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Diffstat (limited to 'src/H5Zpublic.h')
| -rw-r--r-- | src/H5Zpublic.h | 661 |
1 files changed, 536 insertions, 125 deletions
diff --git a/src/H5Zpublic.h b/src/H5Zpublic.h index 97da13c..709e5fd 100644 --- a/src/H5Zpublic.h +++ b/src/H5Zpublic.h @@ -21,201 +21,610 @@ /* Public headers needed by this file */ #include "H5public.h" -/* - * Filter identifiers. Values 0 through 255 are for filters defined by the - * HDF5 library. Values 256 through 511 are available for testing new - * filters. Subsequent values should be obtained from the HDF5 development - * team at help@hdfgroup.org. These values will never change because they - * appear in the HDF5 files. +/** + * \brief Filter identifiers + * + * \details Values 0 through 255 are for filters defined by the HDF5 library. + * Values 256 through 511 are available for testing new filters. + * Subsequent values should be obtained from the HDF5 development team + * at mailto:help@hdfgroup.org. These values will never change because + * they appear in the HDF5 files. */ typedef int H5Z_filter_t; /* Filter IDs */ -#define H5Z_FILTER_ERROR (-1) /*no filter */ -#define H5Z_FILTER_NONE 0 /*reserved indefinitely */ -#define H5Z_FILTER_DEFLATE 1 /*deflation like gzip */ -#define H5Z_FILTER_SHUFFLE 2 /*shuffle the data */ -#define H5Z_FILTER_FLETCHER32 3 /*fletcher32 checksum of EDC */ -#define H5Z_FILTER_SZIP 4 /*szip compression */ -#define H5Z_FILTER_NBIT 5 /*nbit compression */ -#define H5Z_FILTER_SCALEOFFSET 6 /*scale+offset compression */ -#define H5Z_FILTER_RESERVED 256 /*filter ids below this value are reserved for library use */ - -#define H5Z_FILTER_MAX 65535 /*maximum filter id */ +/** + * no filter + */ +#define H5Z_FILTER_ERROR (-1) +/** + * reserved indefinitely +*/ +#define H5Z_FILTER_NONE 0 +/** + * deflation like gzip + */ +#define H5Z_FILTER_DEFLATE 1 +/** + * shuffle the data + */ +#define H5Z_FILTER_SHUFFLE 2 +/** + * fletcher32 checksum of EDC +*/ +#define H5Z_FILTER_FLETCHER32 3 +/** + * szip compression + */ +#define H5Z_FILTER_SZIP 4 +/** + * nbit compression + */ +#define H5Z_FILTER_NBIT 5 +/** + * scale+offset compression + */ +#define H5Z_FILTER_SCALEOFFSET 6 +/** + * filter ids below this value are reserved for library use + */ +#define H5Z_FILTER_RESERVED 256 +/** + * maximum filter id + */ +#define H5Z_FILTER_MAX 65535 /* General macros */ -#define H5Z_FILTER_ALL 0 /* Symbol to remove all filters in H5Premove_filter */ -#define H5Z_MAX_NFILTERS 32 /* Maximum number of filters allowed in a pipeline */ - /* (should probably be allowed to be an - * unlimited amount, but currently each - * filter uses a bit in a 32-bit field, - * so the format would have to be - * changed to accommodate that) - */ +/** + * Symbol to remove all filters in H5Premove_filter() + */ +#define H5Z_FILTER_ALL 0 +/** + * Maximum number of filters allowed in a pipeline + * + * \internal (should probably be allowed to be an unlimited amount, but + * currently each filter uses a bit in a 32-bit field, so the format + * would have to be changed to accommodate that) + */ +#define H5Z_MAX_NFILTERS 32 /* Flags for filter definition (stored) */ -#define H5Z_FLAG_DEFMASK 0x00ff /*definition flag mask */ -#define H5Z_FLAG_MANDATORY 0x0000 /*filter is mandatory */ -#define H5Z_FLAG_OPTIONAL 0x0001 /*filter is optional */ +/** + * definition flag mask + */ +#define H5Z_FLAG_DEFMASK 0x00ff +/** + * filter is mandatory + */ +#define H5Z_FLAG_MANDATORY 0x0000 +/** + * filter is optional + */ +#define H5Z_FLAG_OPTIONAL 0x0001 /* Additional flags for filter invocation (not stored) */ -#define H5Z_FLAG_INVMASK 0xff00 /*invocation flag mask */ -#define H5Z_FLAG_REVERSE 0x0100 /*reverse direction; read */ -#define H5Z_FLAG_SKIP_EDC 0x0200 /*skip EDC filters for read */ +/** + * invocation flag mask + */ +#define H5Z_FLAG_INVMASK 0xff00 +/** + * reverse direction; read + */ +#define H5Z_FLAG_REVERSE 0x0100 +/** + * skip EDC filters for read + */ +#define H5Z_FLAG_SKIP_EDC 0x0200 /* Special parameters for szip compression */ /* [These are aliases for the similar definitions in szlib.h, which we can't * include directly due to the duplication of various symbols with the zlib.h * header file] */ -#define H5_SZIP_ALLOW_K13_OPTION_MASK 1 -#define H5_SZIP_CHIP_OPTION_MASK 2 -#define H5_SZIP_EC_OPTION_MASK 4 -#define H5_SZIP_NN_OPTION_MASK 32 -#define H5_SZIP_MAX_PIXELS_PER_BLOCK 32 +/** + * \ingroup SZIP */ +#define H5_SZIP_ALLOW_K13_OPTION_MASK 1 +/** + * \ingroup SZIP */ +#define H5_SZIP_CHIP_OPTION_MASK 2 +/** + * \ingroup SZIP */ +#define H5_SZIP_EC_OPTION_MASK 4 +/** + * \ingroup SZIP */ +#define H5_SZIP_NN_OPTION_MASK 32 +/** + * \ingroup SZIP */ +#define H5_SZIP_MAX_PIXELS_PER_BLOCK 32 /* Macros for the shuffle filter */ -#define H5Z_SHUFFLE_USER_NPARMS 0 /* Number of parameters that users can set */ -#define H5Z_SHUFFLE_TOTAL_NPARMS 1 /* Total number of parameters for filter */ +/** + * \ingroup SHUFFLE + * Number of parameters that users can set for the shuffle filter +*/ +#define H5Z_SHUFFLE_USER_NPARMS 0 +/** + * \ingroup SHUFFLE + * Total number of parameters for the shuffle filter + */ +#define H5Z_SHUFFLE_TOTAL_NPARMS 1 /* Macros for the szip filter */ -#define H5Z_SZIP_USER_NPARMS 2 /* Number of parameters that users can set */ -#define H5Z_SZIP_TOTAL_NPARMS 4 /* Total number of parameters for filter */ -#define H5Z_SZIP_PARM_MASK 0 /* "User" parameter for option mask */ -#define H5Z_SZIP_PARM_PPB 1 /* "User" parameter for pixels-per-block */ -#define H5Z_SZIP_PARM_BPP 2 /* "Local" parameter for bits-per-pixel */ -#define H5Z_SZIP_PARM_PPS 3 /* "Local" parameter for pixels-per-scanline */ +/** + * \ingroup SZIP + * Number of parameters that users can set for SZIP + */ +#define H5Z_SZIP_USER_NPARMS 2 +/** + * \ingroup SZIP + * Total number of parameters for SZIP filter + */ +#define H5Z_SZIP_TOTAL_NPARMS 4 +/** + * \ingroup SZIP + * "User" parameter for option mask + */ +#define H5Z_SZIP_PARM_MASK 0 +/** + * \ingroup SZIP + * "User" parameter for pixels-per-block + */ +#define H5Z_SZIP_PARM_PPB 1 +/** + * \ingroup SZIP + * "Local" parameter for bits-per-pixel + */ +#define H5Z_SZIP_PARM_BPP 2 +/** + * \ingroup SZIP + * "Local" parameter for pixels-per-scanline + */ +#define H5Z_SZIP_PARM_PPS 3 /* Macros for the nbit filter */ -#define H5Z_NBIT_USER_NPARMS 0 /* Number of parameters that users can set */ +/** + * \ingroup NBIT + * Number of parameters that users can set for the N-bit filter + */ +#define H5Z_NBIT_USER_NPARMS 0 /* Number of parameters that users can set */ /* Macros for the scale offset filter */ -#define H5Z_SCALEOFFSET_USER_NPARMS 2 /* Number of parameters that users can set */ +/** + * \ingroup SCALEOFFSET + * Number of parameters that users can set for the scale-offset filter + */ +#define H5Z_SCALEOFFSET_USER_NPARMS 2 + /* Special parameters for ScaleOffset filter*/ +/** + * \ingroup SCALEOFFSET */ #define H5Z_SO_INT_MINBITS_DEFAULT 0 +/** + * \ingroup SCALEOFFSET */ typedef enum H5Z_SO_scale_type_t { H5Z_SO_FLOAT_DSCALE = 0, H5Z_SO_FLOAT_ESCALE = 1, H5Z_SO_INT = 2 } H5Z_SO_scale_type_t; -/* Current version of the H5Z_class_t struct */ +/** + * Current version of the H5Z_class_t struct + */ #define H5Z_CLASS_T_VERS (1) -/* Values to decide if EDC is enabled for reading data */ +/** + * \ingroup FLETCHER32 + * Values to decide if EDC is enabled for reading data + */ typedef enum H5Z_EDC_t { - H5Z_ERROR_EDC = -1, /* error value */ - H5Z_DISABLE_EDC = 0, - H5Z_ENABLE_EDC = 1, - H5Z_NO_EDC = 2 /* must be the last */ + H5Z_ERROR_EDC = -1, /**< error value */ + H5Z_DISABLE_EDC = 0, + H5Z_ENABLE_EDC = 1, + H5Z_NO_EDC = 2 /**< sentinel */ } H5Z_EDC_t; /* Bit flags for H5Zget_filter_info */ #define H5Z_FILTER_CONFIG_ENCODE_ENABLED (0x0001) #define H5Z_FILTER_CONFIG_DECODE_ENABLED (0x0002) -/* Return values for filter callback function */ +/** + * Return values for filter callback function + */ typedef enum H5Z_cb_return_t { - H5Z_CB_ERROR = -1, - H5Z_CB_FAIL = 0, /* I/O should fail if filter fails. */ - H5Z_CB_CONT = 1, /* I/O continues if filter fails. */ - H5Z_CB_NO = 2 + H5Z_CB_ERROR = -1, + H5Z_CB_FAIL = 0, /**< I/O should fail if filter fails. */ + H5Z_CB_CONT = 1, /**< I/O continues if filter fails. */ + H5Z_CB_NO = 2 } H5Z_cb_return_t; -/* Filter callback function definition */ -typedef H5Z_cb_return_t (*H5Z_filter_func_t)(H5Z_filter_t filter, void *buf, size_t buf_size, void *op_data); +/** + * Filter callback function definition + */ +typedef H5Z_cb_return_t (*H5Z_filter_func_t)(H5Z_filter_t filter, void* buf, + size_t buf_size, void* op_data); -/* Structure for filter callback property */ +/** + * Structure for filter callback property + */ typedef struct H5Z_cb_t { - H5Z_filter_func_t func; - void * op_data; + H5Z_filter_func_t func; + void *op_data; } H5Z_cb_t; #ifdef __cplusplus extern "C" { #endif -/* - * Before a dataset gets created, the "can_apply" callbacks for any filters used - * in the dataset creation property list are called - * with the dataset's dataset creation property list, the dataset's datatype and - * a dataspace describing a chunk (for chunked dataset storage). +/** + * \details Before a dataset gets created, the \c can_apply callbacks for any + * filters used in the dataset creation property list are called with + * the dataset's dataset creation property list, the dataset's + * datatype and a dataspace describing a chunk (for chunked dataset + * storage). * - * The "can_apply" callback must determine if the combination of the dataset - * creation property list setting, the datatype and the dataspace represent a - * valid combination to apply this filter to. For example, some cases of - * invalid combinations may involve the filter not operating correctly on - * certain datatypes (or certain datatype sizes), or certain sizes of the chunk - * dataspace. + * The \c can_apply callback must determine if the combination of the + * dataset creation property list setting, the datatype and the + * dataspace represent a valid combination to apply this filter to. + * For example, some cases of invalid combinations may involve the + * filter not operating correctly on certain datatypes (or certain + * datatype sizes), or certain sizes of the chunk dataspace. * - * The "can_apply" callback can be the NULL pointer, in which case, the library - * will assume that it can apply to any combination of dataset creation - * property list values, datatypes and dataspaces. + * The \c can_apply callback can be the NULL pointer, in which case, + * the library will assume that it can apply to any combination of + * dataset creation property list values, datatypes and dataspaces. * - * The "can_apply" callback returns positive a valid combination, zero for an - * invalid combination and negative for an error. + * The \c can_apply callback returns positive a valid combination, + * zero for an invalid combination and negative for an error. */ +//! [H5Z_can_apply_func_t_snip] typedef htri_t (*H5Z_can_apply_func_t)(hid_t dcpl_id, hid_t type_id, hid_t space_id); - -/* - * After the "can_apply" callbacks are checked for new datasets, the "set_local" - * callbacks for any filters used in the dataset creation property list are - * called. These callbacks receive the dataset's private copy of the dataset - * creation property list passed in to H5Dcreate (i.e. not the actual property - * list passed in to H5Dcreate) and the datatype ID passed in to H5Dcreate - * (which is not copied and should not be modified) and a dataspace describing - * the chunk (for chunked dataset storage) (which should also not be modified). +//! [H5Z_can_apply_func_t_snip] +/** + * \details After the "can_apply" callbacks are checked for new datasets, the + * \c set_local callbacks for any filters used in the dataset creation + * property list are called. These callbacks receive the dataset's + * private copy of the dataset creation property list passed in to + * H5Dcreate() (i.e. not the actual property list passed in to + * H5Dcreate()) and the datatype ID passed in to H5Dcreate() (which is + * not copied and should not be modified) and a dataspace describing + * the chunk (for chunked dataset storage) (which should also not be + * modified). * - * The "set_local" callback must set any parameters that are specific to this - * dataset, based on the combination of the dataset creation property list - * values, the datatype and the dataspace. For example, some filters perform - * different actions based on different datatypes (or datatype sizes) or - * different number of dimensions or dataspace sizes. + * The \c set_local callback must set any parameters that are specific + * to this dataset, based on the combination of the dataset creation + * property list values, the datatype and the dataspace. For example, + * some filters perform different actions based on different datatypes + * (or datatype sizes) or different number of dimensions or dataspace + * sizes. * - * The "set_local" callback can be the NULL pointer, in which case, the library - * will assume that there are no dataset-specific settings for this filter. + * The \c set_local callback can be the NULL pointer, in which case, + * the library will assume that there are no dataset-specific settings + * for this filter. * - * The "set_local" callback must return non-negative on success and negative - * for an error. + * The \c set_local callback must return non-negative on success and + * negative for an error. */ +//! [H5Z_set_local_func_t_snip] typedef herr_t (*H5Z_set_local_func_t)(hid_t dcpl_id, hid_t type_id, hid_t space_id); - -/* - * A filter gets definition flags and invocation flags (defined above), the - * client data array and size defined when the filter was added to the - * pipeline, the size in bytes of the data on which to operate, and pointers - * to a buffer and its allocated size. +//! [H5Z_set_local_func_t_snip] +/** + * \details A filter gets definition flags and invocation flags (defined + * above), the client data array and size defined when the filter was + * added to the pipeline, the size in bytes of the data on which to + * operate, and pointers to a buffer and its allocated size. * - * The filter should store the result in the supplied buffer if possible, - * otherwise it can allocate a new buffer, freeing the original. The - * allocated size of the new buffer should be returned through the BUF_SIZE - * pointer and the new buffer through the BUF pointer. + * The filter should store the result in the supplied buffer if + * possible, otherwise it can allocate a new buffer, freeing the + * original. The allocated size of the new buffer should be returned + * through the \p buf_size pointer and the new buffer through the \p + * buf pointer. * - * The return value from the filter is the number of bytes in the output - * buffer. If an error occurs then the function should return zero and leave - * all pointer arguments unchanged. + * The return value from the filter is the number of bytes in the + * output buffer. If an error occurs then the function should return + * zero and leave all pointer arguments unchanged. */ +//! [H5Z_func_t_snip] typedef size_t (*H5Z_func_t)(unsigned int flags, size_t cd_nelmts, const unsigned int cd_values[], size_t nbytes, size_t *buf_size, void **buf); - -/* +//! [H5Z_func_t_snip] +/** * The filter table maps filter identification numbers to structs that * contain a pointers to the filter function and timing statistics. */ +//! [H5Z_class2_t_snip] typedef struct H5Z_class2_t { - int version; /* Version number of the H5Z_class_t struct */ - H5Z_filter_t id; /* Filter ID number */ - unsigned encoder_present; /* Does this filter have an encoder? */ - unsigned decoder_present; /* Does this filter have a decoder? */ - const char * name; /* Comment for debugging */ - H5Z_can_apply_func_t can_apply; /* The "can apply" callback for a filter */ - H5Z_set_local_func_t set_local; /* The "set local" callback for a filter */ - H5Z_func_t filter; /* The actual filter function */ + int version; /**< Version number of the H5Z_class_t struct */ + H5Z_filter_t id; /**< Filter ID number */ + unsigned encoder_present; /**< Does this filter have an encoder? */ + unsigned decoder_present; /**< Does this filter have a decoder? */ + const char *name; /**< Comment for debugging */ + H5Z_can_apply_func_t can_apply; /**< The "can apply" callback for a filter */ + H5Z_set_local_func_t set_local; /**< The "set local" callback for a filter */ + H5Z_func_t filter; /**< The actual filter function */ } H5Z_class2_t; +//! [H5Z_class2_t_snip] +/** + * \ingroup H5Z + * + * \brief Registers a new filter with the HDF5 library + * + * \param[in] cls A pointer to a buffer for the struct containing the + * filter-definition + * + * \return \herr_t + * + * \details H5Zregister() registers a new filter with the HDF5 library. + * + * \details Making a new filter available to an application is a two-step + * process. The first step is to write the three filter callback + * functions described below: \c can_apply, \c set_local, and \c + * filter. This call to H5Zregister(), registering the filter with the + * library, is the second step. The can_apply and set_local fields can + * be set to NULL if they are not required for the filter being + * registered. + * + * H5Zregister() accepts a single parameter, a pointer to a buffer for + * the \p cls data structure. That data structure must conform to one + * of the following definitions: + * \snippet this H5Z_class1_t_snip + * or + * \snippet this H5Z_class2_t_snip + * + * \c version is a library-defined value reporting the version number + * of the #H5Z_class_t struct. This currently must be set to + * #H5Z_CLASS_T_VERS. + * + * \c id is the identifier for the new filter. This is a user-defined + * value between #H5Z_FILTER_RESERVED and #H5Z_FILTER_MAX. These + * values are defined in the HDF5 source file H5Zpublic.h, but the + * symbols #H5Z_FILTER_RESERVED and #H5Z_FILTER_MAX should always be + * used instead of the literal values. + * + * \c encoder_present is a library-defined value indicating whether + * the filter’s encoding capability is available to the application. + * + * \c decoder_present is a library-defined value indicating whether + * the filter’s encoding capability is available to the application. + * + * \c name is a descriptive comment used for debugging, may contain a + * descriptive name for the filter, and may be the null pointer. + * + * \c can_apply, described in detail below, is a user-defined callback + * function which determines whether the combination of the dataset + * creation property list values, the datatype, and the dataspace + * represent a valid combination to apply this filter to. + * + * \c set_local, described in detail below, is a user-defined callback + * function which sets any parameters that are specific to this + * dataset, based on the combination of the dataset creation property + * list values, the datatype, and the dataspace. + * + * \c filter, described in detail below, is a user-defined callback + * function which performs the action of the filter. + * + * The statistics associated with a filter are not reset by this + * function; they accumulate over the life of the library. + * + * #H5Z_class_t is a macro which maps to either H5Z_class1_t or + * H5Z_class2_t, depending on the needs of the application. To affect + * only this macro, H5Z_class_t_vers may be defined to either 1 or 2. + * Otherwise, it will behave in the same manner as other API + * compatibility macros. See API Compatibility Macros in HDF5 for more + * information. H5Z_class1_t matches the #H5Z_class_t structure that is + * used in the 1.6.x versions of the HDF5 library. + * + * H5Zregister() will automatically detect which structure type has + * been passed in, regardless of the mapping of the #H5Z_class_t macro. + * However, the application must make sure that the fields are filled + * in according to the correct structure definition if the macro is + * used to declare the structure. + * + * \Bold{The callback functions:}\n Before H5Zregister() can link a + * filter into an application, three callback functions must be + * defined as described in the HDF5 library header file H5Zpublic.h. + * + * When a filter is applied to the fractal heap for a group (e.g., + * when compressing group metadata) and if the can apply and set local + * callback functions have been defined for that filter, HDF5 passes + * the value -1 for all parameters for those callback functions. This + * is done to ensure that the filter will not be applied to groups if + * it relies on these parameters, as they are not applicable to group + * fractal heaps; to operate on group fractal heaps, a filter must be + * capable of operating on an opaque block of binary data. + * + * The \Emph{can apply} callback function must return a positive value + * for a valid combination, zero for an invalid combination, and a + * negative value for an error. + * \snippet this H5Z_can_apply_func_t_snip + * + * Before a dataset is created, the \Emph{can apply} callbacks for any + * filters used in the dataset creation property list are called with + * the dataset's dataset creation property list, \c dcpl_id, the + * dataset's datatype, \p type_id, and a dataspace describing a chunk, + * \p space_id, (for chunked dataset storage). + * + * This callback must determine whether the combination of the dataset + * creation property list settings, the datatype, and the dataspace + * represent a valid combination to which to apply this filter. For + * example, an invalid combination may involve the filter not + * operating correctly on certain datatypes, on certain datatype + * sizes, or on certain sizes of the chunk dataspace. If this filter + * is enabled through H5Pset_filter() as optional and the can apply + * function returns 0, the library will skip the filter in the filter + * pipeline. + * + * This callback can be the NULL pointer, in which case the library + * will assume that the filter can be applied to a dataset with any + * combination of dataset creation property list values, datatypes, + * and dataspaces. + * + * The \Emph{set local} callback function is defined as follows: + * \snippet this H5Z_set_local_func_t_snip + * + * After the can apply callbacks are checked for a new dataset, the + * \Emph{set local} callback functions for any filters used in the + * dataset creation property list are called. These callbacks receive + * \c dcpl_id, the dataset's private copy of the dataset creation + * property list passed in to H5Dcreate() (i.e. not the actual + * property list passed in to H5Dcreate()); \c type_id, the datatype + * identifier passed in to H5Dcreate(), which is not copied and should + * not be modified; and \c space_id, a dataspace describing the chunk + * (for chunked dataset storage), which should also not be modified. + * + * The set local callback must set any filter parameters that are + * specific to this dataset, based on the combination of the dataset + * creation property list values, the datatype, and the dataspace. For + * example, some filters perform different actions based on different + * datatypes, datatype sizes, numbers of dimensions, or dataspace + * sizes. + * + * The \Emph{set local} callback may be the NULL pointer, in which + * case, the library will assume that there are no dataset-specific + * settings for this filter. + * + * The \Emph{set local} callback function must return a non-negative + * value on success and a negative value for an error. + * + * The \Emph{filter operation} callback function, defining the + * filter's operation on the data, is defined as follows: + * \snippet this H5Z_func_t_snip + * + * The parameters \c flags, \c cd_nelmts, and \c cd_values are the + * same as for the function H5Pset_filter(). The one exception is that + * an additional flag, #H5Z_FLAG_REVERSE, is set when the filter is + * called as part of the input pipeline. + * + * The parameter \c buf points to the input buffer which has a size of + * \c buf_size bytes, \c nbytes of which are valid data. + * + * The filter should perform the transformation in place if possible. + * If the transformation cannot be done in place, then the filter + * should allocate a new buffer with malloc() and assign it to \c buf, + * assigning the allocated size of that buffer to \c buf_size. The old + * buffer should be freed by calling free(). + * + * If successful, the \Emph{filter operation} callback function + * returns the number of valid bytes of data contained in \c buf. In + * the case of failure, the return value is 0 (zero) and all pointer + * arguments are left unchanged. + * + * \version 1.8.6 Return type for the \Emph{can apply} callback function, + * \ref H5Z_can_apply_func_t, changed to \ref htri_t. + * \version 1.8.5 Semantics of the \Emph{can apply} and \Emph{set local} + * callback functions changed to accommodate the use of filters + * with group fractal heaps. + * \version 1.8.3 #H5Z_class_t renamed to H5Z_class2_t, H5Z_class1_t structure + * introduced for backwards compatibility with release 1.6.x, + * and #H5Z_class_t macro introduced in this release. Function + * modified to accept either structure type. + * \version 1.8.0 The fields \c version, \c encoder_present, and + * \c decoder_present were added to the #H5Z_class_t \c struct + * in this release. + * \version 1.6.0 This function was substantially revised in Release 1.6.0 with + * a new #H5Z_class_t struct and new set local and can apply + * callback functions. + * + */ H5_DLL herr_t H5Zregister(const void *cls); +/** + * \ingroup H5Z + * + * \brief Unregisters a filter. + * + * \param[in] id Identifier of the filter to be unregistered. + * \return \herr_t + * + * \details H5Zunregister() unregisters the filter specified in \p id. + * + * \details This function first iterates through all opened datasets and + * groups. If an open object that uses this filter is found, the + * function will fail with a message indicating that an object using + * the filter is still open. All open files are then flushed to make + * sure that all cached data that may use this filter are written out. + * + * If the application is a parallel program, all processes that + * participate in collective data write should call this function to + * ensure that all data is flushed. + * + * After a call to H5Zunregister(), the filter specified in filter + * will no longer be available to the application. + * + * \version 1.8.12 Function modified to check for open objects using the + * filter. + * \since 1.6.0 + */ H5_DLL herr_t H5Zunregister(H5Z_filter_t id); +/** + * \ingroup H5Z + * + * \brief Determines whether a filter is available + * + * \param[in] id Filter identifier + * \return \htri_t + * + * \details H5Zfilter_avail() determines whether the filter specified in \p id + * is available to the application. + * + * \since 1.6.0 + */ H5_DLL htri_t H5Zfilter_avail(H5Z_filter_t id); +/** + * \ingroup H5Z + * + * \brief Retrieves information about a filter + * + * \param[in] filter Filter identifier + * \param[out] filter_config_flags A bit field encoding the returned filter + * information + * \return \herr_t + * + * \details H5Zget_filter_info() retrieves information about a filter. At + * present, this means that the function retrieves a filter's + * configuration flags, indicating whether the filter is configured to + * decode data, to encode data, neither, or both. + * + * If \p filter_config_flags is not set to NULL prior to the function + * call, the returned parameter contains a bit field specifying the + * available filter configuration. The configuration flag values can + * then be determined through a series of bitwise AND operations, as + * described below. + * + * Valid filter configuration flags include the following: + * <table> + * <tr><td>#H5Z_FILTER_CONFIG_ENCODE_ENABLED</td> + * <td>Encoding is enabled for this filter</td></tr> + * <tr><td>#H5Z_FILTER_CONFIG_DECODE_ENABLED</td> + * <td>Decoding is enabled for this filter</td></tr> + * </table> + * + * A bitwise AND of the returned \p filter_config_flags and a valid + * filter configuration flag will reveal whether the related + * configuration option is available. For example, if the value of + * \code + * H5Z_FILTER_CONFIG_ENCODE_ENABLED & filter_config_flags + * \endcode + * is true, i.e., greater than 0 (zero), the queried filter + * is configured to encode data; if the value is \c FALSE, i.e., equal to + * 0 (zero), the filter is not so configured. + * + * If a filter is not encode-enabled, the corresponding \c H5Pset_* + * function will return an error if the filter is added to a dataset + * creation property list (which is required if the filter is to be + * used to encode that dataset). For example, if the + * #H5Z_FILTER_CONFIG_ENCODE_ENABLED flag is not returned for the SZIP + * filter, #H5Z_FILTER_SZIP, a call to H5Pset_szip() will fail. + * + * If a filter is not decode-enabled, the application will not be able + * to read an existing file encoded with that filter. + * + * This function should be called, and the returned \p + * filter_config_flags analyzed, before calling any other function, + * such as H5Pset_szip() , that might require a particular filter + * configuration. + * + * \since 1.6.3 + */ H5_DLL herr_t H5Zget_filter_info(H5Z_filter_t filter, unsigned int *filter_config_flags); /* Symbols defined for compatibility with previous versions of the HDF5 API. @@ -224,17 +633,19 @@ H5_DLL herr_t H5Zget_filter_info(H5Z_filter_t filter, unsigned int *filter_confi */ #ifndef H5_NO_DEPRECATED_SYMBOLS -/* +/** * The filter table maps filter identification numbers to structs that * contain a pointers to the filter function and timing statistics. */ +//! [H5Z_class1_t_snip] typedef struct H5Z_class1_t { - H5Z_filter_t id; /* Filter ID number */ - const char * name; /* Comment for debugging */ - H5Z_can_apply_func_t can_apply; /* The "can apply" callback for a filter */ - H5Z_set_local_func_t set_local; /* The "set local" callback for a filter */ - H5Z_func_t filter; /* The actual filter function */ + H5Z_filter_t id; /**< Filter ID number */ + const char *name; /**< Comment for debugging */ + H5Z_can_apply_func_t can_apply; /**< The "can apply" callback for a filter */ + H5Z_set_local_func_t set_local; /**< The "set local" callback for a filter */ + H5Z_func_t filter; /**< The actual filter function */ } H5Z_class1_t; +//! [H5Z_class1_t_snip] #endif /* H5_NO_DEPRECATED_SYMBOLS */ |