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SynLZ.pas
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SynLZ.pas
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/// SynLZ Compression routines
// - licensed under a MPL/GPL/LGPL tri-license; version 1.18
unit SynLZ;
{
This file is part of Synopse SynLZ Compression.
Synopse SynLZ Compression. Copyright (C) 2015 Arnaud Bouchez
Synopse Informatique - http://synopse.info
*** BEGIN LICENSE BLOCK *****
Version: MPL 1.1/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Mozilla Public License Version
1.1 (the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.mozilla.org/MPL
Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
for the specific language governing rights and limitations under the License.
The Original Code is Synopse SynLZ Compression.
The Initial Developer of the Original Code is Arnaud Bouchez.
Portions created by the Initial Developer are Copyright (C) 2015
the Initial Developer. All Rights Reserved.
Contributor(s):
Alternatively, the contents of this file may be used under the terms of
either the GNU General Public License Version 2 or later (the "GPL"), or
the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the MPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the MPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****
SynLZ Compression / Decompression library
=========================================
by Arnaud Bouchez http://bouchez.info
* SynLZ is a very FAST lossless data compression library
written in optimized pascal code for Delphi 3 up to Delphi 2009
with a tuned asm version available
* symetrical compression and decompression speed (which is
very rare above all other compression algorithms in the wild)
* good compression rate (usualy better than LZO)
* fastest averrage compression speed (ideal for xml/text communication, e.g.)
SynLZ implements a new compression algorithm with the following features:
* hashing+dictionary compression in one pass, with no huffman table
* optimized 32bits control word, embedded in the data stream
* in-memory compression (the dictionary is the input stream itself)
* compression and decompression have the same speed (both use hashing)
* thread safe and lossless algorithm
* supports overlapping compression and in-place decompression
* code size for compression/decompression functions is smaller than LZO's
The contents of this file are subject to the Mozilla Public License
Version 1.1 (the "License"); you may not use this file except in
compliance with the License. You may obtain a copy of the License at
http://www.mozilla.org/MPL
Software distributed under the License is distributed on an "AS IS"
basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
License for the specific language governing rights and limitations
under the License.
The Initial Developer of the Original Code is Arnaud Bouchez.
This work is Copyright (C)2008 Arnaud Bouchez - http://bouchez.info
Conversion notes:
- this format is NOT stream compatible with any lz* official format
=> use it internally in your application, not as exchange format
- very small code size (less than 1KB for both compressor/decompressor)
- the uncompressed data length is stored in the beginning of the stream
and can be retrieved easily for proper out_p memory allocation
- please give correct data to the decompressor (i.e. first CRC in_p data)
=> we recommend our very fast Adler32 procedure, or a zip-like container
- a 2nd more tuned algorithm is included, but is somewhat slower in practice
=> use SynLZ[de]compres1*() functions in your applications
- tested and benchmarked with a lot of data types/sizes
=> use the asm code, which is very tuned: SynLZ[de]compress1asm()
- tested under Delphi 7, Delphi 2007 and Delphi 2009
- a hashing limitation makes SynLZ sometimes unable to pack continuous
blocks of same byte -> SynLZ is perfect for xml/text, but SynLZO
is prefered for database files
- if you include it in your application, please give me some credits:
"use SynLZ compression by http://bouchez.info"
- use at your own risk!
Some benchmark on a Sempron computer:
- compression is 20 times faster than zip, decompression 3 times
- same compression ratio as lzo algo, but faster (up to 2x) on compression
- the R and W intermediate speed are at the compressed stream level, i.e.
the speed which used for disk usage -> you see that SynLZ behaves
very well for real-time data compression, for backup purpose e.g.
(a typical SATA disk drive has a speed of 50-70 MB/s)
KLOG.xml 6034 bytes
lz1 asm 1287 21.3% R 256 MB/s W 54 MB/s R 71 MB/s W 334 MB/s
lz1 pas 1287 21.3% R 184 MB/s W 39 MB/s R 58 MB/s W 274 MB/s
lz2 pas 1274 21.1% R 173 MB/s W 36 MB/s R 57 MB/s W 274 MB/s
lzo C 1347 22.3% R 185 MB/s W 41 MB/s R 111 MB/s W 501 MB/s
zip 806 13.4% R 14 MB/s W 1 MB/s R 14 MB/s W 110 MB/s
MiniLZO.cs 25252 bytes
lz1 asm 5775 22.9% R 246 MB/s W 56 MB/s R 70 MB/s W 306 MB/s
lz1 pas 5775 22.9% R 178 MB/s W 40 MB/s R 58 MB/s W 253 MB/s
lz2 pas 5762 22.8% R 166 MB/s W 37 MB/s R 57 MB/s W 250 MB/s
lzo C 5846 23.2% R 164 MB/s W 38 MB/s R 103 MB/s W 448 MB/s
zip 3707 14.7% R 15 MB/s W 2 MB/s R 22 MB/s W 154 MB/s
TestLZO.exe 158720 bytes
lz1 asm 110686 69.7% R 127 MB/s W 88 MB/s R 80 MB/s W 115 MB/s
lz1 pas 110686 69.7% R 98 MB/s W 68 MB/s R 63 MB/s W 90 MB/s
lz2 pas 109004 68.7% R 88 MB/s W 60 MB/s R 60 MB/s W 88 MB/s
lzo C 108202 68.2% R 40 MB/s W 27 MB/s R 164 MB/s W 241 MB/s
zip 88786 55.9% R 5 MB/s W 3 MB/s R 33 MB/s W 60 MB/s
Browsing.sq3db 46047232 bytes (46MB)
lz1 asm 19766884 42.9% R 171 MB/s W 73 MB/s R 73 MB/s W 171 MB/s
lz1 pas 19766884 42.9% R 130 MB/s W 56 MB/s R 59 MB/s W 139 MB/s
lz2 pas 19707346 42.8% R 123 MB/s W 52 MB/s R 59 MB/s W 139 MB/s
lzo asm 20629084 44.8% R 89 MB/s W 40 MB/s R 135 MB/s W 302 MB/s
lzo C 20629083 44.8% R 66 MB/s W 29 MB/s R 145 MB/s W 325 MB/s
zip 15564126 33.8% R 6 MB/s W 2 MB/s R 30 MB/s W 91 MB/s
TRKCHG.DBF 4572297 bytes (4MB)
lz1 asm 265782 5.8% R 430 MB/s W 25 MB/s R 29 MB/s W 510 MB/s
lz1 pas 265782 5.8% R 296 MB/s W 17 MB/s R 28 MB/s W 483 MB/s
lz2 pas 274773 6.0% R 258 MB/s W 15 MB/s R 27 MB/s W 450 MB/s
lzo C 266897 5.8% R 318 MB/s W 18 MB/s R 41 MB/s W 702 MB/s
zip 158408 3.5% R 25 MB/s W 0 MB/s R 11 MB/s W 318 MB/s
CATENA5.TXT 6358752 bytes
lz1 asm 3275269 51.5% R 132 MB/s W 68 MB/s R 66 MB/s W 129 MB/s
lz1 pas 3275269 51.5% R 103 MB/s W 53 MB/s R 57 MB/s W 112 MB/s
lz2 pas 3277397 51.5% R 95 MB/s W 49 MB/s R 57 MB/s W 112 MB/s
lzo C 3289373 51.7% R 63 MB/s W 33 MB/s R 90 MB/s W 175 MB/s
zip 2029096 31.9% R 4 MB/s W 1 MB/s R 29 MB/s W 91 MB/s
Benchmark update - introducing LZ4 at http://code.google.com/p/lz4
190 MB file containing pascal sources, on a Core 2 duo PC:
LZ4 compression = 1.25 sec, comp. size = 71 MB, decompression = 0.44 sec
SynLZ compression = 1.09 sec, comp. size = 63 MB, decompression = 0.99 sec
zip (1) compression = 6.44 sec, comp. size = 52 MB, decompression = 1.49 sec
zip (6) compression = 20.1 sec, comp. size = 42 MB, decompression = 1.35 sec
Note: zip decompression here uses fast asm optimized version of SynZip.pas
Decompression is slower in SynLZ, due to the algorithm used: it does recreate
the hash table even at decompression, while it is not needed by LZ4.
Having the hash table at hand allows more patterns to be available, so
compression ratio is better, at the expand of a slower speed.
Conclusion:
SynLZ compresses better than LZ4,
SynLZ is faster to compress than LZ4,
but SynLZ is slower to decompress than LZ4,
and SynLZ is still very competitive for our Client-Server mORMot purpose ;)
Revision history
Version 1.6
- first release, associated with the main Synopse SQLite3 framework
Version 1.13
- code modifications to compile with Delphi 5 compiler
- comment refactoring (mostly for inclusion in SynProject documentation)
- new CompressSynLZ function, for THttpSocket.RegisterCompress - this
function will return 'synlzo' as "ACCEPT-ENCODING:" HTTP header parameter
Version 1.15
- force ignore asm version of the code if PUREPASCAL conditional is defined
Version 1.16
- fixed potential GPF issue in Hash32() function
Version 1.17
- Use RawByteString type for CompressSynLZ() function prototype
Version 1.18
- unit fixed and tested with Delphi XE2 and up 64-bit compiler
- introducing SynLZCompress1/SynLZDecompress1 low-level functions
- added SynLZdecompress1partial() function for partial and secure (but slower)
decompression - implements feature request [82ca067959]
- removed several compilation hints when assertions are set to off
}
interface
{$I Synopse.inc}
/// get maximum possible (worse) compressed size for out_p
function SynLZcompressdestlen(in_len: integer): integer;
/// get uncompressed size from lz-compressed buffer (to reserve memory, e.g.)
function SynLZdecompressdestlen(in_p: PAnsiChar): integer;
/// 1st compression algorithm uses hashing with a 32bits control word
function SynLZcompress1pas(src: PAnsiChar; size: integer; dst: PAnsiChar): integer;
/// 1st compression algorithm uses hashing with a 32bits control word
// - this is the fastest pure pascal implementation
function SynLZdecompress1pas(src: PAnsiChar; size: integer; dst: PAnsiChar): Integer;
/// 1st compression algorithm uses hashing with a 32bits control word
// - this overload function is slower, but will allow to uncompress only the start
// of the content (e.g. to read some metadata header)
// - it will also check for dst buffer overflow, so will be more secure than
// other functions, which expect the content to be verified (e.g. via CRC)
function SynLZdecompress1partial(src: PAnsiChar; size: integer; dst: PAnsiChar;
maxDst: Integer): Integer;
{$ifndef PUREPASCAL}
/// optimized asm version of the 1st compression algorithm
function SynLZcompress1asm(src: PAnsiChar; size: integer; dst: PAnsiChar): integer;
/// optimized asm version of the 1st compression algorithm
function SynLZdecompress1asm(src: PAnsiChar; size: integer; dst: PAnsiChar): Integer;
{$endif PUREPASCAL}
/// 2nd compression algorithm optimizing pattern copy
// - this algorithm is a bit smaller, but slower, so the 1st method is preferred
function SynLZcompress2(src: PAnsiChar; size: integer; dst: PAnsiChar): integer;
/// 2nd compression algorithm optimizing pattern copy
// - this algorithm is a bit smaller, but slower, so the 1st method is preferred
function SynLZdecompress2(src: PAnsiChar; size: integer; dst: PAnsiChar): Integer;
var
/// fastest available SynLZ compression (using 1st algorithm)
SynLZCompress1: function(src: PAnsiChar; size: integer; dst: PAnsiChar): integer
= {$ifdef PUREPASCAL}SynLZcompress1pas{$else}SynLZcompress1asm{$endif};
/// fastest available SynLZ decompression (using 1st algorithm)
SynLZDecompress1: function(src: PAnsiChar; size: integer; dst: PAnsiChar): integer
= {$ifdef PUREPASCAL}SynLZDecompress1pas{$else}SynLZDecompress1asm{$endif};
implementation
function SynLZcompressdestlen(in_len: integer): integer;
// get maximum possible (worse) compressed size for out_p
begin
result := in_len+in_len shr 3+16; // worse case
end;
{$ifndef FPC}
type
PtrUInt = {$ifdef CPUX64} NativeUInt {$else} cardinal {$endif};
{$endif}
{$ifdef DELPHI5OROLDER}
type // Delphi 5 doesn't have those base types defined :(
PByte = ^Byte;
PWord = ^Word;
PInteger = ^Integer;
PCardinal = ^Cardinal;
IntegerArray = array[0..$effffff] of Integer;
PIntegerArray = ^IntegerArray;
{$endif}
function SynLZdecompressdestlen(in_p: PAnsiChar): integer;
// get uncompressed size from lz-compressed buffer (to reserve memory, e.g.)
begin
result := pWord(in_p)^;
inc(in_p,2);
if result and $8000<>0 then
result := (result and $7fff) or (integer(pWord(in_p)^) shl 15);
end;
procedure movechars(s,d: PAnsiChar; t: integer); {$ifdef HASINLINE}inline;{$endif}
// fast code for unaligned and overlapping (see {$define WT}) small blocks
// this code is sometimes used rather than system.Move() by decompress2()
var i: integer;
begin
for i := 1 to t do begin
d^ := s^;
inc(d);
inc(s);
end;
end;
{$ifndef PUREPASCAL}
function SynLZcompress1asm(src: PAnsiChar; size: integer; dst: PAnsiChar): integer;
asm
push ebp
push ebx
push esi
push edi
push eax
mov eax, 8
@@0906: add esp, -4092
push eax
dec eax
jnz @@0906
mov eax, [esp+8000H]
add esp, -32
mov esi, ecx
mov [esp], edx
mov edi, eax
mov [esp+8H], esi
mov eax,[esp]
cmp eax, 32768
jl @@0889
and eax, 7FFFH
or eax, 8000H
mov [esi], ax
mov eax, [esp]
shr eax, 15
mov [esi+2], ax
add esi, 4
jmp @@0891
@@0890: mov eax, 2
jmp @@0904
@@0889: mov [esi], ax
test eax,eax
jz @@0890
add esi,2
@@0891: mov eax, [esp]
add eax, edi
mov [esp+0CH], eax
mov eax, [esp+0CH]
sub eax, 11
mov [esp+10H], eax
xor ebx, ebx
mov eax, esi
mov [esp+18H], eax
xor edx, edx
mov [eax], edx
add esi, 4
lea eax, [esp+24H]
xor ecx, ecx
mov edx, 16384
call system.@fillchar
// main loop:
cmp edi, [esp+10H]
ja @@0900
@@0892: mov edx, [edi]
mov eax, edx
shr edx, 12
xor edx, eax
and edx, 0FFFH
mov ebp, [esp+edx*4+24H]
mov ecx, [esp+edx*4+4024H]
mov [esp+edx*4+24H], edi
xor ecx, eax
mov [esp+1CH], ecx
test ecx, 0FFFFFFH
mov [esp+edx*4+4024H], eax
jnz @@0897
mov eax, edi
or ebp,ebp
jz @@0897
sub eax, ebp
cmp eax, 2
mov ecx, [esp+18H]
jle @@0897
mov eax,[ecx]
lea edi,[edi+2]
bts eax,ebx
add ebp, 2
mov [ecx],eax
mov ecx, [esp+0CH]
mov eax, 1
sub ecx, edi
dec ecx
mov [esp+20H], ecx
cmp ecx, 271
jl @@0894
mov dword ptr [esp+20H], 271
jmp @@0894
@@0893: inc eax
@@0894: mov cl, [ebp+eax]
cmp cl, [edi+eax]
jnz @@0895
cmp eax, [esp+20H]
jge @@0895
@@1893: inc eax
@@1894: mov cl, [ebp+eax]
cmp cl, [edi+eax]
jnz @@0895
cmp eax, [esp+20H]
jge @@0895
@@2893: inc eax
@@2894: mov cl, [ebp+eax]
cmp cl, [edi+eax]
jnz @@0895
cmp eax, [esp+20H]
jl @@0893
@@0895: add edi, eax
shl edx, 4
cmp eax, 15
jg @@0896
or eax, edx
mov word ptr [esi], ax
add esi, 2
jmp @@0898
@@0896: sub eax, 16
mov [esi], dx
mov [esi+2H], al
add esi, 3
jmp @@0898
@@0897: mov al, [edi]
mov [esi], al
inc edi
inc esi
@@0898: cmp bl, 31
jnc @@0899
cmp edi, [esp+10H]
lea ebx,[ebx+1]
jbe @@0892
jmp @@0900
@@0899: mov [esp+18H], esi
xor edx, edx
mov [esi], edx
add esi, 4
xor ebx, ebx
cmp edi, [esp+10H]
jbe @@0892
@@0900: cmp edi, [esp+0CH]
jnc @@0903
@@0901: mov al, [edi]
mov [esi], al
inc edi
inc esi
cmp bl, 31
jnc @@0902
cmp edi, [esp+0CH]
lea ebx,[ebx+1]
jc @@0901
jmp @@0903
@@0902: xor ebx, ebx
mov [esi], ebx
lea esi,[esi+4]
cmp edi, [esp+0CH]
jc @@0901
@@0903: mov eax, esi
sub eax, [esp+8H]
@@0904: add esp, 32804
pop edi
pop esi
pop ebx
pop ebp
end;
{$endif PUREPASCAL}
type
TByteArray = array[0..3] of byte;
PByteArray = ^TByteArray;
function SynLZcompress1pas(src: PAnsiChar; size: integer; dst: PAnsiChar): integer;
var dst_beg, // initial dst value
src_end, // real last byte available in src
src_endmatch, // last byte to try for hashing
o: pAnsiChar;
CWbit: byte;
CWpoint: PInteger;
h, v, cached: integer;
t, tmax: integer;
offset: array[0..4095] of PAnsiChar; // 16KB+16KB=32KB hashing code
cache: array[0..4095] of integer;
begin
dst_beg := dst;
// 1. store in_len
if size>=$8000 then begin
pWord(dst)^ := $8000 or (size and $7fff);
pWord(dst+2)^ := size shr 15;
inc(dst,4);
end else begin
pWord(dst)^ := size ; // src<32768 -> stored as word, otherwise as integer
if size=0 then begin
result := 2;
exit;
end;
inc(dst,2);
end;
// 2. compress
src_end := src+size;
src_endmatch := src_end-(6+5);
CWbit := 0;
CWpoint := pointer(dst);
pInteger(dst)^ := 0;
inc(dst,sizeof(CWpoint^));
fillchar(offset,sizeof(offset),0); // fast 16KB reset to 0
// 1. main loop to search using hash[]
if src<=src_endmatch then
repeat
v := pInteger(src)^;
h := ((v shr 12) xor v) and 4095;
o := offset[h];
offset[h] := src;
cached := v xor cache[h];
cache[h] := v;
if (cached and $00ffffff=0) and (o<>nil) and (src-o>2) then begin
CWpoint^ := CWpoint^ or (1 shl CWbit);
inc(src,2);
inc(o,2);
t := 1;
tmax := src_end-src-1;
if tmax>=(255+16) then
tmax := (255+16);
while (o[t]=src[t]) and (t<tmax) do
inc(t);
inc(src,t);
h := h shl 4;
// here we have always t>0
if t<=15 then begin // mark 2 to 17 bytes -> size=1..15
pWord(dst)^ := integer(t or h);
inc(dst,2);
end else begin // mark 18 to (255+16) bytes -> size=0, next byte=t
dec(t,16);
pWord(dst)^ := h; // size=0
dst[2] := ansichar(t);
inc(dst,3);
end;
end else begin
dst^ := src^;
inc(src);
inc(dst);
end;
if CWbit<31 then begin
inc(CWbit);
if src<=src_endmatch then continue else break;
end else begin
CWpoint := pointer(dst);
pInteger(dst)^ := 0;
inc(dst,sizeof(CWpoint^));
CWbit := 0;
if src<=src_endmatch then continue else break;
end;
until false;
// 2. store remaining bytes
if src<src_end then
repeat
dst^ := src^;
inc(src);
inc(dst);
if CWbit<31 then begin
inc(CWbit);
if src<src_end then continue else break;
end else begin
pInteger(dst)^ := 0;
inc(dst,4);
CWbit := 0;
if src<src_end then continue else break;
end;
until false;
result := dst-dst_beg;
end;
const
bitlut: array[0..15] of integer =
(4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0);
function SynLZdecompress1b(src: PAnsiChar; size: integer; dst: PAnsiChar): Integer;
// this routine was trying to improve speed, but was slower
var last_hashed: PAnsiChar; // initial src and dst value
src_end: PAnsiChar;
CWbit: integer;
CW, v, t, h: integer;
offset: array[0..4095] of PAnsiChar; // 16KB hashing code
label nextCW;
begin
// src_beg := src;
// dst_beg := dst;
src_end := src+size;
// 1. retrieve out_len
result := pWord(src)^;
if result=0 then exit;
inc(src,2);
if result and $8000<>0 then begin
result := (result and $7fff) or (integer(pWord(src)^) shl 15);
inc(src,2);
end;
// 2. decompress
last_hashed := dst-1;
CWbit := 32;
nextCW:
CW := pInteger(src)^;
inc(src,4);
CWbit := CWbit-32;
if src<src_end then
repeat
if CW and 1=0 then begin
if CWbit<(32-4) then begin
pInteger(dst)^ := pInteger(src)^;
v := bitlut[CW and 15];
inc(src,v);
inc(dst,v);
inc(CWbit,v);
CW := CW shr v;
if src>=src_end then break;
while last_hashed<dst-3 do begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
end else begin
dst^ := src^;
inc(src);
inc(dst);
if src>=src_end then break;
if last_hashed<dst-3 then begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
inc(CWbit);
CW := CW shr 1;
if CWbit<32 then
continue else
goto nextCW;
end;
end else begin
h := pWord(src)^;
inc(src,2);
t := (h and 15)+2;
h := h shr 4;
if t=2 then begin
t := ord(src^)+(16+2);
inc(src);
end;
if dst-offset[h]<t then
movechars(offset[h],dst,t) else
move(offset[h]^,dst^,t);
while last_hashed<dst do begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
inc(dst,t);
if src>=src_end then break;
last_hashed := dst-1;
inc(CWbit);
CW := CW shr 1;
if CWbit<32 then
continue else
goto nextCW;
end;
until false;
// assert(result=dst-dst_beg);
end;
{$ifndef PUREPASCAL}
function SynLZdecompress1asm(src: PAnsiChar; size: integer; dst: PAnsiChar): Integer;
asm
push ebp
push ebx
push esi
push edi
push eax
mov eax, 4
@@0906: add esp, -4092
push eax
dec eax
jnz @@0906
mov eax, [esp+4000H]
add esp, -24
mov esi, ecx
mov ebx, eax
mov [esp+8H], esi
add edx, ebx
mov [esp+10H], edx
movzx eax, word ptr [ebx]
mov [esp], eax
or eax,eax
je @@0917
add ebx, 2
mov eax, [esp]
test ah, 80H
jz @@0907
and eax, 7FFFH
movzx edx, word ptr [ebx]
shl edx, 15
or eax, edx
mov [esp], eax
add ebx, 2
@@0907: lea ebp, [esi-1]
@@0908: mov ecx, [ebx]
add ebx, 4
mov [esp+14H], ecx
cmp ebx, [esp+10H]
mov edi, 1
jnc @@0917
@@0909: mov ecx, [esp+14H]
@@090A: test ecx, edi
jnz @@0911
mov al, byte ptr [ebx]
inc ebx
mov byte ptr [esi], al
inc esi
cmp ebx, [esp+10H]
lea eax, [esi-3]
jnc @@0917
cmp eax, ebp
jbe @@0910
inc ebp
mov eax, [ebp]
mov edx, eax
shr eax, 12
xor eax, edx
and eax, 0FFFH
mov [esp+eax*4+1CH], ebp
@@0910: add edi, edi
jnz @@090A
jmp @@0908
@@0911: movzx edx, word ptr [ebx]
add ebx, 2
mov eax, edx
and edx, 0FH
add edx, 2
shr eax, 4
cmp edx,2
jnz @@0912
movzx edx, byte ptr [ebx]
inc ebx
add edx, 18
@@0912: mov eax, [esp+eax*4+1CH]
mov ecx, esi
mov [esp+18H], edx
sub ecx, eax
cmp ecx, edx
jl @@0913
mov ecx, edx
mov edx, esi
call move
@@0914: cmp esi, ebp
jbe @@0916
@@0915: inc ebp
mov edx, [ebp]
mov eax, edx
shr edx, 12
xor eax, edx
and eax, 0FFFH
cmp esi, ebp
mov [esp+eax*4+1CH], ebp
ja @@0915
@@0916: add esi, [esp+18H]
cmp ebx, [esp+10H]
jnc @@0917
add edi, edi
lea ebp, [esi-1]
jz @@0908
jmp @@0909
@@0913: mov ecx, edx
mov edx, esi
call movechars
jmp @@0914
@@0917: mov eax, [esp]
add esp, 16412
pop edi
pop esi
pop ebx
pop ebp
end;
{$endif PUREPASCAL}
function SynLZdecompress1pas(src: PAnsiChar; size: integer; dst: PAnsiChar): Integer;
var last_hashed: PAnsiChar; // initial src and dst value
src_end: PAnsiChar;
CWbit: integer;
CW, v, t, h: integer;
offset: array[0..4095] of PAnsiChar; // 16KB hashing code
label nextCW;
begin
src_end := src+size;
// 1. retrieve out_len
result := pWord(src)^;
if result=0 then exit;
inc(src,2);
if result and $8000<>0 then begin
result := (result and $7fff) or (integer(pWord(src)^) shl 15);
inc(src,2);
end;
// 2. decompress
last_hashed := dst-1;
nextCW:
CW := pInteger(src)^;
inc(src,4);
CWbit := 1;
if src<src_end then
repeat
if CW and CWbit=0 then begin
dst^ := src^;
inc(src);
inc(dst);
if src>=src_end then break;
if last_hashed<dst-3 then begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
CWbit := CWbit shl 1;
if CWbit<>0 then
continue else
goto nextCW;
end else begin
h := pWord(src)^;
inc(src,2);
t := (h and 15)+2;
h := h shr 4;
if t=2 then begin
t := ord(src^)+(16+2);
inc(src);
end;
if dst-offset[h]<t then // avoid overlaping move() bug
movechars(offset[h],dst,t) else
move(offset[h]^,dst^,t);
if src>=src_end then break;
while last_hashed<dst do begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
inc(dst,t);
last_hashed := dst-1;
CWbit := CWbit shl 1;
if CWbit<>0 then
continue else
goto nextCW;
end;
until false;
end;
function SynLZdecompress1partial(src: PAnsiChar; size: integer; dst: PAnsiChar; maxDst: Integer): Integer;
var last_hashed: PAnsiChar; // initial src and dst value
src_end,dst_End: PAnsiChar;
CWbit: integer;
CW, v, t, h: integer;
offset: array[0..4095] of PAnsiChar; // 16KB hashing code
label nextCW;
begin
src_end := src+size;
// 1. retrieve out_len
result := pWord(src)^;
if result=0 then exit;
inc(src,2);
if result and $8000<>0 then begin
result := (result and $7fff) or (integer(pWord(src)^) shl 15);
inc(src,2);
end;
if maxDst<result then
result := maxDst;
if result<=0 then
exit; // nothing to decompress
dst_end := dst+result; // will also avoid any buffer overflow errors
// 2. decompress
last_hashed := dst-1;
nextCW:
CW := pInteger(src)^;
inc(src,4);
CWbit := 1;
if src<src_end then
repeat
if CW and CWbit=0 then begin
dst^ := src^;
inc(src);
inc(dst);
if (src>=src_end) or (dst>=dst_end) then break;
if last_hashed<dst-3 then begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
CWbit := CWbit shl 1;
if CWbit<>0 then
continue else
goto nextCW;
end else begin
h := pWord(src)^;
inc(src,2);
t := (h and 15)+2;
h := h shr 4;
if t=2 then begin
t := ord(src^)+(16+2);
inc(src);
end;
if dst+t>=dst_end then begin
movechars(offset[h],dst,dst_end-dst);
break;
end;
if dst-offset[h]<t then // avoid overlaping move() bug
movechars(offset[h],dst,t) else
move(offset[h]^,dst^,t);
if src>=src_end then break;
while last_hashed<dst do begin
inc(last_hashed);
v := pInteger(last_hashed)^;
offset[((v shr 12) xor v) and 4095] := last_hashed;
end;
inc(dst,t);
last_hashed := dst-1;
CWbit := CWbit shl 1;
if CWbit<>0 then
continue else
goto nextCW;
end;
until false;
end;
function SynLZcompress2(src: PAnsiChar; size: integer; dst: PAnsiChar): integer;
var dst_beg, // initial dst value
src_end, // real last byte available in src
src_endmatch, // last byte to try for hashing
o: pAnsiChar;
CWbit: byte;
CWpoint: PInteger;
h, v, cached: integer;
t, tmax, tdiff, i: integer;
offset: array[0..4095] of PAnsiChar; // 16KB+16KB=32KB hashing code
cache: array[0..4095] of integer;
label dotdiff;
begin
dst_beg := dst;
// 1. store in_len
if size>=$8000 then begin
pWord(dst)^ := $8000 or (size and $7fff);
pWord(dst+2)^ := size shr 15;
inc(dst,4);
end else begin
pWord(dst)^ := size ; // src<32768 -> stored as word, otherwise as integer
if size=0 then begin
result := 2;
exit;
end;
inc(dst,2);
end;
// 2. compress
src_end := src+size;
src_endmatch := src_end-(6+5);
CWbit := 0;
CWpoint := pointer(dst);
pInteger(dst)^ := 0;
inc(dst,sizeof(CWpoint^));
tdiff := 0;
fillchar(offset,sizeof(offset),0); // fast 16KB reset to 0
// 1. main loop to search using hash[]
if src<=src_endmatch then
repeat
v := pInteger(src)^;
h := ((v shr 12) xor v) and 4095;
o := offset[h];
offset[h] := src;
cached := v xor cache[h];
cache[h] := v;
if (cached and $00ffffff=0) and (o<>nil) and (src-o>2) then begin
// SetBit(CWpoint,CWbit);
// asm movzx eax,byte ptr CWbit; bts [CWpoint],eax; end
if tdiff<>0 then begin
dec(src,tdiff);
dotdiff:v := tdiff;
if v<=8 then begin
if CWBit+v>31 then begin
for i := CWBit to 31 do begin
dst^ := src^;
inc(dst);
inc(src);
end;
CWpoint := pointer(dst);
pInteger(dst)^ := 0;
inc(dst,4);
CWBit := (CWBit+v) and 31;
for i := 1 to CWBit do begin
dst^ := src^;
inc(dst);
inc(src);
end;
end else begin
inc(CWBit,v);
for i := 1 to v do begin
dst^ := src^;
inc(dst);
inc(src);
end;
end;
end else begin
CWpoint^ := CWpoint^ or (1 shl CWbit);
dec(v,9);
if v>15 then begin
v := 15; // v=9..24 -> h=0..15
dst^ := #$ff; // size=15 -> tdiff
end else
dst^ := ansichar((v shl 4) or 15); // size=15 -> tdiff
inc(dst);