hcl/lib/h2-io-file.adb

640 lines
18 KiB
Ada

with H2.Ascii;
separate (H2.IO)
package body File is
package Slim_Ascii renames IO.Slim_Ascii;
package Wide_Ascii renames IO.Wide_Ascii;
--|-----------------------------------------------------------------------
--| PRIVATE ROUTINES
--|-----------------------------------------------------------------------
procedure OS_Read_File (File: in out File_Record;
Buffer: in out System_Byte_Array;
Length: out System_Length) is
begin
OS.File.Read (File.File, Buffer, Length);
File.EOF := (Length <= 0);
end OS_Read_File;
procedure Shift_Buffer (Buffer: in out File_Buffer;
Length: in System_Length) is
pragma Inline (Shift_Buffer);
begin
Buffer.Length := Buffer.Length - Length;
Buffer.Data(Buffer.Data'First .. Buffer.Data'First + Buffer.Length - 1) := Buffer.Data(Buffer.Data'First + Length .. Buffer.Data'First + Length + Buffer.Length - 1);
end Shift_Buffer;
procedure Copy_Array (Dst: in out System_Byte_Array;
Src: in System_Byte_Array;
Length: in System_Length) is
pragma Inline (Copy_Array);
begin
Dst(Dst'First .. Dst'First + Length - 1) := Src(Src'First .. Src'First + Length - 1);
end Copy_Array;
Slim_Line_Terminator: Slim_String := Get_Line_Terminator;
--Wide_Line_Terminator: Wide_String := Get_Line_Terminator;
--|-----------------------------------------------------------------------
--| OPEN AND CLOSE
--|-----------------------------------------------------------------------
function Is_Open (File: in File_Record) return Standard.Boolean is
begin
return OS.File."/="(File.File, null);
end Is_Open;
procedure Open (File: in out File_Record;
Name: in Slim_String;
Flag: in Flag_Record;
Pool: in Storage_Pool_Pointer := null) is
pragma Assert (not Is_Open(File));
begin
OS.File.Open (File.File, Name, Flag, Pool => Pool);
File.Rbuf.First := 0;
File.Rbuf.Last := 0;
File.Rbuf.Length := 0;
File.Wbuf.Length := 0;
File.EOF := Standard.False;
--File.Slim_Line_Break := Get_Line_Terminator;
--File.Wide_Line_Break := Get_Line_Terminator;
end Open;
procedure Open (File: in out File_Record;
Name: in Wide_String;
Flag: in Flag_Record;
Pool: in Storage_Pool_Pointer := null) is
pragma Assert (not Is_Open(File));
begin
OS.File.Open (File.File, Name, Flag, Pool => Pool);
File.Rbuf.Length := 0;
File.Wbuf.Length := 0;
File.EOF := Standard.False;
--File.Slim_Line_Break := Get_Line_Terminator;
--File.Wide_Line_Break := Get_Line_Terminator;
end Open;
procedure Close (File: in out File_Record) is
pragma Assert (Is_Open(File));
begin
Flush (File);
OS.File.Close (File.File);
File.File := null;
end Close;
function Is_Empty (Buf: in File_Buffer) return Standard.Boolean is
pragma Inline (Is_Empty);
begin
return Buf.First >= Buf.Last;
end Is_Empty;
procedure Set_Length (Buf: in out File_Buffer; Length: in System_Length) is
pragma Inline (Set_Length);
begin
Buf.First := Buf.Data'First - 1; -- this should be 0
Buf.Last := Buf.First + Length;
end Set_Length;
procedure Load_Bytes (File: in out File_Record) is
pragma Assert (Is_Open(File));
pragma Assert (Is_Empty(File.Rbuf));
L1: System_Length;
begin
if File.EOF then
-- raise EOF EXCEPTION. ???
null;
else
-- Read bytes into the buffer
OS_Read_File (File, File.Rbuf.Data, L1);
Set_Length (File.Rbuf, L1);
end if;
end Load_Bytes;
procedure Fetch_Byte (File: in out File_Record;
Item: out System_Byte;
Available: out Standard.Boolean) is
begin
-- NOTE: If no data is available, Item is not initialized in this procedure
if Is_Empty(File.Rbuf) then
Load_Bytes (File);
end if;
if Is_Empty(File.Rbuf) then
Available := Standard.False;
else
-- Consume 1 byte
Available := Standard.True;
File.Rbuf.First := File.Rbuf.First + 1;
Item := File.Rbuf.Data(File.Rbuf.First);
end if;
end Fetch_Byte;
procedure Fetch_Bytes (File: in out File_Record;
Item: out System_Byte_Array;
Length: out System_Length) is
pragma Assert (Is_Open(File));
L1, L2: System_Length;
begin
if Is_Empty(File.Rbuf) and then File.EOF then
-- raise EOF EXCEPTION. ???
Length := 0;
else
L1 := File.Rbuf.Last - File.Rbuf.First;
if L1 > 0 then
-- Copy the residue over to the output buffer
if Item'Length <= L1 then
L2 := Item'Length;
else
L2 := L1;
end if;
Copy_Array (Item, File.Rbuf.Data(File.Rbuf.First + 1 .. File.Rbuf.Last), L2);
File.Rbuf.First := File.Rbuf.First + L2;
Length := L2;
else
Length := 0;
end if;
if Item'Length > L1 then
-- Item is not full. the internal read buffer must be empty.
pragma Assert (File.Rbuf.First >= File.Rbuf.Last);
L2 := Item'Length - Length; -- Remaining capacity
If L2 >= File.Rbuf.Data'Length then
-- The remaining capacity of the output buffer is
-- higher than that of the internal buffer. So read
-- directly into the output buffer.
OS_Read_File (File, Item(Item'First + Length .. Item'Last), L2);
Length := Length + L2;
else
-- Read into the internal buffer.
OS_Read_File (File, File.Rbuf.Data, L1);
Set_Length (File.Rbuf, L1);
if L1 < L2 then
-- the actual bytes read may be less than the remaining capacity
L2 := L1;
end if;
-- Copy as many bytes as needed into the output buffer.
Copy_Array (Item(Item'First + Length .. Item'Last), File.Rbuf.Data, L2);
Length := Length + L2;
File.Rbuf.First := File.Rbuf.First + L2;
end if;
end if;
end if;
end Fetch_Bytes;
--|-----------------------------------------------------------------------
--| READ SLIM STRING
--|-----------------------------------------------------------------------
procedure Read (File: in out File_Record;
Buffer: out Slim_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
pragma Assert (Buffer'Length > 0);
Outbuf: System_Byte_Array (Buffer'Range);
for Outbuf'Address use Buffer'Address;
begin
Fetch_Bytes (File, Outbuf, Length);
end Read;
procedure Read_Line (File: in out File_Record;
Buffer: out Slim_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
pragma Assert (Buffer'Length > 0);
Outbuf: System_Byte_Array (Buffer'Range);
for Outbuf'Address use Buffer'Address;
K: System_Length;
begin
K := Outbuf'First - 1;
outer: loop
if Is_Empty(File.Rbuf) then
Load_Bytes (File);
exit when Is_Empty(File.Rbuf);
end if;
while File.Rbuf.First < File.Rbuf.Last loop
K := K + 1;
File.Rbuf.First := File.Rbuf.First + 1;
Outbuf(K) := File.Rbuf.Data(File.Rbuf.First);
if K >= Outbuf'Last or else Outbuf(K) = Slim_Ascii.Pos.LF then -- TODO: different line terminator
exit outer; -- Done
end if;
end loop;
end loop outer;
Length := K + 1 - Outbuf'First;
end Read_Line;
procedure Get_Line (File: in out File_Record;
Buffer: out Slim_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
pragma Assert (Buffer'Length > 0);
Last: System_Length;
begin
Read_Line (File, Buffer, Length);
if Length >= 1 then
Last := Buffer'First + Length - 1;
if Buffer(Last) = Slim_Ascii.LF then
if Last > Buffer'First and then Buffer(Last - 1) = Slim_Ascii.CR then
-- Switch CR/LF to LF
Length := Length - 1;
Buffer(Last - 1) := Slim_Ascii.LF;
end if;
elsif Buffer(Last) = Slim_Ascii.CR then
if Is_Empty(File.Rbuf) then
Load_Bytes (File);
end if;
if not Is_Empty(File.Rbuf) then
if File.Rbuf.Data(File.Rbuf.First + 1) = Slim_Ascii.Pos.LF then
-- Consume LF held in the internal read buffer.
File.Rbuf.First := File.Rbuf.First + 1;
-- Switch CR to LF (End-result: CR/LF to LF)
Buffer(Last) := Slim_Ascii.LF;
end if;
end if;
end if;
end if;
end Get_Line;
--|-----------------------------------------------------------------------
--| READ WIDE STRING
--|-----------------------------------------------------------------------
procedure Read_Wide (File: in out File_Record;
Buffer: out Wide_String;
Length: out System_Length;
Terminator: in Wide_String) is
pragma Assert (Is_Open(File));
pragma Assert (Buffer'Length > 0);
Outbuf: Wide_String renames Buffer;
Inbuf: Slim_String (File.Rbuf.Data'Range);
for Inbuf'Address use File.Rbuf.Data'Address;
L3, L4, I, J, K: System_Length;
begin
K := Outbuf'First - 1;
outer: while K < Outbuf'Last loop
if Is_Empty(File.Rbuf) then
Load_Bytes (File);
exit when Is_Empty(File.Rbuf);
end if;
while File.Rbuf.First < File.Rbuf.Last and K < Outbuf'Last loop
I := File.Rbuf.First + 1;
L3 := Sequence_Length(Inbuf(I)); -- Required number of bytes to compose a wide character
if L3 <= 0 then
-- Potentially illegal sequence
K := K + 1;
Outbuf(K) := Wide_Ascii.Question;
File.Rbuf.First := I;
else
L4 := File.Rbuf.Last - File.Rbuf.First; -- Avaliable number of bytes available in the internal buffer
if L4 < L3 then
-- Insufficient data available. Exit the inner loop to read more.
exit;
end if;
K := K + 1;
begin
J := File.Rbuf.First + L3;
Outbuf(K..K) := Slim_To_Wide(Inbuf(I .. J));
exception
when others =>
Outbuf(K) := Wide_Ascii.Question;
J := I; -- Override J to skip 1 byte only.
end;
File.Rbuf.First := J;
end if;
if Terminator'Length > 0 and then
Outbuf(K) = Terminator(Terminator'First) then
-- TODO: compare more characters in terminator, not just the first charactrer
exit outer;
end if;
end loop;
end loop outer;
Length := K + 1 - Outbuf'First;
end Read_Wide;
procedure Read (File: in out File_Record;
Buffer: out Wide_String;
Length: out System_Length) is
Terminator: Wide_String(1..0);
begin
Read_Wide (File, Buffer, Length, Terminator);
end Read;
procedure Read_Line (File: in out File_Record;
Buffer: out Wide_String;
Length: out System_Length) is
Terminator: constant Wide_String(1..1) := (1 => Wide_Ascii.LF);
begin
Read_Wide (File, Buffer, Length, Terminator);
end Read_Line;
procedure Get_Line (File: in out File_Record;
Buffer: out Wide_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
pragma Assert (Buffer'Length > 0);
Last: System_Length;
begin
Read_Line (File, Buffer, Length);
if Length >= 1 then
Last := Buffer'First + Length - 1;
if Buffer(Last) = Wide_Ascii.LF then
if Last > Buffer'First and then Buffer(Last - 1) = Wide_Ascii.CR then
-- Switch CR/LF to LF
Length := Length - 1;
Buffer(Last - 1) := Wide_Ascii.LF;
end if;
elsif Buffer(Last) = Wide_Ascii.CR then
-- if the last character in the output buffer is CR,
-- i need to inspect the first character in the internal
-- read buffer to determine if it's CR/LF.
if Is_Empty(File.Rbuf) then
Load_Bytes (File);
end if;
if not Is_Empty(File.Rbuf) then
declare
Inbuf: Slim_String (File.Rbuf.Data'Range);
for Inbuf'Address use File.Rbuf.Data'Address;
L3, I, J: System_Length;
W: Wide_String(1..1);
begin
I := File.Rbuf.First + 1;
L3 := Sequence_Length(Inbuf(I)); -- Required number of bytes to compose a wide character
if L3 in 1 .. File.Rbuf.Last - File.Rbuf.First then
J := File.Rbuf.First + L3;
begin
W := Slim_To_Wide(Inbuf(I .. J));
exception
when others =>
W(1) := Wide_Ascii.NUL;
end;
if W(1) = Wide_Ascii.LF then
-- Consume LF held in the internal read buffer.
File.Rbuf.First := J;
-- Switch CR to LF (End-result: CR/LF to LF)
Buffer(Last) := Wide_Ascii.LF;
end if;
end if;
end;
end if;
end if;
end if;
end Get_Line;
--|-----------------------------------------------------------------------
--| WRITE SLIM STRING
--|-----------------------------------------------------------------------
procedure Write (File: in out File_Record;
Buffer: in Slim_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
Wbuf: File_Buffer renames File.Wbuf;
Inbuf: System_Byte_Array (Buffer'Range);
for Inbuf'Address use Buffer'Address;
F, L: System_Length;
begin
-- This procedure attempts to write as many bytes as requested.
-- However, under a certain condition, it may not be able to
-- process the input buffer in full.
if Wbuf.Length > 0 then
-- Some residue data in the internal buffer.
if Inbuf'Length <= Wbuf.Data'Length - Wbuf.Length then
-- Copy the input to the internal buffer to reduce OS calls
F := Wbuf.Data'First + Wbuf.Length - 1;
L := F + Inbuf'Length - 1;
Wbuf.Data(F .. L) := Inbuf;
Flush (File);
Length := Inbuf'Length;
return;
end if;
-- Flush the residue first.
Flush (File);
end if;
L := 0;
while L < Inbuf'Length loop
--begin
OS.File.Write (File.File, Inbuf, F);
--exception
-- when OS.Would_Block_Exception =>
-- -- Cannot write the input in full.
-- -- Copy some to to the internal buffer
-- L := L + as much as copied;
-- exit;
-- when others =>
-- raise;
--end;
L := L + F;
end loop;
Length := L;
end Write;
procedure Write_Line (File: in out File_Record;
Buffer: in Slim_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
Wbuf: File_Buffer renames File.Wbuf;
Inbuf: System_Byte_Array (Buffer'Range);
for Inbuf'Address use Buffer'Address;
I, J, LF: System_Length;
begin
-- This procedure attempts to write the input up to the last line
-- terminator. It buffers the remaining input after the terminator.
-- The input may not include any line terminators.
LF := Wbuf.Data'First - 1;
I := Inbuf'First - 1;
while I < Inbuf'Last loop
I := I + 1;
J := Wbuf.Data'First + Wbuf.Length;
Wbuf.Data(J) := Inbuf(I);
Wbuf.Length := Wbuf.Length + 1;
if Wbuf.Data(J) = Slim_Ascii.Pos.LF then -- TODO: different line terminator
-- Remeber the index of the line terminator
LF := J;
end if;
if Wbuf.Length >= Wbuf.Data'Length then
-- The internal write buffer is full.
Flush (File);
LF := Wbuf.Data'First - 1;
end if;
end loop;
-- The line terminator was found. Write up to the terminator.
-- Keep the rest in the internal buffer.
while LF in Wbuf.Data'First .. Wbuf.Length loop
OS.File.Write (File.File, Wbuf.Data(Wbuf.Data'First .. LF), J);
Shift_Buffer (Wbuf, J);
LF := LF - J;
end loop;
Length := I - Inbuf'First + 1;
end Write_Line;
--|-----------------------------------------------------------------------
--| WRITE WIDE STRING
--|-----------------------------------------------------------------------
procedure Write (File: in out File_Record;
Buffer: in Wide_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
Wbuf: File_Buffer renames File.Wbuf;
F, L, I: System_Length;
begin
I := Buffer'First - 1;
while I < Buffer'Last loop
I := I + 1;
declare
Tmp: Slim_String := Wide_To_Slim(Buffer(I..I));
Tmp2: System_Byte_Array(Tmp'Range);
for Tmp2'Address use Tmp'Address;
begin
F := Wbuf.Data'First + Wbuf.Length;
L := F + Tmp2'Length - 1;
if L > Wbuf.Data'Last then
-- The multi-byte sequence for the current character
-- can't fit into the internal buffer. Flush the
-- buffer and attempt to fit it in.
Flush (File);
F := Wbuf.Data'First;
L := F + Tmp2'Length - 1;
end if;
Wbuf.Data(F..L) := Tmp2;
Wbuf.Length := Wbuf.Length + Tmp2'Length;
end;
end loop;
Flush (File);
Length := I - Buffer'First + 1;
end Write;
procedure Write_Line (File: in out File_Record;
Buffer: in Wide_String;
Length: out System_Length) is
pragma Assert (Is_Open(File));
Wbuf: File_Buffer renames File.Wbuf;
F, L, I, LF: System_Length;
begin
LF := Wbuf.Data'First - 1;
I := Buffer'First - 1;
while I < Buffer'Last loop
I := I + 1;
--if Buffer(I) = Wide_Ascii.LF then
--else
--end if;
declare
Tmp: Slim_String := Wide_To_Slim(Buffer(I..I));
Tmp2: System_Byte_Array(Tmp'Range);
for Tmp2'Address use Tmp'Address;
begin
F := Wbuf.Data'First + Wbuf.Length;
L := F + Tmp2'Length - 1;
if L > Wbuf.Data'Last then
-- The multi-byte sequence for the current character
-- can't fit into the internal buffer. Flush the
-- buffer and attempt to fit it in.
Flush (File);
F := Wbuf.Data'First;
L := F + Tmp2'Length - 1;
LF := Wbuf.Data'First - 1;
end if;
Wbuf.Data(F..L) := Tmp2;
Wbuf.Length := Wbuf.Length + Tmp2'Length;
if Buffer(I) = Wide_Ascii.LF then -- TODO: different line terminator
LF := L;
end if;
end;
end loop;
-- The line terminator was found. Write up to the terminator.
-- Keep the rest in the internal buffer.
while LF in Wbuf.Data'First .. Wbuf.Length loop
OS.File.Write (File.File, Wbuf.Data(Wbuf.Data'First .. LF), L);
Shift_Buffer (Wbuf, L);
LF := LF - L;
end loop;
Length := I - Buffer'First + 1;
end Write_Line;
--|-----------------------------------------------------------------------
--| FLUSH AND DRAIN
--|-----------------------------------------------------------------------
procedure Flush (File: in out File_Record) is
pragma Assert (Is_Open(File));
Wbuf: File_Buffer renames File.Wbuf;
Length: System_Length;
begin
while Wbuf.Length > 0 loop
--begin
OS.File.Write (File.File, Wbuf.Data(Wbuf.Data'First .. Wbuf.Length), Length);
--exception
-- when Would_Block_Exception =>
-- -- Flush must write all it can.
-- null;
-- when others =>
-- raise;
--end;
Shift_Buffer (Wbuf, Length);
end loop;
end Flush;
procedure Drain (File: in out File_Record) is
pragma Assert (Is_Open(File));
begin
File.Wbuf.Length := 0;
end Drain;
end File;