Class CEZDecompressor

class CEZDecompressor : public CEZZStream;

Description

The CEZDecompressor class provides in-memory de-compression functions, including integrity checks of the compressed data. This version of the library supports only one compression / de-compression method (deflation / inflation). De-compression can be done in a single step (using CEZDecompressor::DecompressL(TDes8 &,const TDesC8 &)) if the buffers are large enough (for example if an input file is mmap'ed), or can be done by repeated calls of the CEZDecompressor::InflateL() function. The source data is de-compressed to the target buffer (both source and target contained within the buffer manager argument).

Derivation

• CBase - Base class for all classes to be instantiated on the heap.

• CEZZStream - Represents a zip stream

• CEZDecompressor - The CEZDecompressor class provides in-memory de-compression functions, including...

Members

Defined in CEZDecompressor:

• DecompressL(TDes8 &,const TDesC8 &)De-compresses the data in the given buffer
• EInflateDictionaryError
• EInflateInitlialiserError
• EInflateTerminated
• EInflateVersionError
• EMaxWBits
• InflateL()De-compress the data to the buffer in stages, return value indicates if the de-c...
• NewL(MEZBufferManager &,TInt)Creates a new CEZDecompressor object
• NewL(MEZBufferManager &,const TDesC8 &,TInt)Overload of CEZDecompressor constructor takes aDictionary argument
• NewLC(MEZBufferManager &,TInt)Creates a new CEZDecompressor object and leaves it on the CleanupStack
• NewLC(MEZBufferManager &,const TDesC8 &,TInt)Overload of CEZDecompressor constructor takes aDictionary argument
• ResetL(MEZBufferManager &)Resets the current de-compression operation, with the new buffer manager
• anonymousDecompression panic values
• anonymousWindow Bits - the base two logarithm of the window size (the size of the history...

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• Extension_(TUint,TAny *&,TAny *)Extension function
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

Inherited from CEZZStream:

• Adler32()constReturn the value of the uncompressed data
• AvailIn()constReturn the number of bytes available at the next input byte
• AvailOut()constReturn the remaining free space at next output byte target
• EBufError
• EDataError
• EStreamError
• EUnexpected
• EVersionError
• OutputDescriptor()constReturn a decriptor pointer to the output buffer
• Progress(TInt)constReturn the progress of the current operation - that is the percentage of bytes w...
• SetInput(const TDesC8 &)Set the stream's input buffer
• SetOutput(TDes8 &)Set the stream's output buffer
• TotalIn()constReturn the total number of input bytes read so far
• TotalOut()constReturn the total number of bytes output so far
• iOutputBufferLength
• iOutputPointer
• iStream

IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager &aInit, TInt aWindowBits=EMaxWBits);

Description

Creates a new CEZDecompressor object and leaves it on the CleanupStack

Parameters

MEZBufferManager &aInit buffer manager to handle both input and output buffers TInt aWindowBits the base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. Larger values of this parameter result in better compression at the expense of memory usage.

Return value

CEZDecompressor * the new CEZDecompressor object (on the CleanupStack)

IMPORT_C static CEZDecompressor* NewL(MEZBufferManager &aInit, TInt aWindowBits=EMaxWBits);

Description

Creates a new CEZDecompressor object

Parameters

MEZBufferManager &aInit buffer manager to handle both input and output buffers TInt aWindowBits the base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. Larger values of this parameter result in better compression at the expense of memory usage.

Return value

CEZDecompressor * the new CEZDecompressor object

IMPORT_C static CEZDecompressor* NewLC(MEZBufferManager &aInit, const TDesC8 &aDictionary, TInt aWindowBits=EMaxWBits);

Description

Overload of CEZDecompressor constructor takes aDictionary argument

Parameters

MEZBufferManager &aInit buffer manager to handle both input and output buffers const TDesC8 &aDictionary used to initialize the de-compression dictionary from the given byte sequence. The compressor and decompressor must use exactly the same dictionary. TInt aWindowBits the base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. Larger values of this parameter result in better compression at the expense of memory usage.

Return value

CEZDecompressor * the new CEZDecompressor object (on the CleanupStack)

IMPORT_C static CEZDecompressor* NewL(MEZBufferManager &aInit, const TDesC8 &aDictionary, TInt aWindowBits=EMaxWBits);

Description

Overload of CEZDecompressor constructor takes aDictionary argument

Parameters

MEZBufferManager &aInit buffer manager to handle both input and output buffers const TDesC8 &aDictionary used to initialize the de-compression dictionary from the given byte sequence. The compressor and decompressor must use exactly the same dictionary. TInt aWindowBits the base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. Larger values of this parameter result in better compression at the expense of memory usage.

Return value

CEZDecompressor * the new CEZDecompressor object

IMPORT_C void ResetL(MEZBufferManager &aInit);

Description

Resets the current de-compression operation, with the new buffer manager

Parameters

MEZBufferManager &aInit new buffer manager to handle the new input and output buffers

Leave codes

KEZlibErrStream There is a problem with the stream ... Any of the System wide error codes

IMPORT_C TBool InflateL();

Description

De-compress the data to the buffer in stages, return value indicates if the de-compression has finalised or if further calls are necessary

Return value

TBool ETrue if the function must be called again, EFalse if compression is finalised

Leave codes

KEZlibErrStream There is a problem with the stream KEZlibErrBuf There is a problem with the buffer KEZlibErrData There is a problem with the data KEZlibErrUnexpected Unexpected programming error ... Any of the System wide error codes

IMPORT_C static void DecompressL(TDes8 &aDestination, const TDesC8 &aSource);

Description

De-compresses the data in the given buffer

Parameters

TDes8 &aDestination the target buffer for the de-compressed data const TDesC8 &aSource the buffer containing the compressed data

Leave codes

KEZLibErrBuf There is a problem with the buffer KEZLIbErrData There is a problem with the data ... Any of the system wide error codes

n/a

Description

Decompression panic values

EInflateInitlialiserError EInflateVersionError EInflateTerminated EInflateDictionaryError

n/a

Description

Window Bits - the base two logarithm of the window size (the size of the history buffer)

EMaxWBits