mfile.h

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#ifndef MFILE_H
#define MFILE_H
 
#if !defined( DEBUG_THRESHOLD )
#  define DEBUG_THRESHOLD 1
#endif /* !DEBUG_THRESHOLD */
 
#ifndef UPRINTF_BUFFER_SZ_MAX
#  define UPRINTF_BUFFER_SZ_MAX 1024
#endif /* !UPRINTF_BUFFER_SZ_MAX */
 
#if !defined( MFILE_MMAP ) && \
   !defined( RETROFLAT_API_WINCE ) && \
   !defined( RETROFLAT_API_PALM )
#  include <sys/stat.h>
#endif /* !MFILE_MMAP */
 
/* TODO: async file_open() call that kicks off download to mem buffer that can
 *       be checked with looped check function.
 */
 
#ifndef MAUG_PATH_SZ_MAX
#  define MAUG_PATH_SZ_MAX 256
#endif /* !MAUG_PATH_SZ_MAX */
 
#define MFILE_CADDY_TYPE_FILE 0x01
 
#define MFILE_CADDY_TYPE_MEM_BUFFER 0x80
 /* maug_mfile_types */
 
#define MFILE_FLAG_READ_ONLY     0x01
 
#define MFILE_FLAG_HANDLE_LOCKED 0x02
 
#define MFILE_READ_FLAG_LSBF     0x01
 
#define MFILE_READ_FLAG_MSBF     0x01
 
#define MFILE_ASSIGN_FLAG_TRIM_EXT 0x01
 
#ifndef MFILE_READ_TRACE_LVL
#  define MFILE_READ_TRACE_LVL 0
#endif /* !MFILE_READ_TRACE_LVL */
 
#ifndef MFILE_WRITE_TRACE_LVL
#  define MFILE_WRITE_TRACE_LVL 0
#endif /* !MFILE_WRITE_TRACE_LVL */
 
#ifndef MFILE_SEEK_TRACE_LVL
#  define MFILE_SEEK_TRACE_LVL 0
#endif /* !MFILE_SEEK_TRACE_LVL */
 
#ifndef MFILE_CONTENTS_TRACE_LVL
#  define MFILE_CONTENTS_TRACE_LVL 0
#endif /* !MFILE_CONTENTS_TRACE_LVL */
 
typedef char retroflat_asset_path[MAUG_PATH_SZ_MAX + 1];
 
#define mfile_cmp_path( a, b ) strncmp( a, b, MAUG_PATH_SZ_MAX )
 /* maug_retroflt_assets */
 
struct MFILE_CADDY;
typedef struct MFILE_CADDY mfile_t;
 
typedef off_t (*mfile_cursor_t)( struct MFILE_CADDY* p_file );
typedef off_t (*mfile_has_bytes_t)( struct MFILE_CADDY* p_file );
typedef MERROR_RETVAL (*mfile_read_byte_t)(
   struct MFILE_CADDY* p_file, uint8_t* buf );
typedef MERROR_RETVAL (*mfile_read_block_t)(
   struct MFILE_CADDY* p_file, uint8_t* buf, size_t buf_sz );
typedef MERROR_RETVAL (*mfile_seek_t)( struct MFILE_CADDY* p_file, off_t pos );
typedef MERROR_RETVAL (*mfile_read_int_t)(
   struct MFILE_CADDY* p_file, uint8_t* buf, size_t buf_sz, uint8_t flags );
typedef MERROR_RETVAL (*mfile_read_line_t)(
   struct MFILE_CADDY* p_file, char* buf, off_t buf_sz, uint8_t flags );
typedef MERROR_RETVAL (*mfile_printf_t)(
   struct MFILE_CADDY* p_file, uint8_t flags, const char* fmt, ... );
typedef MERROR_RETVAL (*mfile_write_block_t)(
   struct MFILE_CADDY* p_f, const uint8_t* buf, size_t buf_sz );
 
off_t mfile_mem_cursor( struct MFILE_CADDY* p_file );
off_t mfile_mem_has_bytes( struct MFILE_CADDY* p_file );
MERROR_RETVAL mfile_mem_read_byte( struct MFILE_CADDY* p_file, uint8_t* buf );
MERROR_RETVAL mfile_mem_read_block(
   struct MFILE_CADDY* p_file, uint8_t* buf, size_t buf_sz );
MERROR_RETVAL mfile_mem_seek( struct MFILE_CADDY* p_file, off_t pos );
MERROR_RETVAL mfile_mem_read_line(
   struct MFILE_CADDY* p_f, char* buffer, off_t buffer_sz, uint8_t flags );
MERROR_RETVAL mfile_mem_vprintf(
   mfile_t* p_file, uint8_t flags, const char* fmt, va_list args );
 
MERROR_RETVAL mfile_mem_write_block(
   struct MFILE_CADDY* p_f, const uint8_t* buf, size_t buf_sz );
 
MERROR_RETVAL mfile_plt_init();
 
typedef MERROR_RETVAL (*mfile_vprintf_t)(
   struct MFILE_CADDY* p_file, uint8_t flags, const char* fmt, va_list args );
 
/* Load the platform-specific file API. */
#include <mrapifil.h>
#include <mrapilog.h>
 
struct MFILE_CADDY {
   uint8_t type;
   union MFILE_HANDLE h;
   off_t last_read;
   off_t mem_cursor;
   uint8_t* mem_buffer;
   uint8_t flags;
   off_t sz;
   char filename[MAUG_PATH_SZ_MAX + 1];
   mfile_has_bytes_t has_bytes;
   mfile_cursor_t cursor;
   mfile_read_byte_t read_byte;
   mfile_read_block_t read_block;
   mfile_seek_t seek;
   mfile_read_int_t read_int;
   mfile_read_line_t read_line;
   mfile_printf_t printf;
   mfile_vprintf_t vprintf;
   mfile_write_block_t write_block;
};
 
typedef struct MFILE_CADDY mfile_t;
 
MERROR_RETVAL mfile_assign_path(
   retroflat_asset_path tgt, const retroflat_asset_path src, uint8_t flags );
 
off_t mfile_file_has_bytes( struct MFILE_CADDY* p_file );
 
MERROR_RETVAL mfile_file_read_byte( struct MFILE_CADDY* p_file, uint8_t* buf );
 
MERROR_RETVAL mfile_file_read_block(
   struct MFILE_CADDY* p_file, uint8_t* buf, size_t buf_sz );
 
MERROR_RETVAL mfile_file_read_int(
   struct MFILE_CADDY* p_f, uint8_t* buf, size_t buf_sz, uint8_t flags );
 
MERROR_RETVAL mfile_file_seek( struct MFILE_CADDY* p_file, off_t pos );
 
MERROR_RETVAL mfile_file_read_line(
   struct MFILE_CADDY* p_f, char* buffer, off_t buffer_sz, uint8_t flags );
 
MERROR_RETVAL mfile_file_printf(
   struct MFILE_CADDY* p_f, uint8_t flags, const char* fmt, ... );
 
MERROR_RETVAL mfile_file_write_block(
   struct MFILE_CADDY* p_f, const uint8_t* buf, size_t buf_sz );
 
MERROR_RETVAL mfile_file_vprintf(
   struct MFILE_CADDY* p_f, uint8_t flags, const char* fmt, va_list args );
 
#define mfile_get_sz( p_file ) ((p_file)->sz)
 
MERROR_RETVAL mfile_lock_buffer(
   MAUG_MHANDLE, void* ptr, off_t, mfile_t* p_file );
 
MERROR_RETVAL mfile_open_read( const char* filename, mfile_t* p_file );
 
MERROR_RETVAL mfile_open_write( const char* filename, mfile_t* p_file );
 
void mfile_close( mfile_t* p_file );
 
#ifdef MFILE_C
 
#include <mrapifil.h>
#include <mrapilog.h>
 
off_t mfile_file_has_bytes( struct MFILE_CADDY* p_file ) {
   size_t cursor = 0;
   cursor = p_file->cursor( p_file );
   if( p_file->sz > cursor ) {
#if MFILE_READ_TRACE_LVL > 0
      debug_printf( MFILE_READ_TRACE_LVL,
         "file has " OFF_T_FMT " bytes left...",
         p_file->sz - cursor );
#endif /* MFILE_READ_TRACE_LVL */
      return p_file->sz - cursor;
   } else {
#if MFILE_READ_TRACE_LVL > 0
      /* TODO: Improved error message/handling. */
      debug_printf( MFILE_READ_TRACE_LVL, "file has error bytes left!" );
#endif /* MFILE_READ_TRACE_LVL */
      return 0;
   }
}
 
/* === */
 
MERROR_RETVAL mfile_assign_path(
   retroflat_asset_path tgt, const retroflat_asset_path src, uint8_t flags
) {
   MERROR_RETVAL retval = MERROR_OK;
   char* ext_ptr = NULL;
 
   maug_snprintf( tgt, MAUG_PATH_SZ_MAX, "%s", src );
 
   if( MFILE_ASSIGN_FLAG_TRIM_EXT == (MFILE_ASSIGN_FLAG_TRIM_EXT & flags) ) {
      ext_ptr = maug_strrchr( tgt, '.' );
      if( NULL != ext_ptr ) {
         *ext_ptr = '\0';
      }
   }
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_file_read_int(
   struct MFILE_CADDY* p_file, uint8_t* buf, size_t buf_sz, uint8_t flags
) {
   MERROR_RETVAL retval = MERROR_OK;
 
   if(
#ifdef MAUG_LSBF
      MFILE_READ_FLAG_LSBF == (MFILE_READ_FLAG_LSBF & flags)
#elif defined( MAUG_MSBF )
      MFILE_READ_FLAG_MSBF != (MFILE_READ_FLAG_MSBF & flags)
#endif
   ) {
      debug_printf( MFILE_READ_TRACE_LVL, "reading integer forward" );
      /* Shrink the buffer moving right and read into it. */
      retval = p_file->read_block( p_file, buf, buf_sz );
 
   } else {
      debug_printf( MFILE_READ_TRACE_LVL, "reading integer reversed" );
      /* Move to the end of the output buffer and read backwards. */
      while( 0 < buf_sz ) {
         retval = p_file->read_byte( p_file, (buf + (buf_sz - 1)) );
         maug_cleanup_if_not_ok();
         buf_sz--;
      }
   }
 
cleanup:
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_file_printf(
   struct MFILE_CADDY* p_file, uint8_t flags, const char* fmt, ...
) {
   MERROR_RETVAL retval = MERROR_OK;
   va_list vargs;
 
   va_start( vargs, fmt );
   retval = p_file->vprintf( p_file, flags, fmt, vargs );
   va_end( vargs );
 
   return retval;
}
 
/* === */
 
off_t mfile_mem_cursor( struct MFILE_CADDY* p_file ) {
   return p_file->mem_cursor;
}
 
/* === */
 
off_t mfile_mem_has_bytes( struct MFILE_CADDY* p_file ) {
   return p_file->sz - p_file->mem_cursor;
} 
 
/* === */
 
static MERROR_RETVAL mfile_mem_lock( struct MFILE_CADDY* p_f ) {
   MERROR_RETVAL retval = MERROR_OK;
 
   assert(
      MFILE_FLAG_HANDLE_LOCKED != (MFILE_FLAG_HANDLE_LOCKED & p_f->flags) );
 
   assert( MFILE_CADDY_TYPE_MEM_BUFFER == p_f->type );
 
   /* Only lock if this buffer uses a handle and not a pointer. */
   if( (MAUG_MHANDLE)NULL != p_f->h.mem ) {
      assert( NULL == p_f->mem_buffer );
      maug_mlock( p_f->h.mem, p_f->mem_buffer );
      p_f->flags |= MFILE_FLAG_HANDLE_LOCKED;
   }
 
   return retval;
}
 
/* === */
 
static void mfile_mem_release( struct MFILE_CADDY* p_f ) {
 
   assert( MFILE_CADDY_TYPE_MEM_BUFFER == p_f->type );
   
   if( MFILE_FLAG_HANDLE_LOCKED == (MFILE_FLAG_HANDLE_LOCKED & p_f->flags) ) {
      maug_munlock( p_f->h.mem, p_f->mem_buffer );
      p_f->flags &= ~MFILE_FLAG_HANDLE_LOCKED;
   }
}
 
/* === */
 
MERROR_RETVAL mfile_mem_read_byte( struct MFILE_CADDY* p_file, uint8_t* buf ) {
   return p_file->read_block( p_file, buf, 1 );
}
 
/* === */
 
MERROR_RETVAL mfile_mem_read_block(
   struct MFILE_CADDY* p_file, uint8_t* buf, size_t buf_sz
) {
   MERROR_RETVAL retval = MERROR_OK;
 
   if( p_file->mem_cursor >= p_file->sz ) {
      return MERROR_FILE;
   }
 
   retval = mfile_mem_lock( p_file );
   maug_cleanup_if_not_ok();
 
   while( 0 < buf_sz-- ) {
      *(buf++) = p_file->mem_buffer[p_file->mem_cursor++];
   }
 
cleanup:
 
   mfile_mem_release( p_file );
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_mem_seek( struct MFILE_CADDY* p_file, off_t pos ) {
   MERROR_RETVAL retval = MERROR_OK;
 
   assert( MFILE_CADDY_TYPE_MEM_BUFFER == p_file->type );
 
   p_file->mem_cursor = pos;
 
   debug_printf( MFILE_SEEK_TRACE_LVL,
      "seeking memory buffer to position " OFF_T_FMT " (" OFF_T_FMT ")",
      pos, p_file->mem_cursor );
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_mem_read_line(
   struct MFILE_CADDY* p_f, char* buffer, off_t buffer_sz, uint8_t flags
) {
   MERROR_RETVAL retval = MERROR_OK;
   off_t i = 0;
 
   assert( MFILE_CADDY_TYPE_MEM_BUFFER == p_f->type );
 
   while( i < buffer_sz - 1 && p_f->has_bytes( p_f ) ) {
      /* Check for potential overflow. */
      if( i + 1 >= buffer_sz ) {
         error_printf( "overflow reading string from file!" );
         retval = MERROR_FILE;
         break;
      }
 
      p_f->read_int( p_f, (uint8_t*)&(buffer[i]), 1, 0 );
      if( '\n' == buffer[i] ) {
         /* Break on newline and overwrite it below. */
         break;
      }
      i++;
   }
 
   assert( i < buffer_sz ); /* while() above stops before buffer_sz! */
 
   /* Append a null terminator. */
   buffer[i] = '\0';
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_mem_vprintf(
   mfile_t* p_file, uint8_t flags, const char* fmt, va_list args
) {
   MERROR_RETVAL retval = MERROR_OK;
 
   if( MFILE_FLAG_READ_ONLY == (MFILE_FLAG_READ_ONLY & p_file->flags) ) {
      return MERROR_FILE;
   }
 
   /* TODO: Enable writing to memory buffer. */
   error_printf( "writing to memory buffer not currently supported!" );
 
   /* TODO: Expand buffer and reflect this in sz if writing beyond the end
    *       of the buffer.
    */
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_mem_write_block(
   struct MFILE_CADDY* p_f, const uint8_t* buf, size_t buf_sz
) {
   MERROR_RETVAL retval = MERROR_OK;
   ssize_t mv_sz = 0;
 
   if( 0 == buf_sz ) {
      /* Short-circuit empty writes. */
      return MERROR_OK;
   }
 
   if( MFILE_FLAG_READ_ONLY == (MFILE_FLAG_READ_ONLY & p_f->flags) ) {
      return MERROR_FILE;
   }
 
   retval = mfile_mem_lock( p_f );
   maug_cleanup_if_not_ok();
 
#if MFILE_WRITE_TRACE_LVL > 0
   debug_printf( MFILE_WRITE_TRACE_LVL, "p: %p, sz: %u, cur: %u, buf_sz: %u\n",
      p_f->mem_buffer, p_f->sz, p_f->mem_cursor, buf_sz );
#endif /* MFILE_WRITE_TRACE_LVL */
 
   mv_sz = (p_f->sz - (p_f->mem_cursor + buf_sz));
   if( 0 < mv_sz ) {
      memmove(
         &(p_f->mem_buffer[p_f->mem_cursor + buf_sz]),
         &(p_f->mem_buffer[p_f->mem_cursor]),
         mv_sz );
   }
 
   memcpy( &(p_f->mem_buffer[p_f->mem_cursor]), buf, buf_sz );
   p_f->mem_cursor += buf_sz;
 
   /* TODO: Expand buffer and reflect this in sz if writing beyond the end
    *       of the buffer.
    */
 
cleanup:
 
   mfile_mem_release( p_f );
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_lock_buffer(
   MAUG_MHANDLE handle, void* ptr, off_t handle_sz, mfile_t* p_file
) {
   MERROR_RETVAL retval = MERROR_OK;
 
   debug_printf( MFILE_SEEK_TRACE_LVL,
      "locking handle %p as file %p (" OFF_T_FMT " bytes)...",
      handle, p_file, handle_sz );
 
   maug_mzero( p_file, sizeof( struct MFILE_CADDY ) );
   
   /* Determine if this is based on a handle or a pointer. */
   if( (MAUG_MHANDLE)NULL == handle && NULL != ptr ) {
      p_file->mem_buffer = ptr;
   } else if( (MAUG_MHANDLE)NULL != handle && NULL == ptr ) {
      p_file->h.mem = handle;
      /* maug_mlock( handle, p_file->mem_buffer ); */
   } else {
      error_printf( "must specify handle or pointer!" );
      retval = MERROR_FILE;
      goto cleanup;
   }
 
   p_file->type = MFILE_CADDY_TYPE_MEM_BUFFER;
 
   p_file->has_bytes = mfile_mem_has_bytes;
   p_file->cursor = mfile_mem_cursor;
   p_file->read_byte = mfile_mem_read_byte;
   p_file->read_block = mfile_mem_read_block;
   p_file->read_int = mfile_file_read_int;
   p_file->seek = mfile_mem_seek;
   p_file->read_line = mfile_mem_read_line;
   p_file->write_block = mfile_mem_write_block;
 
   p_file->sz = handle_sz;
 
cleanup:
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_open_read( const char* filename, mfile_t* p_file ) {
   MERROR_RETVAL retval = MERROR_OK;
 
   /* Call the platform-specific actual file opener from mrapifil.h. */
   retval = mfile_plt_open_read( filename, p_file );
 
   if( MERROR_OK == retval ) {
      /* Store filename. */
      maug_mzero( p_file->filename, MAUG_PATH_SZ_MAX );
      maug_strncpy( p_file->filename, filename, MAUG_PATH_SZ_MAX );
   }
 
   return retval;
}
 
/* === */
 
MERROR_RETVAL mfile_open_write( const char* filename, mfile_t* p_file ) {
   MERROR_RETVAL retval = MERROR_OK;
 
   retval = mfile_plt_open_write( filename, p_file );
 
   if( MERROR_OK == retval ) {
      /* Store filename. */
      maug_mzero( p_file->filename, MAUG_PATH_SZ_MAX );
      maug_strncpy( p_file->filename, filename, MAUG_PATH_SZ_MAX );
   }
 
   return retval;
}
 
/* === */
 
void mfile_close( mfile_t* p_file ) {
#  if MFILE_SEEK_TRACE_LVL > 0
   debug_printf( MFILE_SEEK_TRACE_LVL, "closing file..." );
#  endif /* MFILE_SEEK_TRACE_LVL */
#  ifdef MFILE_MMAP
   munmap( bytes_ptr_h, bytes_sz );
#  else
   /* maug_mfree( bytes_ptr_h ); */
   switch( p_file->type ) {
   case 0:
      /* Do nothing silently. */
      break;
 
   case MFILE_CADDY_TYPE_FILE:
      mfile_plt_close( p_file );
      p_file->type = 0;
      break;
 
   case MFILE_CADDY_TYPE_MEM_BUFFER:
      if( NULL != p_file->mem_buffer ) {
         maug_munlock( p_file->h.mem, p_file->mem_buffer );
         debug_printf( MFILE_SEEK_TRACE_LVL,
            "unlocked handle %p from file %p...",
            p_file->h.mem, p_file );
         p_file->type = 0;
      }
      break;
      
   default:
      error_printf( "unknown file type: %d", (p_file)->type );
      break;
   }
#  endif /* MFILE_MMAP */
}
 
#endif /* MFILE_C */
 /* maug_mfile */
 
#endif /* !MFILE_H */