cell_t sdWriteFile( void *ptr, cell_t Size, int32_t nItems, FileStream * Stream );
cell_t sdSeekFile( FileStream * Stream, off_t Position, int32_t Mode );
cell_t sdRenameFile( const char *OldName, const char *NewName );
+ cell_t sdDeleteFile( const char *FileName );
+ ThrowCode sdResizeFile( FileStream *, ucell_t SizeLo, ucell_t SizeHi );
off_t sdTellFile( FileStream * Stream );
cell_t sdCloseFile( FileStream * Stream );
cell_t sdInputChar( FileStream *stream );
typedef FILE FileStream;
#define sdOpenFile fopen
- #define sdDeleteFile remove
+ #define sdDeleteFile remove
#define sdFlushFile fflush
#define sdReadFile fread
#define sdWriteFile fwrite
#define PF_SEEK_CUR (SEEK_CUR)
#define PF_SEEK_END (SEEK_END)
+ ThrowCode sdResizeFile( FileStream *, ucell_t SizeLo, ucell_t SizeHi );
+
/*
** printf() is only used for debugging purposes.
** It is not required for normal operation.
--- /dev/null
+/***************************************************************
+** File access routines based on ANSI C (no Unix stuff).
+**
+** This file is part of pForth
+**
+** The pForth software code is dedicated to the public domain,
+** and any third party may reproduce, distribute and modify
+** the pForth software code or any derivative works thereof
+** without any compensation or license. The pForth software
+** code is provided on an "as is" basis without any warranty
+** of any kind, including, without limitation, the implied
+** warranties of merchantability and fitness for a particular
+** purpose and their equivalents under the laws of any jurisdiction.
+**
+****************************************************************/
+
+#include "../pf_all.h"
+
+#ifndef PF_NO_FILEIO
+
+#include <limits.h> /* For LONG_MAX */
+
+typedef int bool_t;
+
+/* Copy SIZE bytes from File FROM to File TO. Return non-FALSE on error. */
+static bool_t CopyFile( FileStream *From, FileStream *To, long Size)
+{
+ bool_t Error = TRUE;
+ size_t Diff = Size;
+ size_t BufSize = 512;
+ char *Buffer = pfAllocMem( BufSize );
+ if( Buffer != 0 )
+ {
+ while( Diff > 0 )
+ {
+ size_t N = MIN( Diff, BufSize );
+ if( fread( Buffer, 1, N, From ) < N ) goto cleanup;
+ if( fwrite( Buffer, 1, N, To ) < N ) goto cleanup;
+ Diff -= N;
+ }
+ Error = FALSE;
+
+ cleanup:
+ pfFreeMem( Buffer );
+ }
+ return Error;
+}
+
+/* Shrink the file FILE to NEWSIZE. Return non-FALSE on error.
+ *
+ * There's no direct way to do this in ANSI C. The closest thing we
+ * have is freopen(3), which truncates a file to zero length if we use
+ * "w+b" as mode argument. So we do this:
+ *
+ * 1. copy original content to temporary file
+ * 2. re-open and truncate FILE
+ * 3. copy the temporary file to FILE
+ *
+ * Unfortunately, "w+b" may not be the same mode as the original mode
+ * of FILE. I don't see a away to avoid this, though.
+ *
+ * We call freopen with NULL as path argument, because we don't know
+ * the actual file-name. It seems that the trick with path=NULL is
+ * not part of C89 but it's in C99.
+ */
+static bool_t TruncateFile( FileStream *File, long Newsize )
+{
+ bool_t Error = TRUE;
+ if( fseek( File, 0, SEEK_SET ) == 0)
+ {
+ FileStream *TmpFile = tmpfile();
+ if( TmpFile != NULL )
+ {
+ if( CopyFile( File, TmpFile, Newsize )) goto cleanup;
+ if( fseek( TmpFile, 0, SEEK_SET ) != 0 ) goto cleanup;
+ if( freopen( NULL, "w+b", File ) == NULL ) goto cleanup;
+ if( CopyFile( TmpFile, File, Newsize )) goto cleanup;
+ Error = FALSE;
+
+ cleanup:
+ fclose( TmpFile );
+ }
+ }
+ return Error;
+}
+
+/* Write DIFF 0 bytes to FILE. Return non-FALSE on error. */
+static bool_t ExtendFile( FileStream *File, size_t Diff )
+{
+ bool_t Error = TRUE;
+ size_t BufSize = 512;
+ char * Buffer = pfAllocMem( BufSize );
+ if( Buffer != 0 )
+ {
+ pfSetMemory( Buffer, 0, BufSize );
+ while( Diff > 0 )
+ {
+ size_t N = MIN( Diff, BufSize );
+ if( fwrite( Buffer, 1, N, File ) < N ) goto cleanup;
+ Diff -= N;
+ }
+ Error = FALSE;
+ cleanup:
+ pfFreeMem( Buffer );
+ }
+ return Error;
+}
+
+/* Return non-FALSE if the double-cell unsigned number LO/HI
+ * is greater then LONG_MAX.
+ */
+static bool_t IsGreaterThanLongMax( ucell_t Lo, ucell_t Hi )
+{
+ return (Hi != 0) || (Lo > LONG_MAX);
+}
+
+ThrowCode sdResizeFile( FileStream *File, ucell_t SizeLo, ucell_t SizeHi )
+{
+ bool_t Error = TRUE;
+ if( !IsGreaterThanLongMax( SizeLo, SizeHi ) )
+ {
+ long Newsize = (long) SizeLo;
+ if( fseek( File, 0, SEEK_END ) == 0 )
+ {
+ long Oldsize = ftell( File );
+ if( Oldsize != -1L )
+ {
+ Error = ( Oldsize <= Newsize
+ ? ExtendFile( File, Newsize - Oldsize )
+ : TruncateFile( File, Newsize ));
+ }
+ }
+ }
+ return Error ? THROW_RESIZE_FILE : 0;
+}
+
+#endif /* !PF_NO_FILEIO */
projects / pforth / commitdiff