path: root/src/H5D.c

/****************************************************************************
* NCSA HDF                                                                 *
* Software Development Group                                               *
* National Center for Supercomputing Applications                          *
* University of Illinois at Urbana-Champaign                               *
* 605 E. Springfield, Champaign IL 61820                                   *
*                                                                          *
* For conditions of distribution and use, see the accompanying             *
* hdf/COPYING file.                                                        *
*                                                                          *
****************************************************************************/

#ifdef RCSID
static char RcsId[] = "@(#)$Revision$";
#endif

/* $Id$ */

/*LINTLIBRARY */
/*+
   FILE
       H5D.c
   HDF5 Dataset routines

   EXPORTED ROUTINES
       H5Dcreate    -- Create a dataset
       H5Drelease   -- Release access to a dataset

   LIBRARY-SCOPED ROUTINES

   LOCAL ROUTINES
       H5P_init_interface    -- initialize the interface
   + */

#include <H5private.h>  /* Generic Functions */
#include <H5Aprivate.h> /* Atoms */
#include <H5Dprivate.h> /* Dataset functions */
#include <H5Eprivate.h> /* Error handling */

#define PABLO_MASK	H5D_mask

/*--------------------- Locally scoped variables -----------------------------*/

/* Whether we've installed the library termination function yet for this interface */
static intn interface_initialize_g = FALSE;
static herr_t H5D_init_interface(void);

/*--------------------------------------------------------------------------
NAME
   H5D_init_interface -- Initialize interface-specific information
USAGE
    herr_t H5D_init_interface()
   
RETURNS
   SUCCEED/FAIL
DESCRIPTION
    Initializes any interface-specific data or routines.

--------------------------------------------------------------------------*/
static herr_t H5D_init_interface(void)
{
    herr_t ret_value = SUCCEED;
    FUNC_ENTER (H5D_init_interface, NULL, FAIL);

    /* Initialize the atom group for the file IDs */
    ret_value=H5Ainit_group(H5_DATASET,H5A_DATASETID_HASHSIZE,H5D_RESERVED_ATOMS);

    FUNC_LEAVE(ret_value);
}	/* H5D_init_interface */

/*--------------------------------------------------------------------------
 NAME
    H5D_create
 PURPOSE
    Create a new HDF5 dataset object
 USAGE
    hatom_t H5D_create(owner_id, type, name)
        hatom_t owner_id;       IN: Group/file which owns this object
        hobjtype_t type;        IN: Type of object to create
        const char *name;       IN: Name of the object
 RETURNS
    Returns ID (atom) on success, FAIL on failure
 DESCRIPTION
        This function actually creates the dataset object.
--------------------------------------------------------------------------*/
hatom_t H5D_create(hatom_t owner_id, hobjtype_t type, const char *name)
{
    H5D_dataset_t *new_dset;        /* new dataset object to create */
    hatom_t ret_value = SUCCEED;

    FUNC_ENTER(H5D_create, H5D_init_interface, FAIL);

    /* Clear errors and check args and all the boring stuff. */
    H5ECLEAR;

    /* Allocate space for the new dataset */
    if((new_dset=HDmalloc(sizeof(H5D_dataset_t)))==NULL)
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL);
    
    /* Initialize the dataset object */
    if(H5Aatom_group(owner_id)==H5_FILE)
        new_dset->file=owner_id;
    else
        new_dset->file=H5Mget_file(owner_id);
    new_dset->parent=owner_id;      /* set the owner's ID */
    new_dset->name=HDstrdup(name);  /* make a copy of the dataset name */
    new_dset->modified=BTRUE;       /* Yep, we're new... */
    new_dset->type=0;
    new_dset->dim=0;
    new_dset->header=(-1);          /* don't know where we are... */
    new_dset->data=(-1);            /* don't know where we should put the data, either... */

    /* Register the new datatype and get an ID for it */
    if((ret_value=H5Aregister_atom(H5_DATASET, (const VOIDP)new_dset))==FAIL)
        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

    /* Normal function cleanup */

    FUNC_LEAVE(ret_value);
} /* end H5D_create() */

/*--------------------------------------------------------------------------
 NAME
    H5Dset_info
 PURPOSE
    Set the type and dimensionality of a dataset.
 USAGE
    herr_t H5Dset_info(oid)
        hatom_t oid;       IN: Dataset object to modify
        hatom_t tid;       IN: Datatype object to use as node element
        hatom_t did;       IN: Dimensionality object to use as dataspace
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
        This function sets the datatype and dataspace of a dataset.
--------------------------------------------------------------------------*/
herr_t H5Dset_info(hatom_t oid, hatom_t tid, hatom_t did)
{
    H5D_dataset_t *dataset;         /* dataset object to modify */
    herr_t        ret_value = SUCCEED;

    FUNC_ENTER(H5Dset_info, H5D_init_interface, FAIL);

    /* Clear errors and check args and all the boring stuff. */
    H5ECLEAR;

    /* Check that we've received correctly typed parameters */
    if(H5Aatom_group(tid)!=H5_DATATYPE || H5Aatom_group(did)!=H5_DATASPACE)
        HGOTO_ERROR(H5E_ATOM, H5E_BADTYPE, FAIL);

    /* Get the object */
    if((dataset=H5Aatom_object(oid))==NULL)
        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL);
    /* Check that the datatype & dataspace haven't already been initialized */
    if(dataset->type!=0 || dataset->dim!=0)
        HGOTO_ERROR(H5E_FUNC, H5E_ALREADYINIT, FAIL);

    dataset->type=tid;
    dataset->dim=did;
    dataset->modified=BTRUE;       /* indicate the values have changed */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

    /* Normal function cleanup */

    FUNC_LEAVE(ret_value);
} /* end H5Dset_info() */

/*--------------------------------------------------------------------------
 NAME
    H5Dwrite
 PURPOSE
    Write data for a dataset
 USAGE
    herr_t H5Dset_info(oid)
        hatom_t oid;       IN: Dataset object to modify
        hatom_t did;       IN: Dimensionality object to use as dataspace for I/O
        VOIDP buf;         IN: Buffer with data to write to the file
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
        This function writes dataset object data to the file.  The dataspace
    ID determines the slice/hyper-slab/portion of the dataset to write.
    H5P_SCALAR is a special value which indicates that the entire dataset is
    to be written out.  (For datasets which have a scalar dataspace for the
    entire dataset, this is somewhat redundant.... :-)
--------------------------------------------------------------------------*/
herr_t H5Dwrite(hatom_t oid, hatom_t did, VOIDP buf)
{
    H5D_dataset_t *dataset;         /* dataset object to release */
#if 0
    uintn   towrite;        /* number of bytes to write out */
#endif
    herr_t        ret_value = SUCCEED;

    FUNC_ENTER(H5Dwrite, H5D_init_interface, FAIL);

    /* Clear errors and check args and all the boring stuff. */
    H5ECLEAR;

    /* Check that we've received correctly typed parameters */
    if(H5Aatom_group(did)!=H5_DATASPACE)
        HGOTO_ERROR(H5E_ATOM, H5E_BADTYPE, FAIL);
    if(buf==NULL)
        HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL);

    /* Get the object */
    if((dataset=H5Aatom_object(oid))==NULL)
        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL);
    /* Check that the datatype & dataspace haven't already been initialized */
    if(dataset->type==0 || dataset->dim==0)
        HGOTO_ERROR(H5E_FUNC, H5E_UNINITIALIZED, FAIL);

#if 0
    towrite=H5Tsize(dataset->type)*H5Pnelem(did);
#endif
/* Check memory to disk datatype conversions, etc. */
/* data out */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

    /* Normal function cleanup */

    FUNC_LEAVE(ret_value);
} /* end H5Dwrite() */

/*--------------------------------------------------------------------------
 NAME
    H5D_flush
 PURPOSE
    Flush an an HDF5 dataset object to disk.
 USAGE
    herr_t H5D_flush(oid)
        hatom_t oid;       IN: Object to flush to disk
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
        This function flushes a dataset to disk.  (i.e. makes the disk version
    agree with what's in memory, it does _not_ update the memory version with
    any changes on disk)
--------------------------------------------------------------------------*/
herr_t H5D_flush(hatom_t oid)
{
    H5D_dataset_t *dataset;         /* dataset object to release */
    herr_t        ret_value = SUCCEED;

    FUNC_ENTER(H5D_flush, H5D_init_interface, FAIL);

    /* Clear errors and check args and all the boring stuff. */
    H5ECLEAR;

    /* Get the object */
    if((dataset=H5Aatom_object(oid))==NULL)
        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL);
    /* Check if we have information to flush to the file... */
    if(dataset->modified==BTRUE)
      {
        /* Check if we need to create the dataset header and insert the dataset in the file's hierarchy */
        if(dataset->header==0)
          {
            H5G_entry_t d_sym;
            H5F_root_symtype_t root_type=H5F_root_type(dataset->file);
            hdf5_file_t *file;
            group_t dset_parent=H5Aatom_group(dataset->parent);

            /* Get the dataset's file... (I'm not fond of this. -QAK) */
            if((file=H5Aatom_object(dataset->file))==NULL)
                HGOTO_ERROR(H5E_INTERNAL, H5E_BADATOM, FAIL);

            /* Flush object header, etc. to the file... */
            if(root_type==H5F_ROOT_ERROR)
                HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL);

            /* construct dataset symbol-table entry */
            d_sym.name_off=0;
            /* allocate the dataset's object header */
            if((d_sym.header=H5O_new(file, 1, 0))<0)
                HRETURN_ERROR (H5E_SYM, H5E_CANTINIT, FAIL);
            d_sym.type=H5G_NOTHING_CACHED;
            dataset->header=d_sym.header;

            /* Insert dataset into parent directory, if there is one */
            if(dset_parent!=H5_FILE ||
                    (dset_parent==H5_FILE && root_type==H5F_ROOT_DIRECTORY))
              {
                uintn namelen;  /* length of parent directory's name */
                char *name;     /* pointer to parent directory's name */

                /* Get the name of the parent directory */
                if((namelen=H5Mname_len(dataset->parent))==UFAIL)
                    HGOTO_ERROR(H5E_DIRECTORY, H5E_BADVALUE, FAIL);
                if((name=HDmalloc(namelen+1))==NULL);
                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL);
                if(H5Mget_name(dataset->parent,name)==FAIL)
                    HGOTO_ERROR(H5E_DIRECTORY, H5E_NOTFOUND, FAIL);

                /* Insert the dataset into the parent directory */
                if(H5G_insert (file, NULL, name, dataset->name, &d_sym)==FAIL)
                    HGOTO_ERROR(H5E_DIRECTORY, H5E_CANTINSERT, FAIL);
                HDfree(name);
              } /* end if */
            else    /* insert dataset as root-object, or into root-directory */
              {
                if(root_type==H5F_ROOT_DATASET || H5F_ROOT_UNKNOWN)
                  {
                    /* Make the root directory and stuff the dataset into it */
                    if(H5G_mkroot (file, H5G_DEFAULT_ROOT_SIZE)==FAIL)
                        HGOTO_ERROR(H5E_DIRECTORY, H5E_CANTCREATE, FAIL);
                    if(H5G_insert (file, NULL, NULL, dataset->name, &d_sym)==FAIL)
                        HGOTO_ERROR(H5E_DIRECTORY, H5E_CANTINSERT, FAIL);
                  } /* end if */
                else
                  {
                    /* Set the root of the file to point to the dataset */
                    if(root_type==H5F_ROOT_NONE)
                        H5G_set_root(file, dataset->name, &d_sym);
                  } /* end else */
              } /* end else */
            
            /* Add the appropriate messages for the dataset */
          } /* end if */
      } /* end if */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

    /* Normal function cleanup */

    FUNC_LEAVE(ret_value);
} /* end H5D_flush() */

/*--------------------------------------------------------------------------
 NAME
    H5D_release
 PURPOSE
    Release access to an HDF5 dataset object.
 USAGE
    herr_t H5D_release(oid)
        hatom_t oid;       IN: Object to release access to
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
        This function releases a dataset from active use by a user.
--------------------------------------------------------------------------*/
herr_t H5D_release(hatom_t oid)
{
    H5D_dataset_t *dataset;         /* dataset object to release */
    herr_t        ret_value = SUCCEED;

    FUNC_ENTER(H5D_release, H5D_init_interface, FAIL);

    /* Clear errors and check args and all the boring stuff. */
    H5ECLEAR;

    /* Get the dataset so we can check for changes and release it */
    if((dataset=H5Aatom_object(oid))==NULL)
        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL);

    /* Check if we have information to flush to the file... */
    if(dataset->modified==BTRUE)
        H5D_flush(oid);

    /* relase the memory used for the dataset */
    if(dataset->name!=NULL)
        HDfree(dataset->name);
    HDfree(dataset);

    /* Delete the dataset from the atom group */
    if(H5Aatom_object(oid)==NULL)
        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

    /* Normal function cleanup */

    FUNC_LEAVE(ret_value);
} /* end H5D_release() */