hstore_compat.c File Reference

#include "postgres.h"
#include "hstore.h"

Include dependency graph for hstore_compat.c:

Go to the source code of this file.

Data Structures
struct	HOldEntry

Functions
static int	hstoreValidNewFormat (HStore *hs)
static int	hstoreValidOldFormat (HStore *hs)
HStore *	hstoreUpgrade (Datum orig)
	PG_FUNCTION_INFO_V1 (hstore_version_diag)
Datum	hstore_version_diag (PG_FUNCTION_ARGS)

Function Documentation

hstore_version_diag()

Datum hstore_version_diag

(

PG_FUNCTION_ARGS

)

Definition at line 352 of file hstore_compat.c.

{
    HStore     *hs = (HStore *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
    int         valid_new = hstoreValidNewFormat(hs);
    int         valid_old = hstoreValidOldFormat(hs);
 
    PG_RETURN_INT32(valid_old * 10 + valid_new);
}

References hstoreValidNewFormat(), hstoreValidOldFormat(), PG_DETOAST_DATUM, PG_GETARG_DATUM, and PG_RETURN_INT32.

hstoreUpgrade()

HStore* hstoreUpgrade

(

Datum

orig

)

Definition at line 236 of file hstore_compat.c.

{
    HStore     *hs = (HStore *) PG_DETOAST_DATUM(orig);
    int         valid_new;
    int         valid_old;
 
    /* Return immediately if no conversion needed */
    if (hs->size_ & HS_FLAG_NEWVERSION)
        return hs;
 
    /* Do we have a writable copy? If not, make one. */
    if ((void *) hs == (void *) DatumGetPointer(orig))
        hs = (HStore *) PG_DETOAST_DATUM_COPY(orig);
 
    if (hs->size_ == 0 ||
        (VARSIZE(hs) < 32768 && HSE_ISFIRST((ARRPTR(hs)[0]))))
    {
        HS_SETCOUNT(hs, HS_COUNT(hs));
        HS_FIXSIZE(hs, HS_COUNT(hs));
        return hs;
    }
 
    valid_new = hstoreValidNewFormat(hs);
    valid_old = hstoreValidOldFormat(hs);
 
    if (!valid_old || hs->size_ == 0)
    {
        if (valid_new)
        {
            /*
             * force the "new version" flag and the correct varlena length.
             */
            HS_SETCOUNT(hs, HS_COUNT(hs));
            HS_FIXSIZE(hs, HS_COUNT(hs));
            return hs;
        }
        else
        {
            elog(ERROR, "invalid hstore value found");
        }
    }
 
    /*
     * this is the tricky edge case. It is only possible in some quite extreme
     * cases (the hstore must have had a lot of wasted padding space at the
     * end). But the only way a "new" hstore value could get here is if we're
     * upgrading in place from a pre-release version of hstore-new (NOT
     * contrib/hstore), so we work off the following assumptions: 1. If you're
     * moving from old contrib/hstore to hstore-new, you're required to fix up
     * any potential conflicts first, e.g. by running ALTER TABLE ... USING
     * col::text::hstore; on all hstore columns before upgrading. 2. If you're
     * moving from old contrib/hstore to new contrib/hstore, then "new" values
     * are impossible here 3. If you're moving from pre-release hstore-new to
     * hstore-new, then "old" values are impossible here 4. If you're moving
     * from pre-release hstore-new to new contrib/hstore, you're not doing so
     * as an in-place upgrade, so there is no issue So the upshot of all this
     * is that we can treat all the edge cases as "new" if we're being built
     * as hstore-new, and "old" if we're being built as contrib/hstore.
     *
     * XXX the WARNING can probably be downgraded to DEBUG1 once this has been
     * beta-tested. But for now, it would be very useful to know if anyone can
     * actually reach this case in a non-contrived setting.
     */
 
    if (valid_new)
    {
#ifdef HSTORE_IS_HSTORE_NEW
        elog(WARNING, "ambiguous hstore value resolved as hstore-new");
 
        /*
         * force the "new version" flag and the correct varlena length.
         */
        HS_SETCOUNT(hs, HS_COUNT(hs));
        HS_FIXSIZE(hs, HS_COUNT(hs));
        return hs;
#else
        elog(WARNING, "ambiguous hstore value resolved as hstore-old");
#endif
    }
 
    /*
     * must have an old-style value. Overwrite it in place as a new-style one.
     */
    {
        int         count = hs->size_;
        HEntry     *new_entries = ARRPTR(hs);
        HOldEntry  *old_entries = (HOldEntry *) ARRPTR(hs);
        int         i;
 
        for (i = 0; i < count; ++i)
        {
            uint32      pos = old_entries[i].pos;
            uint32      keylen = old_entries[i].keylen;
            uint32      vallen = old_entries[i].vallen;
            bool        isnull = old_entries[i].valisnull;
 
            if (isnull)
                vallen = 0;
 
            new_entries[2 * i].entry = (pos + keylen) & HENTRY_POSMASK;
            new_entries[2 * i + 1].entry = (((pos + keylen + vallen) & HENTRY_POSMASK)
                                            | ((isnull) ? HENTRY_ISNULL : 0));
        }
 
        if (count)
            new_entries[0].entry |= HENTRY_ISFIRST;
        HS_SETCOUNT(hs, count);
        HS_FIXSIZE(hs, count);
    }
 
    return hs;
}

References ARRPTR, DatumGetPointer(), elog, HEntry::entry, ERROR, HENTRY_ISFIRST, HENTRY_ISNULL, HENTRY_POSMASK, HS_COUNT, HS_FIXSIZE, HS_FLAG_NEWVERSION, HS_SETCOUNT, HSE_ISFIRST, hstoreValidNewFormat(), hstoreValidOldFormat(), i, HOldEntry::keylen, PG_DETOAST_DATUM, PG_DETOAST_DATUM_COPY, HOldEntry::pos, HStore::size_, HOldEntry::valisnull, HOldEntry::vallen, VARSIZE, and WARNING.

hstoreValidNewFormat()

static int hstoreValidNewFormat ( HStore *  hs )

static

Definition at line 119 of file hstore_compat.c.

{
    int         count = HS_COUNT(hs);
    HEntry     *entries = ARRPTR(hs);
    int         buflen = (count) ? HSE_ENDPOS(entries[2 * (count) - 1]) : 0;
    int         vsize = CALCDATASIZE(count, buflen);
    int         i;
 
    if (hs->size_ & HS_FLAG_NEWVERSION)
        return 2;
 
    if (count == 0)
        return 2;
 
    if (!HSE_ISFIRST(entries[0]))
        return 0;
 
    if (vsize > VARSIZE(hs))
        return 0;
 
    /* entry position must be nondecreasing */
 
    for (i = 1; i < 2 * count; ++i)
    {
        if (HSE_ISFIRST(entries[i])
            || (HSE_ENDPOS(entries[i]) < HSE_ENDPOS(entries[i - 1])))
            return 0;
    }
 
    /* key length must be nondecreasing and keys must not be null */
 
    for (i = 1; i < count; ++i)
    {
        if (HSTORE_KEYLEN(entries, i) < HSTORE_KEYLEN(entries, i - 1))
            return 0;
        if (HSE_ISNULL(entries[2 * i]))
            return 0;
    }
 
    if (vsize != VARSIZE(hs))
        return 1;
 
    return 2;
}

References ARRPTR, CALCDATASIZE, HS_COUNT, HS_FLAG_NEWVERSION, HSE_ENDPOS, HSE_ISFIRST, HSE_ISNULL, HSTORE_KEYLEN, i, HStore::size_, and VARSIZE.

Referenced by hstore_version_diag(), and hstoreUpgrade().

hstoreValidOldFormat()

static int hstoreValidOldFormat ( HStore *  hs )

static

Definition at line 171 of file hstore_compat.c.

{
    int         count = hs->size_;
    HOldEntry  *entries = (HOldEntry *) ARRPTR(hs);
    int         vsize;
    int         lastpos = 0;
    int         i;
 
    if (hs->size_ & HS_FLAG_NEWVERSION)
        return 0;
 
    /* New format uses an HEntry for key and another for value */
    StaticAssertStmt(sizeof(HOldEntry) == 2 * sizeof(HEntry),
                     "old hstore format is not upward-compatible");
 
    if (count == 0)
        return 2;
 
    if (count > 0xFFFFFFF)
        return 0;
 
    if (CALCDATASIZE(count, 0) > VARSIZE(hs))
        return 0;
 
    if (entries[0].pos != 0)
        return 0;
 
    /* key length must be nondecreasing */
 
    for (i = 1; i < count; ++i)
    {
        if (entries[i].keylen < entries[i - 1].keylen)
            return 0;
    }
 
    /*
     * entry position must be strictly increasing, except for the first entry
     * (which can be ""=>"" and thus zero-length); and all entries must be
     * properly contiguous
     */
 
    for (i = 0; i < count; ++i)
    {
        if (entries[i].pos != lastpos)
            return 0;
        lastpos += (entries[i].keylen
                    + ((entries[i].valisnull) ? 0 : entries[i].vallen));
    }
 
    vsize = CALCDATASIZE(count, lastpos);
 
    if (vsize > VARSIZE(hs))
        return 0;
 
    if (vsize != VARSIZE(hs))
        return 1;
 
    return 2;
}

References ARRPTR, CALCDATASIZE, HS_FLAG_NEWVERSION, i, HOldEntry::keylen, HStore::size_, StaticAssertStmt, HOldEntry::valisnull, and VARSIZE.

Referenced by hstore_version_diag(), and hstoreUpgrade().

PG_FUNCTION_INFO_V1()

PG_FUNCTION_INFO_V1

(

hstore_version_diag

)