ttmmap.c

神龙卡开发原代码

/*******************************************************************
 *
 *  ttmmap.c                                                     2.0
 *
 *    Memory-Mapped file component ( replaces ttfile.c ).
 *
 *  Copyright 1996-1999 by
 *  David Turner, Robert Wilhelm, and Werner Lemberg
 *
 *  This file is part of the FreeType project, and may only be used
 *  modified and distributed under the terms of the FreeType project
 *  license, LICENSE.TXT. By continuing to use, modify or distribute
 *  this file you indicate that you have read the license and
 *  understand and accept it fully.
 *
 *  Changes between 2.0 and 1.3 :
 *
 *  - adopted new design/separation introduced in ttfile.c 2.0
 *
 ******************************************************************/

#include "ttconfig.h"

#include <stdio.h>
#include <string.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <sys/mman.h>
#ifndef MAP_FILE
#define MAP_FILE  0x00
#endif

/*
 * The prototype for munmap() is not provided on SunOS.  This needs to
 * have a check added later to see if the GNU C library is being used.
 * If so, then this prototype is not needed.
 */
#if defined(__sun__) && !defined(SVR4) && !defined(__SVR4)
  extern int  munmap( caddr_t  addr, int  len );
#endif

#include <sys/stat.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif


#include "freetype.h"
#include "tttypes.h"
#include "ttdebug.h"
#include "ttengine.h"
#include "ttmutex.h"
#include "ttmemory.h"
#include "ttfile.h"     /* our prototypes */

  /* This definition is mandatory for each file component! */
  EXPORT_FUNC
  const TFileFrame  TT_Null_FileFrame = { NULL, 0, 0 };
  
  /* It has proven useful to do some bounds checks during   */
  /* development phase.  Define DEBUG_FILE when compiling   */
  /* this component to enable them.                         */

#ifdef DEBUG_FILE
#define CHECK_FRAME( frame, n )                          \
  do {                                                   \
    if ( frame.cursor + n > frame.address + frame.size ) \
      Panic( "Frame boundary error!\n" );                \
  } while ( 0 )
#else
#define CHECK_FRAME( frame, n ) \
  do {                          \
  } while( 0 )
#endif

  struct _TFileMap
  {
    String*  base;       /* base address of mapped file       */
    Int      refcount;   /* reference count for mmaped region */
    Long     size;       /* stream size in file               */
    Long     offset;     /* offset in file                    */
  };

  typedef struct _TFileMap  TFileMap;

#define MAP_Address( map )  (Byte*)( (map)->base + (map)->offset )

  /* The stream record structure */
  typedef struct _TStream_Rec
  {
    TFileMap*  map;     /* mapped file description */
    Long       pos ;    /* cursor in mapped file   */
  } TStream_Rec;

  typedef TStream_Rec*  PStream_Rec;

#define STREAM2REC( x )  ( (TStream_Rec*)HANDLE_Val( x ) )


#ifndef TT_CONFIG_OPTION_THREAD_SAFE
  
  /*******************************************************************/
  /*******************************************************************/
  /*******************************************************************/
  /****                                                           ****/
  /****  N O N   R E E N T R A N T   I M P L E M E N T A T I O N  ****/
  /****                                                           ****/
  /*******************************************************************/
  /*******************************************************************/
  /*******************************************************************/

  /* The TFile_Component structure holds all the data that was */
  /* previously declared static or global in this component.   */
  /*                                                           */
  /* It is accessible through the 'engine.file_component'      */
  /* variable in re-entrant builds, or directly through the    */
  /* static 'files' variable in other builds.                  */

  struct _TFile_Component
  {
    TMutex       lock;        /* used by the thread-safe build only */
    PStream_Rec  stream;      /* current stream  */
    TFileFrame   frame;       /* current frame   */
  };

  typedef struct _TFile_Component  TFile_Component;

/* The macro CUR_Stream denotes the current input stream              */
/* Note that for the re-entrant version, the 'stream' name has been   */
/* chosen according to the macro STREAM_ARGS.                         */

/* The macro CUR_Frame denotes the current file frame               */
/* Note that for the re-entrant version, the 'frame' name has been  */
/* chosen according to the macro FRAME_ARGS.                        */

/* The macro STREAM_VAR is used when calling public functions */
/* that need an 'optional' stream argument.                   */

#define CUR_Stream   files.stream            /* thread-safe macros */
#define CUR_Frame    files.frame

#define STREAM_VARS  /* void */
#define STREAM_VAR   /* void */
  
  /* the 'files' variable is only defined in non-reentrant builds */

  static TFile_Component  files;



/*******************************************************************
 *
 *  Function    :  TTFile_Init
 *
 *  Description :  Initializes the File component.
 *
 ******************************************************************/

 LOCAL_FUNC
 TT_Error  TTFile_Init( PEngine_Instance  engine )
 {
   MUTEX_Create( files.lock );
   files.stream = NULL;
   ZERO_Frame( files.frame );

   return TT_Err_Ok;
 }


/*******************************************************************
 *
 *  Function    :  TTFile_Done
 *
 *  Description :  Finalizes the File component.
 *
 ******************************************************************/

 LOCAL_FUNC
 TT_Error  TTFile_Done( PEngine_Instance  engine )
 {
   MUTEX_Destroy( files.lock );

   return TT_Err_Ok;
 }


/*******************************************************************
 *
 *  Function    : TT_Use_Stream
 *
 *  Description : Copies or duplicates a given stream.
 *
 *  Input  :  org_stream   original stream
 *            stream       target stream (copy or duplicate)
 *
 *  Output :  Error code
 *
 ******************************************************************/

  EXPORT_FUNC
  TT_Error  TT_Use_Stream( TT_Stream   org_stream,
                           TT_Stream*  stream )
  {
    MUTEX_Lock( files.lock );
    *stream = org_stream;
    files.stream = STREAM2REC( org_stream );  /* set current stream */

    return TT_Err_Ok;
  }


/*******************************************************************
 *
 *  Function    : TT_Done_Stream
 *
 *  Description : Releases a given stream.
 *
 *  Input  :  stream
 *
 *  Output :  Error code
 *
 ******************************************************************/

 EXPORT_FUNC
 TT_Error  TT_Done_Stream( TT_Stream*  stream )
 {
   HANDLE_Set( *stream, NULL );
   MUTEX_Release( files.lock );

   return TT_Err_Ok;
 }

#else /* TT_CONFIG_OPTION_THREAD_SAFE */

  /*******************************************************************/
  /*******************************************************************/
  /*******************************************************************/
  /********                                                   ********/
  /********  R E E N T R A N T   I M P L E M E N T A T I O N  ********/
  /********                                                   ********/
  /*******************************************************************/
  /*******************************************************************/
  /*******************************************************************/

#define CUR_Stream   STREAM2REC( stream )      /* re-entrant macros */
#define CUR_Frame    (*frame)

#define STREAM_VARS  stream,
#define STREAM_VAR   stream


/*******************************************************************
 *
 *  Function    :  TTFile_Init
 *
 *  Description :  Initializes the File component.
 *
 ******************************************************************/

 LOCAL_FUNC
 TT_Error  TTFile_Init( PEngine_Instance  engine )
 {
   engine.file_component = NULL;

   return TT_Err_Ok;
 }


/*******************************************************************
 *
 *  Function    :  TTFile_Done
 *
 *  Description :  Finalizes the File component.
 *
 ******************************************************************/

 LOCAL_FUNC
 TT_Error  TTFile_Done( PEngine_Instance  engine )
 {
   return TT_Err_Ok;
 }


/*******************************************************************
 *
 *  Function    : TT_Use_Stream
 *
 *  Description : Copies or duplicates a given stream.
 *
 *  Input  :  org_stream   original stream
 *            stream       target stream (copy or duplicate)
 *
 *  Output :  Error code.  The output stream is set to NULL in
 *            case of Failure.
 *
 ******************************************************************/

  EXPORT_FUNC
  TT_Error  TT_Use_Stream( TT_Stream   input_stream,
                           TT_Stream*  copy )
  {
    TT_Error     error;
    PStream_Rec  stream_rec;
    PStream_Rec  copy_rec;


    stream_rec = STREAM2REC( input_stream );

    if ( ALLOC( copy_rec, sizeof ( TStream_Rec ) ) )
      goto Fail;

    HANDLE_Set( *copy, copy_rec );

    copy_rec->map->refcount++;
    copy_rec->pos = 0;

    return TT_Err_Ok;

  Fail:
    HANDLE_Set( *copy, NULL );
    return error;
  }


/*******************************************************************
 *
 *  Function    : TT_Done_Stream
 *
 *  Description : Releases a given stream.
 *
 *  Input  :  stream
 *
 *  Output :  error code
 *
 ******************************************************************/

 EXPORT_FUNC
 TT_Error  TT_Done_Stream( TT_Stream*  stream )
 {
   return TT_Close_Stream( stream );
 }

#endif /* TT_CONFIG_OPTION_THREAD_SAFE */


  /*******************************************************************/
  /*******************************************************************/
  /*******************************************************************/
  /***********                                             ***********/
  /***********  C O M M O N   I M P L E M E N T A T I O N  ***********/
  /***********                                             ***********/
  /*******************************************************************/
  /*******************************************************************/
  /*******************************************************************/

/*******************************************************************
 *
 *  Function    :  AllocateMap
 *
 *  Description :  Allocates a new map from the table.
 *
 *  Output :  Pointer to new stream rec.  NULL in case of failure.
 *
 ******************************************************************/

  static 
  TFileMap*  Allocate_Map( void )
  {
    TFileMap*  result;


    if ( MEM_Alloc( result, sizeof ( TFileMap ) ) )
      return NULL;

    result->refcount = 1;
    return result;
  }


/*******************************************************************
 *
 *  Function    :  ReleaseMap
 *
 *  Description :  Releases a used map to the table if reference i
 *                 counter reaches zero.
 *
 *  Input  :  map
 *
 *  Output :  None.
 *
 *  Note : Called by TT_Close_File()
 *
 ******************************************************************/

  static 
  void  Release_Map ( TFileMap*  map )
  {
    map->refcount--;
    if ( map->refcount <= 0 )
    {
      munmap ( (void*)map->base, map->size );
      FREE( map );
    }
  }


/*******************************************************************
 *
 *  Function    :  TT_Open_Stream
 *
 *  Description :  Opens the font file and saves the total file size.
 *
 *  Input  :  error          address of stream's error variable
 *                           (re-entrant build only).
 *            filepathname   pathname of the file to open
 *            stream         address of target TT_Stream structure
 *
 *  Output :  SUCCESS on success, FAILURE on error.
 *            The target stream is set to -1 in case of failure.
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  TT_Open_Stream( const String*  filepathname, 
                            TT_Stream*     stream )
  {
    TT_Error     error;
    Int          file;
    PStream_Rec  stream_rec;
    TFileMap*    map;
    struct stat  stat_buf;


    if ( ALLOC( *stream, sizeof ( TStream_Rec ) ) )
      return error;

    map = Allocate_Map();
    if ( !map )
    {
      error = TT_Err_Out_Of_Memory;
      goto Memory_Fail;
    }

    stream_rec = STREAM2REC( *stream );

    file = open( (String*)filepathname, O_RDONLY );
    if ( file < 0 )
      goto File_Fail;

    if ( fstat( file, &stat_buf ) < 0 )
      goto Map_Fail;

    map->offset = 0;
    map->size   = stat_buf.st_size + map->offset;
    map->base   = mmap( NULL,
                        map->size,
                        PROT_READ,
                        MAP_FILE | MAP_PRIVATE,
                        file,
                        0 );

    if ( (long)map->base == -1 )
      goto Map_Fail;

    close( file );

    stream_rec->map = map;
    stream_rec->pos = 0;

#ifndef TT_CONFIG_OPTION_THREAD_SAFE
    CUR_Stream = stream_rec;
#endif

    return TT_Err_Ok;

  Map_Fail:
    close( file );

  File_Fail:
    error = TT_Err_Could_Not_Open_File;
    FREE( map );

  Memory_Fail:
    FREE( *stream );
    return error;
  }


/*******************************************************************
 *
 *  Function    : TT_Close_Stream
 *
 *  Description : Closes a stream.
 *
 *  Input  :  stream
 *
 *  Output :  SUCCESS (always)
 *
 ******************************************************************/

  LOCAL_FUNC
  TT_Error  TT_Close_Stream( TT_Stream*  stream )
  {
    PStream_Rec  rec = STREAM2REC( *stream );


    Release_Map( rec->map );
    FREE( rec );

    HANDLE_Set( *stream, NULL );
    return TT_Err_Ok;