Difference between revisions of "LMD VCL - ZLib support"
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| + | {{Head-StartRes}} | ||
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== Introduction == | == Introduction == | ||
| − | LMD | + | Since 2007 series the LMD shared Runtime provides built-in ZLib library to compress/decompress any data. This is a native pascal solution and it doesn't require any external obj or dll files. |
== Units == | == Units == | ||
| − | LMDZCommonUnit.pas - Common code and types for compress/decompress routines | + | * LMDZCommonUnit.pas - Common code and types for compress/decompress routines (raw ZLib api) |
| − | LMDZCompressUnit.pas - Unit that contain compression code (raw ZLib api) | + | * LMDZCompressUnit.pas - Unit that contain compression code (raw ZLib api) |
| − | LMDZUncompressUnit.pas - Unit with uncompression code (raw ZLib api) | + | * LMDZUncompressUnit.pas - Unit with uncompression code (raw ZLib api) |
| − | LMDZLib.pas - TStream wrappers that provide interface to compress/decompress data directly into any TStream descendants. | + | * LMDZLib.pas - TStream wrappers that provide interface to compress/decompress data directly into any TStream descendants. |
== LMDZLib interface == | == LMDZLib interface == | ||
| Line 15: | Line 17: | ||
..., LMDZLib, ...; | ..., LMDZLib, ...; | ||
| − | // | + | // code before using TLMDCompressionStream |
... | ... | ||
var | var | ||
| Line 39: | Line 41: | ||
LDataStream := TLMDCompressionStream.Create(clDefault, LFileStream); | LDataStream := TLMDCompressionStream.Create(clDefault, LFileStream); | ||
try | try | ||
| − | LDataStream(FSomeData, FSizeOfSomeData); | + | LDataStream.Write(FSomeData, FSizeOfSomeData); |
| + | finally | ||
| + | LDestStream.Free; | ||
| + | end; | ||
| + | finally | ||
| + | LFileStream.Free; | ||
| + | end; | ||
| + | end; | ||
| + | ... | ||
| + | </delphi> | ||
| + | |||
| + | TLMDDecompressionStream can be used as decompression layer for stream with compressed data. Example: | ||
| + | |||
| + | <delphi> | ||
| + | uses | ||
| + | ..., LMDZLib, ...; | ||
| + | |||
| + | // code before using TLMDDecompressionStream | ||
| + | ... | ||
| + | var | ||
| + | LDataStream: TFileStream; | ||
| + | begin | ||
| + | LDataStream := TFileStream.Create(FileName, fmOpenRead); | ||
| + | try | ||
| + | LDataStream.Read(FSomeData, FSizeOfSomeData); | ||
| + | finally | ||
| + | LDataStream.Free; | ||
| + | end; | ||
| + | end; | ||
| + | ... | ||
| + | |||
| + | // code with TLMDDecompressionStream | ||
| + | ... | ||
| + | var | ||
| + | LDataStream: TLMDDecompressionStream; | ||
| + | LFileStream: TFileStream; | ||
| + | begin | ||
| + | LFileStream := TFileStream.Create(FileName, fmOpenRead); | ||
| + | try | ||
| + | LDataStream := TLMDDecompressionStream.Create(LFileStream); | ||
| + | try | ||
| + | LDataStream.Read(FSomeData, FSizeOfSomeData); | ||
finally | finally | ||
LDestStream.Free; | LDestStream.Free; | ||
| Line 49: | Line 92: | ||
... | ... | ||
</delphi> | </delphi> | ||
| + | |||
| + | As you can note required changes in your code are minimal. | ||
Latest revision as of 13:52, 5 October 2008
<< Back to Getting started or Product Resources page
Introduction
Since 2007 series the LMD shared Runtime provides built-in ZLib library to compress/decompress any data. This is a native pascal solution and it doesn't require any external obj or dll files.
Units
- LMDZCommonUnit.pas - Common code and types for compress/decompress routines (raw ZLib api)
- LMDZCompressUnit.pas - Unit that contain compression code (raw ZLib api)
- LMDZUncompressUnit.pas - Unit with uncompression code (raw ZLib api)
- LMDZLib.pas - TStream wrappers that provide interface to compress/decompress data directly into any TStream descendants.
LMDZLib interface
TLMDCompressionStream wrapper class that compress data directly to any TStream descendant, and has transparent interface that compatible with TStream, so you can easily add compression for exists application. Example:
<delphi> uses
..., LMDZLib, ...;
// code before using TLMDCompressionStream ... var
LDataStream: TFileStream;
begin
LDataStream := TFileStream.Create(FileName, fmCreate); try LDataStream(FSomeData, FSizeOfSomeData); finally LDataStream.Free; end;
end; ...
// code with TLMDCompressionStream ... var
LDataStream: TLMDCompressionStream; LFileStream: TFileStream;
begin
LFileStream := TFileStream.Create(FileName, fmCreate);
try
LDataStream := TLMDCompressionStream.Create(clDefault, LFileStream);
try
LDataStream.Write(FSomeData, FSizeOfSomeData);
finally
LDestStream.Free;
end;
finally
LFileStream.Free;
end;
end; ... </delphi>
TLMDDecompressionStream can be used as decompression layer for stream with compressed data. Example:
<delphi> uses
..., LMDZLib, ...;
// code before using TLMDDecompressionStream ... var
LDataStream: TFileStream;
begin
LDataStream := TFileStream.Create(FileName, fmOpenRead); try LDataStream.Read(FSomeData, FSizeOfSomeData); finally LDataStream.Free; end;
end; ...
// code with TLMDDecompressionStream ... var
LDataStream: TLMDDecompressionStream; LFileStream: TFileStream;
begin
LFileStream := TFileStream.Create(FileName, fmOpenRead);
try
LDataStream := TLMDDecompressionStream.Create(LFileStream);
try
LDataStream.Read(FSomeData, FSizeOfSomeData);
finally
LDestStream.Free;
end;
finally
LFileStream.Free;
end;
end; ... </delphi>
As you can note required changes in your code are minimal.
