path: root/src/H5MFaggr.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * Programmer:	Quincey Koziol
 *              Tuesday, January  8, 2008
 *
 * Purpose:	Routines for aggregating free space allocations
 *
 */

/****************/
/* Module Setup */
/****************/

#define H5F_FRIEND      /*suppress error about including H5Fpkg	  */
#include "H5MFmodule.h" /* This source code file is part of the H5MF module */

/***********/
/* Headers */
/***********/
#include "H5private.h"  /* Generic Functions			*/
#include "H5Eprivate.h" /* Error handling		  	*/
#include "H5Fpkg.h"     /* File access				*/
#include "H5MFpkg.h"    /* File memory management		*/

/****************/
/* Local Macros */
/****************/

/******************/
/* Local Typedefs */
/******************/
#define EXTEND_THRESHOLD 0.10F

/********************/
/* Package Typedefs */
/********************/

/********************/
/* Local Prototypes */
/********************/
static herr_t  H5MF__aggr_free(H5F_t *f, H5FD_mem_t type, H5F_blk_aggr_t *aggr);
static haddr_t H5MF__aggr_alloc(H5F_t *f, H5F_blk_aggr_t *aggr, H5F_blk_aggr_t *other_aggr, H5FD_mem_t type,
                                hsize_t size);
static herr_t  H5MF__aggr_reset(H5F_t *f, H5F_blk_aggr_t *aggr);
static htri_t  H5MF__aggr_can_shrink_eoa(H5F_t *f, H5FD_mem_t type, H5F_blk_aggr_t *aggr);

/*********************/
/* Package Variables */
/*********************/

/*****************************/
/* Library Private Variables */
/*****************************/

/*******************/
/* Local Variables */
/*******************/

/*-------------------------------------------------------------------------
 * Function:    H5MF_aggr_vfd_alloc
 *
 * Purpose:     Allocate SIZE bytes of file memory via H5MF__aggr_alloc()
 *		and return the relative address where that contiguous chunk
 *		of file memory exists.
 *		The TYPE argument describes the purpose for which the storage
 *		is being requested.
 *
 * Return:      Success:        The file address of new chunk.
 *              Failure:        HADDR_UNDEF
 *
 * Programmer:  Vailin Choi; July 1st, 2009
 *		(The coding is from H5MF_alloc().)
 *
 *-------------------------------------------------------------------------
 */
haddr_t
H5MF_aggr_vfd_alloc(H5F_t *f, H5FD_mem_t alloc_type, hsize_t size)
{
    haddr_t ret_value = HADDR_UNDEF; /* Return value */

    FUNC_ENTER_NOAPI(HADDR_UNDEF)
#ifdef H5MF_AGGR_DEBUG
    HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_type, size);
#endif /* H5MF_AGGR_DEBUG */

    /* check arguments */
    HDassert(f);
    HDassert(f->shared);
    HDassert(f->shared->lf);
    HDassert(size > 0);

    /* Couldn't find anything from the free space manager, go allocate some */
    if (alloc_type != H5FD_MEM_DRAW && alloc_type != H5FD_MEM_GHEAP) {
        /* Handle metadata differently from "raw" data */
        if (HADDR_UNDEF == (ret_value = H5MF__aggr_alloc(f, &(f->shared->meta_aggr), &(f->shared->sdata_aggr),
                                                         alloc_type, size)))
            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate metadata")
    } /* end if */
    else {
        /* Allocate "raw" data: H5FD_MEM_DRAW and H5FD_MEM_GHEAP */
        if (HADDR_UNDEF == (ret_value = H5MF__aggr_alloc(f, &(f->shared->sdata_aggr), &(f->shared->meta_aggr),
                                                         H5FD_MEM_DRAW, size)))
            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate raw data")
    } /* end else */

    /* Sanity check for overlapping into file's temporary allocation space */
    HDassert(H5F_addr_le((ret_value + size), f->shared->tmp_addr));

done:
#ifdef H5MF_AGGR_DEBUG
    HDfprintf(stderr, "%s: Leaving: ret_value = %a, size = %Hu\n", FUNC, ret_value, size);
#endif /* H5MF_AGGR_DEBUG */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF_aggr_vfd_alloc() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_alloc
 *
 * Purpose:     Try to allocate SIZE bytes of memory from an aggregator
 *              block if possible.
 *
 * Return:      Success:    The format address of the new file memory.
 *              Failure:    The undefined address HADDR_UNDEF
 *
 * Programmer:  Quincey Koziol
 *              Thursday, December 13, 2007
 *
 *-------------------------------------------------------------------------
 */
static haddr_t
H5MF__aggr_alloc(H5F_t *f, H5F_blk_aggr_t *aggr, H5F_blk_aggr_t *other_aggr, H5FD_mem_t type, hsize_t size)
{
    haddr_t eoa_frag_addr = HADDR_UNDEF; /* Address of fragment at EOA */
    hsize_t eoa_frag_size = 0;           /* Size of fragment at EOA */
    haddr_t eoa           = HADDR_UNDEF; /* Initial EOA for the file */
    haddr_t ret_value     = HADDR_UNDEF; /* Return value */

    FUNC_ENTER_STATIC
#ifdef H5MF_AGGR_DEBUG
    HDfprintf(stderr, "%s: type = %u, size = %Hu\n", FUNC, (unsigned)type, size);
#endif /* H5MF_AGGR_DEBUG */

    /* check args */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);
    HDassert(other_aggr);
    HDassert(other_aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             other_aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);
    HDassert(other_aggr->feature_flag != aggr->feature_flag);
    HDassert(type >= H5FD_MEM_DEFAULT && type < H5FD_MEM_NTYPES);
    HDassert(size > 0);

    /* Get the EOA for the file */
    if (HADDR_UNDEF == (eoa = H5F_get_eoa(f, type)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, HADDR_UNDEF, "Unable to get eoa")

    /*
     * If the aggregation feature is enabled for this file and strategy is not H5F_FILE_SPACE_NONE,
     * allocate "generic" space and sub-allocate out of that, if possible.
     * Otherwise just allocate through H5F__alloc().
     */
    if ((f->shared->feature_flags & aggr->feature_flag) &&
        f->shared->fs_strategy != H5F_FSPACE_STRATEGY_NONE) {
        haddr_t    aggr_frag_addr = HADDR_UNDEF; /* Address of aggregrator fragment */
        hsize_t    aggr_frag_size = 0;           /* Size of aggregator fragment */
        hsize_t    alignment;                    /* Alignment of this section */
        hsize_t    aggr_mis_align = 0;           /* Mis-alignment of aggregator */
        H5FD_mem_t alloc_type, other_alloc_type; /* Current aggregator & 'other' aggregator types */

#ifdef H5MF_AGGR_DEBUG
        HDfprintf(stderr, "%s: aggr = {%a, %Hu, %Hu}\n", FUNC, aggr->addr, aggr->tot_size, aggr->size);
#endif /* H5MF_AGGR_DEBUG */

        /* Turn off alignment if allocation < threshold */
        alignment = H5F_ALIGNMENT(f);
        if (!((alignment > 1) && (size >= H5F_THRESHOLD(f))))
            alignment = 0; /* no alignment */

        /* Generate fragment if aggregator is mis-aligned */
        if (alignment && H5F_addr_gt(aggr->addr, 0) &&
            (aggr_mis_align = (aggr->addr + H5F_BASE_ADDR(f)) % alignment)) {
            aggr_frag_addr = aggr->addr;
            aggr_frag_size = alignment - aggr_mis_align;
        } /* end if */

        alloc_type = aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ? H5FD_MEM_DEFAULT : H5FD_MEM_DRAW;
        other_alloc_type =
            other_aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ? H5FD_MEM_DEFAULT : H5FD_MEM_DRAW;

        /* Check if the space requested is larger than the space left in the block */
        if ((size + aggr_frag_size) > aggr->size) {
            htri_t extended = FALSE; /* Whether the file was extended */

            /* Check if the block asked for is too large for 'normal' aggregator block */
            if (size >= aggr->alloc_size) {
                hsize_t ext_size = size + aggr_frag_size;

                /* Check for overlapping into file's temporary allocation space */
                if (H5F_addr_gt((aggr->addr + aggr->size + ext_size), f->shared->tmp_addr))
                    HGOTO_ERROR(
                        H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF,
                        "'normal' file space allocation request will overlap into 'temporary' file space")

                if ((aggr->addr > 0) &&
                    (extended = H5F__try_extend(f, alloc_type, (aggr->addr + aggr->size), ext_size)) < 0)
                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't extending space")
                else if (extended) {
                    /* aggr->size is unchanged */
                    ret_value = aggr->addr + aggr_frag_size;
                    aggr->addr += ext_size;
                    aggr->tot_size += ext_size;
                }
                else {
                    /* Release "other" aggregator, if it exists, is at the end of the allocated space,
                     * has allocated more than one block and the unallocated space is greater than its
                     * allocation block size.
                     */
                    if ((other_aggr->size > 0) && (H5F_addr_eq((other_aggr->addr + other_aggr->size), eoa)) &&
                        (other_aggr->tot_size > other_aggr->size) &&
                        ((other_aggr->tot_size - other_aggr->size) >= other_aggr->alloc_size)) {
                        if (H5MF__aggr_free(f, other_alloc_type, other_aggr) < 0)
                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF,
                                        "can't free aggregation block")
                    } /* end if */

                    /* Allocate space from the VFD (i.e. at the end of the file) */
                    if (HADDR_UNDEF ==
                        (ret_value = H5F__alloc(f, alloc_type, size, &eoa_frag_addr, &eoa_frag_size)))
                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")
                } /* end else */
            }     /* end if */
            else {
                hsize_t ext_size = aggr->alloc_size;

                /* Allocate another block */
#ifdef H5MF_AGGR_DEBUG
                HDfprintf(stderr, "%s: Allocating block\n", FUNC);
#endif /* H5MF_AGGR_DEBUG */

                if (aggr_frag_size > (ext_size - size))
                    ext_size += (aggr_frag_size - (ext_size - size));

                /* Check for overlapping into file's temporary allocation space */
                if (H5F_addr_gt((aggr->addr + aggr->size + ext_size), f->shared->tmp_addr))
                    HGOTO_ERROR(
                        H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF,
                        "'normal' file space allocation request will overlap into 'temporary' file space")

                if ((aggr->addr > 0) &&
                    (extended = H5F__try_extend(f, alloc_type, (aggr->addr + aggr->size), ext_size)) < 0)
                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't extending space")
                else if (extended) {
                    aggr->addr += aggr_frag_size;
                    aggr->size += (ext_size - aggr_frag_size);
                    aggr->tot_size += ext_size;
                } /* end else-if */
                else {
                    haddr_t new_space; /* Address of new space allocated */

                    /* Release "other" aggregator, if it exists, is at the end of the allocated space,
                     * has allocated more than one block and the unallocated space is greater than its
                     * allocation block size.
                     */
                    if ((other_aggr->size > 0) && (H5F_addr_eq((other_aggr->addr + other_aggr->size), eoa)) &&
                        (other_aggr->tot_size > other_aggr->size) &&
                        ((other_aggr->tot_size - other_aggr->size) >= other_aggr->alloc_size)) {
                        if (H5MF__aggr_free(f, other_alloc_type, other_aggr) < 0)
                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF,
                                        "can't free aggregation block")
                    } /* end if */

                    /* Allocate space from the VFD (i.e. at the end of the file) */
                    if (HADDR_UNDEF == (new_space = H5F__alloc(f, alloc_type, aggr->alloc_size,
                                                               &eoa_frag_addr, &eoa_frag_size)))
                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")

                    /* Return the unused portion of the block to a free list */
                    if (aggr->size > 0)
                        if (H5MF_xfree(f, alloc_type, aggr->addr, aggr->size) < 0)
                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF,
                                        "can't free aggregation block")

                    /* If the block is not to be aligned, fold the eoa fragment
                     * into the newly allocated aggregator, as it could have
                     * been allocated in an aligned manner if the aggregator
                     * block is larger than the threshold */
                    if (eoa_frag_size && !alignment) {
                        HDassert(eoa_frag_addr + eoa_frag_size == new_space);
                        aggr->addr     = eoa_frag_addr;
                        aggr->size     = aggr->alloc_size + eoa_frag_size;
                        aggr->tot_size = aggr->size;

                        /* Reset EOA fragment */
                        eoa_frag_addr = HADDR_UNDEF;
                        eoa_frag_size = 0;
                    } /* end if */
                    else {
                        /* Point the aggregator at the newly allocated block */
                        aggr->addr     = new_space;
                        aggr->size     = aggr->alloc_size;
                        aggr->tot_size = aggr->alloc_size;
                    } /* end else */
                }     /* end else */

                /* Allocate space out of the metadata block */
                ret_value = aggr->addr;
                aggr->size -= size;
                aggr->addr += size;
            } /* end else */

            /* Freeing any possible fragment due to file allocation */
            if (eoa_frag_size)
                if (H5MF_xfree(f, alloc_type, eoa_frag_addr, eoa_frag_size) < 0)
                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free eoa fragment")

            /* Freeing any possible fragment due to alignment in the block after extension */
            if (extended && aggr_frag_size)
                if (H5MF_xfree(f, alloc_type, aggr_frag_addr, aggr_frag_size) < 0)
                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free aggregation fragment")
        } /* end if */
        else {
            /* Allocate space out of the block */
            ret_value = aggr->addr + aggr_frag_size;
            aggr->size -= (size + aggr_frag_size);
            aggr->addr += (size + aggr_frag_size);

            /* free any possible fragment */
            if (aggr_frag_size)
                if (H5MF_xfree(f, alloc_type, aggr_frag_addr, aggr_frag_size) < 0)
                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free aggregation fragment")
        } /* end else */
    }     /* end if */
    else {
        /* Allocate data from the file */
        if (HADDR_UNDEF == (ret_value = H5F__alloc(f, type, size, &eoa_frag_addr, &eoa_frag_size)))
            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")

        /* Check if fragment was generated */
        if (eoa_frag_size)
            /* Put fragment on the free list */
            if (H5MF_xfree(f, type, eoa_frag_addr, eoa_frag_size) < 0)
                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free eoa fragment")
    } /* end else */

    /* Sanity check for overlapping into file's temporary allocation space */
    HDassert(H5F_addr_le((ret_value + size), f->shared->tmp_addr));

    /* Post-condition sanity check */
    if (H5F_ALIGNMENT(f) && size >= H5F_THRESHOLD(f))
        HDassert(!((ret_value + H5FD_get_base_addr(f->shared->lf)) % H5F_ALIGNMENT(f)));

done:
#ifdef H5MF_AGGR_DEBUG
    HDfprintf(stderr, "%s: ret_value = %a\n", FUNC, ret_value);
#endif /* H5MF_AGGR_DEBUG */
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF__aggr_alloc() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_try_extend
 *
 * Purpose:	Check if a block is inside an aggregator block and extend it
 *              if possible.
 *
 * Note:
 *	        When the block to be extended adjoins the aggregator--
 *		    1) When the aggregator is at end of file:
 *		       A) If the request is below the threshold, extend the block into the aggregator
 *		       B) If the request is above the threshold,
 *			    a) extend the aggregator by aggr->alloc_size or the extended amount
 *			    b) extend the block into the aggregator
 *		    2) When the aggregator is not at end of file:
 *		       Extended the block into the aggregator if it has enough space to satisfy the request
 *
 * Return:	Success:	TRUE(1)  - Block was extended
 *                              FALSE(0) - Block could not be extended
 * 		Failure:	FAIL
 *
 * Programmer:  Quincey Koziol
 *              Thursday, December 13, 2007
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5MF__aggr_try_extend(H5F_t *f, H5F_blk_aggr_t *aggr, H5FD_mem_t type, haddr_t blk_end,
                      hsize_t extra_requested)
{
    htri_t ret_value = FALSE; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check args */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);

    /* Check if this aggregator is active */
    if (f->shared->feature_flags & aggr->feature_flag) {
        /*
         * If the block being tested adjoins the beginning of the aggregator
         *      block, check if the aggregator can accommodate the extension.
         */
        if (H5F_addr_eq(blk_end, aggr->addr)) {
            haddr_t eoa; /* EOA for the file */

            /* Get the EOA for the file */
            if (HADDR_UNDEF == (eoa = H5F_get_eoa(f, type)))
                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "Unable to get eoa")

            /* If the aggregator is at the end of file: */
            if (H5F_addr_eq(eoa, aggr->addr + aggr->size)) {
                /* If extra_requested is below percentage threshold, extend block into the aggregator. */
                if (extra_requested <= (hsize_t)(EXTEND_THRESHOLD * (float)aggr->size)) {
                    aggr->size -= extra_requested;
                    aggr->addr += extra_requested;

                    /* Indicate success */
                    HGOTO_DONE(TRUE);
                } /* end if */
                /*
                 * If extra_requested is above percentage threshold:
                 * 1) "bubble" up the aggregator by aggr->alloc_size or extra_requested
                 * 2) extend the block into the aggregator
                 */
                else {
                    hsize_t extra = (extra_requested < aggr->alloc_size) ? aggr->alloc_size : extra_requested;

                    if ((ret_value = H5F__try_extend(f, type, (aggr->addr + aggr->size), extra)) < 0)
                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending file")
                    else if (ret_value == TRUE) {
                        /* Shift the aggregator block by the extra requested */
                        /* (allocates the space for the extra_requested) */
                        aggr->addr += extra_requested;

                        /* Add extra to the aggregator's total allocated amount */
                        aggr->tot_size += extra;

                        /* Account for any space added to the aggregator */
                        /* (either 0 (if extra_requested > aggr->alloc_size) or
                         *      (aggr->alloc_size - extra_requested) -QAK
                         */
                        aggr->size += extra;
                        aggr->size -= extra_requested;
                    } /* end else-if */
                }     /* end else */
            }         /* end if */
            else {
                /* The aggreator is not at end of file */
                /* Check if aggregator has enough internal space to satisfy the extension. */
                if (aggr->size >= extra_requested) {
                    /* Extend block into aggregator */
                    aggr->size -= extra_requested;
                    aggr->addr += extra_requested;

                    /* Indicate success */
                    HGOTO_DONE(TRUE);
                } /* end if */
            }     /* end else */
        }         /* end if */
    }             /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF__aggr_try_extend() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_can_absorb
 *
 * Purpose:	Check if a section adjoins an aggregator block and one can
 *              absorb the other.
 *
 * Return:	Success:	TRUE(1)  - Section or aggregator can be absorbed
 *                              FALSE(0) - Section and aggregator can not be absorbed
 * 		Failure:	FAIL
 *
 * Programmer:  Quincey Koziol
 *              Friday, February  1, 2008
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5MF__aggr_can_absorb(const H5F_t *f, const H5F_blk_aggr_t *aggr, const H5MF_free_section_t *sect,
                      H5MF_shrink_type_t *shrink)
{
    htri_t ret_value = FALSE; /* Return value */

    FUNC_ENTER_PACKAGE_NOERR

    /* Check args */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);
    HDassert(sect);
    HDassert(shrink);

    /* Check if this aggregator is active */
    if (f->shared->feature_flags & aggr->feature_flag) {
        /* Check if the block adjoins the beginning or end of the aggregator */
        if (H5F_addr_eq((sect->sect_info.addr + sect->sect_info.size), aggr->addr) ||
            H5F_addr_eq((aggr->addr + aggr->size), sect->sect_info.addr)) {
#ifdef H5MF_AGGR_DEBUG
            HDfprintf(stderr, "%s: section {%a, %Hu} adjoins aggr = {%a, %Hu}\n", "H5MF__aggr_can_absorb",
                      sect->sect_info.addr, sect->sect_info.size, aggr->addr, aggr->size);
#endif /* H5MF_AGGR_DEBUG */
            /* Check if aggregator would get too large and should be absorbed into section */
            if ((aggr->size + sect->sect_info.size) >= aggr->alloc_size)
                *shrink = H5MF_SHRINK_SECT_ABSORB_AGGR;
            else
                *shrink = H5MF_SHRINK_AGGR_ABSORB_SECT;

            /* Indicate success */
            HGOTO_DONE(TRUE)
        } /* end if */
    }     /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF__aggr_can_absorb() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_absorb
 *
 * Purpose:	Absorb a free space section into an aggregator block or
 *              vice versa.
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:  Quincey Koziol
 *              Friday, February  1, 2008
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5MF__aggr_absorb(const H5F_t H5_ATTR_UNUSED *f, H5F_blk_aggr_t *aggr, H5MF_free_section_t *sect,
                  hbool_t allow_sect_absorb)
{
    FUNC_ENTER_PACKAGE_NOERR

    /* Check args */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);
    HDassert(f->shared->feature_flags & aggr->feature_flag);
    HDassert(sect);

    /* Check if aggregator would get too large and should be absorbed into section */
    if ((aggr->size + sect->sect_info.size) >= aggr->alloc_size && allow_sect_absorb) {
        /* Check if the section adjoins the beginning or end of the aggregator */
        if (H5F_addr_eq((sect->sect_info.addr + sect->sect_info.size), aggr->addr)) {
#ifdef H5MF_AGGR_DEBUG
            HDfprintf(stderr, "%s: aggr {%a, %Hu} adjoins front of section = {%a, %Hu}\n",
                      "H5MF__aggr_absorb", aggr->addr, aggr->size, sect->sect_info.addr,
                      sect->sect_info.size);
#endif /* H5MF_AGGR_DEBUG */
            /* Absorb aggregator onto end of section */
            sect->sect_info.size += aggr->size;
        } /* end if */
        else {
            /* Sanity check */
            HDassert(H5F_addr_eq((aggr->addr + aggr->size), sect->sect_info.addr));

#ifdef H5MF_AGGR_DEBUG
            HDfprintf(stderr, "%s: aggr {%a, %Hu} adjoins end of section = {%a, %Hu}\n", "H5MF__aggr_absorb",
                      aggr->addr, aggr->size, sect->sect_info.addr, sect->sect_info.size);
#endif /* H5MF_AGGR_DEBUG */
            /* Absorb aggregator onto beginning of section */
            sect->sect_info.addr -= aggr->size;
            sect->sect_info.size += aggr->size;
        } /* end if */

        /* Reset aggregator */
        aggr->tot_size = 0;
        aggr->addr     = 0;
        aggr->size     = 0;
    } /* end if */
    else {
        /* Check if the section adjoins the beginning or end of the aggregator */
        if (H5F_addr_eq((sect->sect_info.addr + sect->sect_info.size), aggr->addr)) {
#ifdef H5MF_AGGR_DEBUG
            HDfprintf(stderr, "%s: section {%a, %Hu} adjoins front of aggr = {%a, %Hu}\n",
                      "H5MF__aggr_absorb", sect->sect_info.addr, sect->sect_info.size, aggr->addr,
                      aggr->size);
#endif /* H5MF_AGGR_DEBUG */
            /* Absorb section onto front of aggregator */
            aggr->addr -= sect->sect_info.size;
            aggr->size += sect->sect_info.size;

            /* Sections absorbed onto front of aggregator count against the total
             * amount of space aggregated together.
             */
            aggr->tot_size -= MIN(aggr->tot_size, sect->sect_info.size);
        } /* end if */
        else {
            /* Sanity check */
            HDassert(H5F_addr_eq((aggr->addr + aggr->size), sect->sect_info.addr));

#ifdef H5MF_AGGR_DEBUG
            HDfprintf(stderr, "%s: section {%a, %Hu} adjoins end of aggr = {%a, %Hu}\n", "H5MF__aggr_absorb",
                      sect->sect_info.addr, sect->sect_info.size, aggr->addr, aggr->size);
#endif /* H5MF_AGGR_DEBUG */
            /* Absorb section onto end of aggregator */
            aggr->size += sect->sect_info.size;
        } /* end if */
        /* Sanity check */
        HDassert(!allow_sect_absorb || (aggr->size < aggr->alloc_size));
    } /* end else */

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5MF__aggr_absorb() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_query
 *
 * Purpose:     Query a block aggregator's current address & size info
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:  Quincey Koziol
 *              Thursday, December 13, 2007
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5MF__aggr_query(const H5F_t *f, const H5F_blk_aggr_t *aggr, haddr_t *addr, hsize_t *size)
{
    FUNC_ENTER_PACKAGE_NOERR

    /* Check args */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);

    /* Check if this aggregator is active */
    if (f->shared->feature_flags & aggr->feature_flag) {
        if (addr)
            *addr = aggr->addr;
        if (size)
            *size = aggr->size;
    } /* end if */

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5MF__aggr_query() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_reset
 *
 * Purpose:     Reset a block aggregator, returning any space back to file
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:  Quincey Koziol
 *              Thursday, December 13, 2007
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5MF__aggr_reset(H5F_t *f, H5F_blk_aggr_t *aggr)
{
    H5FD_mem_t alloc_type;          /* Type of file memory to work with */
    herr_t     ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_STATIC

    /* Check args */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);

    /* Set the type of memory in the file */
    alloc_type = (aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA
                      ? H5FD_MEM_DEFAULT
                      : H5FD_MEM_DRAW); /* Type of file memory to work with */

    /* Check if this aggregator is active */
    if (f->shared->feature_flags & aggr->feature_flag) {
        haddr_t tmp_addr; /* Temporary holder for aggregator address */
        hsize_t tmp_size; /* Temporary holder for aggregator size */

        /* Retain aggregator info */
        tmp_addr = aggr->addr;
        tmp_size = aggr->size;
#ifdef H5MF_AGGR_DEBUG
        HDfprintf(stderr, "%s: tmp_addr = %a, tmp_size = %Hu\n", FUNC, tmp_addr, tmp_size);
#endif /* H5MF_AGGR_DEBUG */

        /* Reset aggregator block information */
        aggr->tot_size = 0;
        aggr->addr     = 0;
        aggr->size     = 0;

        /* Return the unused portion of the metadata block to the file */
        if (tmp_size > 0 && (H5F_INTENT(f) & H5F_ACC_RDWR))
            if (H5MF_xfree(f, alloc_type, tmp_addr, tmp_size) < 0)
                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't release aggregator's free space")
    } /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF__aggr_reset() */

/*-------------------------------------------------------------------------
 * Function:    H5MF_free_aggrs
 *
 * Purpose:     Reset a metadata & small block aggregators, returning any space
 *		back to file
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:  Vailin Choi
 *	        July 1st, 2009
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5MF_free_aggrs(H5F_t *f)
{
    H5F_blk_aggr_t *first_aggr;              /* First aggregator to reset */
    H5F_blk_aggr_t *second_aggr;             /* Second aggregator to reset */
    haddr_t         ma_addr   = HADDR_UNDEF; /* Base "metadata aggregator" address */
    hsize_t         ma_size   = 0;           /* Size of "metadata aggregator" */
    haddr_t         sda_addr  = HADDR_UNDEF; /* Base "small data aggregator" address */
    hsize_t         sda_size  = 0;           /* Size of "small data aggregator" */
    herr_t          ret_value = SUCCEED;     /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    HDassert(f);
    HDassert(f->shared);
    HDassert(f->shared->lf);

    /* Retrieve metadata aggregator info, if available */
    if (H5MF__aggr_query(f, &(f->shared->meta_aggr), &ma_addr, &ma_size) < 0)
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query metadata aggregator stats")

    /* Retrieve 'small data' aggregator info, if available */
    if (H5MF__aggr_query(f, &(f->shared->sdata_aggr), &sda_addr, &sda_size) < 0)
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query small data aggregator stats")

    /* Make certain we release the aggregator that's later in the file first */
    /* (so the file shrinks properly) */
    if (H5F_addr_defined(ma_addr) && H5F_addr_defined(sda_addr)) {
        if (H5F_addr_lt(ma_addr, sda_addr)) {
            first_aggr  = &(f->shared->sdata_aggr);
            second_aggr = &(f->shared->meta_aggr);
        } /* end if */
        else {
            first_aggr  = &(f->shared->meta_aggr);
            second_aggr = &(f->shared->sdata_aggr);
        } /* end else */
    }     /* end if */
    else {
        first_aggr  = &(f->shared->meta_aggr);
        second_aggr = &(f->shared->sdata_aggr);
    } /* end else */

    /* Release the unused portion of the metadata and "small data" blocks back
     * to the free lists in the file.
     */
    if (H5MF__aggr_reset(f, first_aggr) < 0)
        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't reset metadata block")
    if (H5MF__aggr_reset(f, second_aggr) < 0)
        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't reset 'small data' block")
done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF_free_aggrs() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_can_shrink_eoa
 *
 * Purpose:     Check if the remaining space in the aggregator is at EOA
 *
 * Return:      Success:        non-negative (TRUE/FALSE)
 *              Failure:        negative
 *
 * Programmer:  Vailin Choi
 *
 *-------------------------------------------------------------------------
 */
static htri_t
H5MF__aggr_can_shrink_eoa(H5F_t *f, H5FD_mem_t type, H5F_blk_aggr_t *aggr)
{
    haddr_t eoa       = HADDR_UNDEF; /* EOA for the file */
    htri_t  ret_value = FALSE;       /* Return value */

    FUNC_ENTER_STATIC

    /* Sanity check */
    HDassert(f);
    HDassert(aggr);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);

    /* Get the EOA for the file */
    if (HADDR_UNDEF == (eoa = H5F_get_eoa(f, type)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "Unable to get eoa")

    /* Check if the aggregator is at EOA */
    if (aggr->size > 0 && H5F_addr_defined(aggr->addr))
        ret_value = H5F_addr_eq(eoa, aggr->addr + aggr->size);

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5MF__aggr_can_shrink_eoa() */

/*-------------------------------------------------------------------------
 * Function:    H5MF__aggr_free
 *
 * Purpose:     Free the aggregator's space in the file.
 *
 * Note:        Does _not_ put the space on a free list
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:  Vailin Choi
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5MF__aggr_free(H5F_t *f, H5FD_mem_t type, H5F_blk_aggr_t *aggr)
{
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_STATIC

    /* Sanity check */
    HDassert(f);
    HDassert(f->shared->lf);
    HDassert(aggr);
    HDassert(H5F_addr_defined(aggr->addr));
    HDassert(aggr->size > 0);
    HDassert(H5F_INTENT(f) & H5F_ACC_RDWR);
    HDassert(aggr->feature_flag == H5FD_FEAT_AGGREGATE_METADATA ||
             aggr->feature_flag == H5FD_FEAT_AGGREGATE_SMALLDATA);
    HDassert(f->shared->feature_flags & aggr->feature_flag);

    /* Free the remaining space at EOA in the aggregator */
    if (H5F__free(f, type, aggr->addr, aggr->size) < 0)
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't free aggregation block")

    /* Reset the aggregator */
    aggr->tot_size = 0;
    aggr->addr     = HADDR_UNDEF;
    aggr->size     = 0;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5MF__aggr_free() */

/*-------------------------------------------------------------------------
 * Function:    H5MF_aggrs_try_shrink_eoa
 *
 * Purpose:     Check the metadata & small block aggregators to see if
 *		EOA shrink is possible; if so, shrink each aggregator
 *
 * Return:      Success:        Non-negative
 *              Failure:        Negative
 *
 * Programmer:  Vailin Choi
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5MF_aggrs_try_shrink_eoa(H5F_t *f)
{
    htri_t ma_status;        /* Whether the metadata aggregator can shrink the EOA */
    htri_t sda_status;       /* Whether the small data aggregator can shrink the EOA */
    htri_t ret_value = FAIL; /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    HDassert(f);
    HDassert(f->shared);

    if ((ma_status = H5MF__aggr_can_shrink_eoa(f, H5FD_MEM_DEFAULT, &(f->shared->meta_aggr))) < 0)
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query metadata aggregator stats")
    if (ma_status > 0)
        if (H5MF__aggr_free(f, H5FD_MEM_DEFAULT, &(f->shared->meta_aggr)) < 0)
            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")

    if ((sda_status = H5MF__aggr_can_shrink_eoa(f, H5FD_MEM_DRAW, &(f->shared->sdata_aggr))) < 0)
        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query small data aggregator stats")
    if (sda_status > 0)
        if (H5MF__aggr_free(f, H5FD_MEM_DRAW, &(f->shared->sdata_aggr)) < 0)
            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")

    ret_value = (ma_status || sda_status);

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5MF_aggrs_try_shrink_eoa() */