Example #1
0
/*
 * Estimate the space needed for a hashtable containing the given number
 * of entries of given size.
 * NOTE: this is used to estimate the footprint of hashtables in shared
 * memory; therefore it does not count HTAB which is in local memory.
 * NB: assumes that all hash structure parameters have default values!
 */
long
hash_estimate_size(long num_entries, Size entrysize)
{
	long		size = 0;
	long		nBuckets,
				nSegments,
				nDirEntries,
				nElementAllocs,
				elementSize;

	/* estimate number of buckets wanted */
	nBuckets = 1L << my_log2((num_entries - 1) / DEF_FFACTOR + 1);
	/* # of segments needed for nBuckets */
	nSegments = 1L << my_log2((nBuckets - 1) / DEF_SEGSIZE + 1);
	/* directory entries */
	nDirEntries = DEF_DIRSIZE;
	while (nDirEntries < nSegments)
		nDirEntries <<= 1;		/* dir_alloc doubles dsize at each call */

	/* fixed control info */
	size += MAXALIGN(sizeof(HASHHDR));	/* but not HTAB, per above */
	/* directory */
	size += MAXALIGN(nDirEntries * sizeof(HASHSEGMENT));
	/* segments */
	size += nSegments * MAXALIGN(DEF_SEGSIZE * sizeof(HASHBUCKET));
	/* elements --- allocated in groups of HASHELEMENT_ALLOC_INCR */
	elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
	nElementAllocs = (num_entries - 1) / HASHELEMENT_ALLOC_INCR + 1;
	size += nElementAllocs * HASHELEMENT_ALLOC_INCR * elementSize;

	return size;
}
Example #2
0
/***********************************************************************
 * Mix two arrays in log space.
 ***********************************************************************/
void mix_log_arrays
  (float    mixing, /* Percent of array2 that will be retained. */
   ARRAY_T* array1,
   ARRAY_T* array2)
{
  int   i_item;
  int   num_items;
  ATYPE mixed_value;

  check_null_array(array1);
  check_null_array(array2);

  /* Verify that the arrays are of the same length. */
  check_array_dimensions(TRUE, array1, array2);

  /* Verify that we've got a reasonable mixing parameter. */
  if ((mixing > 1.0) || (mixing < 0.0)) {
    die("Invalid mixing parameter (%g).\n", mixing);
  }

  num_items = get_array_length(array1);
  for (i_item = 0; i_item < num_items; i_item++) {
    mixed_value
      = LOG_SUM(my_log2(1.0 - mixing) + get_array_item(i_item, array1),
		my_log2(mixing) + get_array_item(i_item, array2));
    set_array_item(i_item, mixed_value, array2);
  }
}
Example #3
0
/**************************************************************************
*	get_scaled_lo_prior_dist
*
*	Takes a scaled distribution of priors and creates a scaled distribution of
*	log odds priors. The parameters for the scaling of the input priors are
*	in the PRIOR_DIST_T data structure. The output distribution of log odss
*	priors are scaled to be in the same range as the PSSM	log odds using
*	the input parameters pssm_range, pssm_scale, and pssm_offset.
*
*	Special handling is required for a uniform distribution of priors.
*	In that case the max_prior == min_prior, and the distribution only 
*	contains one bin.
*
* Returns a new array containing the scaled log odds priors
**************************************************************************/
ARRAY_T  *get_scaled_lo_prior_dist(
  PRIOR_DIST_T *prior_dist,
  double alpha,			   
  int pssm_range,
  double pssm_scale,
  double pssm_offset
) {

  assert(prior_dist != NULL);
  // Alocate enought space for elements in [0 ... pssm_range]
  ARRAY_T *scaled_lo_prior_dist = allocate_array(pssm_range + 1);

  if (prior_dist != NULL) {

    ARRAY_T *dist_array = get_prior_dist_array(prior_dist);
    int len_prior_dist = get_array_length(dist_array);
    double max_prior = get_prior_dist_maximum(prior_dist);
    double min_prior = get_prior_dist_minimum(prior_dist);
    double prior_dist_scale = get_prior_dist_scale(prior_dist);
    double prior_dist_offset = get_prior_dist_offset(prior_dist);
    init_array(0.0L, scaled_lo_prior_dist);
    if (max_prior == min_prior) {
        // Special case for uniform priors
        double value = 1.0;
        double lo_prior = my_log2(alpha * max_prior / (1.0L - (alpha * max_prior)));
        // Convert lo_prior to PSSM scale
        int scaled_index = raw_to_scaled(lo_prior, 1.0L, pssm_scale, pssm_offset);
        set_array_item(scaled_index, value, scaled_lo_prior_dist);
    }
    else {
      int prior_index = 0;
      for (prior_index = 0; prior_index < len_prior_dist; ++prior_index) {
        double value = get_array_item(prior_index, dist_array);
        // Convert index giving scaled prior to raw prior.
        double scaled_prior = ((double) prior_index) + 0.5L;
        double prior \
          = scaled_to_raw(scaled_prior, 1, prior_dist_scale, prior_dist_offset);
        double lo_prior = my_log2(alpha * prior / (1.0L - (alpha * prior)));
        // Scale raw lo_prior using parameters from PSSM.
        int scaled_index = raw_to_scaled(lo_prior, 1.0L, pssm_scale, pssm_offset);
        if (scaled_index < pssm_range) {
          double old_value = get_array_item(scaled_index, scaled_lo_prior_dist);
          set_array_item(scaled_index, value + old_value, scaled_lo_prior_dist);
        }
      }
    }
  }

  return scaled_lo_prior_dist;

}
Example #4
0
/* calculate first power of 2 >= num, bounded to what will fit in an int */
static int
next_pow2_int(long num)
{
	if (num > INT_MAX / 2)
		num = INT_MAX / 2;
	return 1 << my_log2(num);
}
Example #5
0
/***********************************************************************
 * Calculates the information content of a position of the motif.
 *
 * Assumes that alph_size does not include ambigious characters.
 ***********************************************************************/
static inline double position_information_content(
  MOTIF_T *a_motif,
  int position
) {
  int i;
  double H, item;
  ARRAY_T *freqs;

  H = 0;
  freqs = get_matrix_row(position, a_motif->freqs);
  for (i = 0; i < a_motif->alph_size; ++i) {
    item = get_array_item(i, freqs);
    H -= item*my_log2(item);
  }
  return my_log2(a_motif->alph_size) - H;
}
Example #6
0
/*
 * Select an appropriate directory size for a hashtable with the given
 * maximum number of entries.
 * This is only needed for hashtables in shared memory, whose directories
 * cannot be expanded dynamically.
 * NB: assumes that all hash structure parameters have default values!
 *
 * XXX this had better agree with the behavior of init_htab()...
 */
long
hash_select_dirsize(long num_entries)
{
	long		nBuckets,
				nSegments,
				nDirEntries;

	/* estimate number of buckets wanted */
	nBuckets = 1L << my_log2((num_entries - 1) / DEF_FFACTOR + 1);
	/* # of segments needed for nBuckets */
	nSegments = 1L << my_log2((nBuckets - 1) / DEF_SEGSIZE + 1);
	/* directory entries */
	nDirEntries = DEF_DIRSIZE;
	while (nDirEntries < nSegments)
		nDirEntries <<= 1;		/* dir_alloc doubles dsize at each call */

	return nDirEntries;
}
Example #7
0
/***********************************************************************
 * Convert an array to and from logs (base 2).
 ***********************************************************************/
void log_array
  (ARRAY_T* array)
{
  int i_item;
  int num_items;

  check_null_array(array);

  num_items = get_array_length(array);
  for (i_item = 0; i_item < num_items; i_item++) {
    set_array_item(i_item, my_log2(get_array_item(i_item, array)), array);
  }
}
Example #8
0
/*
 * Estimate the space needed for a hashtable containing the given number
 * of entries of given size.
 * NOTE: this is used to estimate the footprint of hashtables in shared
 * memory; therefore it does not count HTAB which is in local memory.
 * NB: assumes that all hash structure parameters have default values!
 */
Size
hash_estimate_size(long num_entries, Size entrysize)
{
	Size		size;
	long		nBuckets,
				nSegments,
				nDirEntries,
				nElementAllocs,
				elementSize,
				elementAllocCnt;

	/* estimate number of buckets wanted */
	nBuckets = 1L << my_log2((num_entries - 1) / DEF_FFACTOR + 1);
	/* # of segments needed for nBuckets */
	nSegments = 1L << my_log2((nBuckets - 1) / DEF_SEGSIZE + 1);
	/* directory entries */
	nDirEntries = DEF_DIRSIZE;
	while (nDirEntries < nSegments)
		nDirEntries <<= 1;		/* dir_alloc doubles dsize at each call */

	/* fixed control info */
	size = MAXALIGN(sizeof(HASHHDR));	/* but not HTAB, per above */
	/* directory */
	size = add_size(size, mul_size(nDirEntries, sizeof(HASHSEGMENT)));
	/* segments */
	size = add_size(size, mul_size(nSegments,
								MAXALIGN(DEF_SEGSIZE * sizeof(HASHBUCKET))));
	/* elements --- allocated in groups of choose_nelem_alloc() entries */
	elementAllocCnt = choose_nelem_alloc(entrysize);
	nElementAllocs = (num_entries - 1) / elementAllocCnt + 1;
	elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
	size = add_size(size,
					mul_size(nElementAllocs,
							 mul_size(elementAllocCnt, elementSize)));

	return size;
}
INT32 bdev_open(struct super_block *sb)
{
BD_INFO_T *p_bd = &(EXFAT_SB(sb)->bd_info);

if (p_bd->opened) return(FFS_SUCCESS);

p_bd->sector_size = bdev_logical_block_size(sb->s_bdev);
p_bd->sector_size_bits = my_log2(p_bd->sector_size);
p_bd->sector_size_mask = p_bd->sector_size - 1;
p_bd->num_sectors = i_size_read(sb->s_bdev->bd_inode) >> p_bd->sector_size_bits;

p_bd->opened = TRUE;

return(FFS_SUCCESS);
}
Example #10
0
static double
SECTION
power1(double x, double y) {
  double z,a,aa,error, t,a1,a2,y1,y2;
  z = my_log2(x,&aa,&error);
  t = y*134217729.0;
  y1 = t - (t-y);
  y2 = y - y1;
  t = z*134217729.0;
  a1 = t - (t-z);
  a2 = z - a1;
  a = y*z;
  aa = ((y1*a1-a)+y1*a2+y2*a1)+y2*a2+aa*y;
  a1 = a+aa;
  a2 = (a-a1)+aa;
  error = error*ABS(y);
  t = __exp1(a1,a2,1.9e16*error);
  return (t >= 0)?t:__slowpow(x,y,z);
}
Example #11
0
/*
 * Take the counts from an ambiguous character and evenly distribute
 * them among the corresponding concrete characters.
 *
 * This function operates in log space.
 */
static void dist_ambig(ALPH_T alph, char ambig, char *concrete_chars, 
    ARRAY_T* freqs) {
  PROB_T ambig_count, concrete_count;
  int ambig_index, num_concretes, i, concrete_index;

  // Get the count to be distributed.
  ambig_index = alph_index(alph, ambig);
  ambig_count = get_array_item(ambig_index, freqs);
  // Divide it by the number of corresponding concrete characters.
  num_concretes = strlen(concrete_chars);
  ambig_count -= my_log2((PROB_T)num_concretes);
  // Distribute it in equal portions to the given concrete characters.
  for (i = 0; i < num_concretes; i++) {
    concrete_index = alph_index(alph, concrete_chars[i]);
    concrete_count = get_array_item(concrete_index, freqs);
    // Add the ambiguous counts.
    concrete_count = LOG_SUM(concrete_count, ambig_count);
    set_array_item(concrete_index, concrete_count, freqs);
  }
  // Set the ambiguous count to zero.
  set_array_item(ambig_index, LOG_ZERO, freqs);
}
/**
 * Function for finding and opening either all MCA components, or the one
 * that was specifically requested via a MCA parameter.
 */
static int mca_mpool_base_open(mca_base_open_flag_t flags)
{
    /* Open up all available components - and populate the
       ompi_mpool_base_framework.framework_components list */
    if (OMPI_SUCCESS != 
        mca_base_framework_components_open(&ompi_mpool_base_framework, flags)) {
        return OMPI_ERROR;
    }
  
     /* Initialize the list so that in mca_mpool_base_close(), we can
        iterate over it (even if it's empty, as in the case of ompi_info) */

    OBJ_CONSTRUCT(&mca_mpool_base_modules, opal_list_t);
  
    /* get the page size for this architecture*/ 
    mca_mpool_base_page_size = sysconf(_SC_PAGESIZE); 
    mca_mpool_base_page_size_log = my_log2(mca_mpool_base_page_size); 

    /* setup tree for tracking MPI_Alloc_mem */ 
    mca_mpool_base_tree_init();
    
    return OMPI_SUCCESS;
}
Example #13
0
/**************************************************************************
 * Convert a given array to or from logs.
 **************************************************************************/
void convert_to_from_log_array
  (BOOLEAN_T to_log,
   ARRAY_T*  source_array,
   ARRAY_T*  target_array)
{
  int num_items;
  int i_item;
  ATYPE new_value;

  // If the source is null, just return.
  if (source_array == NULL) 
    return;

  num_items = get_array_length(source_array);
  for (i_item = 0; i_item < num_items; i_item++) {
    if (to_log) {
      new_value = my_log2(get_array_item(i_item, source_array));
    } else {
      new_value = EXP2(get_array_item(i_item, source_array));
    }
    set_array_item(i_item, new_value, target_array);
  }
}
Example #14
0
/**************************************************************************
*	get_max_lo_priors
*
*	Returns the maximum log-odds prior from the disbtribution of priors.
*
**************************************************************************/
double get_max_lo_prior(PRIOR_DIST_T *prior_dist, double alpha) {
  double max_prior = get_prior_dist_maximum(prior_dist);
  return my_log2((alpha * max_prior) / (1.0L - alpha * max_prior));
}
Example #15
0
/// Parse the .lzma header and display information about it.
static bool
lzmainfo(const char *name, FILE *f)
{
	uint8_t buf[13];
	const size_t size = fread(buf, 1, sizeof(buf), f);
	if (size != 13) {
		fprintf(stderr, "%s: %s: %s\n", progname, name,
				ferror(f) ? strerror(errno)
				: _("File is too small to be a .lzma file"));
		return true;
	}

	lzma_filter filter = { .id = LZMA_FILTER_LZMA1 };

	// Parse the first five bytes.
	switch (lzma_properties_decode(&filter, NULL, buf, 5)) {
	case LZMA_OK:
		break;

	case LZMA_OPTIONS_ERROR:
		fprintf(stderr, "%s: %s: %s\n", progname, name,
				_("Not a .lzma file"));
		return true;

	case LZMA_MEM_ERROR:
		fprintf(stderr, "%s: %s\n", progname, strerror(ENOMEM));
		exit(EXIT_FAILURE);

	default:
		fprintf(stderr, "%s: %s\n", progname,
				_("Internal error (bug)"));
		exit(EXIT_FAILURE);
	}

	// Uncompressed size
	uint64_t uncompressed_size = 0;
	for (size_t i = 0; i < 8; ++i)
		uncompressed_size |= (uint64_t)(buf[5 + i]) << (i * 8);

	// Display the results. We don't want to translate these and also
	// will use MB instead of MiB, because someone could be parsing
	// this output and we don't want to break that when people move
	// from LZMA Utils to XZ Utils.
	if (f != stdin)
		printf("%s\n", name);

	printf("Uncompressed size:             ");
	if (uncompressed_size == UINT64_MAX)
		printf("Unknown");
	else
		printf("%" PRIu64 " MB (%" PRIu64 " bytes)",
				(uncompressed_size + 512 * 1024)
					/ (1024 * 1024),
				uncompressed_size);

	lzma_options_lzma *opt = filter.options;

	printf("\nDictionary size:               "
			"%" PRIu32 " MB (2^%" PRIu32 " bytes)\n"
			"Literal context bits (lc):     %" PRIu32 "\n"
			"Literal pos bits (lp):         %" PRIu32 "\n"
			"Number of pos bits (pb):       %" PRIu32 "\n",
			(opt->dict_size + 512 * 1024) / (1024 * 1024),
			my_log2(opt->dict_size), opt->lc, opt->lp, opt->pb);

	free(opt);

	return false;
}
Example #16
0
static int
init_htab (HTAB *hashp, int nelem)
{
    register SEG_OFFSET	*segp;
    register int nbuckets;
    register int nsegs;
    int	l2;
    HHDR	*hctl;
    
    hctl = hashp->hctl;
    /*
     * Divide number of elements by the fill factor and determine a desired
     * number of buckets.  Allocate space for the next greater power of
     * two number of buckets
     */
    nelem = (nelem - 1) / hctl->ffactor + 1;
    
    l2 = my_log2(nelem);
    nbuckets = 1 << l2;
    
    hctl->max_bucket = hctl->low_mask = nbuckets - 1;
    hctl->high_mask = (nbuckets << 1) - 1;
    
    nsegs = (nbuckets - 1) / hctl->ssize + 1;
    nsegs = 1 << my_log2(nsegs);
    
    if ( nsegs > hctl->dsize ) {
	hctl->dsize  = nsegs;
    }
    
    /* Use two low order bits of points ???? */
    /*
      if ( !(hctl->mem = bit_alloc ( nbuckets )) ) return(-1);
      if ( !(hctl->mod = bit_alloc ( nbuckets )) ) return(-1);
      */
    
    /* allocate a directory */
    if (!(hashp->dir)) {
	hashp->dir = 
	    (SEG_OFFSET *)hashp->alloc(hctl->dsize * sizeof(SEG_OFFSET));
	if (! hashp->dir)
	    return(-1);
    }
    
    /* Allocate initial segments */
    for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++ ) {
	*segp = seg_alloc(hashp);
	if ( *segp == (SEG_OFFSET)0 ) {
	    hash_destroy(hashp);
	    return (0);
	}
    }
    
# if HASH_DEBUG
    fprintf(stderr, "%s\n%s%x\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%x\n%s%x\n%s%d\n%s%d\n",
	    "init_htab:",
	    "TABLE POINTER   ", hashp,
	    "BUCKET SIZE     ", hctl->bsize,
	    "BUCKET SHIFT    ", hctl->bshift,
	    "DIRECTORY SIZE  ", hctl->dsize,
	    "SEGMENT SIZE    ", hctl->ssize,
	    "SEGMENT SHIFT   ", hctl->sshift,
	    "FILL FACTOR     ", hctl->ffactor,
	    "MAX BUCKET      ", hctl->max_bucket,
	    "HIGH MASK       ", hctl->high_mask,
	    "LOW  MASK       ", hctl->low_mask,
	    "NSEGS           ", hctl->nsegs,
	    "NKEYS           ", hctl->nkeys );
# endif
    return (0);
}
Example #17
0
HTAB *
hash_create(int nelem, HASHCTL *info, int flags)
{
    register HHDR *	hctl;
    HTAB * 		hashp;
    
    
    hashp = (HTAB *) MEM_ALLOC((unsigned long) sizeof(HTAB));
    memset(hashp, 0, sizeof(HTAB)); 
    
    if ( flags & HASH_FUNCTION ) {
	hashp->hash    = info->hash;
    } else {
	/* default */
	hashp->hash	 = string_hash;
    }
    
    if ( flags & HASH_SHARED_MEM )  {
	/* ctl structure is preallocated for shared memory tables */
	
	hashp->hctl     = (HHDR *) info->hctl;
	hashp->segbase  = (char *) info->segbase; 
	hashp->alloc    = info->alloc;
	hashp->dir 	  = (SEG_OFFSET *)info->dir;
	
	/* hash table already exists, we're just attaching to it */
	if (flags & HASH_ATTACH) {
	    return(hashp);
	}
	
    } else {
	/* setup hash table defaults */
	
	hashp->alloc	  = (dhalloc_ptr) MEM_ALLOC;
	hashp->dir	  = NULL;
	hashp->segbase  = NULL;
	
    }
    
    if (! hashp->hctl) {
	hashp->hctl = (HHDR *) hashp->alloc((unsigned long)sizeof(HHDR));
	if (! hashp->hctl) {
	    return(0);
	}
    }
    
    if ( !hdefault(hashp) ) return(0);
    hctl = hashp->hctl;
#ifdef HASH_STATISTICS
    hctl->accesses = hctl->collisions = 0;
#endif
    
    if ( flags & HASH_BUCKET )   {
	hctl->bsize   = info->bsize;
	hctl->bshift  = my_log2(info->bsize);
    }
    if ( flags & HASH_SEGMENT )  {
	hctl->ssize   = info->ssize;
	hctl->sshift  = my_log2(info->ssize);
    }
    if ( flags & HASH_FFACTOR )  {
	hctl->ffactor = info->ffactor;
    }
    
    /*
     * SHM hash tables have fixed maximum size (allocate
     * a maximal sized directory).
     */
    if ( flags & HASH_DIRSIZE )  {
	hctl->max_dsize = my_log2(info->max_size);
	hctl->dsize     = my_log2(info->dsize);
    }
    /* hash table now allocates space for key and data
     * but you have to say how much space to allocate 
     */
    if ( flags & HASH_ELEM ) {
	hctl->keysize    = info->keysize; 
	hctl->datasize   = info->datasize;
    }
    if ( flags & HASH_ALLOC )  {
	hashp->alloc = info->alloc;
    }
    
    if ( init_htab (hashp, nelem ) ) {
	hash_destroy(hashp);
	return(0);
    }
    return(hashp);
}
Example #18
0
/*
 * hash_create -- create a new dynamic hash table
 *
 *	tabname: a name for the table (for debugging purposes)
 *	nelem: maximum number of elements expected
 *	*info: additional table parameters, as indicated by flags
 *	flags: bitmask indicating which parameters to take from *info
 *
 * Note: for a shared-memory hashtable, nelem needs to be a pretty good
 * estimate, since we can't expand the table on the fly.  But an unshared
 * hashtable can be expanded on-the-fly, so it's better for nelem to be
 * on the small side and let the table grow if it's exceeded.  An overly
 * large nelem will penalize hash_seq_search speed without buying much.
 */
HTAB *
hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
{
	HTAB	   *hashp;
	HASHHDR    *hctl;

	/*
	 * For shared hash tables, we have a local hash header (HTAB struct) that
	 * we allocate in TopMemoryContext; all else is in shared memory.
	 *
	 * For non-shared hash tables, everything including the hash header is in
	 * a memory context created specially for the hash table --- this makes
	 * hash_destroy very simple.  The memory context is made a child of either
	 * a context specified by the caller, or TopMemoryContext if nothing is
	 * specified.
	 */
	if (flags & HASH_SHARED_MEM)
	{
		/* Set up to allocate the hash header */
		CurrentDynaHashCxt = TopMemoryContext;
	}
	else
	{
		/* Create the hash table's private memory context */
		if (flags & HASH_CONTEXT)
			CurrentDynaHashCxt = info->hcxt;
		else
			CurrentDynaHashCxt = TopMemoryContext;
		CurrentDynaHashCxt = AllocSetContextCreate(CurrentDynaHashCxt,
												   tabname,
												   ALLOCSET_DEFAULT_MINSIZE,
												   ALLOCSET_DEFAULT_INITSIZE,
												   ALLOCSET_DEFAULT_MAXSIZE);
	}

	/* Initialize the hash header, plus a copy of the table name */
	hashp = (HTAB *) DynaHashAlloc(sizeof(HTAB) + strlen(tabname) +1);
	MemSet(hashp, 0, sizeof(HTAB));

	hashp->tabname = (char *) (hashp + 1);
	strcpy(hashp->tabname, tabname);

	if (flags & HASH_FUNCTION)
		hashp->hash = info->hash;
	else
		hashp->hash = string_hash;		/* default hash function */

	/*
	 * If you don't specify a match function, it defaults to string_compare if
	 * you used string_hash (either explicitly or by default) and to memcmp
	 * otherwise.  (Prior to PostgreSQL 7.4, memcmp was always used.)
	 */
	if (flags & HASH_COMPARE)
		hashp->match = info->match;
	else if (hashp->hash == string_hash)
		hashp->match = (HashCompareFunc) string_compare;
	else
		hashp->match = memcmp;

	/*
	 * Similarly, the key-copying function defaults to strlcpy or memcpy.
	 */
	if (flags & HASH_KEYCOPY)
		hashp->keycopy = info->keycopy;
	else if (hashp->hash == string_hash)
		hashp->keycopy = (HashCopyFunc) strlcpy;
	else
		hashp->keycopy = memcpy;

	if (flags & HASH_ALLOC)
		hashp->alloc = info->alloc;
	else
		hashp->alloc = DynaHashAlloc;

	if (flags & HASH_SHARED_MEM)
	{
		/*
		 * ctl structure and directory are preallocated for shared memory
		 * tables.	Note that HASH_DIRSIZE and HASH_ALLOC had better be set as
		 * well.
		 */
		hashp->hctl = info->hctl;
		hashp->dir = (HASHSEGMENT *) (((char *) info->hctl) + sizeof(HASHHDR));
		hashp->hcxt = NULL;
		hashp->isshared = true;

		/* hash table already exists, we're just attaching to it */
		if (flags & HASH_ATTACH)
		{
			/* make local copies of some heavily-used values */
			hctl = hashp->hctl;
			hashp->keysize = hctl->keysize;
			hashp->ssize = hctl->ssize;
			hashp->sshift = hctl->sshift;

			return hashp;
		}
	}
	else
	{
		/* setup hash table defaults */
		hashp->hctl = NULL;
		hashp->dir = NULL;
		hashp->hcxt = CurrentDynaHashCxt;
		hashp->isshared = false;
	}

	if (!hashp->hctl)
	{
		hashp->hctl = (HASHHDR *) hashp->alloc(sizeof(HASHHDR));
		if (!hashp->hctl)
			ereport(ERROR,
					(errcode(ERRCODE_OUT_OF_MEMORY),
					 errmsg("out of memory")));
	}

	hashp->frozen = false;

	hdefault(hashp);

	hctl = hashp->hctl;

	if (flags & HASH_PARTITION)
	{
		/* Doesn't make sense to partition a local hash table */
		Assert(flags & HASH_SHARED_MEM);

		/*
		 * The number of partitions had better be a power of 2. Also, it must
		 * be less than INT_MAX (see init_htab()), so call the int version of
		 * next_pow2.
		 */
		Assert(info->num_partitions == next_pow2_int(info->num_partitions));

		hctl->num_partitions = info->num_partitions;
	}

	if (flags & HASH_SEGMENT)
	{
		hctl->ssize = info->ssize;
		hctl->sshift = my_log2(info->ssize);
		/* ssize had better be a power of 2 */
		Assert(hctl->ssize == (1L << hctl->sshift));
	}
	if (flags & HASH_FFACTOR)
		hctl->ffactor = info->ffactor;

	/*
	 * SHM hash tables have fixed directory size passed by the caller.
	 */
	if (flags & HASH_DIRSIZE)
	{
		hctl->max_dsize = info->max_dsize;
		hctl->dsize = info->dsize;
	}

	/*
	 * hash table now allocates space for key and data but you have to say how
	 * much space to allocate
	 */
	if (flags & HASH_ELEM)
	{
		Assert(info->entrysize >= info->keysize);
		hctl->keysize = info->keysize;
		hctl->entrysize = info->entrysize;
	}

	/* make local copies of heavily-used constant fields */
	hashp->keysize = hctl->keysize;
	hashp->ssize = hctl->ssize;
	hashp->sshift = hctl->sshift;

	/* Build the hash directory structure */
	if (!init_htab(hashp, nelem))
		elog(ERROR, "failed to initialize hash table \"%s\"", hashp->tabname);

	/*
	 * For a shared hash table, preallocate the requested number of elements.
	 * This reduces problems with run-time out-of-shared-memory conditions.
	 *
	 * For a non-shared hash table, preallocate the requested number of
	 * elements if it's less than our chosen nelem_alloc.  This avoids wasting
	 * space if the caller correctly estimates a small table size.
	 */
	if ((flags & HASH_SHARED_MEM) ||
		nelem < hctl->nelem_alloc)
	{
		if (!element_alloc(hashp, (int) nelem))
			ereport(ERROR,
					(errcode(ERRCODE_OUT_OF_MEMORY),
					 errmsg("out of memory")));
	}

	if (flags & HASH_FIXED_SIZE)
		hashp->isfixed = true;
	return hashp;
}
Example #19
0
static bool
init_htab(HTAB *hashp, long nelem)
{
	HASHHDR    *hctl = hashp->hctl;
	HASHSEGMENT *segp;
	int			nbuckets;
	int			nsegs;

	/*
	 * Divide number of elements by the fill factor to determine a desired
	 * number of buckets.  Allocate space for the next greater power of
	 * two number of buckets
	 */
	nelem = (nelem - 1) / hctl->ffactor + 1;

	nbuckets = 1 << my_log2(nelem);

	hctl->max_bucket = hctl->low_mask = nbuckets - 1;
	hctl->high_mask = (nbuckets << 1) - 1;

	/*
	 * Figure number of directory segments needed, round up to a power of
	 * 2
	 */
	nsegs = (nbuckets - 1) / hctl->ssize + 1;
	nsegs = 1 << my_log2(nsegs);

	/*
	 * Make sure directory is big enough. If pre-allocated directory is
	 * too small, choke (caller screwed up).
	 */
	if (nsegs > hctl->dsize)
	{
		if (!(hashp->dir))
			hctl->dsize = nsegs;
		else
			return false;
	}

	/* Allocate a directory */
	if (!(hashp->dir))
	{
		CurrentDynaHashCxt = hashp->hcxt;
		hashp->dir = (HASHSEGMENT *)
			hashp->alloc(hctl->dsize * sizeof(HASHSEGMENT));
		if (!hashp->dir)
			return false;
	}

	/* Allocate initial segments */
	for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++)
	{
		*segp = seg_alloc(hashp);
		if (*segp == NULL)
			return false;
	}

#if HASH_DEBUG
	fprintf(stderr, "init_htab:\n%s%p\n%s%ld\n%s%ld\n%s%d\n%s%ld\n%s%u\n%s%x\n%s%x\n%s%ld\n%s%ld\n",
			"TABLE POINTER   ", hashp,
			"DIRECTORY SIZE  ", hctl->dsize,
			"SEGMENT SIZE    ", hctl->ssize,
			"SEGMENT SHIFT   ", hctl->sshift,
			"FILL FACTOR     ", hctl->ffactor,
			"MAX BUCKET      ", hctl->max_bucket,
			"HIGH MASK       ", hctl->high_mask,
			"LOW  MASK       ", hctl->low_mask,
			"NSEGS           ", hctl->nsegs,
			"NENTRIES        ", hctl->nentries);
#endif
	return true;
}
Example #20
0
/* calculate first power of 2 >= num, bounded to what will fit in a long */
static long
next_pow2_long(long num)
{
	/* my_log2's internal range check is sufficient */
	return 1L << my_log2(num);
}
Example #21
0
      static base_t my_log2p1(const base_t &i) 
	{
	  return my_log2(i+1.0);
	}
Example #22
0
HTAB *
hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
{
	HTAB	   *hashp;
	HASHHDR    *hctl;

	/* First time through, create a memory context for hash tables */
	if (!DynaHashCxt)
		DynaHashCxt = AllocSetContextCreate(TopMemoryContext,
											"DynaHash",
											ALLOCSET_DEFAULT_MINSIZE,
											ALLOCSET_DEFAULT_INITSIZE,
											ALLOCSET_DEFAULT_MAXSIZE);

	/* Select allocation context for this hash table */
	if (flags & HASH_CONTEXT)
		CurrentDynaHashCxt = info->hcxt;
	else
		CurrentDynaHashCxt = DynaHashCxt;

	/* Initialize the hash header */
	hashp = (HTAB *) MEM_ALLOC(sizeof(HTAB));
	if (!hashp)
		return NULL;
	MemSet(hashp, 0, sizeof(HTAB));

	hashp->tabname = (char *) MEM_ALLOC(strlen(tabname) + 1);
	strcpy(hashp->tabname, tabname);

	if (flags & HASH_FUNCTION)
		hashp->hash = info->hash;
	else
		hashp->hash = string_hash;		/* default hash function */

	/*
	 * If you don't specify a match function, it defaults to strncmp() if
	 * you used string_hash (either explicitly or by default) and to
	 * memcmp() otherwise.  (Prior to PostgreSQL 7.4, memcmp() was always
	 * used.)
	 */
	if (flags & HASH_COMPARE)
		hashp->match = info->match;
	else if (hashp->hash == string_hash)
		hashp->match = (HashCompareFunc) strncmp;
	else
		hashp->match = memcmp;

	/*
	 * Similarly, the key-copying function defaults to strncpy() or memcpy().
	 */
	if (hashp->hash == string_hash)
		hashp->keycopy = (HashCopyFunc) strncpy;
	else
		hashp->keycopy = memcpy;

	if (flags & HASH_SHARED_MEM)
	{
		/*
		 * ctl structure is preallocated for shared memory tables. Note
		 * that HASH_DIRSIZE had better be set as well.
		 */
		hashp->hctl = info->hctl;
		hashp->dir = info->dir;
		hashp->alloc = info->alloc;
		hashp->hcxt = NULL;
		hashp->isshared = true;

		/* hash table already exists, we're just attaching to it */
		if (flags & HASH_ATTACH)
			return hashp;
	}
	else
	{
		/* setup hash table defaults */
		hashp->hctl = NULL;
		hashp->dir = NULL;
		hashp->alloc = MEM_ALLOC;
		hashp->hcxt = CurrentDynaHashCxt;
		hashp->isshared = false;
	}

	if (!hashp->hctl)
	{
		hashp->hctl = (HASHHDR *) hashp->alloc(sizeof(HASHHDR));
		if (!hashp->hctl)
			return NULL;
	}

	if (!hdefault(hashp))
		return NULL;

	hctl = hashp->hctl;
#ifdef HASH_STATISTICS
	hctl->accesses = hctl->collisions = 0;
#endif

	if (flags & HASH_SEGMENT)
	{
		hctl->ssize = info->ssize;
		hctl->sshift = my_log2(info->ssize);
		/* ssize had better be a power of 2 */
		Assert(hctl->ssize == (1L << hctl->sshift));
	}
	if (flags & HASH_FFACTOR)
		hctl->ffactor = info->ffactor;

	/*
	 * SHM hash tables have fixed directory size passed by the caller.
	 */
	if (flags & HASH_DIRSIZE)
	{
		hctl->max_dsize = info->max_dsize;
		hctl->dsize = info->dsize;
	}

	/*
	 * hash table now allocates space for key and data but you have to say
	 * how much space to allocate
	 */
	if (flags & HASH_ELEM)
	{
		hctl->keysize = info->keysize;
		hctl->entrysize = info->entrysize;
	}

	if (flags & HASH_ALLOC)
		hashp->alloc = info->alloc;
	else
	{
		/* remaining hash table structures live in child of given context */
		hashp->hcxt = AllocSetContextCreate(CurrentDynaHashCxt,
											"DynaHashTable",
											ALLOCSET_DEFAULT_MINSIZE,
											ALLOCSET_DEFAULT_INITSIZE,
											ALLOCSET_DEFAULT_MAXSIZE);
		CurrentDynaHashCxt = hashp->hcxt;
	}

	if (!init_htab(hashp, nelem))
	{
		hash_destroy(hashp);
		return NULL;
	}
	return hashp;
}
Example #23
0
/* ----------------------------------------------------------------
 *		ExecHashTableCreate
 *
 *		create an empty hashtable data structure for hashjoin.
 * ----------------------------------------------------------------
 */
HashJoinTable
ExecHashTableCreate(Hash *node, List *hashOperators, bool keepNulls)
{
	HashJoinTable hashtable;
	Plan	   *outerNode;
	int			nbuckets;
	int			nbatch;
	int			num_skew_mcvs;
	int			log2_nbuckets;
	int			nkeys;
	int			i;
	ListCell   *ho;
	MemoryContext oldcxt;

	/*
	 * Get information about the size of the relation to be hashed (it's the
	 * "outer" subtree of this node, but the inner relation of the hashjoin).
	 * Compute the appropriate size of the hash table.
	 */
	outerNode = outerPlan(node);

	ExecChooseHashTableSize(outerNode->plan_rows, outerNode->plan_width,
							OidIsValid(node->skewTable),
							&nbuckets, &nbatch, &num_skew_mcvs);

#ifdef HJDEBUG
	printf("nbatch = %d, nbuckets = %d\n", nbatch, nbuckets);
#endif

	/* nbuckets must be a power of 2 */
	log2_nbuckets = my_log2(nbuckets);
	Assert(nbuckets == (1 << log2_nbuckets));

	/*
	 * Initialize the hash table control block.
	 *
	 * The hashtable control block is just palloc'd from the executor's
	 * per-query memory context.
	 */
	hashtable = (HashJoinTable) palloc(sizeof(HashJoinTableData));
	hashtable->nbuckets = nbuckets;
	hashtable->log2_nbuckets = log2_nbuckets;
	hashtable->buckets = NULL;
	hashtable->keepNulls = keepNulls;
	hashtable->skewEnabled = false;
	hashtable->skewBucket = NULL;
	hashtable->skewBucketLen = 0;
	hashtable->nSkewBuckets = 0;
	hashtable->skewBucketNums = NULL;
	hashtable->nbatch = nbatch;
	hashtable->curbatch = 0;
	hashtable->nbatch_original = nbatch;
	hashtable->nbatch_outstart = nbatch;
	hashtable->growEnabled = true;
	hashtable->totalTuples = 0;
	hashtable->innerBatchFile = NULL;
	hashtable->outerBatchFile = NULL;
	hashtable->spaceUsed = 0;
	hashtable->spacePeak = 0;
	hashtable->spaceAllowed = work_mem * 1024L;
	hashtable->spaceUsedSkew = 0;
	hashtable->spaceAllowedSkew =
		hashtable->spaceAllowed * SKEW_WORK_MEM_PERCENT / 100;

	/*
	 * Get info about the hash functions to be used for each hash key. Also
	 * remember whether the join operators are strict.
	 */
	nkeys = list_length(hashOperators);
	hashtable->outer_hashfunctions =
		(FmgrInfo *) palloc(nkeys * sizeof(FmgrInfo));
	hashtable->inner_hashfunctions =
		(FmgrInfo *) palloc(nkeys * sizeof(FmgrInfo));
	hashtable->hashStrict = (bool *) palloc(nkeys * sizeof(bool));
	i = 0;
	foreach(ho, hashOperators)
	{
		Oid			hashop = lfirst_oid(ho);
		Oid			left_hashfn;
		Oid			right_hashfn;

		if (!get_op_hash_functions(hashop, &left_hashfn, &right_hashfn))
			elog(ERROR, "could not find hash function for hash operator %u",
				 hashop);
		fmgr_info(left_hashfn, &hashtable->outer_hashfunctions[i]);
		fmgr_info(right_hashfn, &hashtable->inner_hashfunctions[i]);
		hashtable->hashStrict[i] = op_strict(hashop);
		i++;
	}
Example #24
0
/*
 * Compute derived fields of hctl and build the initial directory/segment
 * arrays
 */
static bool
init_htab(HTAB *hashp, long nelem)
{
	HASHHDR    *hctl = hashp->hctl;
	HASHSEGMENT *segp;
	long		lnbuckets;
	int			nbuckets;
	int			nsegs;

	/*
	 * initialize mutex if it's a partitioned table
	 */
	if (IS_PARTITIONED(hctl))
		SpinLockInit(&hctl->mutex);

	/*
	 * Divide number of elements by the fill factor to determine a desired
	 * number of buckets.  Allocate space for the next greater power of two
	 * number of buckets
	 */
	lnbuckets = (nelem - 1) / hctl->ffactor + 1;

	nbuckets = 1 << my_log2(lnbuckets);

	/*
	 * In a partitioned table, nbuckets must be at least equal to
	 * num_partitions; were it less, keys with apparently different partition
	 * numbers would map to the same bucket, breaking partition independence.
	 * (Normally nbuckets will be much bigger; this is just a safety check.)
	 */
	while (nbuckets < hctl->num_partitions)
		nbuckets <<= 1;

	hctl->max_bucket = hctl->low_mask = nbuckets - 1;
	hctl->high_mask = (nbuckets << 1) - 1;

	/*
	 * Figure number of directory segments needed, round up to a power of 2
	 */
	nsegs = (nbuckets - 1) / hctl->ssize + 1;
	nsegs = 1 << my_log2(nsegs);

	/*
	 * Make sure directory is big enough. If pre-allocated directory is too
	 * small, choke (caller screwed up).
	 */
	if (nsegs > hctl->dsize)
	{
		if (!(hashp->dir))
			hctl->dsize = nsegs;
		else
			return false;
	}

	/* Allocate a directory */
	if (!(hashp->dir))
	{
		CurrentDynaHashCxt = hashp->hcxt;
		hashp->dir = (HASHSEGMENT *)
			hashp->alloc(hctl->dsize * sizeof(HASHSEGMENT));
		if (!hashp->dir)
			return false;
	}

	/* Allocate initial segments */
	for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++)
	{
		*segp = seg_alloc(hashp);
		if (*segp == NULL)
			return false;
	}

	/* Choose number of entries to allocate at a time */
	hctl->nelem_alloc = choose_nelem_alloc(hctl->entrysize);

#if HASH_DEBUG
	fprintf(stderr, "init_htab:\n%s%p\n%s%ld\n%s%ld\n%s%d\n%s%ld\n%s%u\n%s%x\n%s%x\n%s%ld\n%s%ld\n",
			"TABLE POINTER   ", hashp,
			"DIRECTORY SIZE  ", hctl->dsize,
			"SEGMENT SIZE    ", hctl->ssize,
			"SEGMENT SHIFT   ", hctl->sshift,
			"FILL FACTOR     ", hctl->ffactor,
			"MAX BUCKET      ", hctl->max_bucket,
			"HIGH MASK       ", hctl->high_mask,
			"LOW  MASK       ", hctl->low_mask,
			"NSEGS           ", hctl->nsegs,
			"NENTRIES        ", hctl->nentries);
#endif
	return true;
}
Example #25
0
/* ----------------------------------------------------------------
 *		ExecHashTableCreate
 *
 *		create an empty hashtable data structure for hashjoin.
 * ----------------------------------------------------------------
 */
HashJoinTable
ExecHashTableCreate(HashState *hashState, HashJoinState *hjstate, List *hashOperators, uint64 operatorMemKB)
{
	HashJoinTable hashtable;
	Plan	   *outerNode;
	int			nbuckets;
	int			nbatch;
	int			log2_nbuckets;
	int			nkeys;
	int			i;
	ListCell   *ho;
	MemoryContext oldcxt;

	START_MEMORY_ACCOUNT(hashState->ps.plan->memoryAccountId);
	{
	Hash *node = (Hash *) hashState->ps.plan;

	/*
	 * Get information about the size of the relation to be hashed (it's the
	 * "outer" subtree of this node, but the inner relation of the hashjoin).
	 * Compute the appropriate size of the hash table.
	 */
	outerNode = outerPlan(node);

	ExecChooseHashTableSize(outerNode->plan_rows, outerNode->plan_width,
							&nbuckets, &nbatch, operatorMemKB);

#ifdef HJDEBUG
    elog(LOG, "HJ: nbatch = %d, nbuckets = %d\n", nbatch, nbuckets);
#endif

	/* nbuckets must be a power of 2 */
	log2_nbuckets = my_log2(nbuckets);
	Assert(nbuckets == (1 << log2_nbuckets));

	/*
	 * Initialize the hash table control block.
	 *
	 * The hashtable control block is just palloc'd from the executor's
	 * per-query memory context.
	 */
	hashtable = (HashJoinTable) palloc0(sizeof(HashJoinTableData));
	hashtable->nbuckets = nbuckets;
	hashtable->log2_nbuckets = log2_nbuckets;
	hashtable->buckets = NULL;
	hashtable->bloom = NULL;
	hashtable->nbatch = nbatch;
	hashtable->curbatch = 0;
	hashtable->nbatch_original = nbatch;
	hashtable->nbatch_outstart = nbatch;
	hashtable->growEnabled = true;
	hashtable->totalTuples = 0;
	hashtable->batches = NULL;
	hashtable->work_set = NULL;
	hashtable->state_file = NULL;
	hashtable->spaceAllowed = operatorMemKB * 1024L;
	hashtable->stats = NULL;
	hashtable->eagerlyReleased = false;
	hashtable->hjstate = hjstate;

	/*
	 * Get info about the hash functions to be used for each hash key. Also
	 * remember whether the join operators are strict.
	 */
	nkeys = list_length(hashOperators);
	hashtable->outer_hashfunctions =
		(FmgrInfo *) palloc(nkeys * sizeof(FmgrInfo));
	hashtable->inner_hashfunctions =
		(FmgrInfo *) palloc(nkeys * sizeof(FmgrInfo));
	hashtable->hashStrict = (bool *) palloc(nkeys * sizeof(bool));
	i = 0;
	foreach(ho, hashOperators)
	{
		Oid			hashop = lfirst_oid(ho);
		Oid			left_hashfn;
		Oid			right_hashfn;

		if (!get_op_hash_functions(hashop, &left_hashfn, &right_hashfn))
			elog(ERROR, "could not find hash function for hash operator %u",
				 hashop);
		fmgr_info(left_hashfn, &hashtable->outer_hashfunctions[i]);
		fmgr_info(right_hashfn, &hashtable->inner_hashfunctions[i]);
		hashtable->hashStrict[i] = op_strict(hashop);
		i++;
	}

	/*
	 * Create temporary memory contexts in which to keep the hashtable working
	 * storage.  See notes in executor/hashjoin.h.
	 */
	hashtable->hashCxt = AllocSetContextCreate(CurrentMemoryContext,
											   "HashTableContext",
											   ALLOCSET_DEFAULT_MINSIZE,
											   ALLOCSET_DEFAULT_INITSIZE,
											   ALLOCSET_DEFAULT_MAXSIZE);

	hashtable->batchCxt = AllocSetContextCreate(hashtable->hashCxt,
												"HashBatchContext",
												ALLOCSET_DEFAULT_MINSIZE,
												ALLOCSET_DEFAULT_INITSIZE,
												ALLOCSET_DEFAULT_MAXSIZE);

	/* CDB */ /* track temp buf file allocations in separate context */
	hashtable->bfCxt = AllocSetContextCreate(CurrentMemoryContext,
											 "hbbfcxt",
											 ALLOCSET_DEFAULT_MINSIZE,
											 ALLOCSET_DEFAULT_INITSIZE,
											 ALLOCSET_DEFAULT_MAXSIZE);

	/* Allocate data that will live for the life of the hashjoin */
	oldcxt = MemoryContextSwitchTo(hashtable->hashCxt);

#ifdef HJDEBUG
	{
		/* Memory needed to allocate hashtable->batches, which consists of nbatch pointers */
		int md_batch_size =  (nbatch * sizeof(hashtable->batches[0])) / (1024 * 1024);
		/* Memory needed to allocate hashtable->batches entries, which consist of nbatch HashJoinBatchData structures */
		int md_batch_data_size = (nbatch * sizeof(HashJoinBatchData)) / (1024 * 1024);

		/* Memory needed to allocate hashtable->buckets, which consists of nbuckets  HashJoinTuple structures*/
		int md_buckets_size = (nbuckets * sizeof(HashJoinTuple)) / (1024 * 1024);

		/* Memory needed to allocate hashtable->bloom, which consists of nbuckets int64 values */
		int md_bloom_size = (nbuckets * sizeof(uint64)) / (1024 * 1024);

		/* Total memory needed for the hashtable metadata */
		int md_tot = md_batch_size + md_batch_data_size + md_buckets_size + md_bloom_size;

		elog(LOG, "About to allocate HashTable. HT_MEMORY=%dMB Memory needed for metadata: MDBATCH_ARR=%dMB, MDBATCH_DATA=%dMB, MDBUCKETS_ARR=%dMB, MDBLOOM_ARR=%dMB, TOTAL=%dMB",
				(int) (hashtable->spaceAllowed / (1024 * 1024)),
				md_batch_size, md_batch_data_size, md_buckets_size, md_bloom_size, md_tot);

		elog(LOG, "sizeof(hashtable->batches[0])=%d, sizeof(HashJoinBatchData)=%d, sizeof(HashJoinTuple)=%d, sizeof(uint64)=%d",
				(int) sizeof(hashtable->batches[0]), (int) sizeof(HashJoinBatchData),
				(int) sizeof(HashJoinTuple), (int) sizeof(uint64));
	}
#endif

	/* array of BatchData ptrs */
	hashtable->batches =
		(HashJoinBatchData **)palloc(nbatch * sizeof(hashtable->batches[0]));

	/* one BatchData entry per initial batch */
	for (i = 0; i < nbatch; i++)
		hashtable->batches[i] =
			(HashJoinBatchData *)palloc0(sizeof(HashJoinBatchData));

	/*
	 * Prepare context for the first-scan space allocations; allocate the
	 * hashbucket array therein, and set each bucket "empty".
	 */
	MemoryContextSwitchTo(hashtable->batchCxt);

	hashtable->buckets = (HashJoinTuple *)
		palloc0(nbuckets * sizeof(HashJoinTuple));

	if(gp_hashjoin_bloomfilter!=0)
		hashtable->bloom = (uint64*) palloc0(nbuckets * sizeof(uint64));

	MemoryContextSwitchTo(oldcxt);
	}