagickULLConstant(0xd800000000000000));
 148         }
 149         crc_xor[i]=alpha;
 150       }
 151       crc_initial=MagickTrue;
 152     }
 153   crc=0;
 154   for (i=0; i < (MagickOffsetType) length; i++)
 155     crc=crc_xor[(crc ^ message[i]) & 0xff] ^ (crc >> 8);
 156   return(crc);
 157 }
 158
 159 static inline MagickSizeType MagickMin(const MagickSizeType x,
 160   const MagickSizeType y)
 161 {
 162   if (x < y)
 163     return(x);
 164   return(y);
 165 }
 166
 167 static inline MagickOffsetType dpc_read(int file,const MagickSizeType length,
 168   unsigned char *restrict message)
 169 {
 170   register MagickOffsetType
 171     i;
 172
 173   ssize_t
 174     count;
 175
 176   count=0;
 177   for (i=0; i < (MagickOffsetType) length; i+=count)
 178   {
 179     count=recv(file,message+i,(size_t) MagickMin(length-i,(MagickSizeType)
 180       SSIZE_MAX),0);
 181     if (count <= 0)
 182       {
 183         count=0;
 184         if (errno != EINTR)
 185           break;
 186       }
 187   }
 188   return(i);
 189 }
 190
 191 static int ConnectPixelCacheServer(const char *hostname,const int port,
 192   MagickSizeType *session_key,ExceptionInfo *exception)
 193 {
 194 #if defined(MAGICKCORE_HAVE_SOCKET)
 195   char
 196     service[MaxTextExtent];
 197
 198   const char
 199     *shared_secret;
 200
 201   int
 202     client_socket,
 203     status;
 204
 205   MagickOffsetType
 206     count;
 207
 208   register unsigned char
 209     *p;
 210
 211   struct addrinfo
 212     hint,
 213     *result;
 214
 215   unsigned char
 216     secret[MaxTextExtent],
 217     session[2*MaxTextExtent];
 218
 219   /*
 220     Connect to distributed pixel cache and get session key.
 221   */
 222   *session_key=0;
 223   shared_secret=GetPolicyValue("shared-secret");
 224   if (shared_secret == (const char *) NULL)
 225     {
 226       (void) ThrowMagickException(exception,GetMagickModule(),CacheError,
 227         "DistributedPixelCache","'%s'","shared secret expected");
 228       return(-1);
 229     }
 230   p=session;
 231   (void) CopyMagickString((char *) p,shared_secret,MaxTextExtent);
 232   p+=strlen(shared_secret);
 233   (void) ResetMagickMemory(&hint,0,sizeof(hint));
 234   hint.ai_family=AF_INET;
 235   hint.ai_socktype=SOCK_STREAM;
 236   hint.ai_flags=AI_PASSIVE;
 237   (void) FormatLocaleString(service,MaxTextExtent,"%d",port);
 238   status=getaddrinfo(hostname,service,&hint,&result);
 239   if (status != 0)
 240     {
 241       (void) ThrowMagickException(exception,GetMagickModule(),CacheError,
 242         "DistributedPixelCache","'%s'",hostname);
 243       return(-1);
 244     }
 245   client_socket=socket(result->ai_family,result->ai_socktype,
 246     result->ai_protocol);
 247   if (client_socket == -1)
 248     {
 249       (void) ThrowMagickException(exception,GetMagickModule(),CacheError,
 250         "DistributedPixelCache","'%s'",hostname);
 251       return(-1);
 252     }
 253   status=connect(client_socket,result->ai_addr,result->ai_addrlen);
 254   if (status == -1)
 255     {
 256       (void) ThrowMagickException(exception,GetMagickModule(),CacheError,
 257         "DistributedPixelCache","'%s'",hostname);
 258       return(-1);
 259     }
 260   count=recv(client_socket,secret,MaxTextExtent,0);
 261   if (count != -1)
 262     {
 263       MagickSizeType
 264         signature;
 265
 266       (void) memcpy(p,secret,(size_t) count);
 267       p+=count;
 268       signature=MagickLibVersion;
 269       (void) memcpy(p,&signature,sizeof(signature));
 270       p+=sizeof(signature);
 271       signature=MAGICKCORE_QUANTUM_DEPTH;
 272       (void) memcpy(p,&signature,sizeof(signature));
 273       p+=sizeof(signature);
 274       signature=MAGICKCORE_HDRI_ENABLE;
 275       (void) memcpy(p,&signature,sizeof(signature));
 276       p+=sizeof(signature);
 277       *session_key=CRC64(session,p-session);
 278     }
 279   if (*session_key == 0)
 280     {
 281       close(client_socket);
 282       client_socket=(-1);
 283     }
 284   return(client_socket);
 285 #else
 286   (void) ThrowMagickException(exception,GetMagickModule(),MissingDelegateError,
 287     "DelegateLibrarySupportNotBuiltIn","distributed pixel cache");
 288   return(MagickFalse);
 289 #endif
 290 }
 291
 292 static char *GetHostname(int *port,ExceptionInfo *exception)
 293 {
 294   char
 295     *host,
 296     *hosts,
 297     **hostlist;
 298
 299   int
 300     argc;
 301
 302   register ssize_t
 303     i;
 304
 305   static size_t
 306     id = 0;
 307
 308   /*
 309     Parse host list (e.g. 192.168.100.1:6668,192.168.100.2:6668).
 310   */
 311   hosts=(char *) GetImageRegistry(StringRegistryType,"cache:hosts",
 312     exception);
 313   if (hosts == (char *) NULL)
 314     {
 315       *port=DPCPort;
 316       return(AcquireString(DPCHostname));
 317     }
 318   (void) SubstituteString(&hosts,","," ");
 319   hostlist=StringToArgv(hosts,&argc);
 320   hosts=DestroyString(hosts);
 321   if (hostlist == (char **) NULL)
 322     {
 323       *port=DPCPort;
 324       return(AcquireString(DPCHostname));
 325     }
 326   hosts=AcquireString(hostlist[(id++ % (argc-1))+1]);
 327   for (i=0; i < (ssize_t) argc; i++)
 328     hostlist[i]=DestroyString(hostlist[i]);
 329   hostlist=(char **) RelinquishMagickMemory(hostlist);
 330   (void) SubstituteString(&hosts,":"," ");
 331   hostlist=StringToArgv(hosts,&argc);
 332   if (hostlist == (char **) NULL)
 333     {
 334       *port=DPCPort;
 335       return(AcquireString(DPCHostname));
 336     }
 337   host=AcquireString(hostlist[1]);
 338   if (hostlist[2] == (char *) NULL)
 339     *port=DPCPort;
 340   else
 341     *port=StringToLong(hostlist[2]);
 342   for (i=0; i < (ssize_t) argc; i++)
 343     hostlist[i]=DestroyString(hostlist[i]);
 344   hostlist=(char **) RelinquishMagickMemory(hostlist);
 345   return(host);
 346 }
 347
 348 MagickPrivate DistributeCacheInfo *AcquireDistributeCacheInfo(
 349   ExceptionInfo *exception)
 350 {
 351   char
 352     *hostname;
 353
 354   DistributeCacheInfo
 355     *server_info;
 356
 357   MagickSizeType
 358     session_key;
 359
 360   /*
 361     Connect to the distributed pixel cache server.
 362   */
 363   server_info=(DistributeCacheInfo *) AcquireMagickMemory(sizeof(*server_info));
 364   if (server_info == (DistributeCacheInfo *) NULL)
 365     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
 366   (void) ResetMagickMemory(server_info,0,sizeof(*server_info));
 367   server_info->signature=MagickSignature;
 368   server_info->port=0;
 369   hostname=GetHostname(&server_info->port,exception);
 370   session_key=0;
 371   server_info->file=ConnectPixelCacheServer(hostname,server_info->port,
 372     &session_key,exception);
 373   server_info->session_key=session_key;
 374   (void) CopyMagickString(server_info->hostname,hostname,MaxTextExtent);
 375   hostname=DestroyString(hostname);
 376   if (server_info->file == -1)
 377     server_info=DestroyDistributeCacheInfo(server_info);
 378   return(server_info);
 379 }
 380 \f
 381 /*
 382 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 383 %                                                                             %
 384 %                                                                             %
 385 %                                                                             %
 386 +   D e s t r o y D i s t r i b u t e C a c h e I n f o                       %
 387 %                                                                             %
 388 %                                                                             %
 389 %                                                                             %
 390 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 391 %
 392 %  DestroyDistributeCacheInfo() deallocates memory associated with an
 393 %  DistributeCacheInfo structure.
 394 %
 395 %  The format of the DestroyDistributeCacheInfo method is:
 396 %
 397 %      DistributeCacheInfo *DestroyDistributeCacheInfo(
 398 %        DistributeCacheInfo *server_info)
 399 %
 400 %  A description of each parameter follows:
 401 %
 402 %    o server_info: the distributed cache info.
 403 %
 404 */
 405 MagickPrivate DistributeCacheInfo *DestroyDistributeCacheInfo(
 406   DistributeCacheInfo *server_info)
 407 {
 408   assert(server_info != (DistributeCacheInfo *) NULL);
 409   assert(server_info->signature == MagickSignature);
 410   if (server_info->file > 0)
 411     (void) close(server_info->file);
 412   server_info->signature=(~MagickSignature);
 413   server_info=(DistributeCacheInfo *) RelinquishMagickMemory(server_info);
 414   return(server_info);
 415 }
 416 \f
 417 /*
 418 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 419 %                                                                             %
 420 %                                                                             %
 421 %                                                                             %
 422 +   D i s t r i b u t e P i x e l C a c h e S e r v e r                       %
 423 %                                                                             %
 424 %                                                                             %
 425 %                                                                             %
 426 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 427 %
 428 %  DistributePixelCacheServer() waits on the specified port for commands to
 429 %  create, read, update, or destroy a pixel cache.
 430 %
 431 %  The format of the DistributePixelCacheServer() method is:
 432 %
 433 %      void DistributePixelCacheServer(const int port)
 434 %
 435 %  A description of each parameter follows:
 436 %
 437 %    o port: connect the distributed pixel cache at this port.
 438 %
 439 %    o exception: return any errors or warnings in this structure.
 440 %
 441 */
 442
 443 static MagickBooleanType DestroyDistributeCache(SplayTreeInfo *registry,
 444   int file,const MagickSizeType session_key)
 445 {
 446   /*
 447     Destroy distributed pixel cache.
 448   */
 449   return(DeleteNodeFromSplayTree(registry,(const void *) session_key));
 450 }
 451
 452 static inline MagickOffsetType dpc_send(int file,const MagickSizeType length,
 453   const unsigned char *restrict message)
 454 {
 455   MagickOffsetType
 456     count;
 457
 458   register MagickOffsetType
 459     i;
 460
 461   /*
 462     Ensure a complete message is sent.
 463   */
 464   count=0;
 465   for (i=0; i < (MagickOffsetType) length; i+=count)
 466   {
 467     count=(MagickOffsetType) send(file,message+i,(size_t) MagickMin(length-i,
 468       (MagickSizeType) SSIZE_MAX),MSG_NOSIGNAL);
 469     if (count <= 0)
 470       {
 471         count=0;
 472         if (errno != EINTR)
 473           break;
 474       }
 475   }
 476   return(i);
 477 }
 478
 479 static MagickBooleanType OpenDistributeCache(SplayTreeInfo *registry,
 480   int file,const MagickSizeType session_key,ExceptionInfo *exception)
 481 {
 482   Image
 483     *image;
 484
 485   MagickBooleanType
 486     status;
 487
 488   MagickOffsetType
 489     count;
 490
 491   MagickSizeType
 492     length;
 493
 494   register unsigned char
 495     *p;
 496
 497   unsigned char
 498     message[MaxTextExtent];
 499
 500   /*
 501     Open distributed pixel cache.
 502   */
 503   image=AcquireImage((ImageInfo *) NULL,exception);
 504   if (image == (Image *) NULL)
 505     return(MagickFalse);
 506   length=sizeof(image->storage_class)+sizeof(image->colorspace)+
 507     sizeof(image->alpha_trait)+sizeof(image->mask)+sizeof(image->columns)+
 508     sizeof(image->rows)+sizeof(image->number_channels)+MaxPixelChannels*
 509     sizeof(*image->channel_map)+sizeof(image->metacontent_extent);
 510   count=dpc_read(file,length,message);
 511   if (count != (MagickOffsetType) length)
 512     return(MagickFalse);
 513   /*
 514     Deserialize image attributes.
 515   */
 516   p=message;
 517   (void) memcpy(&image->storage_class,p,sizeof(image->storage_class));
 518   p+=sizeof(image->storage_class);
 519   (void) memcpy(&image->colorspace,p,sizeof(image->colorspace));
 520   p+=sizeof(image->colorspace);
 521   (void) memcpy(&image->alpha_trait,p,sizeof(image->alpha_trait));
 522   p+=sizeof(image->alpha_trait);
 523   (void) memcpy(&image->mask,p,sizeof(image->mask));
 524   p+=sizeof(image->mask);
 525   (void) memcpy(&image->columns,p,sizeof(image->columns));
 526   p+=sizeof(image->columns);
 527   (void) memcpy(&image->rows,p,sizeof(image->rows));
 528   p+=sizeof(image->rows);
 529   (void) memcpy(&image->number_channels,p,sizeof(image->number_channels));
 530   p+=sizeof(image->number_channels);
 531   (void) memcpy(image->channel_map,p,MaxPixelChannels*
 532     sizeof(*image->channel_map));
 533   p+=MaxPixelChannels*sizeof(*image->channel_map);
 534   (void) memcpy(&image->metacontent_extent,p,sizeof(image->metacontent_extent));
 535   p+=sizeof(image->metacontent_extent);
 536   status=AddValueToSplayTree(registry,(const void *) session_key,image);
 537   return(status);
 538 }
 539
 540 static MagickBooleanType ReadDistributeCacheMetacontent(SplayTreeInfo *registry,
 541   int file,const MagickSizeType session_key,ExceptionInfo *exception)
 542 {
 543   const unsigned char
 544     *metacontent;
 545
 546   Image
 547     *image;
 548
 549   MagickOffsetType
 550     count;
 551
 552   MagickSizeType
 553     length;
 554
 555   RectangleInfo
 556     region;
 557
 558   register const Quantum
 559     *p;
 560
 561   register unsigned char
 562     *q;
 563
 564   unsigned char
 565     message[MaxTextExtent];
 566
 567   /*
 568     Read distributed pixel cache metacontent.
 569   */
 570   image=(Image *) GetValueFromSplayTree(registry,(const void *) session_key);
 571   if (image == (Image *) NULL)
 572     return(MagickFalse);
 573   length=sizeof(region.width)+sizeof(region.height)+sizeof(region.x)+
 574     sizeof(region.y)+sizeof(length);
 575   count=dpc_read(file,length,message);
 576   if (count != (MagickOffsetType) length)
 577     return(MagickFalse);
 578   q=message;
 579   (void) memcpy(&region.width,q,sizeof(region.width));
 580   q+=sizeof(region.width);
 581   (void) memcpy(&region.height,q,sizeof(region.height));
 582   q+=sizeof(region.height);
 583   (void) memcpy(&region.x,q,sizeof(region.x));
 584   q+=sizeof(region.x);
 585   (void) memcpy(&region.y,q,sizeof(region.y));
 586   q+=sizeof(region.y);
 587   (void) memcpy(&length,q,sizeof(length));
 588   q+=sizeof(length);
 589   p=GetVirtualPixels(image,region.x,region.y,region.width,region.height,
 590     exception);
 591   if (p == (const Quantum *) NULL)
 592     return(MagickFalse);
 593   metacontent=GetVirtualMetacontent(image);
 594   count=dpc_send(file,length,metacontent);
 595   if (count != (MagickOffsetType) length)
 596     return(MagickFalse);
 597   return(MagickTrue);
 598 }
 599
 600 static MagickBooleanType ReadDistributeCachePixels(SplayTreeInfo *registry,
 601   int file,const MagickSizeType session_key,ExceptionInfo *exception)
 602 {
 603   Image
 604     *image;
 605
 606   MagickOffsetType
 607     count;
 608
 609   MagickSizeType
 610     length;
 611
 612   RectangleInfo
 613     region;
 614
 615   register const Quantum
 616     *p;
 617
 618   register unsigned char
 619     *q;
 620
 621   unsigned char
 622     message[MaxTextExtent];
 623
 624   /*
 625     Read distributed pixel cache pixels.
 626   */
 627   image=(Image *) GetValueFromSplayTree(registry,(const void *) session_key);
 628   if (image == (Image *) NULL)
 629     return(MagickFalse);
 630   length=sizeof(region.width)+sizeof(region.height)+sizeof(region.x)+
 631     sizeof(region.y)+sizeof(length);
 632   count=dpc_read(file,length,message);
 633   if (count != (MagickOffsetType) length)
 634     return(MagickFalse);
 635   q=message;
 636   (void) memcpy(&region.width,q,sizeof(region.width));
 637   q+=sizeof(region.width);
 638   (void) memcpy(&region.height,q,sizeof(region.height));
 639   q+=sizeof(region.height);
 640   (void) memcpy(&region.x,q,sizeof(region.x));
 641   q+=sizeof(region.x);
 642   (void) memcpy(&region.y,q,sizeof(region.y));
 643   q+=sizeof(region.y);
 644   (void) memcpy(&length,q,sizeof(length));
 645   q+=sizeof(length);
 646   p=GetVirtualPixels(image,region.x,region.y,region.width,region.height,
 647     exception);
 648   if (p == (const Quantum *) NULL)
 649     return(MagickFalse);
 650   count=dpc_send(file,length,(unsigned char *) p);
 651   if (count != (MagickOffsetType) length)
 652     return(MagickFalse);
 653   return(MagickTrue);
 654 }
 655
 656 static void *RelinquishImageRegistry(void *image)
 657 {
 658   return((void *) DestroyImageList((Image *) image));
 659 }
 660
 661 static MagickBooleanType WriteDistributeCacheMetacontent(
 662   SplayTreeInfo *registry,int file,const MagickSizeType session_key,
 663   ExceptionInfo *exception)
 664 {
 665   Image
 666     *image;
 667
 668   MagickOffsetType
 669     count;
 670
 671   MagickSizeType
 672     length;
 673
 674   RectangleInfo
 675     region;
 676
 677   register Quantum
 678     *q;
 679
 680   register unsigned char
 681     *p;
 682
 683   unsigned char
 684     message[MaxTextExtent],
 685     *metacontent;
 686
 687   /*
 688     Write distributed pixel cache metacontent.
 689   */
 690   image=(Image *) GetValueFromSplayTree(registry,(const void *) session_key);
 691   if (image == (Image *) NULL)
 692     return(MagickFalse);
 693   length=sizeof(region.width)+sizeof(region.height)+sizeof(region.x)+
 694     sizeof(region.y)+sizeof(length);
 695   count=dpc_read(file,length,message);
 696   if (count != (MagickOffsetType) length)
 697     return(MagickFalse);
 698   p=message;
 699   (void) memcpy(&region.width,p,sizeof(region.width));
 700   p+=sizeof(region.width);
 701   (void) memcpy(&region.height,p,sizeof(region.height));
 702   p+=sizeof(region.height);
 703   (void) memcpy(&region.x,p,sizeof(region.x));
 704   p+=sizeof(region.x);
 705   (void) memcpy(&region.y,p,sizeof(region.y));
 706   p+=sizeof(region.y);
 707   (void) memcpy(&length,p,sizeof(length));
 708   p+=sizeof(length);
 709   q=GetAuthenticPixels(image,region.x,region.y,region.width,region.height,
 710     exception);
 711   if (q == (Quantum *) NULL)
 712     return(MagickFalse);
 713   metacontent=GetAuthenticMetacontent(image);
 714   count=dpc_read(file,length,metacontent);
 715   if (count != (MagickOffsetType) length)
 716     return(MagickFalse);
 717   return(SyncAuthenticPixels(image,exception));
 718 }
 719
 720 static MagickBooleanType WriteDistributeCachePixels(SplayTreeInfo *registry,
 721   int file,const MagickSizeType session_key,ExceptionInfo *exception)
 722 {
 723   Image
 724     *image;
 725
 726   MagickOffsetType
 727     count;
 728
 729   MagickSizeType
 730     length;
 731
 732   RectangleInfo
 733     region;
 734
 735   register Quantum
 736     *q;
 737
 738   register unsigned char
 739     *p;
 740
 741   unsigned char
 742     message[MaxTextExtent];
 743
 744   /*
 745     Write distributed pixel cache pixels.
 746   */
 747   image=(Image *) GetValueFromSplayTree(registry,(const void *) session_key);
 748   if (image == (Image *) NULL)
 749     return(MagickFalse);
 750   length=sizeof(region.width)+sizeof(region.height)+sizeof(region.x)+
 751     sizeof(region.y)+sizeof(length);
 752   count=dpc_read(file,length,message);
 753   if (count != (MagickOffsetType) length)
 754     return(MagickFalse);
 755   p=message;
 756   (void) memcpy(&region.width,p,sizeof(region.width));
 757   p+=sizeof(region.width);
 758   (void) memcpy(&region.height,p,sizeof(region.height));
 759   p+=sizeof(region.height);
 760   (void) memcpy(&region.x,p,sizeof(region.x));
 761   p+=sizeof(region.x);
 762   (void) memcpy(&region.y,p,sizeof(region.y));
 763   p+=sizeof(region.y);
 764   (void) memcpy(&length,p,sizeof(length));
 765   p+=sizeof(length);
 766   q=GetAuthenticPixels(image,region.x,region.y,region.width,region.height,
 767     exception);
 768   if (q == (Quantum *) NULL)
 769     return(MagickFalse);
 770   count=dpc_read(file,length,(unsigned char *) q);
 771   if (count != (MagickOffsetType) length)
 772     return(MagickFalse);
 773   return(SyncAuthenticPixels(image,exception));
 774 }
 775
 776 static void *DistributePixelCacheClient(void *socket)
 777 {
 778   const char
 779     *shared_secret;
 780
 781   ExceptionInfo
 782     *exception;
 783
 784   int
 785     client_socket;
 786
 787   MagickBooleanType
 788     status;
 789
 790   MagickOffsetType
 791     count;
 792
 793   MagickSizeType
 794     key,
 795     session_key,
 796     signature;
 797
 798   register unsigned char
 799     *p;
 800
 801   RandomInfo
 802     *random_info;
 803
 804   SplayTreeInfo
 805     *registry;
 806
 807   StringInfo
 808     *secret;
 809
 810   unsigned char
 811     command,
 812     session[2*MaxTextExtent];
 813
 814   /*
 815     Distributed pixel cache client.
 816   */
 817   shared_secret=GetPolicyValue("shared-secret");
 818   if (shared_secret == (const char *) NULL)
 819     ThrowFatalException(CacheFatalError,"shared secret expected");
 820   p=session;
 821   (void) CopyMagickString((char *) p,shared_secret,MaxTextExtent);
 822   p+=strlen(shared_secret);
 823   random_info=AcquireRandomInfo();
 824   secret=GetRandomKey(random_info,DPCSessionKeyLength);
 825   (void) memcpy(p,GetStringInfoDatum(secret),DPCSessionKeyLength);
 826   p+=DPCSessionKeyLength;
 827   signature=MagickLibVersion;
 828   (void) memcpy(p,&signature,sizeof(signature));
 829   p+=sizeof(signature);
 830   signature=MAGICKCORE_QUANTUM_DEPTH;
 831   (void) memcpy(p,&signature,sizeof(signature));
 832   p+=sizeof(signature);
 833   signature=MAGICKCORE_HDRI_ENABLE;
 834   (void) memcpy(p,&signature,sizeof(signature));
 835   p+=sizeof(signature);
 836   session_key=CRC64(session,p-session);
 837   random_info=DestroyRandomInfo(random_info);
 838   exception=AcquireExceptionInfo();
 839   registry=NewSplayTree((int (*)(const void *,const void *)) NULL,
 840     (void *(*)(void *)) NULL,RelinquishImageRegistry);
 841   client_socket=(*(int *) socket);
 842   count=dpc_send(client_socket,DPCSessionKeyLength,GetStringInfoDatum(secret));
 843   secret=DestroyStringInfo(secret);
 844   for ( ; ; )
 845   {
 846     count=dpc_read(client_socket,1,(unsigned char *) &command);
 847     if (count <= 0)
 848       break;
 849     count=dpc_read(client_socket,sizeof(key),(unsigned char *) &key);
 850     if ((count != (MagickOffsetType) sizeof(key)) || (key != session_key))
 851       break;
 852     status=MagickFalse;
 853     switch (command)
 854     {
 855       case 'o':
 856       {
 857         status=OpenDistributeCache(registry,client_socket,session_key,
 858           exception);
 859         count=dpc_send(client_socket,sizeof(status),(unsigned char *) &status);
 860         break;
 861       }
 862       case 'r':
 863       {
 864         status=ReadDistributeCachePixels(registry,client_socket,session_key,
 865           exception);
 866         break;
 867       }
 868       case 'R':
 869       {
 870         status=ReadDistributeCacheMetacontent(registry,client_socket,
 871           session_key,exception);
 872         break;
 873       }
 874       case 'w':
 875       {
 876         status=WriteDistributeCachePixels(registry,client_socket,session_key,
 877           exception);
 878         break;
 879       }
 880       case 'W':
 881       {
 882         status=WriteDistributeCacheMetacontent(registry,client_socket,
 883           session_key,exception);
 884         break;
 885       }
 886       case 'd':
 887       {
 888         status=DestroyDistributeCache(registry,client_socket,session_key);
 889         break;
 890       }
 891       default:
 892         break;
 893     }
 894     if (status == MagickFalse)
 895       break;
 896     if (command == 'd')
 897       break;
 898   }
 899   count=dpc_send(client_socket,sizeof(status),(unsigned char *) &status);
 900   (void) close(client_socket);
 901   exception=DestroyExceptionInfo(exception);
 902   registry=DestroySplayTree(registry);
 903   return((void *) NULL);
 904 }
 905
 906 MagickExport void DistributePixelCacheServer(const int port,
 907   ExceptionInfo *exception)
 908 {
 909 #if defined(MAGICKCORE_HAVE_SOCKET) && defined(MAGICKCORE_THREAD_SUPPORT)
 910   char
 911     service[MaxTextExtent];
 912
 913   int
 914     server_socket,
 915     status;
 916
 917   pthread_attr_t
 918     attributes;
 919
 920   pthread_t
 921     threads;
 922
 923   register struct addrinfo
 924     *p;
 925
 926   struct addrinfo
 927     hint,
 928     *result;
 929
 930   struct sockaddr_in
 931     address;
 932
 933   /*
 934     Launch distributed pixel cache server.
 935   */
 936   (void) ResetMagickMemory(&hint,0,sizeof(hint));
 937   hint.ai_family=AF_INET;
 938   hint.ai_socktype=SOCK_STREAM;
 939   hint.ai_flags=AI_PASSIVE;
 940   (void) FormatLocaleString(service,MaxTextExtent,"%d",port);
 941   status=getaddrinfo((const char *) NULL,service,&hint,&result);
 942   if (status != 0)
 943     ThrowFatalException(CacheFatalError,"UnableToListen");
 944   for (p=result; p != (struct addrinfo *) NULL; p=p->ai_next)
 945   {
 946     int
 947       one;
 948
 949     server_socket=socket(p->ai_family,p->ai_socktype,p->ai_protocol);
 950     if (server_socket == -1)
 951       continue;
 952     one=1;
 953     status=setsockopt(server_socket,SOL_SOCKET,SO_REUSEADDR,&one,(socklen_t)
 954       sizeof(one));
 955     if (status == -1)
 956       continue;
 957     status=bind(server_socket,p->ai_addr,p->ai_addrlen);
 958     if (status == -1)
 959       {
 960         (void) close(status);
 961         continue;
 962       }
 963     break;
 964   }
 965   if (p == (struct addrinfo *) NULL)
 966     ThrowFatalException(CacheFatalError,"UnableToBind");
 967   freeaddrinfo(result);
 968   status=listen(server_socket,DPCPendingConnections);
 969   if (status != 0)
 970     ThrowFatalException(CacheFatalError,"UnableToListen");
 971   pthread_attr_init(&attributes);
 972   for ( ; ; )
 973   {
 974     int
 975       client_socket;
 976
 977     socklen_t
 978       length;
 979
 980     length=(socklen_t) sizeof(address);
 981     client_socket=accept(server_socket,(struct sockaddr *) &address,&length);
 982     if (client_socket == -1)
 983       ThrowFatalException(CacheFatalError,"UnableToEstablishConnection");
 984     status=pthread_create(&threads,&attributes,DistributePixelCacheClient,
 985       (void *) &client_socket);
 986     if (status == -1)
 987       ThrowFatalException(CacheFatalError,"UnableToCreateClientThread");
 988   }
 989   (void) close(server_socket);
 990 #else
 991   ThrowFatalException(MissingDelegateError,"distributed pixel cache");
 992 #endif
 993 }
 994 \f
 995 /*
 996 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 997 %                                                                             %
 998 %                                                                             %
 999 %                                                                             %
1000 +   G e t D i s t r i b u t e C a c h e F i l e                               %
1001 %                                                                             %
1002 %                                                                             %
1003 %                                                                             %
1004 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1005 %
1006 %  GetDistributeCacheFile() returns the file associated with this
1007 %  DistributeCacheInfo structure.
1008 %
1009 %  The format of the GetDistributeCacheFile method is:
1010 %
1011 %      int GetDistributeCacheFile(const DistributeCacheInfo *server_info)
1012 %
1013 %  A description of each parameter follows:
1014 %
1015 %    o server_info: the distributed cache info.
1016 %
1017 */
1018 MagickPrivate int GetDistributeCacheFile(const DistributeCacheInfo *server_info)
1019 {
1020   assert(server_info != (DistributeCacheInfo *) NULL);
1021   assert(server_info->signature == MagickSignature);
1022   return(server_info->file);
1023 }
1024 \f
1025 /*
1026 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1027 %                                                                             %
1028 %                                                                             %
1029 %                                                                             %
1030 +   G e t D i s t r i b u t e C a c h e H o s t n a m e                       %
1031 %                                                                             %
1032 %                                                                             %
1033 %                                                                             %
1034 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1035 %
1036 %  GetDistributeCacheHostname() returns the hostname associated with this
1037 %  DistributeCacheInfo structure.
1038 %
1039 %  The format of the GetDistributeCacheHostname method is:
1040 %
1041 %      const char *GetDistributeCacheHostname(
1042 %        const DistributeCacheInfo *server_info)
1043 %
1044 %  A description of each parameter follows:
1045 %
1046 %    o server_info: the distributed cache info.
1047 %
1048 */
1049 MagickPrivate const char *GetDistributeCacheHostname(
1050   const DistributeCacheInfo *server_info)
1051 {
1052   assert(server_info != (DistributeCacheInfo *) NULL);
1053   assert(server_info->signature == MagickSignature);
1054   return(server_info->hostname);
1055 }
1056 \f
1057 /*
1058 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1059 %                                                                             %
1060 %                                                                             %
1061 %                                                                             %
1062 +   G e t D i s t r i b u t e C a c h e P o r t                               %
1063 %                                                                             %
1064 %                                                                             %
1065 %                                                                             %
1066 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1067 %
1068 %  GetDistributeCachePort() returns the port associated with this
1069 %  DistributeCacheInfo structure.
1070 %
1071 %  The format of the GetDistributeCachePort method is:
1072 %
1073 %      int GetDistributeCachePort(const DistributeCacheInfo *server_info)
1074 %
1075 %  A description of each parameter follows:
1076 %
1077 %    o server_info: the distributed cache info.
1078 %
1079 */
1080 MagickPrivate int GetDistributeCachePort(const DistributeCacheInfo *server_info)
1081 {
1082   assert(server_info != (DistributeCacheInfo *) NULL);
1083   assert(server_info->signature == MagickSignature);
1084   return(server_info->port);
1085 }
1086 \f
1087 /*
1088 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1089 %                                                                             %
1090 %                                                                             %
1091 %                                                                             %
1092 +   O p e n D i s t r i b u t e P i x e l C a c h e                           %
1093 %                                                                             %
1094 %                                                                             %
1095 %                                                                             %
1096 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1097 %
1098 %  OpenDistributePixelCache() opens a pixel cache on a remote server.
1099 %
1100 %  The format of the OpenDistributePixelCache method is:
1101 %
1102 %      MagickBooleanType *OpenDistributePixelCache(
1103 %        DistributeCacheInfo *server_info,Image *image)
1104 %
1105 %  A description of each parameter follows:
1106 %
1107 %    o server_info: the distributed cache info.
1108 %
1109 %    o image: the image.
1110 %
1111 */
1112 MagickPrivate MagickBooleanType OpenDistributePixelCache(
1113   DistributeCacheInfo *server_info,Image *image)
1114 {
1115   MagickBooleanType
1116     status;
1117
1118   MagickOffsetType
1119     count;
1120
1121   register unsigned char
1122     *p;
1123
1124   unsigned char
1125     message[MaxTextExtent];
1126
1127   /*
1128     Open distributed pixel cache.
1129   */
1130   assert(server_info != (DistributeCacheInfo *) NULL);
1131   assert(server_info->signature == MagickSignature);
1132   assert(image != (Image *) NULL);
1133   assert(image->signature == MagickSignature);
1134   p=message;
1135   *p++='o';  /* open */
1136   /*
1137     Serialize image attributes (see ValidatePixelCacheMorphology()).
1138   */
1139   (void) memcpy(p,&server_info->session_key,sizeof(server_info->session_key));
1140   p+=sizeof(server_info->session_key);
1141   (void) memcpy(p,&image->storage_class,sizeof(image->storage_class));
1142   p+=sizeof(image->storage_class);
1143   (void) memcpy(p,&image->colorspace,sizeof(image->colorspace));
1144   p+=sizeof(image->colorspace);
1145   (void) memcpy(p,&image->alpha_trait,sizeof(image->alpha_trait));
1146   p+=sizeof(image->alpha_trait);
1147   (void) memcpy(p,&image->mask,sizeof(image->mask));
1148   p+=sizeof(image->mask);
1149   (void) memcpy(p,&image->columns,sizeof(image->columns));
1150   p+=sizeof(image->columns);
1151   (void) memcpy(p,&image->rows,sizeof(image->rows));
1152   p+=sizeof(image->rows);
1153   (void) memcpy(p,&image->number_channels,sizeof(image->number_channels));
1154   p+=sizeof(image->number_channels);
1155   (void) memcpy(p,image->channel_map,MaxPixelChannels*
1156     sizeof(*image->channel_map));
1157   p+=MaxPixelChannels*sizeof(*image->channel_map);
1158   (void) memcpy(p,&image->metacontent_extent,sizeof(image->metacontent_extent));
1159   p+=sizeof(image->metacontent_extent);
1160   count=dpc_send(server_info->file,p-message,message);
1161   if (count != (MagickOffsetType) (p-message))
1162     return(MagickFalse);
1163   status=MagickFalse;
1164   count=dpc_read(server_info->file,sizeof(status),(unsigned char *) &status);
1165   if (count != (MagickOffsetType) sizeof(status))
1166     return(MagickFalse);
1167   return(status);
1168 }
1169 \f
1170 /*
1171 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1172 %                                                                             %
1173 %                                                                             %
1174 %                                                                             %
1175 +   R e a d D i s t r i b u t e P i x e l C a c h e M e t a c o n t e n t     %
1176 %                                                                             %
1177 %                                                                             %
1178 %                                                                             %
1179 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1180 %
1181 %  ReadDistributePixelCacheMetacontents() reads metacontent from the specified
1182 %  region of the distributed pixel cache.
1183 %
1184 %  The format of the ReadDistributePixelCacheMetacontents method is:
1185 %
1186 %      MagickOffsetType ReadDistributePixelCacheMetacontents(
1187 %        DistributeCacheInfo *server_info,const RectangleInfo *region,
1188 %        const MagickSizeType length,unsigned char *metacontent)
1189 %
1190 %  A description of each parameter follows:
1191 %
1192 %    o server_info: the distributed cache info.
1193 %
1194 %    o image: the image.
1195 %
1196 %    o region: read the metacontent from this region of the image.
1197 %
1198 %    o length: the length in bytes of the metacontent.
1199 %
1200 %    o metacontent: read these metacontent from the pixel cache.
1201 %
1202 */
1203 MagickPrivate MagickOffsetType ReadDistributePixelCacheMetacontent(
1204   DistributeCacheInfo *server_info,const RectangleInfo *region,
1205   const MagickSizeType length,unsigned char *metacontent)
1206 {
1207   MagickOffsetType
1208     count;
1209
1210   register unsigned char
1211     *p;
1212
1213   unsigned char
1214     message[MaxTextExtent];
1215
1216   /*
1217     Read distributed pixel cache metacontent.
1218   */
1219   assert(server_info != (DistributeCacheInfo *) NULL);
1220   assert(server_info->signature == MagickSignature);
1221   assert(region != (RectangleInfo *) NULL);
1222   assert(metacontent != (unsigned char *) NULL);
1223   if (length > (MagickSizeType) SSIZE_MAX)
1224     return(-1);
1225   p=message;
1226   *p++='R';
1227   (void) memcpy(p,&server_info->session_key,sizeof(server_info->session_key));
1228   p+=sizeof(server_info->session_key);
1229   (void) memcpy(p,&region->width,sizeof(region->width));
1230   p+=sizeof(region->width);
1231   (void) memcpy(p,&region->height,sizeof(region->height));
1232   p+=sizeof(region->height);
1233   (void) memcpy(p,&region->x,sizeof(region->x));
1234   p+=sizeof(region->x);
1235   (void) memcpy(p,&region->y,sizeof(region->y));
1236   p+=sizeof(region->y);
1237   (void) memcpy(p,&length,sizeof(length));
1238   p+=sizeof(length);
1239   count=dpc_send(server_info->file,p-message,message);
1240   if (count != (MagickOffsetType) (p-message))
1241     return(-1);
1242   return(dpc_read(server_info->file,length,metacontent));
1243 }
1244 \f
1245 /*
1246 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1247 %                                                                             %
1248 %                                                                             %
1249 %                                                                             %
1250 +   R e a d D i s t r i b u t e P i x e l C a c h e P i x e l s               %
1251 %                                                                             %
1252 %                                                                             %
1253 %                                                                             %
1254 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1255 %
1256 %  ReadDistributePixelCachePixels() reads pixels from the specified region of
1257 %  the distributed pixel cache.
1258 %
1259 %  The format of the ReadDistributePixelCachePixels method is:
1260 %
1261 %      MagickOffsetType ReadDistributePixelCachePixels(
1262 %        DistributeCacheInfo *server_info,const RectangleInfo *region,
1263 %        const MagickSizeType length,unsigned char *pixels)
1264 %
1265 %  A description of each parameter follows:
1266 %
1267 %    o server_info: the distributed cache info.
1268 %
1269 %    o image: the image.
1270 %
1271 %    o region: read the pixels from this region of the image.
1272 %
1273 %    o length: the length in bytes of the pixels.
1274 %
1275 %    o pixels: read these pixels from the pixel cache.
1276 %
1277 */
1278 MagickPrivate MagickOffsetType ReadDistributePixelCachePixels(
1279   DistributeCacheInfo *server_info,const RectangleInfo *region,
1280   const MagickSizeType length,unsigned char *pixels)
1281 {
1282   MagickOffsetType
1283     count;
1284
1285   register unsigned char
1286     *p;
1287
1288   unsigned char
1289     message[MaxTextExtent];
1290
1291   /*
1292     Read distributed pixel cache pixels.
1293   */
1294   assert(server_info != (DistributeCacheInfo *) NULL);
1295   assert(server_info->signature == MagickSignature);
1296   assert(region != (RectangleInfo *) NULL);
1297   assert(pixels != (unsigned char *) NULL);
1298   if (length > (MagickSizeType) SSIZE_MAX)
1299     return(-1);
1300   p=message;
1301   *p++='r';
1302   (void) memcpy(p,&server_info->session_key,sizeof(server_info->session_key));
1303   p+=sizeof(server_info->session_key);
1304   (void) memcpy(p,&region->width,sizeof(region->width));
1305   p+=sizeof(region->width);
1306   (void) memcpy(p,&region->height,sizeof(region->height));
1307   p+=sizeof(region->height);
1308   (void) memcpy(p,&region->x,sizeof(region->x));
1309   p+=sizeof(region->x);
1310   (void) memcpy(p,&region->y,sizeof(region->y));
1311   p+=sizeof(region->y);
1312   (void) memcpy(p,&length,sizeof(length));
1313   p+=sizeof(length);
1314   count=dpc_send(server_info->file,p-message,message);
1315   if (count != (MagickOffsetType) (p-message))
1316     return(-1);
1317   return(dpc_read(server_info->file,length,pixels));
1318 }
1319 \f
1320 /*
1321 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1322 %                                                                             %
1323 %                                                                             %
1324 %                                                                             %
1325 +   R e l i n q u i s h D i s t r i b u t e P i x e l C a c h e               %
1326 %                                                                             %
1327 %                                                                             %
1328 %                                                                             %
1329 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1330 %
1331 %  RelinquishDistributePixelCache() frees resources acquired with
1332 %  OpenDistributePixelCache().
1333 %
1334 %  The format of the RelinquishDistributePixelCache method is:
1335 %
1336 %      MagickBooleanType RelinquishDistributePixelCache(
1337 %        DistributeCacheInfo *server_info)
1338 %
1339 %  A description of each parameter follows:
1340 %
1341 %    o server_info: the distributed cache info.
1342 %
1343 */
1344 MagickPrivate MagickBooleanType RelinquishDistributePixelCache(
1345   DistributeCacheInfo *server_info)
1346 {
1347   MagickBooleanType
1348     status;
1349
1350   MagickOffsetType
1351     count;
1352
1353   register unsigned char
1354     *p;
1355
1356   unsigned char
1357     message[MaxTextExtent];
1358
1359   /*
1360     Delete distributed pixel cache.
1361   */
1362   assert(server_info != (DistributeCacheInfo *) NULL);
1363   assert(server_info->signature == MagickSignature);
1364   p=message;
1365   *p++='d';
1366   (void) memcpy(p,&server_info->session_key,sizeof(server_info->session_key));
1367   p+=sizeof(server_info->session_key);
1368   count=dpc_send(server_info->file,p-message,message);
1369   if (count != (MagickOffsetType) (p-message))
1370     return(MagickFalse);
1371   count=dpc_read(server_info->file,sizeof(status),(unsigned char *) &status);
1372   if (count != (MagickOffsetType) sizeof(status))
1373     return(MagickFalse);
1374   return(status);
1375 }
1376 \f
1377 /*
1378 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1379 %                                                                             %
1380 %                                                                             %
1381 %                                                                             %
1382 +   W r i t e D i s t r i b u t e P i x e l C a c h e M e t a c o n t e n t   %
1383 %                                                                             %
1384 %                                                                             %
1385 %                                                                             %
1386 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1387 %
1388 %  WriteDistributePixelCacheMetacontents() writes image metacontent to the
1389 %  specified region of the distributed pixel cache.
1390 %
1391 %  The format of the WriteDistributePixelCacheMetacontents method is:
1392 %
1393 %      MagickOffsetType WriteDistributePixelCacheMetacontents(
1394 %        DistributeCacheInfo *server_info,const RectangleInfo *region,
1395 %        const MagickSizeType length,const unsigned char *metacontent)
1396 %
1397 %  A description of each parameter follows:
1398 %
1399 %    o server_info: the distributed cache info.
1400 %
1401 %    o image: the image.
1402 %
1403 %    o region: write the metacontent to this region of the image.
1404 %
1405 %    o length: the length in bytes of the metacontent.
1406 %
1407 %    o metacontent: write these metacontent to the pixel cache.
1408 %
1409 */
1410 MagickPrivate MagickOffsetType WriteDistributePixelCacheMetacontent(
1411   DistributeCacheInfo *server_info,const RectangleInfo *region,
1412   const MagickSizeType length,const unsigned char *metacontent)
1413 {
1414   MagickOffsetType
1415     count;
1416
1417   register unsigned char
1418     *p;
1419
1420   unsigned char
1421     message[MaxTextExtent];
1422
1423   /*
1424     Write distributed pixel cache metacontent.
1425   */
1426   assert(server_info != (DistributeCacheInfo *) NULL);
1427   assert(server_info->signature == MagickSignature);
1428   assert(region != (RectangleInfo *) NULL);
1429   assert(metacontent != (unsigned char *) NULL);
1430   if (length > (MagickSizeType) SSIZE_MAX)
1431     return(-1);
1432   p=message;
1433   *p++='W';
1434   (void) memcpy(p,&server_info->session_key,sizeof(server_info->session_key));
1435   p+=sizeof(server_info->session_key);
1436   (void) memcpy(p,&region->width,sizeof(region->width));
1437   p+=sizeof(region->width);
1438   (void) memcpy(p,&region->height,sizeof(region->height));
1439   p+=sizeof(region->height);
1440   (void) memcpy(p,&region->x,sizeof(region->x));
1441   p+=sizeof(region->x);
1442   (void) memcpy(p,&region->y,sizeof(region->y));
1443   p+=sizeof(region->y);
1444   (void) memcpy(p,&length,sizeof(length));
1445   p+=sizeof(length);
1446   count=dpc_send(server_info->file,p-message,message);
1447   if (count != (MagickOffsetType) (p-message))
1448     return(-1);
1449   return(dpc_send(server_info->file,length,metacontent));
1450 }
1451 \f
1452 /*
1453 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1454 %                                                                             %
1455 %                                                                             %
1456 %                                                                             %
1457 +   W r i t e D i s t r i b u t e P i x e l C a c h e P i x e l s             %
1458 %                                                                             %
1459 %                                                                             %
1460 %                                                                             %
1461 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1462 %
1463 %  WriteDistributePixelCachePixels() writes image pixels to the specified
1464 %  region of the distributed pixel cache.
1465 %
1466 %  The format of the WriteDistributePixelCachePixels method is:
1467 %
1468 %      MagickBooleanType WriteDistributePixelCachePixels(
1469 %        DistributeCacheInfo *server_info,const RectangleInfo *region,
1470 %        const MagickSizeType length,const unsigned char *pixels)
1471 %
1472 %  A description of each parameter follows:
1473 %
1474 %    o server_info: the distributed cache info.
1475 %
1476 %    o image: the image.
1477 %
1478 %    o region: write the pixels to this region of the image.
1479 %
1480 %    o length: the length in bytes of the pixels.
1481 %
1482 %    o pixels: write these pixels to the pixel cache.
1483 %
1484 */
1485 MagickPrivate MagickOffsetType WriteDistributePixelCachePixels(
1486   DistributeCacheInfo *server_info,const RectangleInfo *region,
1487   const MagickSizeType length,const unsigned char *pixels)
1488 {
1489   MagickOffsetType
1490     count;
1491
1492   register unsigned char
1493     *p;
1494
1495   unsigned char
1496     message[MaxTextExtent];
1497
1498   /*
1499     Write distributed pixel cache pixels.
1500   */
1501   assert(server_info != (DistributeCacheInfo *) NULL);
1502   assert(server_info->signature == MagickSignature);
1503   assert(region != (RectangleInfo *) NULL);
1504   assert(pixels != (const unsigned char *) NULL);
1505   if (length > (MagickSizeType) SSIZE_MAX)
1506     return(-1);
1507   p=message;
1508   *p++='w';
1509   (void) memcpy(p,&server_info->session_key,sizeof(server_info->session_key));
1510   p+=sizeof(server_info->session_key);
1511   (void) memcpy(p,&region->width,sizeof(region->width));
1512   p+=sizeof(region->width);
1513   (void) memcpy(p,&region->height,sizeof(region->height));
1514   p+=sizeof(region->height);
1515   (void) memcpy(p,&region->x,sizeof(region->x));
1516   p+=sizeof(region->x);
1517   (void) memcpy(p,&region->y,sizeof(region->y));
1518   p+=sizeof(region->y);
1519   (void) memcpy(p,&length,sizeof(length));
1520   p+=sizeof(length);
1521   count=dpc_send(server_info->file,p-message,message);
1522   if (count != (MagickOffsetType) (p-message))
1523     return(-1);
1524   return(dpc_send(server_info->file,length,pixels));
1525 }