python3-h5py 2.2.1-1build2 / usr / lib / python3 / dist-packages / h5py / h5p.pyx

# This file is part of h5py, a Python interface to the HDF5 library.
#
# http://www.h5py.org
#
# Copyright 2008-2013 Andrew Collette and contributors
#
# License:  Standard 3-clause BSD; see "license.txt" for full license terms
#           and contributor agreement.

"""
    HDF5 property list interface.
"""

include "config.pxi"

# Compile-time imports
from utils cimport  require_tuple, convert_dims, convert_tuple, \
                    emalloc, efree, \
                    check_numpy_write, check_numpy_read
from numpy cimport ndarray, import_array
from h5t cimport TypeID, py_create
from h5ac cimport CacheConfig
from h5py import _objects

# Initialization
import_array()

# === C API ===================================================================

cdef hid_t pdefault(PropID pid):

    if pid is None:
        return <hid_t>H5P_DEFAULT
    return pid.id

cdef object propwrap(hid_t id_in):

    clsid = H5Pget_class(id_in)
    try:
        if H5Pequal(clsid, H5P_FILE_CREATE):
            pcls = PropFCID
        elif H5Pequal(clsid, H5P_FILE_ACCESS):
            pcls = PropFAID
        elif H5Pequal(clsid, H5P_DATASET_CREATE):
            pcls = PropDCID
        elif H5Pequal(clsid, H5P_DATASET_XFER):
            pcls = PropDXID
        elif H5Pequal(clsid, H5P_OBJECT_COPY):
            pcls = PropCopyID
        elif H5Pequal(clsid, H5P_LINK_CREATE):
            pcls = PropLCID
        elif H5Pequal(clsid, H5P_LINK_ACCESS):
            pcls = PropLAID
        elif H5Pequal(clsid, H5P_GROUP_CREATE):
            pcls = PropGCID
        elif H5Pequal(clsid, H5P_DATASET_ACCESS):
            pcls = PropDAID
        elif H5Pequal(clsid, H5P_OBJECT_CREATE):
            pcls = PropOCID

        else:
            raise ValueError("No class found for ID %d" % id_in)

        return pcls.open(id_in)
    finally:
        H5Pclose_class(clsid)

cdef object lockcls(hid_t id_in):
    cdef PropClassID pid
    pid = PropClassID.open(id_in)
    pid.locked = 1
    return pid


# === Public constants and data structures ====================================

# Property list classes
# These need to be locked, as the library won't let you close them.


NO_CLASS       = lockcls(H5P_NO_CLASS)
FILE_CREATE    = lockcls(H5P_FILE_CREATE)
FILE_ACCESS    = lockcls(H5P_FILE_ACCESS)
DATASET_CREATE = lockcls(H5P_DATASET_CREATE)
DATASET_XFER   = lockcls(H5P_DATASET_XFER)
DATASET_ACCESS = lockcls(H5P_DATASET_ACCESS)

OBJECT_COPY = lockcls(H5P_OBJECT_COPY)

LINK_CREATE = lockcls(H5P_LINK_CREATE)
LINK_ACCESS = lockcls(H5P_LINK_ACCESS)
GROUP_CREATE = lockcls(H5P_GROUP_CREATE)
OBJECT_CREATE = lockcls(H5P_OBJECT_CREATE)

CRT_ORDER_TRACKED = H5P_CRT_ORDER_TRACKED
CRT_ORDER_INDEXED = H5P_CRT_ORDER_INDEXED

DEFAULT = None   # In the HDF5 header files this is actually 0, which is an
                 # invalid identifier.  The new strategy for default options
                 # is to make them all None, to better match the Python style
                 # for keyword arguments.


# === Property list functional API ============================================

def create(PropClassID cls not None):
    """(PropClassID cls) => PropID

    Create a new property list as an instance of a class; classes are:

    - FILE_CREATE
    - FILE_ACCESS
    - DATASET_CREATE
    - DATASET_XFER
    - DATASET_ACCESS
    - LINK_CREATE
    - LINK_ACCESS
    - GROUP_CREATE
    - OBJECT_COPY
    - OBJECT_CREATE
    """
    cdef hid_t newid
    newid = H5Pcreate(cls.id)
    return propwrap(newid)

# === Class API ===============================================================

cdef class PropID(ObjectID):

    """
        Base class for all property lists and classes
    """


    def equal(self, PropID plist not None):
        """(PropID plist) => BOOL

        Compare this property list (or class) to another for equality.
        """
        return <bint>(H5Pequal(self.id, plist.id))

    def __richcmp__(self, object other, int how):
        cdef bint truthval = 0
        if how != 2 and how != 3:
            return NotImplemented
        if type(self) == type(other):
            truthval = self.equal(other)

        if how == 2:
            return truthval
        return not truthval

    def __hash__(self):
        raise TypeError("Property lists are unhashable")

cdef class PropClassID(PropID):

    """
        An HDF5 property list class.

        * Hashable: Yes, by identifier
        * Equality: Logical H5P comparison
    """

    def __richcmp__(self, object other, int how):
        return PropID.__richcmp__(self, other, how)

    def __hash__(self):
        """ Since classes are library-created and immutable, they are uniquely
            identified by their HDF5 identifiers.
        """
        return hash(self.id)

cdef class PropInstanceID(PropID):

    """
        Base class for property list instance objects.  Provides methods which
        are common across all HDF5 property list classes.

        * Hashable: No
        * Equality: Logical H5P comparison
    """


    def copy(self):
        """() => PropList newid

         Create a new copy of an existing property list object.
        """
        return type(self)(H5Pcopy(self.id))


    def _close(self):
        """()

        Terminate access through this identifier.  You shouldn't have to
        do this manually, as propery lists are automatically deleted when
        their Python wrappers are freed.
        """
        with _objects.registry.lock:
            H5Pclose(self.id)
            if not self.valid:
                del _objects.registry[self.id]


    def get_class(self):
        """() => PropClassID

        Determine the class of a property list object.
        """
        return PropClassID.open(H5Pget_class(self.id))

cdef class PropCreateID(PropInstanceID):

    """
        Generic object creation property list.
    """
    pass

cdef class PropCopyID(PropInstanceID):

    """
        Generic object copy property list
    """


    def set_copy_object(self, unsigned int flags):
        """(UINT flags)

        Set flags for object copying process.  Legal flags are
        from the h5o.COPY* family:

        h5o.COPY_SHALLOW_HIERARCHY_FLAG
            Copy only immediate members of a group.

        h5o.COPY_EXPAND_SOFT_LINK_FLAG
            Expand soft links into new objects.

        h5o.COPY_EXPAND_EXT_LINK_FLAG
            Expand external link into new objects.

        h5o.COPY_EXPAND_REFERENCE_FLAG
            Copy objects that are pointed to by references.

        h5o.COPY_WITHOUT_ATTR_FLAG
            Copy object without copying attributes.
        """
        H5Pset_copy_object(self.id, flags)


    def get_copy_object(self):
        """() => UINT flags

        Get copy process flags. Legal flags are h5o.COPY*.
        """
        cdef unsigned int flags
        H5Pget_copy_object(self.id, &flags)
        return flags


# === Concrete list implementations ===========================================

# File creation

cdef class PropFCID(PropCreateID):

    """
        File creation property list.
    """


    def get_version(self):
        """() => TUPLE version_info

        Determine version information of various file attributes.
        Elements are:

        0.  UINT Super block version number
        1.  UINT Freelist version number
        2.  UINT Symbol table version number
        3.  UINT Shared object header version number
        """
        cdef herr_t retval
        cdef unsigned int super_
        cdef unsigned int freelist
        cdef unsigned int stab
        cdef unsigned int shhdr

        H5Pget_version(self.id, &super_, &freelist, &stab, &shhdr)

        return (super_, freelist, stab, shhdr)


    def set_userblock(self, hsize_t size):
        """(INT/LONG size)

        Set the file user block size, in bytes.
        Must be a power of 2, and at least 512.
        """
        H5Pset_userblock(self.id, size)


    def get_userblock(self):
        """() => LONG size

        Determine the user block size, in bytes.
        """
        cdef hsize_t size
        H5Pget_userblock(self.id, &size)
        return size


    def set_sizes(self, size_t addr, size_t size):
        """(UINT addr, UINT size)

        Set the addressing offsets and lengths for objects
        in an HDF5 file, in bytes.
        """
        H5Pset_sizes(self.id, addr, size)


    def get_sizes(self):
        """() => TUPLE sizes

        Determine addressing offsets and lengths for objects in an
        HDF5 file, in bytes.  Return value is a 2-tuple with values:

        0.  UINT Address offsets
        1.  UINT Lengths
        """
        cdef size_t addr
        cdef size_t size
        H5Pget_sizes(self.id, &addr, &size)
        return (addr, size)

    def set_link_creation_order(self, unsigned int flags):
        """ (UINT flags)

        Set tracking and indexing of creation order for links added to this group

        flags -- h5p.CRT_ORDER_TRACKED, h5p.CRT_ORDER_INDEXED
        """
        H5Pset_link_creation_order(self.id, flags)

    def get_link_creation_order(self):
        """ () -> UINT flags

        Get tracking and indexing of creation order for links added to this group
        """
        cdef unsigned int flags
        H5Pget_link_creation_order(self.id, &flags)
        return flags


# Dataset creation
cdef class PropDCID(PropOCID):

    """
        Dataset creation property list.
    """


    def set_layout(self, int layout_code):
        """(INT layout_code)

        Set dataset storage strategy; legal values are:

        - h5d.COMPACT
        - h5d.CONTIGUOUS
        - h5d.CHUNKED
        """
        H5Pset_layout(self.id, layout_code)


    def get_layout(self):
        """() => INT layout_code

        Determine the storage strategy of a dataset; legal values are:

        - h5d.COMPACT
        - h5d.CONTIGUOUS
        - h5d.CHUNKED
        """
        return <int>H5Pget_layout(self.id)


    def set_chunk(self, object chunksize):
        """(TUPLE chunksize)

        Set the dataset chunk size.  It's up to you to provide
        values which are compatible with your dataset.
        """
        cdef int rank
        cdef hsize_t* dims
        dims = NULL

        require_tuple(chunksize, 0, -1, "chunksize")
        rank = len(chunksize)

        dims = <hsize_t*>emalloc(sizeof(hsize_t)*rank)
        try:
            convert_tuple(chunksize, dims, rank)
            H5Pset_chunk(self.id, rank, dims)
        finally:
            efree(dims)


    def get_chunk(self):
        """() => TUPLE chunk_dimensions

        Obtain the dataset chunk size, as a tuple.
        """
        cdef int rank
        cdef hsize_t *dims

        rank = H5Pget_chunk(self.id, 0, NULL)
        assert rank >= 0
        dims = <hsize_t*>emalloc(sizeof(hsize_t)*rank)

        try:
            H5Pget_chunk(self.id, rank, dims)
            tpl = convert_dims(dims, rank)
            return tpl
        finally:
            efree(dims)


    def set_fill_value(self, ndarray value not None):
        """(NDARRAY value)

        Set the dataset fill value.  The object provided should be an
        0-dimensional NumPy array; otherwise, the value will be read from
        the first element.
        """
        cdef TypeID tid

        check_numpy_read(value, -1)
        tid = py_create(value.dtype)
        H5Pset_fill_value(self.id, tid.id, value.data)


    def get_fill_value(self, ndarray value not None):
        """(NDARRAY value)

        Read the dataset fill value into a NumPy array.  It will be
        converted to match the array dtype.  If the array has nonzero
        rank, only the first element will contain the value.
        """
        cdef TypeID tid

        check_numpy_write(value, -1)
        tid = py_create(value.dtype)
        H5Pget_fill_value(self.id, tid.id, value.data)


    def fill_value_defined(self):
        """() => INT fill_status

        Determine the status of the dataset fill value.  Return values are:

        - h5d.FILL_VALUE_UNDEFINED
        - h5d.FILL_VALUE_DEFAULT
        - h5d.FILL_VALUE_USER_DEFINED
        """
        cdef H5D_fill_value_t val
        H5Pfill_value_defined(self.id, &val)
        return <int>val


    def set_fill_time(self, int fill_time):
        """(INT fill_time)

        Define when fill values are written to the dataset.  Legal
        values (defined in module h5d) are:

        - h5d.FILL_TIME_ALLOC
        - h5d.FILL_TIME_NEVER
        - h5d.FILL_TIME_IFSET
        """
        H5Pset_fill_time(self.id, <H5D_fill_time_t>fill_time)


    def get_fill_time(self):
        """ () => INT

        Determine when fill values are written to the dataset.  Legal
        values (defined in module h5d) are:

        - h5d.FILL_TIME_ALLOC
        - h5d.FILL_TIME_NEVER
        - h5d.FILL_TIME_IFSET
        """
        cdef H5D_fill_time_t fill_time
        H5Pget_fill_time(self.id, &fill_time)
        return <int>fill_time


    def set_alloc_time(self, int alloc_time):
        """(INT alloc_time)

        Set the storage space allocation time.  One of h5d.ALLOC_TIME*.
        """
        H5Pset_alloc_time(self.id, <H5D_alloc_time_t>alloc_time)


    def get_alloc_time(self):
        """() => INT alloc_time

        Get the storage space allocation time.  One of h5d.ALLOC_TIME*.
        """
        cdef H5D_alloc_time_t alloc_time
        H5Pget_alloc_time(self.id, &alloc_time)
        return <int>alloc_time


    # === Filter functions ====================================================


    def set_filter(self, int filter_code, unsigned int flags=0, object values=None):
        """(INT filter_code, UINT flags=0, TUPLE values=None)

        Set a filter in the pipeline.  Params are:

        filter_code
            One of the following:

            - h5z.FILTER_DEFLATE
            - h5z.FILTER_SHUFFLE
            - h5z.FILTER_FLETCHER32
            - h5z.FILTER_SZIP

        flags
            Bit flags (h5z.FLAG*) setting filter properties

        values
            TUPLE of UINTs giving auxiliary data for the filter
        """
        cdef size_t nelements
        cdef unsigned int *cd_values
        cdef int i
        cd_values = NULL

        require_tuple(values, 1, -1, "values")

        try:
            if values is None or len(values) == 0:
                nelements = 0
                cd_values = NULL
            else:
                nelements = len(values)
                cd_values = <unsigned int*>emalloc(sizeof(unsigned int)*nelements)

                for i from 0<=i<nelements:
                    cd_values[i] = int(values[i])

            H5Pset_filter(self.id, <H5Z_filter_t>filter_code, flags, nelements, cd_values)
        finally:
            efree(cd_values)


    def all_filters_avail(self):
        """() => BOOL

        Determine if all the filters in the pipelist are available to
        the library.
        """
        return <bint>(H5Pall_filters_avail(self.id))


    def get_nfilters(self):
        """() => INT

        Determine the number of filters in the pipeline.
        """
        return H5Pget_nfilters(self.id)


    def get_filter(self, int filter_idx):
        """(UINT filter_idx) => TUPLE filter_info

        Get information about a filter, identified by its index.  Tuple
        elements are:

        0. INT filter code (h5z.FILTER*)
        1. UINT flags (h5z.FLAG*)
        2. TUPLE of UINT values; filter aux data (16 values max)
        3. STRING name of filter (256 chars max)
        """
        cdef list vlist
        cdef int filter_code
        cdef unsigned int flags
        cdef size_t nelements
        cdef unsigned int cd_values[16]
        cdef char name[257]
        cdef int i
        nelements = 16 # HDF5 library actually complains if this is too big.

        if filter_idx < 0:
            raise ValueError("Filter index must be a non-negative integer")

        filter_code = <int>H5Pget_filter(self.id, filter_idx, &flags,
                                         &nelements, cd_values, 256, name)
        name[256] = c'\0'  # in case it's > 256 chars

        vlist = []
        for i from 0<=i<nelements:
            vlist.append(cd_values[i])

        return (filter_code, flags, tuple(vlist), name)


    def _has_filter(self, int filter_code):
        """(INT filter_code)

        Slow & stupid method to determine if a filter is used in this
        property list.  Used because the HDF5 function H5Pget_filter_by_id
        is broken.
        """
        cdef int nfilters
        nfilters = self.get_nfilters()
        for i from 0<=i<nfilters:
            if self.get_filter(i)[0] == filter_code:
                return True
        return False


    def get_filter_by_id(self, int filter_code):
        """(INT filter_code) => TUPLE filter_info or None

        Get information about a filter, identified by its code (one
        of h5z.FILTER*).  If the filter doesn't exist, returns None.
        Tuple elements are:

        0. UINT flags (h5z.FLAG*)
        1. TUPLE of UINT values; filter aux data (16 values max)
        2. STRING name of filter (256 chars max)
        """
        cdef list vlist
        cdef unsigned int flags
        cdef size_t nelements
        cdef unsigned int cd_values[16]
        cdef char name[257]
        cdef herr_t retval
        cdef int i
        nelements = 16 # HDF5 library actually complains if this is too big.

        if not self._has_filter(filter_code):
            # Avoid library segfault
            return None

        retval = H5Pget_filter_by_id(self.id, <H5Z_filter_t>filter_code,
                                     &flags, &nelements, cd_values, 256, name)
        assert nelements <= 16

        name[256] = c'\0'  # In case HDF5 doesn't terminate it properly

        vlist = []
        for i from 0<=i<nelements:
            vlist.append(cd_values[i])

        return (flags, tuple(vlist), name)


    def remove_filter(self, int filter_class):
        """(INT filter_class)

        Remove a filter from the pipeline.  The class code is one of
        h5z.FILTER*.
        """
        H5Premove_filter(self.id, <H5Z_filter_t>filter_class)


    def set_deflate(self, unsigned int level=5):
        """(UINT level=5)

        Enable deflate (gzip) compression, at the given level.
        Valid levels are 0-9, default is 5.
        """
        H5Pset_deflate(self.id, level)


    def set_fletcher32(self):
        """()

        Enable Fletcher32 error correction on this list.
        """
        H5Pset_fletcher32(self.id)


    def set_shuffle(self):
        """()

        Enable to use of the shuffle filter.  Use this immediately before
        the deflate filter to increase the compression ratio.
        """
        H5Pset_shuffle(self.id)


    def set_szip(self, unsigned int options, unsigned int pixels_per_block):
        """(UINT options, UINT pixels_per_block)

        Enable SZIP compression.  See the HDF5 docs for argument meanings,
        and general restrictions on use of the SZIP format.
        """
        H5Pset_szip(self.id, options, pixels_per_block)

    def set_scaleoffset(self, H5Z_SO_scale_type_t scale_type, int scale_factor):
        '''(H5Z_SO_scale_type_t scale_type, INT scale_factor)

        Enable scale/offset (usually lossy) compression; lossless (e.g. gzip)
        compression and other filters may be applied on top of this.

        Note that error detection (i.e. fletcher32) cannot precede this in
        the filter chain, or else all reads on lossily-compressed data will
        fail.'''
        H5Pset_scaleoffset(self.id, scale_type, scale_factor)


# File access
cdef class PropFAID(PropInstanceID):

    """
        File access property list
    """


    def set_fclose_degree(self, int close_degree):
        """(INT close_degree)

        Set the file-close degree, which determines library behavior when
        a file is closed when objects are still open.  Legal values:

        * h5f.CLOSE_WEAK
        * h5f.CLOSE_SEMI
        * h5f.CLOSE_STRONG
        * h5f.CLOSE_DEFAULT
        """
        H5Pset_fclose_degree(self.id, <H5F_close_degree_t>close_degree)


    def get_fclose_degree(self):
        """() => INT close_degree
        - h5fd.
        Get the file-close degree, which determines library behavior when
        a file is closed when objects are still open.  Legal values:

        * h5f.CLOSE_WEAK
        * h5f.CLOSE_SEMI
        * h5f.CLOSE_STRONG
        * h5f.CLOSE_DEFAULT
        """
        cdef H5F_close_degree_t deg
        H5Pget_fclose_degree(self.id, &deg)
        return deg


    def set_fapl_core(self, size_t block_size=64*1024, hbool_t backing_store=1):
        """(UINT increment=64k, BOOL backing_store=True)

        Use the h5fd.CORE (memory-resident) file driver.

        increment
            Chunk size for new memory requests (default 1 meg)

        backing_store
            If True (default), memory contents are associated with an
            on-disk file, which is updated when the file is closed.
            Set to False for a purely in-memory file.
        """
        H5Pset_fapl_core(self.id, block_size, backing_store)


    def get_fapl_core(self):
        """() => TUPLE core_settings

        Determine settings for the h5fd.CORE (memory-resident) file driver.
        Tuple elements are:

        0. UINT "increment": Chunk size for new memory requests
        1. BOOL "backing_store": If True, write the memory contents to
           disk when the file is closed.
        """
        cdef size_t increment
        cdef hbool_t backing_store
        H5Pget_fapl_core(self.id, &increment, &backing_store)
        return (increment, <bint>(backing_store))


    def set_fapl_family(self, hsize_t memb_size=2147483647, PropID memb_fapl=None):
        """(UINT memb_size=2**31-1, PropFAID memb_fapl=None)

        Set up the family driver.

        memb_size
            Member file size

        memb_fapl
            File access property list for each member access
        """
        cdef hid_t plist_id
        plist_id = pdefault(memb_fapl)
        H5Pset_fapl_family(self.id, memb_size, plist_id)


    def get_fapl_family(self):
        """() => TUPLE info

        Determine family driver settings. Tuple values are:

        0. UINT memb_size
        1. PropFAID memb_fapl or None
        """
        cdef hid_t mfapl_id
        cdef hsize_t msize
        cdef PropFAID plist
        plist = None

        H5Pget_fapl_family(self.id, &msize, &mfapl_id)

        if mfapl_id > 0:
            plist = PropFAID.open(mfapl_id)

        return (msize, plist)


    def set_fapl_log(self, char* logfile, unsigned int flags, size_t buf_size):
        """(STRING logfile, UINT flags, UINT buf_size)

        Enable the use of the logging driver.  See the HDF5 documentation
        for details.  Flag constants are stored in module h5fd.
        """
        H5Pset_fapl_log(self.id, logfile, flags, buf_size)


    def set_fapl_sec2(self):
        """()

        Select the "section-2" driver (h5fd.SEC2).
        """
        H5Pset_fapl_sec2(self.id)


    def set_fapl_stdio(self):
        """()

        Select the "stdio" driver (h5fd.STDIO)
        """
        H5Pset_fapl_stdio(self.id)


    def get_driver(self):
        """() => INT driver code

        Return an integer identifier for the driver used by this list.
        Although HDF5 implements these as full-fledged objects, they are
        treated as integers by Python.  Built-in drivers identifiers are
        listed in module h5fd; they are:

        - h5fd.CORE
        - h5fd.FAMILY
        - h5fd.LOG
        - h5fd.MPIO
        - h5fd.MULTI
        - h5fd.SEC2
        - h5fd.STDIO
        """
        return H5Pget_driver(self.id)


    def set_cache(self, int mdc, int rdcc, size_t rdcc_nbytes, double rdcc_w0):
        """(INT mdc, INT rdcc, UINT rdcc_nbytes, DOUBLE rdcc_w0)

        Set the metadata (mdc) and raw data chunk (rdcc) cache properties.
        See the HDF5 docs for a full explanation.
        """
        H5Pset_cache(self.id, mdc, rdcc, rdcc_nbytes, rdcc_w0)


    def get_cache(self):
        """() => TUPLE cache info

        Get the metadata and raw data chunk cache settings.  See the HDF5
        docs for element definitions.  Return is a 4-tuple with entries:

        1. INT mdc:              Number of metadata objects
        2. INT rdcc:             Number of raw data chunks
        3. UINT rdcc_nbytes:     Size of raw data cache
        4. DOUBLE rdcc_w0:       Preemption policy for data cache.
        """
        cdef int mdc, rdcc
        cdef size_t rdcc_nbytes
        cdef double w0

        H5Pget_cache(self.id, &mdc, &rdcc, &rdcc_nbytes, &w0)
        return (mdc, rdcc, rdcc_nbytes, w0)


    def set_sieve_buf_size(self, size_t size):
        """ (UINT size)

        Set the maximum size of the data sieve buffer (in bytes).  This
        buffer can improve I/O performance for hyperslab I/O, by combining
        reads and writes into blocks of the given size.  The default is 64k.
        """
        H5Pset_sieve_buf_size(self.id, size)


    def get_sieve_buf_size(self):
        """ () => UINT size

        Get the current maximum size of the data sieve buffer (in bytes).
        """
        cdef size_t size
        H5Pget_sieve_buf_size(self.id, &size)
        return size

    def set_libver_bounds(self, int low, int high):
        """ (INT low, INT high)

        Set the compatibility level for file format.  Legal values are:

        - h5f.LIBVER_EARLIEST
        - h5f.LIBVER_LATEST
        """
        H5Pset_libver_bounds(self.id, <H5F_libver_t>low, <H5F_libver_t>high)

    def get_libver_bounds(self):
        """ () => (INT low, INT high)

        Get the compatibility level for file format. Returned values are from:

        - h5f.LIBVER_EARLIEST
        - h5f.LIBVER_LATEST
        """
        cdef H5F_libver_t low
        cdef H5F_libver_t high
        H5Pget_libver_bounds(self.id, &low, &high)

        return (<int>low, <int>high)

    IF MPI:
        def set_fapl_mpio(self, Comm comm not None, Info info not None):
            """ (Comm comm, Info info)

            Set MPI-I/O Parallel HDF5 driver.

            Comm: An mpi4py.MPI.Comm instance
            Info: An mpi4py.MPI.Info instance
            """
            H5Pset_fapl_mpio(self.id, comm.ob_mpi, info.ob_mpi) 


        def set_fapl_mpiposix(self, Comm comm not None, bint use_gpfs_hints=0):
            """ (Comm comm, BOOL use_gpfs_hints=0)

            Set MPI-POSIX driver.

            Comm: An mpi4py.MPI.Comm instance
            use_gpfs_hints: Enable internal hints for GPFS file system
            """
            H5Pset_fapl_mpiposix(self.id, comm.ob_mpi, use_gpfs_hints)

    def get_mdc_config(self):
        """() => CacheConfig
        Returns an object that stores all the information about the meta-data cache
        configuration
        """

        cdef CacheConfig config = CacheConfig()

        cdef herr_t  err
        err = H5Fget_mdc_config(self.id, &config.cache_config)
        if err < 0:
            raise RuntimeError("Failed to get hit rate")

        return config

    def set_mdc_config(self, CacheConfig config not None):
        """(CacheConfig) => None
        Returns an object that stores all the information about the meta-data cache
        configuration
        """
        # I feel this should have some sanity checking to make sure that
        cdef herr_t  err
        err = H5Fset_mdc_config(self.id, &config.cache_config)
        if err < 0:
            raise RuntimeError("Failed to get hit rate")


# Link creation
cdef class PropLCID(PropCreateID):

    """ Link creation property list """

    def set_char_encoding(self, int encoding):
        """ (INT encoding)

        Set the character encoding for link names.  Legal values are:

        - h5t.CSET_ASCII
        - h5t.CSET_UTF8
        """
        H5Pset_char_encoding(self.id, <H5T_cset_t>encoding)

    def get_char_encoding(self):
        """ () => INT encoding

        Get the character encoding for link names.  Legal values are:

        - h5t.CSET_ASCII
        - h5t.CSET_UTF8
        """
        cdef H5T_cset_t encoding
        H5Pget_char_encoding(self.id, &encoding)
        return <int>encoding

    def set_create_intermediate_group(self, bint create):
        """(BOOL create)

        Set whether missing intermediate groups are automatically created.
        """
        H5Pset_create_intermediate_group(self.id, create)


    def get_create_intermediate_group(self):
        """() => BOOL

        Determine if missing intermediate groups are automatically created.
        """
        cdef unsigned int create
        H5Pget_create_intermediate_group(self.id, &create)
        return <bint>create

# Link access
cdef class PropLAID(PropInstanceID):

    """ Link access property list """

    def __cinit__(self, *args):
        self._buf = NULL

    def __dealloc__(self):
        efree(self._buf)


    def set_nlinks(self, size_t nlinks):
        """(UINT nlinks)

        Set the maximum traversal depth for soft links
        """
        H5Pset_nlinks(self.id, nlinks)


    def get_nlinks(self):
        """() => UINT

        Get the maximum traversal depth for soft links
        """
        cdef size_t nlinks
        H5Pget_nlinks(self.id, &nlinks)
        return nlinks


    def set_elink_prefix(self, char* prefix):
        """(STRING prefix)

        Set the external link prefix.
        """
        cdef size_t size

        # HDF5 requires that we hang on to this buffer
        efree(self._buf)
        size = strlen(prefix)
        self._buf = <char*>emalloc(size+1)
        strcpy(self._buf, prefix)

        H5Pset_elink_prefix(self.id, self._buf)


    def get_elink_prefix(self):
        """() => STRING prefix

        Get the external link prefix
        """
        cdef char* buf = NULL
        cdef ssize_t size

        size = H5Pget_elink_prefix(self.id, NULL, 0)
        buf = <char*>emalloc(size+1)
        try:
            H5Pget_elink_prefix(self.id, buf, size+1)
            pstr = buf
        finally:
            efree(buf)

        return pstr

    def set_elink_fapl(self, PropID fapl not None):
        """ (PropFAID fapl)

        Set the file access property list used when opening external files.
        """
        H5Pset_elink_fapl(self.id, fapl.id)

    def get_elink_fapl(self):
        """ () => PropFAID fapl

        Get the file access property list used when opening external files.
        """
        cdef hid_t fid
        fid = H5Pget_elink_fapl(self.id)
        if H5Iget_ref(fid) > 1:
            H5Idec_ref(fid)
        return propwrap(fid)

# Group creation
cdef class PropGCID(PropOCID):
    """ Group creation property list """

    def set_link_creation_order(self, unsigned int flags):
        """ (UINT flags)

        Set tracking and indexing of creation order for links added to this group

        flags -- h5p.CRT_ORDER_TRACKED, h5p.CRT_ORDER_INDEXED
        """
        H5Pset_link_creation_order(self.id, flags)

    def get_link_creation_order(self):
        """ () -> UINT flags

        Get tracking and indexing of creation order for links added to this group
        """
        cdef unsigned int flags
        H5Pget_link_creation_order(self.id, &flags)
        return flags


# Object creation property list
cdef class PropOCID(PropCreateID):
    """ Object creation property list

    This seems to be a super class for dataset creation property list
    and group creation property list.

    The documentation is somewhat hazy
    """
    def set_obj_track_times(self,track_times):
        """Sets the recording of times associated with an object."""
        H5Pset_obj_track_times(self.id,track_times)

    def get_obj_track_times(self):
        """
        Determines whether times associated with an object are being recorded.
        """

        cdef hbool_t track_times

        H5Pget_obj_track_times(self.id,&track_times)

        return track_times


# Dataset access
cdef class PropDAID(PropInstanceID):

    """ Dataset access property list """

    def set_chunk_cache(self, size_t rdcc_nslots,size_t rdcc_nbytes, double rdcc_w0):
        """(size_t rdcc_nslots,size_t rdcc_nbytes, double rdcc_w0)

        Sets the raw data chunk cache parameters.
        """
        H5Pset_chunk_cache(self.id,rdcc_nslots,rdcc_nbytes,rdcc_w0)

    def get_chunk_cache(self):
        """() => TUPLE chunk cache info

        Get the metadata and raw data chunk cache settings.  See the HDF5
        docs for element definitions.  Return is a 3-tuple with entries:

        0. size_t rdcc_nslots: Number of chunk slots in the raw data chunk cache hash table.
        1. size_t rdcc_nbytes: Total size of the raw data chunk cache, in bytes.
        2. DOUBLE rdcc_w0:     Preemption policy.
        """
        cdef size_t rdcc_nslots
        cdef size_t rdcc_nbytes
        cdef double rdcc_w0

        H5Pget_chunk_cache(self.id, &rdcc_nslots, &rdcc_nbytes, &rdcc_w0 )
        return (rdcc_nslots,rdcc_nbytes,rdcc_w0)