delphi的压缩单元是那个(50分)

delphi的压缩单元是哪个,忘了

Zlib.pas

在delphi5的安装光盘里， 没有安装到delphi安装路径下，你搜索一下吧。

错了，是Zlib.dcu
你直接Uses Zlib就可以使用了

给你一个我修改过的版本，可以防止解压缩出错

{*******************************************************}
{ }
{ Borland Delphi Supplemental Components }
{ ZLIB Data Compression Interface Unit }
{ }
{ Copyright (c) 1997,99 Inprise Corporation }
{ }
{*******************************************************}


//by adnil: onprogress can be deleted
unit zlib;

interface

uses Sysutils, Classes;

resourcestring
sTargetBufferTooSmall = 'ZLib error: target buffer may be too small';
sInvalidStreamOp = 'Invalid stream operation';

type
TAlloc = function (AppData: Pointer; Items, Size: Integer): Pointer; register;
TFree = procedure (AppData, Block: Pointer); register;

// Internal structure. Ignore.
TZStreamRec = packed record
next_in: PChar; // next input byte
avail_in: Integer; // number of bytes available at next_in
total_in: Integer; // total nb of input bytes read so far

next_out: PChar; // next output byte should be put here
avail_out: Integer; // remaining free space at next_out
total_out: Integer; // total nb of bytes output so far

msg: PChar; // last error message, NULL if no error
internal: Pointer; // not visible by applications

zalloc: TAlloc; // used to allocate the internal state
zfree: TFree; // used to free the internal state
AppData: Pointer; // private data object passed to zalloc and zfree

data_type: Integer; // best guess about the data type: ascii or binary
adler: Integer; // adler32 value of the uncompressed data
reserved: Integer; // reserved for future use
end;

// Abstract ancestor class
TCustomZlibStream = class(TStream)
private
FStrm: TStream;
FStrmPos: Integer;
FOnProgress: TNotifyEvent;
FZRec: TZStreamRec;
FBuffer: array [Word] of Char;
protected
procedure Progress(Sender: TObject); dynamic;
property OnProgress: TNotifyEvent read FOnProgress write FOnProgress;
constructor Create(Strm: TStream);
end;

{ TCompressionStream compresses data on the fly as data is written to it, and
stores the compressed data to another stream.

TCompressionStream is write-only and strictly sequential. Reading from the
stream will raise an exception. Using Seek to move the stream pointer
will raise an exception.

Output data is cached internally, written to the output stream only when
the internal output buffer is full. All pending output data is flushed
when the stream is destroyed.

The Position property returns the number of uncompressed bytes of
data that have been written to the stream so far.

CompressionRate returns the on-the-fly percentage by which the original
data has been compressed: (1 - (CompressedBytes / UncompressedBytes)) * 100
If raw data size = 100 and compressed data size = 25, the CompressionRate
is 75%

The OnProgress event is called each time the output buffer is filled and
written to the output stream. This is useful for updating a progress
indicator when you are writing a large chunk of data to the compression
stream in a single call.}


TCompressionLevel = (clNone, clFastest, clDefault, clMax);

TCompressionStream = class(TCustomZlibStream)
private
function GetCompressionRate: Single;
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;
property CompressionRate: Single read GetCompressionRate;
property OnProgress;
end;

{ TDecompressionStream decompresses data on the fly as data is read from it.

Compressed data comes from a separate source stream. TDecompressionStream
is read-only and unidirectional; you can seek forward in the stream, but not
backwards. The special case of setting the stream position to zero is
allowed. Seeking forward decompresses data until the requested position in
the uncompressed data has been reached. Seeking backwards, seeking relative
to the end of the stream, requesting the size of the stream, and writing to
the stream will raise an exception.

The Position property returns the number of bytes of uncompressed data that
have been read from the stream so far.

The OnProgress event is called each time the internal input buffer of
compressed data is exhausted and the next block is read from the input stream.
This is useful for updating a progress indicator when you are reading a
large chunk of data from the decompression stream in a single call.}

TDecompressionStream = class(TCustomZlibStream)
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;



{ CompressBuf compresses data, buffer to buffer, in one call.
In: InBuf = ptr to compressed data
InBytes = number of bytes in InBuf
Out: OutBuf = ptr to newly allocated buffer containing decompressed data
OutBytes = number of bytes in OutBuf }
procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
out OutBuf: Pointer; out OutBytes: Integer);


{ DecompressBuf decompresses data, buffer to buffer, in one call.
In: InBuf = ptr to compressed data
InBytes = number of bytes in InBuf
OutEstimate = zero, or est. size of the decompressed data
Out: OutBuf = ptr to newly allocated buffer containing decompressed data
OutBytes = number of bytes in OutBuf }
procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer);

{ DecompressToUserBuf decompresses data, buffer to buffer, in one call.
In: InBuf = ptr to compressed data
InBytes = number of bytes in InBuf
Out: OutBuf = ptr to user-allocated buffer to contain decompressed data
BufSize = number of bytes in OutBuf }
procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer;
const OutBuf: Pointer; BufSize: Integer);

const
zlib_Version = '1.0.4';

type
EZlibError = class(Exception);
ECompressionError = class(EZlibError);
EDecompressionError = class(EZlibError);

implementation

const
Z_NO_FLUSH = 0;
Z_PARTIAL_FLUSH = 1;
Z_SYNC_FLUSH = 2;
Z_FULL_FLUSH = 3;
Z_FINISH = 4;

Z_OK = 0;
Z_STREAM_END = 1;
Z_NEED_DICT = 2;
Z_ERRNO = (-1);
Z_STREAM_ERROR = (-2);
Z_DATA_ERROR = (-3);
Z_MEM_ERROR = (-4);
Z_BUF_ERROR = (-5);
Z_VERSION_ERROR = (-6);

Z_NO_COMPRESSION = 0;
Z_BEST_SPEED = 1;
Z_BEST_COMPRESSION = 9;
Z_DEFAULT_COMPRESSION = (-1);

Z_FILTERED = 1;
Z_HUFFMAN_ONLY = 2;
Z_DEFAULT_STRATEGY = 0;

Z_BINARY = 0;
Z_ASCII = 1;
Z_UNKNOWN = 2;

Z_DEFLATED = 8;



{$L Obj/deflate.obj}
{$L Obj/inflate.obj}
{$L Obj/inftrees.obj}
{$L Obj/trees.obj}
{$L Obj/adler32.obj}
{$L Obj/infblock.obj}
{$L Obj/infcodes.obj}
{$L Obj/infutil.obj}
{$L Obj/inffast.obj}

procedure _tr_init; external;
procedure _tr_tally; external;
procedure _tr_flush_block; external;
procedure _tr_align; external;
procedure _tr_stored_block; external;
procedure adler32; external;
procedure inflate_blocks_new; external;
procedure inflate_blocks; external;
procedure inflate_blocks_reset; external;
procedure inflate_blocks_free; external;
procedure inflate_set_dictionary; external;
procedure inflate_trees_bits; external;
procedure inflate_trees_dynamic; external;
procedure inflate_trees_fixed; external;
procedure inflate_trees_free; external;
procedure inflate_codes_new; external;
procedure inflate_codes; external;
procedure inflate_codes_free; external;
procedure _inflate_mask; external;
procedure inflate_flush; external;
procedure inflate_fast; external;

procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl;
begin
FillChar(P^, count, B);
end;

procedure _memcpy(dest, source: Pointer; count: Integer); cdecl;
begin
Move(source^, dest^, count);
end;



// deflate compresses data
function deflateInit_(var strm: TZStreamRec; level: Integer; version: PChar;
recsize: Integer): Integer; external;
function deflate(var strm: TZStreamRec; flush: Integer): Integer; external;
function deflateEnd(var strm: TZStreamRec): Integer; external;

// inflate decompresses data
function inflateInit_(var strm: TZStreamRec; version: PChar;
recsize: Integer): Integer; external;
function inflate(var strm: TZStreamRec; flush: Integer): Integer; external;
function inflateEnd(var strm: TZStreamRec): Integer; external;
function inflateReset(var strm: TZStreamRec): Integer; external;


function zlibAllocMem(AppData: Pointer; Items, Size: Integer): Pointer; register;
begin
// GetMem(Result, Items*Size);
Result := AllocMem(Items * Size);
end;

procedure zlibFreeMem(AppData, Block: Pointer); register;
begin
FreeMem(Block);
end;

{function zlibCheck(code: Integer): Integer;
begin
Result := code;
if code < 0 then
raise EZlibError.Create('error'); //!!
end;}

function CCheck(code: Integer): Integer;
begin
Result := code;
if code < 0 then
raise ECompressionError.Create('error'); //!!
end;

function DCheck(code: Integer): Integer;
begin
Result := code;
if code < 0 then
raise EDecompressionError.Create('error'); //!!
end;

procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
out OutBuf: Pointer; out OutBytes: Integer);
var
strm: TZStreamRec;
P: Pointer;
begin
FillChar(strm, sizeof(strm), 0);
strm.zalloc := zlibAllocMem;
strm.zfree := zlibFreeMem;
OutBytes := ((InBytes + (InBytes div 10) + 12) + 255) and not 255;
GetMem(OutBuf, OutBytes);
try
strm.next_in := InBuf;
strm.avail_in := InBytes;
strm.next_out := OutBuf;
strm.avail_out := OutBytes;
CCheck(deflateInit_(strm, Z_BEST_COMPRESSION, zlib_version, sizeof(strm)));
try
while CCheck(deflate(strm, Z_FINISH)) <> Z_STREAM_END do
begin
P := OutBuf;
Inc(OutBytes, 256);
ReallocMem(OutBuf, OutBytes);
strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P)));
strm.avail_out := 256;
end;
finally
CCheck(deflateEnd(strm));
end;
ReallocMem(OutBuf, strm.total_out);
OutBytes := strm.total_out;
except
FreeMem(OutBuf);
raise
end;
end;


procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer);
var
strm: TZStreamRec;
P: Pointer;
BufInc: Integer;
begin
FillChar(strm, sizeof(strm), 0);
strm.zalloc := zlibAllocMem;
strm.zfree := zlibFreeMem;
BufInc := (InBytes + 255) and not 255;
if OutEstimate = 0 then
OutBytes := BufInc
else
OutBytes := OutEstimate;
GetMem(OutBuf, OutBytes);
try
strm.next_in := InBuf;
strm.avail_in := InBytes;
strm.next_out := OutBuf;
strm.avail_out := OutBytes;
DCheck(inflateInit_(strm, zlib_version, sizeof(strm)));
try
while DCheck(inflate(strm, Z_FINISH)) <> Z_STREAM_END do
begin
P := OutBuf;
Inc(OutBytes, BufInc);
ReallocMem(OutBuf, OutBytes);
strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P)));
strm.avail_out := BufInc;
end;
finally
DCheck(inflateEnd(strm));
end;
ReallocMem(OutBuf, strm.total_out);
OutBytes := strm.total_out;
except
FreeMem(OutBuf);
raise
end;
end;

procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer;
const OutBuf: Pointer; BufSize: Integer);
var
strm: TZStreamRec;
begin
FillChar(strm, sizeof(strm), 0);
strm.zalloc := zlibAllocMem;
strm.zfree := zlibFreeMem;
strm.next_in := InBuf;
strm.avail_in := InBytes;
strm.next_out := OutBuf;
strm.avail_out := BufSize;
DCheck(inflateInit_(strm, zlib_version, sizeof(strm)));
try
if DCheck(inflate(strm, Z_FINISH)) <> Z_STREAM_END then
raise EZlibError.CreateRes(@sTargetBufferTooSmall);
finally
DCheck(inflateEnd(strm));
end;
end;

// TCustomZlibStream

constructor TCustomZLibStream.Create(Strm: TStream);
begin
inherited Create;
FStrm := Strm;
FStrmPos := Strm.Position;
FZRec.zalloc := zlibAllocMem;
FZRec.zfree := zlibFreeMem;
end;

procedure TCustomZLibStream.Progress(Sender: TObject);
begin
if Assigned(FOnProgress) then FOnProgress(Sender);
end;


// TCompressionStream

constructor TCompressionStream.Create(CompressionLevel: TCompressionLevel;
Dest: TStream);
const
Levels: array [TCompressionLevel] of ShortInt =
(Z_NO_COMPRESSION, Z_BEST_SPEED, Z_DEFAULT_COMPRESSION, Z_BEST_COMPRESSION);
begin
inherited Create(Dest);
FZRec.next_out := FBuffer;
FZRec.avail_out := sizeof(FBuffer);
CCheck(deflateInit_(FZRec, Levels[CompressionLevel], zlib_version, sizeof(FZRec)));
end;

destructor TCompressionStream.Destroy;
begin
FZRec.next_in := nil;
FZRec.avail_in := 0;
try
if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
while (CCheck(deflate(FZRec, Z_FINISH)) <> Z_STREAM_END)
and (FZRec.avail_out = 0) do
begin
FStrm.WriteBuffer(FBuffer, sizeof(FBuffer));
FZRec.next_out := FBuffer;
FZRec.avail_out := sizeof(FBuffer);
end;
if FZRec.avail_out < sizeof(FBuffer) then
FStrm.WriteBuffer(FBuffer, sizeof(FBuffer) - FZRec.avail_out);
finally
deflateEnd(FZRec);
end;
inherited Destroy;
end;

function TCompressionStream.Read(var Buffer; Count: Longint): Longint;
begin
raise ECompressionError.CreateRes(@sInvalidStreamOp);
end;

function TCompressionStream.Write(const Buffer; Count: Longint): Longint;
begin
FZRec.next_in := @Buffer;
FZRec.avail_in := Count;
if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
while (FZRec.avail_in > 0) do
begin
CCheck(deflate(FZRec, 0));
if FZRec.avail_out = 0 then
begin
FStrm.WriteBuffer(FBuffer, sizeof(FBuffer));
FZRec.next_out := FBuffer;
FZRec.avail_out := sizeof(FBuffer);
FStrmPos := FStrm.Position;
Progress(Self);
end;
end;
Result := Count;
end;

function TCompressionStream.Seek(Offset: Longint; Origin: Word): Longint;
begin
if (Offset = 0) and (Origin = soFromCurrent) then
Result := FZRec.total_in
else
raise ECompressionError.CreateRes(@sInvalidStreamOp);
end;

function TCompressionStream.GetCompressionRate: Single;
begin
if FZRec.total_in = 0 then
Result := 0
else
Result := (1.0 - (FZRec.total_out / FZRec.total_in)) * 100.0;
end;


// TDecompressionStream

constructor TDecompressionStream.Create(Source: TStream);
begin
inherited Create(Source);
FZRec.next_in := FBuffer;
FZRec.avail_in := 0;
DCheck(inflateInit_(FZRec, zlib_version, sizeof(FZRec)));
end;

destructor TDecompressionStream.Destroy;
begin
FStrm.Seek(-FZRec.avail_in, 1);
inflateEnd(FZRec);
inherited Destroy;
end;

function TDecompressionStream.Read(var Buffer; Count: Longint): Longint;
begin
FZRec.next_out := @Buffer;
FZRec.avail_out := Count;
if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
while (FZRec.avail_out > 0) do
begin
if FZRec.avail_in = 0 then
begin
FZRec.avail_in := FStrm.Read(FBuffer, sizeof(FBuffer));
if FZRec.avail_in = 0 then // missing code
begin // missing code
Result := Count - FZRec.avail_out; // missing code
Exit; // missing code
end; // missing code
FZRec.next_in := FBuffer;
FStrmPos := FStrm.Position;
Progress(Self);
end;
CCheck(inflate(FZRec, 0));
end;
Result := Count;
end;

function TDecompressionStream.Write(const Buffer; Count: Longint): Longint;
begin
raise EDecompressionError.CreateRes(@sInvalidStreamOp);
end;

function TDecompressionStream.Seek(Offset: Longint; Origin: Word): Longint;
var
I: Integer;
Buf: array [0..4095] of Char;
begin
if (Offset = 0) and (Origin = soFromBeginning) then
begin
DCheck(inflateReset(FZRec));
FZRec.next_in := FBuffer;
FZRec.avail_in := 0;
FStrm.Position := 0;
FStrmPos := 0;
end
else if ( (Offset >= 0) and (Origin = soFromCurrent)) or
( ((Offset - FZRec.total_out) > 0) and (Origin = soFromBeginning)) then
begin
if Origin = soFromBeginning then Dec(Offset, FZRec.total_out);
if Offset > 0 then
begin
for I := 1 to Offset div sizeof(Buf) do
ReadBuffer(Buf, sizeof(Buf));
ReadBuffer(Buf, Offset mod sizeof(Buf));
end;
end
else
raise EDecompressionError.CreateRes(@sInvalidStreamOp);
Result := FZRec.total_out;
end;



end.

多人接受答案了。