Freeware ZIP component for Delphi 2010/Delphi XE?

Question

Do you know any free component, compatible with Delphi 2010 or XE to manage ZIP archives (actually, only reading archive contents and extracting files required)?

Please no betas.

I thought about ZipForge from ComponentAce, but it's free only for personal use. No software distribution allowed.

Answer 1

You can get the TurboPower Abbrevia for 2010 from: http://tpabbrevia.sourceforge.net/

Answer 2

you can take a look at this if you like 7zip

Answer 3

If you only need decoding (developed for Delphi 2007, not yet tested under Delphi 2010/XE):

unit UnitZip;

interface

uses
  SysUtils, Classes;

type
  EZipException = class( Exception );

  TZipFileInfo = record
    LastModified:                      TDateTime;
    Crc32:                             Longword;
    CompressedSize:                    Longword;
    UncompressedSize:                  Longword;
  end;

  TZipFileReader = class
  private
    // Information about the memory mapped file
    FFileHandle:                       THandle;
    FFileMapping:                      THandle;
    FMappedAddress:                    Pointer;
    // Location of the ZIPfile in memory. Currently we only support memory mapped ZIPfiles without disk spanning.
    FStart:                            Pointer;
    FSize:                             Longword;
    // ZIP file contents
    FFilenames:                        TStrings;
    function    GetZipFileInfo         ( const FileName: AnsiString ): TZipFileInfo;
  public
    constructor Create                 ( const FileName: string; ZipStartOffset: Int64 = 0; Size: Longword = 0 ); overload;
    constructor Create                 ( const ResourceName, ResourceType: string; Instance: HMODULE = 0 ); overload;
    constructor Create                 ( Buffer: Pointer; Size: Longword ); overload;
    destructor  Destroy;               override;
    function    GetFile                ( const FileName: string ): TBytes; overload;
    function    GetFile                ( FileID: Integer ): TBytes; overload;
    property    FileNames:             TStrings read FFileNames;
    property    FileInfo               [ const FileName: AnsiString ]: TZipFileInfo read GetZipFileInfo;
  end;

implementation

uses
  ZLib, Windows;

const
  cResourceNotFound   = 'Resource not found: %s.%s.';
  cResourceNotLoaded  = 'Resource not loaded: %s.%s.';
  cCannotOpenFile     = 'Cannot open file %s: OS error: %d.';
  cCannotGetFileSize  = 'Cannot get file size of file %s: OS error: %d.';
  cCannotMapFile      = 'Cannot create file mapping of file %s: OS error: %d.';
  cZipFileTooSmall    = 'ZIP file is too small.';
  cZipFileFormatError = 'ZIP file is invalid.';
  cZipBufferInvalid   = 'ZIP memory buffer is invalid.';
  cUnsupportedMethod  = 'ZIP unsupported compression method: %d.';
  cFileNotFoundInZip  = 'File not found in ZIP content: %s';

// ZIP file format records.
// The generic zip file format is ( TLocalFileHeader; Name; Extra; compressed data )* ( TFileHeader; Name; Extra; Remark )* TLastHeader

type
  TFileInfo = packed record
    NeededVersion:                     Word;            // 20
    Flags:                             Word;            // 1=Text,4=extra present
    ZipMethod:                         Word;            // 0=stored 8=deflate
    LastModified:                      Longword;        // time in dos format or Unix Timestamp
    Crc32:                             Longword;
    CompressedSize:                    Longword;
    UncompressedSize:                  Longword;
    NameSize:                          Word;
    ExtraSize:                         Word;
  end;

  TFileHeader = packed record
    Signature:                         Longword;        // $02014b50 PK#1#2
    MadeBy:                            Word;            // Version number, 20
    FileInfo:                          TFileInfo;
    CommentSize:                       Word;            // 0
    FirstDiskNumber:                   Word;            // 0
    IntFileAttr:                       Word;            // 0 = binary; 1 = text
    ExtFileAttr:                       Longword;        // DOS file attributes (Archived=32)
    LocalFileHeaderHeadOff:            Longword;        // @TLocalFileHeader
  end;
  PFileHeader = ^TFileHeader;

  TLocalFileHeader = packed record
    Signature:                         Longword;        // $02014b50 PK#3#4
    FileInfo:                          TFileInfo;
  end;
  PLocalFileHeader = ^TLocalFileHeader;

  TLastHeader = packed record
    Signature:                         Longword;        // $02014b50 PK#5#6
    ThisDiskNumber:                    Word;
    CentralDirDisk:                    Word;
    ThisDiskFileCount:                 Word;
    TotalFileCount:                    Word;
    FileHeaderSize:                    Longword;
    FileHeaderOffset:                  Longword;
    CommentSize:                       Word;
  end;
  PLastHeader = ^TLastHeader;

const
  MagicLastHeader  = $06054b50;
  MagicLocalHeader = $04034b50;
  MagicFileHeader  = $02014b50;

type
  IntPtr = Longword; // NativeInt on Delphi2007 is an Int64 ??

{$if CompilerVersion < 19}
procedure SetAnsiString( var S: AnsiString; P: PAnsiChar; L: Integer ); inline;
begin
  SetString( S, P, L );
end;
{$ifend}

{ TZipFileReader }

constructor TZipFileReader.Create( const FileName: string; ZipStartOffset: Int64; Size: Longword );
begin
  // Open the file in question.
  FFileHandle := CreateFile( PChar( FileName ), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0 );
  if FFileHandle = INVALID_HANDLE_VALUE then raise EZipException.CreateFmt( cCannotOpenFile, [ Filename, GetLastError() ] );
  if Size = 0 then Size := GetFileSize( FFileHandle, nil );
  if Size = INVALID_FILE_SIZE then raise EZipException.CreateFmt( cCannotGetFileSize, [ Filename, GetLastError() ] );

  try
    // Create a file mapping of the file in question
    FFileMapping := CreateFileMapping( FFileHandle, nil, PAGE_READONLY, 0, 0, nil);
    if FFileMapping = 0 then raise EZipException.CreateFmt( cCannotMapFile, [ Filename, GetLastError() ] );

    try
      // Get the file mapped in memory (NOTE: The offset needs to be on the  memory allocation granularity of the system)
      // Hence we assign it it's own pointer -> todo rounding etc.
      FMappedAddress := MapViewOfFile( FFileMapping, FILE_MAP_READ, Int64Rec( ZipStartOffset ).Hi, Int64Rec( ZipStartOffset ).Lo, Size );
      if not Assigned( FMappedAddress ) then EZipException.CreateFmt( cCannotMapFile, [ Filename, GetLastError() ] );
      Create( FMappedAddress, Size );
    except
      CloseHandle( FFileMapping );
      FFileMapping := 0;
      raise;
    end;
  except
    CloseHandle( FFileHandle );
    FFileHandle := 0;
    raise;
  end;
end;

constructor TZipFileReader.Create( const ResourceName, ResourceType: string; Instance: HMODULE );
var
  Resource: HRSRC;
  Global:   HGLOBAL;
begin
  Resource := FindResource( Instance, PChar( ResourceName ), PChar( ResourceType ) );
  if Resource = 0 then raise EZipException.CreateFmt( cResourceNotFound, [ ResourceName, ResourceType ] );
  Global := LoadResource( Instance, Resource );
  if Global = 0 then raise EZipException.CreateFmt( cResourceNotLoaded, [ ResourceName, ResourceType ] );
  Create( LockResource( Global ), SizeofResource( HInstance, Resource ) );
  // Note: kb57808: SizeofResource() returns the resource size rounded up to the alignment size.
end;

constructor TZipFileReader.Create( Buffer: Pointer; Size: Longword );
var
  LastHeader: PLastHeader;
  FileHeader: PFileHeader;
  i, Off:     Longword;
  Name:       AnsiString;
begin
  // Note the location.
  FStart := Buffer;
  FSize  := Size;

  // Some sanity checks.
  if FSize < sizeof( TLocalFileHeader ) + sizeof( TFileHeader ) + sizeof( TLastHeader ) then raise EZipException.Create( cZipFileTooSmall );
  if IsBadReadPtr( Buffer, Size ) then raise EZipException.Create( cZipBufferInvalid );
  if PLongword( Buffer )^ <> MagicLocalHeader then raise EZipException.Create( cZipFileFormatError );

  // Find the last header. Due to the alignment of SizeofResource, we need o search for it.
  LastHeader := Pointer( IntPtr( Buffer ) + Size - sizeof( TLastHeader ) );
  for i := 0 to 31 do begin
    if LastHeader^.Signature = MagicLastHeader then Break;
    Dec( IntPtr( LastHeader ) );
  end;
  if LastHeader^.Signature <> MagicLastHeader then raise EZipException.Create( cZipFileFormatError );

  FFilenames := TStringList.Create();

  Off := LastHeader^.FileHeaderOffset;
  for i := 0 to LastHeader^.TotalFileCount - 1 do begin
    // Get header
    if Off + sizeof( TFileHeader ) >= Size then raise EZipException.Create( cZipFileFormatError );
    FileHeader := Pointer( IntPtr( Buffer ) + Off );
    Inc( Off, sizeof( TFileHeader ) );
    if FileHeader^.Signature <> MagicFileHeader then raise EZipException.Create( cZipFileFormatError );

    // Get filename
    if Off + FileHeader^.FileInfo.NameSize + FileHeader^.FileInfo.ExtraSize >= Size then raise EZipException.Create( cZipFileFormatError );
    SetAnsiString( Name, Pointer( IntPtr( Buffer ) + Off ), FileHeader^.FileInfo.NameSize );
    Inc( Off, FileHeader^.FileInfo.NameSize + FileHeader^.FileInfo.ExtraSize );

    // Save filename and offset into ZIPfile where it can be found.
    FFileNames.AddObject( Name, Pointer( FileHeader^.LocalFileHeaderHeadOff ) );
  end;
  // For quick access.
  TStringList( FFilenames ).Sorted := True;

end;

destructor TZipFileReader.Destroy;
begin
  if Assigned( FMappedAddress ) then UnmapViewOfFile( FMappedAddress );
  if FFileMapping <> 0 then CloseHandle( FFileMapping );
  if FFileHandle  <> 0 then CloseHandle( FFileHandle  );
  inherited Destroy;
end;

function TZipFileReader.GetFile( const FileName: string ): TBytes;
var
  ID: Integer;
begin
  // Convert filename in FileID and access by ID.
  ID := FFilenames.IndexOf( FileName );
  if ID < 0 then raise EZipException.CreateFmt( cFileNotFoundInZip, [ FileName ] );
  Result := GetFile( ID );
end;

function TZipFileReader.GetFile( FileID: Integer ): TBytes;
var
  Off:   Longword;
  Local: PLocalFileHeader;
  ZRec:  TZStreamRec;
const
  ZLibHeader: array [ 0..1 ] of Byte = ( $78, $01 ); // Deflate 32KB window size no preset dictionary.
begin
  // Sanity check
  if ( FileID < 0 ) or ( FileID >= FFilenames.Count ) then raise EZipException.CreateFmt( 'Invalid File ID: %d', [ FileID ] );

  // Get the file header and perform sanity check
  Off := Longword( FFilenames.Objects[ FileID ] );
  if Off + sizeof( TLocalFileHeader ) >= FSize then raise EZipException.Create( cZipFileFormatError );
  Local := Pointer( IntPtr( FStart ) + Off );
  if Local^.Signature <> MagicLocalHeader then raise EZipException.Create( cZipFileFormatError );
  Inc( Off, sizeof( TLocalFileHeader ) + Local^.FileInfo.NameSize + Local^.FileInfo.ExtraSize );
  if Off + Local^.FileInfo.CompressedSize >= FSize then raise EZipException.Create( cZipFileFormatError );
  // note: should we check the name again?

  SetLength( Result, Local^.FileInfo.UncompressedSize );
  if Length( Result ) > 0 then case Local^.FileInfo.ZipMethod of
    0:   begin // STORED
           if Local^.FileInfo.CompressedSize <> Local^.FileInfo.UncompressedSize then raise EZipException.Create( cZipFileFormatError );
           Move( Pointer( IntPtr( FStart ) + Off )^, Result[ 0 ], Local^.FileInfo.UncompressedSize );
         end;
    8:   begin // DEFLATE
           ZeroMemory( @ZRec, sizeof( ZRec ) );
           ZRec.next_in   := @ZLibHeader;
           ZRec.avail_in  := sizeof( ZLibHeader );
           ZRec.total_in  := sizeof( ZLibHeader ) + Local^.FileInfo.CompressedSize;
           ZRec.next_out  := @Result[ 0 ];
           ZRec.avail_out := Local^.FileInfo.UncompressedSize;
           ZRec.total_out := Local^.FileInfo.UncompressedSize;
           ZRec.zalloc    := zlibAllocMem;
           ZRec.zfree     := zlibFreeMem;
           if inflateInit_( ZRec, zlib_Version, sizeof( ZRec ) ) <> 0 then raise EZipException.Create( cZipFileFormatError );
           try
             if not( inflate( ZRec, Z_FULL_FLUSH ) in [ Z_OK, Z_STREAM_END ] ) then raise EZipException.Create( cZipFileFormatError );
             ZRec.next_in   := Pointer( IntPtr( FStart ) + Off );
             ZRec.avail_in  := Local^.FileInfo.CompressedSize;
             if not( inflate( ZRec, Z_FINISH ) in [ Z_OK, Z_STREAM_END ] ) then raise EZipException.Create( cZipFileFormatError );
           finally
             inflateEnd( ZRec );
           end;
         end;
    else raise EZipException.CreateFmt( cUnsupportedMethod, [ Local^.FileInfo.ZipMethod ] );
  end;

  // todo: CRC32 sanity check if requested.
end;

function TZipFileReader.GetZipFileInfo( const FileName: AnsiString ): TZipFileInfo;
var
  FileID: Integer;
  Off:    Longword;
  Local:  PLocalFileHeader;
begin
  // Get the correct file ID
  FileID := FFilenames.IndexOf( FileName );
  if FileID < 0 then raise EZipException.CreateFmt( cFileNotFoundInZip, [ FileName ] );

  // Get the file header and perform sanity check
  Off := Longword( FFilenames.Objects[ FileID ] );
  if Off + sizeof( TLocalFileHeader ) >= FSize then raise EZipException.Create( cZipFileFormatError );
  Local := Pointer( IntPtr( FStart ) + Off );
  if Local^.Signature <> MagicLocalHeader then raise EZipException.Create( cZipFileFormatError );
  Inc( Off, sizeof( TLocalFileHeader ) + Local^.FileInfo.NameSize + Local^.FileInfo.ExtraSize );
  if Off + Local^.FileInfo.CompressedSize >= FSize then raise EZipException.Create( cZipFileFormatError );

  // Return requested data.
  Result.LastModified     := Local^.FileInfo.LastModified;
  Result.Crc32            := Local^.FileInfo.Crc32;
  Result.CompressedSize   := Local^.FileInfo.CompressedSize;
  Result.UncompressedSize := Local^.FileInfo.UncompressedSize;
end;

end.