H5Z: Compression Interface

Compression API Functions

HDF5 supports compression of raw data by compression methods built into the library or defined by an application. A compression method is associated with a dataset when the dataset is created and is applied independently to each storage chunk of the dataset. The dataset must use the H5D_CHUNKED storage layout.

The HDF5 library does not support compression for contiguous datasets because of the difficulty of implementing random access for partial I/O. Compact dataset compression is not supported because it would not produce significant results.

See Compression in the HDF5 User's Guide for further information.

Name: H5Zregister

Signature:

herr_t H5Zregister(H5Z_method_t method, const char *name, H5Z_func_tcfunc, H5Z_func_t ufunc )

Purpose:

Registers new compression and uncompression functions for a method specified by a method number.

Description:

H5Zregister registers new compression and uncompression functions for a method specified by a method number, method. name is used for debugging and may be the null pointer. Either or both of cfunc (the compression function) and ufunc (the uncompression method) may be null pointers.

The statistics associated with a method number are not reset by this function; they accumulate over the life of the library.

Parameters:

H5Z_method_t method

Number specifying compression method.

const char *name

Name associated with the method number.

H5Z_func_t cfunc

Compression method.

H5Z_func_t ufunc

Uncompression method.

Returns:

Returns a non-negative value if successful; otherwise returns a negative value.