1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . S T R E A M S . S T R E A M _ I O --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 with Interfaces.C_Streams; use Interfaces.C_Streams;
34 with System; use System;
36 with System.Soft_Links;
39 with Ada.Unchecked_Conversion;
40 with Ada.Unchecked_Deallocation;
42 package body Ada.Streams.Stream_IO is
44 package FIO renames System.File_IO;
45 package SSL renames System.Soft_Links;
47 subtype AP is FCB.AFCB_Ptr;
49 function To_FCB is new Ada.Unchecked_Conversion (File_Mode, FCB.File_Mode);
50 function To_SIO is new Ada.Unchecked_Conversion (FCB.File_Mode, File_Mode);
51 use type FCB.File_Mode;
52 use type FCB.Shared_Status_Type;
54 -----------------------
55 -- Local Subprograms --
56 -----------------------
58 procedure Set_Position (File : File_Type);
59 -- Sets file position pointer according to value of current index
65 function AFCB_Allocate (Control_Block : Stream_AFCB) return FCB.AFCB_Ptr is
66 pragma Warnings (Off, Control_Block);
68 return new Stream_AFCB;
75 -- No special processing required for closing Stream_IO file
77 procedure AFCB_Close (File : not null access Stream_AFCB) is
78 pragma Warnings (Off, File);
87 procedure AFCB_Free (File : not null access Stream_AFCB) is
88 type FCB_Ptr is access all Stream_AFCB;
89 FT : FCB_Ptr := FCB_Ptr (File);
91 procedure Free is new Ada.Unchecked_Deallocation (Stream_AFCB, FCB_Ptr);
101 procedure Close (File : in out File_Type) is
103 FIO.Close (AP (File)'Unrestricted_Access);
111 (File : in out File_Type;
112 Mode : File_Mode := Out_File;
116 Dummy_File_Control_Block : Stream_AFCB;
117 pragma Warnings (Off, Dummy_File_Control_Block);
118 -- Yes, we know this is never assigned a value, only the tag
119 -- is used for dispatching purposes, so that's expected.
122 FIO.Open (File_Ptr => AP (File),
123 Dummy_FCB => Dummy_File_Control_Block,
124 Mode => To_FCB (Mode),
130 File.Last_Op := Op_Write;
137 procedure Delete (File : in out File_Type) is
139 FIO.Delete (AP (File)'Unrestricted_Access);
146 function End_Of_File (File : File_Type) return Boolean is
148 FIO.Check_Read_Status (AP (File));
149 return Count (File.Index) > Size (File);
156 procedure Flush (File : File_Type) is
158 FIO.Flush (AP (File));
165 function Form (File : File_Type) return String is
167 return FIO.Form (AP (File));
174 function Index (File : File_Type) return Positive_Count is
176 FIO.Check_File_Open (AP (File));
177 return Count (File.Index);
184 function Is_Open (File : File_Type) return Boolean is
186 return FIO.Is_Open (AP (File));
193 function Mode (File : File_Type) return File_Mode is
195 return To_SIO (FIO.Mode (AP (File)));
202 function Name (File : File_Type) return String is
204 return FIO.Name (AP (File));
212 (File : in out File_Type;
217 Dummy_File_Control_Block : Stream_AFCB;
218 pragma Warnings (Off, Dummy_File_Control_Block);
219 -- Yes, we know this is never assigned a value, only the tag
220 -- is used for dispatching purposes, so that's expected.
223 FIO.Open (File_Ptr => AP (File),
224 Dummy_FCB => Dummy_File_Control_Block,
225 Mode => To_FCB (Mode),
232 -- Ensure that the stream index is set properly (e.g., for Append_File)
236 -- Set last operation. The purpose here is to ensure proper handling
237 -- of the initial operation. In general, a write after a read requires
238 -- resetting and doing a seek, so we set the last operation as Read
239 -- for an In_Out file, but for an Out file we set the last operation
240 -- to Op_Write, since in this case it is not necessary to do a seek
241 -- (and furthermore there are situations (such as the case of writing
242 -- a sequential Posix FIFO file) where the lseek would cause problems.
244 if Mode = Out_File then
245 File.Last_Op := Op_Write;
247 File.Last_Op := Op_Read;
257 Item : out Stream_Element_Array;
258 Last : out Stream_Element_Offset;
259 From : Positive_Count)
262 Set_Index (File, From);
263 Read (File, Item, Last);
268 Item : out Stream_Element_Array;
269 Last : out Stream_Element_Offset)
274 FIO.Check_Read_Status (AP (File));
276 -- If last operation was not a read, or if in file sharing mode,
277 -- then reset the physical pointer of the file to match the index
278 -- We lock out task access over the two operations in this case.
280 if File.Last_Op /= Op_Read
281 or else File.Shared_Status = FCB.Yes
283 Locked_Processing : begin
286 FIO.Read_Buf (AP (File), Item'Address, Item'Length, Nread);
293 end Locked_Processing;
296 FIO.Read_Buf (AP (File), Item'Address, Item'Length, Nread);
299 File.Index := File.Index + Count (Nread);
300 Last := Item'First + Stream_Element_Offset (Nread) - 1;
301 File.Last_Op := Op_Read;
304 -- This version of Read is the primitive operation on the underlying
305 -- Stream type, used when a Stream_IO file is treated as a Stream
308 (File : in out Stream_AFCB;
309 Item : out Ada.Streams.Stream_Element_Array;
310 Last : out Ada.Streams.Stream_Element_Offset)
313 Read (File'Unchecked_Access, Item, Last);
320 procedure Reset (File : in out File_Type; Mode : File_Mode) is
322 FIO.Check_File_Open (AP (File));
324 -- Reset file index to start of file for read/write cases. For
325 -- the append case, the Set_Mode call repositions the index.
328 Set_Mode (File, Mode);
331 procedure Reset (File : in out File_Type) is
333 Reset (File, To_SIO (File.Mode));
340 procedure Set_Index (File : File_Type; To : Positive_Count) is
342 FIO.Check_File_Open (AP (File));
343 File.Index := Count (To);
344 File.Last_Op := Op_Other;
351 procedure Set_Mode (File : in out File_Type; Mode : File_Mode) is
353 FIO.Check_File_Open (AP (File));
355 -- If we are switching from read to write, or vice versa, and
356 -- we are not already open in update mode, then reopen in update
357 -- mode now. Note that we can use Inout_File as the mode for the
358 -- call since File_IO handles all modes for all file types.
360 if ((File.Mode = FCB.In_File) /= (Mode = In_File))
361 and then not File.Update_Mode
363 FIO.Reset (AP (File)'Unrestricted_Access, FCB.Inout_File);
364 File.Update_Mode := True;
367 -- Set required mode and position to end of file if append mode
369 File.Mode := To_FCB (Mode);
370 FIO.Append_Set (AP (File));
372 if File.Mode = FCB.Append_File then
373 File.Index := Count (ftell (File.Stream)) + 1;
376 File.Last_Op := Op_Other;
383 procedure Set_Position (File : File_Type) is
384 use type System.CRTL.long;
386 if fseek (File.Stream,
387 System.CRTL.long (File.Index) - 1, SEEK_SET) /= 0
397 function Size (File : File_Type) return Count is
399 FIO.Check_File_Open (AP (File));
401 if File.File_Size = -1 then
402 File.Last_Op := Op_Other;
404 if fseek (File.Stream, 0, SEEK_END) /= 0 then
408 File.File_Size := Stream_Element_Offset (ftell (File.Stream));
411 return Count (File.File_Size);
418 function Stream (File : File_Type) return Stream_Access is
420 FIO.Check_File_Open (AP (File));
421 return Stream_Access (File);
430 Item : Stream_Element_Array;
434 Set_Index (File, To);
440 Item : Stream_Element_Array)
443 FIO.Check_Write_Status (AP (File));
445 -- If last operation was not a write, or if in file sharing mode,
446 -- then reset the physical pointer of the file to match the index
447 -- We lock out task access over the two operations in this case.
449 if File.Last_Op /= Op_Write
450 or else File.Shared_Status = FCB.Yes
452 Locked_Processing : begin
455 FIO.Write_Buf (AP (File), Item'Address, Item'Length);
462 end Locked_Processing;
465 FIO.Write_Buf (AP (File), Item'Address, Item'Length);
468 File.Index := File.Index + Item'Length;
469 File.Last_Op := Op_Write;
470 File.File_Size := -1;
473 -- This version of Write is the primitive operation on the underlying
474 -- Stream type, used when a Stream_IO file is treated as a Stream
477 (File : in out Stream_AFCB;
478 Item : Ada.Streams.Stream_Element_Array)
481 Write (File'Unchecked_Access, Item);
484 end Ada.Streams.Stream_IO;