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+ Added .gz file stream support

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This commit is contained in:
michael 1999-07-09 08:56:19 +00:00
parent e5cb5e30a1
commit 1f7b7a1143
1 changed files with 446 additions and 387 deletions
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75
fcl/inc/zstream.pp
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@ -3,6 +3,7 @@ unit zstream;
interface
uses Sysutils, Classes,zlib;
{$H+}
type
// Error reporting.
@ -29,12 +30,12 @@ type
TCompressionStream = class(TCustomZlibStream)
private
function GetCompressionRate: extended;
public
constructor Create(CompressionLevel: TCompressionLevel; Dest: TStream);
destructor Destroy; override;
function CompressionCheck(code: Integer): Integer;
procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
var OutBuf: Pointer; var OutBytes: Integer);
public
constructor Create(CompressionLevel: TCompressionLevel; Dest: TStream);
destructor Destroy; override;
function Read(var Buffer; Count: Longint): Longint; override;
function Write(const Buffer; Count: Longint): Longint; override;
function Seek(Offset: Longint; Origin: Word): Longint; override;
@ -43,18 +44,33 @@ type
end;
TDecompressionStream = class(TCustomZlibStream)
public
constructor Create(Source: TStream);
destructor Destroy; override;
private
function DecompressionCheck(code: Integer): Integer;
procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
OutEstimate: Integer; var OutBuf: Pointer; var OutBytes: Integer);
public
constructor Create(Source: TStream);
destructor Destroy; override;
function Read(var Buffer; Count: Longint): Longint; override;
function Write(const Buffer; Count: Longint): Longint; override;
function Seek(Offset: Longint; Origin: Word): Longint; override;
property OnProgress;
end;
TGZOpenMode = (gzOpenRead,gzOpenWrite);
TGZFileStream = Class(TStream)
Private
FOpenMode : TGZOpenmode;
FFIle : gzfile;
Public
Constructor Create(FileName: String;FileMode: TGZOpenMode);
Destructor Destroy;override;
Function Read(Var Buffer; Count : longint): longint;override;
function Write(const Buffer; Count: Longint): Longint; override;
function Seek(Offset: Longint; Origin: Word): Longint; override;
end;
implementation
@ -62,6 +78,11 @@ Const
ErrorStrings : array [0..6] of string =
('Unknown error %d','Z_ERRNO','Z_STREAM_ERROR',
'Z_DATA_ERROR','Z_MEM_ERROR','Z_BUF_ERROR','Z_VERSION_ERROR');
SCouldntOpenFile = 'Couldn''t open file : %s';
SReadOnlyStream = 'Decompression streams are read-only';
SWriteOnlyStream = 'Compression streams are write-only';
SSeekError = 'Compression stream seek error';
SInvalidSeek = 'Invalid Compression seek operation';
Type PLongint = ^Longint;
@ -284,7 +305,7 @@ begin
if (Offset = 0) and (Origin = soFromCurrent) then
Result := FZRec.total_in
else
raise ECompressionError.Create('Invalid stream operation');
raise ECompressionError.Create(SInvalidSeek);
end;
function TCompressionStream.GetCompressionRate: extended;
@ -379,10 +400,48 @@ begin
end;
end
else
raise EDecompressionError.Create('Invalid stream operation');
raise EDecompressionError.Create(SInvalidSeek);
Result := FZRec.total_out;
end;
// TGZFileStream
Constructor TGZFileStream.Create(FileName: String;FileMode: TGZOpenMode);
Const OpenStrings : array[TGZOpenMode] of pchar = ('rb','wb');
begin
FOpenMode:=FileMode;
FFile:=gzopen (Pchar(FileName),Openstrings[FileMode]);
If FFile=Nil then
Raise ezlibError.CreateFmt (SCouldntOpenFIle,[FileName]);
end;
Destructor TGZFileStream.Destroy;
begin
gzclose(FFile);
Inherited Destroy;
end;
Function TGZFileStream.Read(Var Buffer; Count : longint): longint;
begin
If FOpenMode=gzOpenWrite then
Raise ezliberror.create(SWriteOnlyStream);
Result:=gzRead(FFile,@Buffer,Count);
end;
function TGZFileStream.Write(const Buffer; Count: Longint): Longint;
begin
If FOpenMode=gzOpenRead then
Raise EzlibError.Create(SReadonlyStream);
Result:=gzWrite(FFile,@Buffer,Count);
end;
function TGZFileStream.Seek(Offset: Longint; Origin: Word): Longint;
begin
Result:=gzseek(FFile,Offset,Origin);
If Result=-1 then
Raise eZlibError.Create(SSeekError);
end;
end.