path: root/MagickCore/magic.c

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                    M   M   AAA    GGGG  IIIII   CCCC                        %
%                    MM MM  A   A  G        I    C                            %
%                    M M M  AAAAA  G GGG    I    C                            %
%                    M   M  A   A  G   G    I    C                            %
%                    M   M  A   A   GGGG  IIIII   CCCC                        %
%                                                                             %
%                                                                             %
%                      MagickCore Image Magic Methods                         %
%                                                                             %
%                              Software Design                                %
%                              Bob Friesenhahn                                %
%                                 July 2000                                   %
%                                                                             %
%                                                                             %
%  Copyright 1999-2020 ImageMagick Studio LLC, a non-profit organization      %
%  dedicated to making software imaging solutions freely available.           %
%                                                                             %
%  You may not use this file except in compliance with the License.  You may  %
%  obtain a copy of the License at                                            %
%                                                                             %
%    https://imagemagick.org/script/license.php                               %
%                                                                             %
%  Unless required by applicable law or agreed to in writing, software        %
%  distributed under the License is distributed on an "AS IS" BASIS,          %
%  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
%  See the License for the specific language governing permissions and        %
%  limitations under the License.                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/

/*
  Include declarations.
*/
#include "MagickCore/studio.h"
#include "MagickCore/blob.h"
#include "MagickCore/client.h"
#include "MagickCore/configure.h"
#include "MagickCore/configure-private.h"
#include "MagickCore/exception.h"
#include "MagickCore/exception-private.h"
#include "MagickCore/linked-list.h"
#include "MagickCore/magic.h"
#include "MagickCore/magic-private.h"
#include "MagickCore/memory_.h"
#include "MagickCore/memory-private.h"
#include "MagickCore/semaphore.h"
#include "MagickCore/string_.h"
#include "MagickCore/string-private.h"
#include "MagickCore/token.h"
#include "MagickCore/utility.h"
#include "MagickCore/utility-private.h"
#include "coders/coders.h"

/*
  Define declarations.
*/
#define AddMagickCoder(coder) Magick ## coder ## Headers

/*
  Typedef declarations.
*/
typedef struct _MagicMapInfo
{
  const char
    name[10];

  const MagickOffsetType
    offset;

  const unsigned char
    *const magic;

  const size_t
    length;
} MagicMapInfo;

struct _MagicInfo
{
  char
    *path,
    *name,
    *target;

  unsigned char
    *magic;

  size_t
    length;

  MagickOffsetType
    offset;

  MagickBooleanType
    exempt,
    stealth;

  size_t
    signature;
};

/*
  Static declarations.
*/
static const MagicMapInfo
  MagicMap[] =
  {
    #include "coders/coders-list.h"
    MagickCoderHeader("CGM", 0, "BEGMF")
    MagickCoderHeader("FIG", 0, "#FIG")
    MagickCoderHeader("HPGL", 0, "IN;")
    MagickCoderHeader("ILBM", 8, "ILBM")
  };

static LinkedListInfo
  *magic_cache = (LinkedListInfo *) NULL,
  *magic_list = (LinkedListInfo *) NULL;

static SemaphoreInfo
  *magic_cache_semaphore = (SemaphoreInfo *) NULL,
  *magic_list_semaphore = (SemaphoreInfo *) NULL;

/*
  Forward declarations.
*/
static MagickBooleanType
  IsMagicListInstantiated(ExceptionInfo *);

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  A c q u i r e M a g i c L i s t                                            %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireMagicList() caches one or more magic configurations which provides a
%  mapping between magic attributes and a magic name.
%
%  The format of the AcquireMagicList method is:
%
%      LinkedListInfo *AcquireMagicList(ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o filename: the font file name.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static int CompareMagickInfoSize(const void *a,const void *b)
{
  MagicInfo
    *ma,
    *mb;

  ma=(MagicInfo *) a;
  mb=(MagicInfo *) b;
  if (ma->offset != mb->offset)
    {
      MagickOffsetType
        max_offset;

      /*
        When the offset is near the start we first search a bit further
        in the stream.
      */
      max_offset=ma->offset > mb->offset ? ma->offset : mb->offset;
      if (max_offset <= 10)
        return((int) (mb->offset-ma->offset));
      else
        return((int) (ma->offset-mb->offset));
    }
  return((int) (mb->length-ma->length));
}

static LinkedListInfo *AcquireMagicList(ExceptionInfo *exception)
{
  LinkedListInfo
    *list;

  MagickStatusType
    status;

  register ssize_t
    i;

  list=NewLinkedList(0);
  status=MagickTrue;
  /*
    Load built-in magic map.
  */
  for (i=0; i < (ssize_t) (sizeof(MagicMap)/sizeof(*MagicMap)); i++)
  {
    MagicInfo
      *magic_info;

    register const MagicMapInfo
      *p;

    p=MagicMap+i;
    magic_info=(MagicInfo *) AcquireMagickMemory(sizeof(*magic_info));
    if (magic_info == (MagicInfo *) NULL)
      {
        (void) ThrowMagickException(exception,GetMagickModule(),
          ResourceLimitError,"MemoryAllocationFailed","`%s'",p->name);
        continue;
      }
    (void) memset(magic_info,0,sizeof(*magic_info));
    magic_info->path=(char *) "[built-in]";
    magic_info->name=(char *) p->name;
    magic_info->offset=p->offset;
    magic_info->target=(char *) p->magic;
    magic_info->magic=(unsigned char *) p->magic;
    magic_info->length=p->length;
    magic_info->exempt=MagickTrue;
    magic_info->signature=MagickCoreSignature;
    status&=InsertValueInSortedLinkedList(list,CompareMagickInfoSize,
      NULL,magic_info);
    if (status == MagickFalse)
      (void) ThrowMagickException(exception,GetMagickModule(),
        ResourceLimitError,"MemoryAllocationFailed","`%s'",magic_info->name);
  }
  return(list);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t M a g i c I n f o                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetMagicInfo() searches the magic list for the specified name and if found
%  returns attributes for that magic.
%
%  The format of the GetMagicInfo method is:
%
%      const MagicInfo *GetMagicInfo(const unsigned char *magic,
%        const size_t length,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o magic: A binary string generally representing the first few characters
%      of the image file or blob.
%
%    o length: the length of the binary signature.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static MagickBooleanType IsMagicCacheInstantiated()
{
  if (magic_cache == (LinkedListInfo *) NULL)
    {
      if (magic_cache_semaphore == (SemaphoreInfo *) NULL)
        ActivateSemaphoreInfo(&magic_cache_semaphore);
      LockSemaphoreInfo(magic_cache_semaphore);
      if (magic_cache == (LinkedListInfo *) NULL)
        magic_cache=NewLinkedList(0);
      UnlockSemaphoreInfo(magic_cache_semaphore);
    }
  return(magic_cache != (LinkedListInfo *) NULL ? MagickTrue : MagickFalse);
}

MagickExport const MagicInfo *GetMagicInfo(const unsigned char *magic,
  const size_t length,ExceptionInfo *exception)
{
  register const MagicInfo
    *p;

  assert(exception != (ExceptionInfo *) NULL);
  if (IsMagicListInstantiated(exception) == MagickFalse)
    return((const MagicInfo *) NULL);
  if (IsMagicCacheInstantiated() == MagickFalse)
    return((const MagicInfo *) NULL);
  /*
    Search for cached entries.
  */
  if (magic != (const unsigned char *) NULL)
    {
      LockSemaphoreInfo(magic_cache_semaphore);
      ResetLinkedListIterator(magic_cache);
      p=(const MagicInfo *) GetNextValueInLinkedList(magic_cache);
      while (p != (const MagicInfo *) NULL)
      {
        if (((size_t) (p->offset+p->length) <= length) &&
            (memcmp(magic+p->offset,p->magic,p->length) == 0))
          break;
        p=(const MagicInfo *) GetNextValueInLinkedList(magic_cache);
      }
      UnlockSemaphoreInfo(magic_cache_semaphore);
      if (p != (const MagicInfo *) NULL)
        return(p);
    }
  /*
    Search for magic tag.
  */
  LockSemaphoreInfo(magic_list_semaphore);
  ResetLinkedListIterator(magic_list);
  p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  if (magic == (const unsigned char *) NULL)
    {
      UnlockSemaphoreInfo(magic_list_semaphore);
      return(p);
    }
  while (p != (const MagicInfo *) NULL)
  {
    assert(p->offset >= 0);
    if (((size_t) (p->offset+p->length) <= length) &&
        (memcmp(magic+p->offset,p->magic,p->length) == 0))
      break;
    p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  }
  UnlockSemaphoreInfo(magic_list_semaphore);
  if (p != (const MagicInfo *) NULL)
    {
      LockSemaphoreInfo(magic_cache_semaphore);
      InsertValueInSortedLinkedList(magic_cache,CompareMagickInfoSize,
        NULL,p);
      UnlockSemaphoreInfo(magic_cache_semaphore);
    }
  return(p);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t M a g i c P a t t e r n E x t e n t                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetMagicPatternExtent() returns the extent of the buffer that is
%  required to check all the MagickInfos. It returns zero if the list is empty.
%
%  The format of the GetMagicPatternExtent method is:
%
%      size_t GetMagicPatternExtent(ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o exception: return any errors or warnings in this structure.
%
*/
MagickExport size_t GetMagicPatternExtent(ExceptionInfo *exception)
{
  register const MagicInfo
    *p;

  size_t
    magickSize,
    max;

  static size_t
    size=0;

  assert(exception != (ExceptionInfo *) NULL);
  if ((size != 0) || (IsMagicListInstantiated(exception) == MagickFalse))
    return(size);
  LockSemaphoreInfo(magic_list_semaphore);
  ResetLinkedListIterator(magic_list);
  max=0;
  p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  while (p != (const MagicInfo *) NULL)
  {
    magickSize=(size_t) (p->offset+p->length);
    if (magickSize > max)
      max=magickSize;
    p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  }
  size=max;
  UnlockSemaphoreInfo(magic_list_semaphore);
  return(size);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t M a g i c I n f o L i s t                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetMagicInfoList() returns any image aliases that match the specified
%  pattern.
%
%  The magic of the GetMagicInfoList function is:
%
%      const MagicInfo **GetMagicInfoList(const char *pattern,
%        size_t *number_aliases,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o pattern: Specifies a pointer to a text string containing a pattern.
%
%    o number_aliases:  This integer returns the number of aliases in the list.
%
%    o exception: return any errors or warnings in this structure.
%
*/

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

static int MagicInfoCompare(const void *x,const void *y)
{
  const MagicInfo
    **p,
    **q;

  p=(const MagicInfo **) x,
  q=(const MagicInfo **) y;
  if (LocaleCompare((*p)->path,(*q)->path) == 0)
    return(LocaleCompare((*p)->name,(*q)->name));
  return(LocaleCompare((*p)->path,(*q)->path));
}

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

MagickExport const MagicInfo **GetMagicInfoList(const char *pattern,
  size_t *number_aliases,ExceptionInfo *exception)
{
  const MagicInfo
    **aliases;

  register const MagicInfo
    *p;

  register ssize_t
    i;

  /*
    Allocate magic list.
  */
  assert(pattern != (char *) NULL);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",pattern);
  assert(number_aliases != (size_t *) NULL);
  *number_aliases=0;
  p=GetMagicInfo((const unsigned char *) NULL,0,exception);
  if (p == (const MagicInfo *) NULL)
    return((const MagicInfo **) NULL);
  aliases=(const MagicInfo **) AcquireQuantumMemory((size_t)
    GetNumberOfElementsInLinkedList(magic_list)+1UL,sizeof(*aliases));
  if (aliases == (const MagicInfo **) NULL)
    return((const MagicInfo **) NULL);
  /*
    Generate magic list.
  */
  LockSemaphoreInfo(magic_list_semaphore);
  ResetLinkedListIterator(magic_list);
  p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  for (i=0; p != (const MagicInfo *) NULL; )
  {
    if ((p->stealth == MagickFalse) &&
        (GlobExpression(p->name,pattern,MagickFalse) != MagickFalse))
      aliases[i++]=p;
    p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  }
  UnlockSemaphoreInfo(magic_list_semaphore);
  qsort((void *) aliases,(size_t) i,sizeof(*aliases),MagicInfoCompare);
  aliases[i]=(MagicInfo *) NULL;
  *number_aliases=(size_t) i;
  return(aliases);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t M a g i c L i s t                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetMagicList() returns any image format aliases that match the specified
%  pattern.
%
%  The format of the GetMagicList function is:
%
%      char **GetMagicList(const char *pattern,size_t *number_aliases,
%        ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o pattern: Specifies a pointer to a text string containing a pattern.
%
%    o number_aliases:  This integer returns the number of image format aliases
%      in the list.
%
%    o exception: return any errors or warnings in this structure.
%
*/

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

static int MagicCompare(const void *x,const void *y)
{
  register const char
    *p,
    *q;

  p=(const char *) x;
  q=(const char *) y;
  return(LocaleCompare(p,q));
}

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

MagickExport char **GetMagicList(const char *pattern,size_t *number_aliases,
  ExceptionInfo *exception)
{
  char
    **aliases;

  register const MagicInfo
    *p;

  register ssize_t
    i;

  /*
    Allocate configure list.
  */
  assert(pattern != (char *) NULL);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",pattern);
  assert(number_aliases != (size_t *) NULL);
  *number_aliases=0;
  p=GetMagicInfo((const unsigned char *) NULL,0,exception);
  if (p == (const MagicInfo *) NULL)
    return((char **) NULL);
  aliases=(char **) AcquireQuantumMemory((size_t)
    GetNumberOfElementsInLinkedList(magic_list)+1UL,sizeof(*aliases));
  if (aliases == (char **) NULL)
    return((char **) NULL);
  LockSemaphoreInfo(magic_list_semaphore);
  ResetLinkedListIterator(magic_list);
  p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  for (i=0; p != (const MagicInfo *) NULL; )
  {
    if ((p->stealth == MagickFalse) &&
        (GlobExpression(p->name,pattern,MagickFalse) != MagickFalse))
      aliases[i++]=ConstantString(p->name);
    p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
  }
  UnlockSemaphoreInfo(magic_list_semaphore);
  qsort((void *) aliases,(size_t) i,sizeof(*aliases),MagicCompare);
  aliases[i]=(char *) NULL;
  *number_aliases=(size_t) i;
  return(aliases);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t M a g i c N a m e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetMagicName() returns the name associated with the magic.
%
%  The format of the GetMagicName method is:
%
%      const char *GetMagicName(const MagicInfo *magic_info)
%
%  A description of each parameter follows:
%
%    o magic_info:  The magic info.
%
*/
MagickExport const char *GetMagicName(const MagicInfo *magic_info)
{
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(magic_info != (MagicInfo *) NULL);
  assert(magic_info->signature == MagickCoreSignature);
  return(magic_info->name);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
+   I s M a g i c L i s t I n s t a n t i a t e d                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  IsMagicListInstantiated() determines if the magic list is instantiated.
%  If not, it instantiates the list and returns it.
%
%  The format of the IsMagicListInstantiated method is:
%
%      MagickBooleanType IsMagicListInstantiated(ExceptionInfo *exception)
%
%  A description of each parameter follows.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static MagickBooleanType IsMagicListInstantiated(ExceptionInfo *exception)
{
  if (magic_list == (LinkedListInfo *) NULL)
    {
      if (magic_list_semaphore == (SemaphoreInfo *) NULL)
        ActivateSemaphoreInfo(&magic_list_semaphore);
      LockSemaphoreInfo(magic_list_semaphore);
      if (magic_list == (LinkedListInfo *) NULL)
        magic_list=AcquireMagicList(exception);
      UnlockSemaphoreInfo(magic_list_semaphore);
    }
  return(magic_list != (LinkedListInfo *) NULL ? MagickTrue : MagickFalse);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  L i s t M a g i c I n f o                                                  %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ListMagicInfo() lists the magic info to a file.
%
%  The format of the ListMagicInfo method is:
%
%      MagickBooleanType ListMagicInfo(FILE *file,ExceptionInfo *exception)
%
%  A description of each parameter follows.
%
%    o file:  An pointer to a FILE.
%
%    o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType ListMagicInfo(FILE *file,
  ExceptionInfo *exception)
{
  const char
    *path;

  const MagicInfo
    **magic_info;

  register ssize_t
    i;

  size_t
    number_aliases;

  ssize_t
    j;

  if (file == (const FILE *) NULL)
    file=stdout;
  magic_info=GetMagicInfoList("*",&number_aliases,exception);
  if (magic_info == (const MagicInfo **) NULL)
    return(MagickFalse);
  path=(const char *) NULL;
  for (i=0; i < (ssize_t) number_aliases; i++)
  {
    if (magic_info[i]->stealth != MagickFalse)
      continue;
    if ((path == (const char *) NULL) ||
        (LocaleCompare(path,magic_info[i]->path) != 0))
      {
        if (magic_info[i]->path != (char *) NULL)
          (void) FormatLocaleFile(file,"\nPath: %s\n\n",magic_info[i]->path);
        (void) FormatLocaleFile(file,"Name      Offset Target\n");
        (void) FormatLocaleFile(file,
          "-------------------------------------------------"
          "------------------------------\n");
      }
    path=magic_info[i]->path;
    (void) FormatLocaleFile(file,"%s",magic_info[i]->name);
    for (j=(ssize_t) strlen(magic_info[i]->name); j <= 9; j++)
      (void) FormatLocaleFile(file," ");
    (void) FormatLocaleFile(file,"%6ld ",(long) magic_info[i]->offset);
    if (magic_info[i]->target != (char *) NULL)
      {
        for (j=0; magic_info[i]->target[j] != '\0'; j++)
          if (isprint((int) ((unsigned char) magic_info[i]->target[j])) != 0)
            (void) FormatLocaleFile(file,"%c",magic_info[i]->target[j]);
          else
            (void) FormatLocaleFile(file,"\\%03o",(unsigned int)
              ((unsigned char) magic_info[i]->target[j]));
      }
    (void) FormatLocaleFile(file,"\n");
  }
  (void) fflush(file);
  magic_info=(const MagicInfo **) RelinquishMagickMemory((void *) magic_info);
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
+   M a g i c C o m p o n e n t G e n e s i s                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  MagicComponentGenesis() instantiates the magic component.
%
%  The format of the MagicComponentGenesis method is:
%
%      MagickBooleanType MagicComponentGenesis(void)
%
*/
MagickPrivate MagickBooleanType MagicComponentGenesis(void)
{
  if (magic_list_semaphore == (SemaphoreInfo *) NULL)
    magic_list_semaphore=AcquireSemaphoreInfo();
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
+   M a g i c C o m p o n e n t T e r m i n u s                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  MagicComponentTerminus() destroys the magic component.
%
%  The format of the MagicComponentTerminus method is:
%
%      MagicComponentTerminus(void)
%
*/

static void *DestroyMagicElement(void *magic_info)
{
  register MagicInfo
    *p;

  p=(MagicInfo *) magic_info;
  if (p->exempt == MagickFalse)
    {
      if (p->path != (char *) NULL)
        p->path=DestroyString(p->path);
      if (p->name != (char *) NULL)
        p->name=DestroyString(p->name);
      if (p->target != (char *) NULL)
        p->target=DestroyString(p->target);
      if (p->magic != (unsigned char *) NULL)
        p->magic=(unsigned char *) RelinquishMagickMemory(p->magic);
    }
  p=(MagicInfo *) RelinquishMagickMemory(p);
  return((void *) NULL);
}

MagickPrivate void MagicComponentTerminus(void)
{
  if (magic_list_semaphore == (SemaphoreInfo *) NULL)
    ActivateSemaphoreInfo(&magic_list_semaphore);
  LockSemaphoreInfo(magic_list_semaphore);
  if (magic_list != (LinkedListInfo *) NULL)
    magic_list=DestroyLinkedList(magic_list,DestroyMagicElement);
  UnlockSemaphoreInfo(magic_list_semaphore);
  RelinquishSemaphoreInfo(&magic_list_semaphore);
  if (magic_cache_semaphore == (SemaphoreInfo *) NULL)
    ActivateSemaphoreInfo(&magic_cache_semaphore);
  LockSemaphoreInfo(magic_cache_semaphore);
  if (magic_cache != (LinkedListInfo *) NULL)
    magic_cache=DestroyLinkedList(magic_cache,(void *(*)(void *)) NULL);
  UnlockSemaphoreInfo(magic_cache_semaphore);
  RelinquishSemaphoreInfo(&magic_cache_semaphore);
}