indextuple.c File Reference

#include "postgres.h"
#include "access/detoast.h"
#include "access/heaptoast.h"
#include "access/htup_details.h"
#include "access/itup.h"
#include "access/toast_internals.h"

Include dependency graph for indextuple.c:

Go to the source code of this file.

Macros
#define	TOAST_INDEX_HACK

Functions
IndexTuple	index_form_tuple (TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
IndexTuple	index_form_tuple_context (TupleDesc tupleDescriptor, const Datum *values, const bool *isnull, MemoryContext context)
Datum	nocache_index_getattr (IndexTuple tup, int attnum, TupleDesc tupleDesc)
void	index_deform_tuple (IndexTuple tup, TupleDesc tupleDescriptor, Datum *values, bool *isnull)
void	index_deform_tuple_internal (TupleDesc tupleDescriptor, Datum *values, bool *isnull, char *tp, bits8 *bp, int hasnulls)
IndexTuple	CopyIndexTuple (IndexTuple source)
IndexTuple	index_truncate_tuple (TupleDesc sourceDescriptor, IndexTuple source, int leavenatts)

Macro Definition Documentation

TOAST_INDEX_HACK

#define TOAST_INDEX_HACK

Definition at line 29 of file indextuple.c.

Function Documentation

CopyIndexTuple()

IndexTuple CopyIndexTuple

(

IndexTuple

source

)

Definition at line 479 of file indextuple.c.

{
    IndexTuple  result;
    Size        size;
 
    size = IndexTupleSize(source);
    result = (IndexTuple) palloc(size);
    memcpy(result, source, size);
    return result;
}

References fb(), IndexTupleSize(), palloc(), and source.

Referenced by _bt_buildadd(), _bt_insert_parent(), _bt_insertonpg(), _bt_load(), _bt_newlevel(), _bt_pagedel(), _bt_swap_posting(), _hash_splitbucket(), _hash_squeezebucket(), btree_xlog_insert(), btree_xlog_split(), gin_check_parent_keys_consistency(), gin_refind_parent(), gistformdownlink(), and index_truncate_tuple().

index_deform_tuple()

void index_deform_tuple	(	IndexTuple	tup,
		TupleDesc	tupleDescriptor,
		Datum *	values,
		bool *	isnull
	)

Definition at line 364 of file indextuple.c.

{
    char       *tp;             /* ptr to tuple data */
    bits8      *bp;             /* ptr to null bitmap in tuple */
 
    /* XXX "knows" t_bits are just after fixed tuple header! */
    bp = (bits8 *) ((char *) tup + sizeof(IndexTupleData));
 
    tp = (char *) tup + IndexInfoFindDataOffset(tup->t_info);
 
    index_deform_tuple_internal(tupleDescriptor, values, isnull,
                                tp, bp, IndexTupleHasNulls(tup));
}

References fb(), index_deform_tuple_internal(), IndexInfoFindDataOffset(), IndexTupleHasNulls(), and values.

Referenced by _bt_check_unique(), comparetup_index_btree_tiebreak(), get_actual_variable_endpoint(), gist_page_items(), index_truncate_tuple(), and StoreIndexTuple().

index_deform_tuple_internal()

void index_deform_tuple_internal	(	TupleDesc	tupleDescriptor,
		Datum *	values,
		bool *	isnull,
		char *	tp,
		bits8 *	bp,
		int	hasnulls
	)

Definition at line 387 of file indextuple.c.

{
    CompactAttribute *cattr;
    int         natts = tupleDescriptor->natts; /* number of atts to extract */
    int         attnum = 0;
    uint32      off = 0;        /* offset in tuple data */
    int         firstNonCacheOffsetAttr;
    int         firstNullAttr;
 
    /* Assert to protect callers who allocate fixed-size arrays */
    Assert(natts <= INDEX_MAX_KEYS);
 
    /* Did someone forget to call TupleDescFinalize()? */
    Assert(tupleDescriptor->firstNonCachedOffsetAttr >= 0);
 
    firstNonCacheOffsetAttr = Min(tupleDescriptor->firstNonCachedOffsetAttr, natts);
 
    if (hasnulls)
    {
        firstNullAttr = first_null_attr(bp, natts);
        firstNonCacheOffsetAttr = Min(firstNonCacheOffsetAttr, firstNullAttr);
    }
    else
        firstNullAttr = natts;
 
    if (firstNonCacheOffsetAttr > 0)
    {
#ifdef USE_ASSERT_CHECKING
        /* In Assert enabled builds, verify attcacheoff is correct */
        off = 0;
#endif
 
        do
        {
            isnull[attnum] = false;
            cattr = TupleDescCompactAttr(tupleDescriptor, attnum);
 
#ifdef USE_ASSERT_CHECKING
            off = att_nominal_alignby(off, cattr->attalignby);
            Assert(off == cattr->attcacheoff);
            off += cattr->attlen;
#endif
 
            values[attnum] = fetch_att_noerr(tp + cattr->attcacheoff, cattr->attbyval,
                                             cattr->attlen);
        } while (++attnum < firstNonCacheOffsetAttr);
 
        off = cattr->attcacheoff + cattr->attlen;
    }
 
    for (; attnum < firstNullAttr; attnum++)
    {
        isnull[attnum] = false;
        cattr = TupleDescCompactAttr(tupleDescriptor, attnum);
 
        /* align 'off', fetch the datum, and increment off beyond the datum */
        values[attnum] = align_fetch_then_add(tp,
                                              &off,
                                              cattr->attbyval,
                                              cattr->attlen,
                                              cattr->attalignby);
    }
 
    for (; attnum < natts; attnum++)
    {
        Assert(hasnulls);
 
        if (att_isnull(attnum, bp))
        {
            values[attnum] = (Datum) 0;
            isnull[attnum] = true;
            continue;
        }
 
        isnull[attnum] = false;
        cattr = TupleDescCompactAttr(tupleDescriptor, attnum);
 
        /* align 'off', fetch the attr's value, and increment off beyond it */
        values[attnum] = align_fetch_then_add(tp,
                                              &off,
                                              cattr->attbyval,
                                              cattr->attlen,
                                              cattr->attalignby);
    }
}

References align_fetch_then_add(), Assert, att_isnull(), att_nominal_alignby, attnum, fb(), fetch_att_noerr(), first_null_attr(), INDEX_MAX_KEYS, Min, TupleDescCompactAttr(), and values.

Referenced by index_deform_tuple(), and spgDeformLeafTuple().

index_form_tuple()

IndexTuple index_form_tuple	(	TupleDesc	tupleDescriptor,
		const Datum *	values,
		const bool *	isnull
	)

Definition at line 44 of file indextuple.c.

{
    return index_form_tuple_context(tupleDescriptor, values, isnull,
                                    CurrentMemoryContext);
}

References CurrentMemoryContext, fb(), index_form_tuple_context(), and values.

Referenced by bt_normalize_tuple(), bt_tuple_present_callback(), btinsert(), GinFormTuple(), gistFormTuple(), hashbuildCallback(), hashinsert(), and index_truncate_tuple().

index_form_tuple_context()

IndexTuple index_form_tuple_context	(	TupleDesc	tupleDescriptor,
		const Datum *	values,
		const bool *	isnull,
		MemoryContext	context
	)

Definition at line 65 of file indextuple.c.

{
    char       *tp;             /* tuple pointer */
    IndexTuple  tuple;          /* return tuple */
    Size        size,
                data_size,
                hoff;
    int         i;
    unsigned short infomask = 0;
    bool        hasnull = false;
    uint16      tupmask = 0;
    int         numberOfAttributes = tupleDescriptor->natts;
 
#ifdef TOAST_INDEX_HACK
    Datum       untoasted_values[INDEX_MAX_KEYS] = {0};
    bool        untoasted_free[INDEX_MAX_KEYS] = {0};
#endif
 
    if (numberOfAttributes > INDEX_MAX_KEYS)
        ereport(ERROR,
                (errcode(ERRCODE_TOO_MANY_COLUMNS),
                 errmsg("number of index columns (%d) exceeds limit (%d)",
                        numberOfAttributes, INDEX_MAX_KEYS)));
 
#ifdef TOAST_INDEX_HACK
    for (i = 0; i < numberOfAttributes; i++)
    {
        Form_pg_attribute att = TupleDescAttr(tupleDescriptor, i);
 
        untoasted_values[i] = values[i];
        untoasted_free[i] = false;
 
        /* Do nothing if value is NULL or not of varlena type */
        if (isnull[i] || att->attlen != -1)
            continue;
 
        /*
         * If value is stored EXTERNAL, must fetch it so we are not depending
         * on outside storage.  This should be improved someday.
         */
        if (VARATT_IS_EXTERNAL(DatumGetPointer(values[i])))
        {
            untoasted_values[i] =
                PointerGetDatum(detoast_external_attr((varlena *)
                                                      DatumGetPointer(values[i])));
            untoasted_free[i] = true;
        }
 
        /*
         * If value is above size target, and is of a compressible datatype,
         * try to compress it in-line.
         */
        if (!VARATT_IS_EXTENDED(DatumGetPointer(untoasted_values[i])) &&
            VARSIZE(DatumGetPointer(untoasted_values[i])) > TOAST_INDEX_TARGET &&
            (att->attstorage == TYPSTORAGE_EXTENDED ||
             att->attstorage == TYPSTORAGE_MAIN))
        {
            Datum       cvalue;
 
            cvalue = toast_compress_datum(untoasted_values[i],
                                          att->attcompression);
 
            if (DatumGetPointer(cvalue) != NULL)
            {
                /* successful compression */
                if (untoasted_free[i])
                    pfree(DatumGetPointer(untoasted_values[i]));
                untoasted_values[i] = cvalue;
                untoasted_free[i] = true;
            }
        }
    }
#endif
 
    for (i = 0; i < numberOfAttributes; i++)
    {
        if (isnull[i])
        {
            hasnull = true;
            break;
        }
    }
 
    if (hasnull)
        infomask |= INDEX_NULL_MASK;
 
    hoff = IndexInfoFindDataOffset(infomask);
#ifdef TOAST_INDEX_HACK
    data_size = heap_compute_data_size(tupleDescriptor,
                                       untoasted_values, isnull);
#else
    data_size = heap_compute_data_size(tupleDescriptor,
                                       values, isnull);
#endif
    size = hoff + data_size;
    size = MAXALIGN(size);      /* be conservative */
 
    tp = (char *) MemoryContextAllocZero(context, size);
    tuple = (IndexTuple) tp;
 
    heap_fill_tuple(tupleDescriptor,
#ifdef TOAST_INDEX_HACK
                    untoasted_values,
#else
                    values,
#endif
                    isnull,
                    tp + hoff,
                    data_size,
                    &tupmask,
                    (hasnull ? (bits8 *) tp + sizeof(IndexTupleData) : NULL));
 
#ifdef TOAST_INDEX_HACK
    for (i = 0; i < numberOfAttributes; i++)
    {
        if (untoasted_free[i])
            pfree(DatumGetPointer(untoasted_values[i]));
    }
#endif
 
    /*
     * We do this because heap_fill_tuple wants to initialize a "tupmask"
     * which is used for HeapTuples, but we want an indextuple infomask. The
     * only relevant info is the "has variable attributes" field. We have
     * already set the hasnull bit above.
     */
    if (tupmask & HEAP_HASVARWIDTH)
        infomask |= INDEX_VAR_MASK;
 
    /* Also assert we got rid of external attributes */
#ifdef TOAST_INDEX_HACK
    Assert((tupmask & HEAP_HASEXTERNAL) == 0);
#endif
 
    /*
     * Here we make sure that the size will fit in the field reserved for it
     * in t_info.
     */
    if ((size & INDEX_SIZE_MASK) != size)
        ereport(ERROR,
                (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                 errmsg("index row requires %zu bytes, maximum size is %zu",
                        size, (Size) INDEX_SIZE_MASK)));
 
    infomask |= size;
 
    /*
     * initialize metadata
     */
    tuple->t_info = infomask;
    return tuple;
}

References Assert, DatumGetPointer(), detoast_external_attr(), ereport, errcode(), errmsg, ERROR, fb(), heap_compute_data_size(), heap_fill_tuple(), HEAP_HASEXTERNAL, HEAP_HASVARWIDTH, i, INDEX_MAX_KEYS, INDEX_NULL_MASK, INDEX_SIZE_MASK, INDEX_VAR_MASK, IndexInfoFindDataOffset(), MAXALIGN, MemoryContextAllocZero(), pfree(), PointerGetDatum(), IndexTupleData::t_info, toast_compress_datum(), TOAST_INDEX_HACK, TOAST_INDEX_TARGET, TupleDescAttr(), values, VARATT_IS_EXTENDED(), VARATT_IS_EXTERNAL(), and VARSIZE().

Referenced by index_form_tuple(), and tuplesort_putindextuplevalues().

index_truncate_tuple()

IndexTuple index_truncate_tuple	(	TupleDesc	sourceDescriptor,
		IndexTuple	source,
		int	leavenatts
	)

Definition at line 508 of file indextuple.c.

{
    TupleDesc   truncdesc;
    Datum       values[INDEX_MAX_KEYS];
    bool        isnull[INDEX_MAX_KEYS];
    IndexTuple  truncated;
 
    Assert(leavenatts <= sourceDescriptor->natts);
 
    /* Easy case: no truncation actually required */
    if (leavenatts == sourceDescriptor->natts)
        return CopyIndexTuple(source);
 
    /* Create temporary truncated tuple descriptor */
    truncdesc = CreateTupleDescTruncatedCopy(sourceDescriptor, leavenatts);
 
    /* Deform, form copy of tuple with fewer attributes */
    index_deform_tuple(source, truncdesc, values, isnull);
    truncated = index_form_tuple(truncdesc, values, isnull);
    truncated->t_tid = source->t_tid;
    Assert(IndexTupleSize(truncated) <= IndexTupleSize(source));
 
    /*
     * Cannot leak memory here, TupleDescCopy() doesn't allocate any inner
     * structure, so, plain pfree() should clean all allocated memory
     */
    pfree(truncdesc);
 
    return truncated;
}

References Assert, CopyIndexTuple(), CreateTupleDescTruncatedCopy(), fb(), index_deform_tuple(), index_form_tuple(), INDEX_MAX_KEYS, IndexTupleSize(), pfree(), source, IndexTupleData::t_tid, and values.

Referenced by _bt_truncate().

nocache_index_getattr()

Datum nocache_index_getattr	(	IndexTuple	tup,
		int	attnum,
		TupleDesc	tupleDesc
	)

Definition at line 229 of file indextuple.c.

{
    CompactAttribute *cattr;
    char       *tp;             /* ptr to data part of tuple */
    bits8      *bp = NULL;      /* ptr to null bitmap in tuple */
    int         data_off;       /* tuple data offset */
    int         off;            /* current offset within data */
    int         startAttr;
    int         firstNullAttr;
    bool        hasnulls = IndexTupleHasNulls(tup);
    int         i;
 
    /* Did someone forget to call TupleDescFinalize()? */
    Assert(tupleDesc->firstNonCachedOffsetAttr >= 0);
 
    attnum--;
 
    data_off = IndexInfoFindDataOffset(tup->t_info);
    tp = (char *) tup + data_off;
 
    /*
     * To minimize the number of attributes we need to look at, start walking
     * the tuple at the attribute with the highest attcacheoff prior to attnum
     * or the first NULL attribute prior to attnum, whichever comes first.
     */
    if (hasnulls)
    {
        bp = (bits8 *) ((char *) tup + sizeof(IndexTupleData));
        firstNullAttr = first_null_attr(bp, attnum);
    }
    else
        firstNullAttr = attnum;
 
    if (tupleDesc->firstNonCachedOffsetAttr > 0 && firstNullAttr > 0)
    {
        /*
         * Try to start with the highest attribute with an attcacheoff that's
         * prior to the one we're looking for, or with the attribute prior to
         * the first NULL attribute, if there is one.
         */
        startAttr = Min(tupleDesc->firstNonCachedOffsetAttr - 1, firstNullAttr - 1);
        off = TupleDescCompactAttr(tupleDesc, startAttr)->attcacheoff;
    }
    else
    {
        /* Otherwise, start at the beginning... */
        startAttr = 0;
        off = 0;
    }
 
    /*
     * Calculate 'off' up to the first NULL attr.  We use two cheaper loops
     * when the tuple has no variable-width columns.  When variable-width
     * columns exists, we use att_addlength_pointer() to move the offset
     * beyond the current attribute.
     */
    if (IndexTupleHasVarwidths(tup))
    {
        /* Calculate the offset up until the first NULL */
        for (i = startAttr; i < firstNullAttr; i++)
        {
            cattr = TupleDescCompactAttr(tupleDesc, i);
 
            off = att_pointer_alignby(off,
                                      cattr->attalignby,
                                      cattr->attlen,
                                      tp + off);
            off = att_addlength_pointer(off, cattr->attlen, tp + off);
        }
 
        /* Calculate the offset for any remaining columns. */
        for (; i < attnum; i++)
        {
            Assert(hasnulls);
 
            if (att_isnull(i, bp))
                continue;
 
            cattr = TupleDescCompactAttr(tupleDesc, i);
 
            off = att_pointer_alignby(off,
                                      cattr->attalignby,
                                      cattr->attlen,
                                      tp + off);
            off = att_addlength_pointer(off, cattr->attlen, tp + off);
        }
    }
    else
    {
        /* Handle tuples with only fixed-width attributes */
 
        /* Calculate the offset up until the first NULL */
        for (i = startAttr; i < firstNullAttr; i++)
        {
            cattr = TupleDescCompactAttr(tupleDesc, i);
 
            Assert(cattr->attlen > 0);
            off = att_nominal_alignby(off, cattr->attalignby);
            off += cattr->attlen;
        }
 
        /* Calculate the offset for any remaining columns. */
        for (; i < attnum; i++)
        {
            Assert(hasnulls);
 
            if (att_isnull(i, bp))
                continue;
 
            cattr = TupleDescCompactAttr(tupleDesc, i);
 
            Assert(cattr->attlen > 0);
            off = att_nominal_alignby(off, cattr->attalignby);
            off += cattr->attlen;
        }
    }
 
    cattr = TupleDescCompactAttr(tupleDesc, attnum);
    off = att_pointer_alignby(off, cattr->attalignby,
                              cattr->attlen, tp + off);
    return fetchatt(cattr, tp + off);
}

References Assert, att_addlength_pointer, att_isnull(), att_nominal_alignby, att_pointer_alignby, CompactAttribute::attcacheoff, attnum, fb(), fetchatt, first_null_attr(), i, IndexInfoFindDataOffset(), IndexTupleHasNulls(), IndexTupleHasVarwidths(), Min, and TupleDescCompactAttr().

Referenced by index_getattr().