/* ----------
* heap_tuple_untoast_attr -
*
* Public entry point to get back a toasted value from compression
* or external storage.
* ----------
*/
varattrib *
heap_tuple_untoast_attr(varattrib *attr)
{
varattrib *result;
if (VARATT_IS_EXTERNAL(attr))
{
if (VARATT_IS_COMPRESSED(attr))
{
/* ----------
* This is an external stored compressed value
* Fetch it from the toast heap and decompress.
* ----------
*/
varattrib *tmp;
tmp = toast_fetch_datum(attr);
result = (varattrib *) palloc(attr->va_content.va_external.va_rawsize
+ VARHDRSZ);
VARATT_SIZEP(result) = attr->va_content.va_external.va_rawsize
+ VARHDRSZ;
pglz_decompress((PGLZ_Header *) tmp, VARATT_DATA(result));
pfree(tmp);
}
else
{
/*
* This is an external stored plain value
*/
result = toast_fetch_datum(attr);
}
}
else if (VARATT_IS_COMPRESSED(attr))
{
/*
* This is a compressed value inside of the main tuple
*/
result = (varattrib *) palloc(attr->va_content.va_compressed.va_rawsize
+ VARHDRSZ);
VARATT_SIZEP(result) = attr->va_content.va_compressed.va_rawsize
+ VARHDRSZ;
pglz_decompress((PGLZ_Header *) attr, VARATT_DATA(result));
}
else
/*
* This is a plain value inside of the main tuple - why am I
* called?
*/
return attr;
return result;
}
/* ----------
* heap_tuple_untoast_attr_slice -
*
* Public entry point to get back part of a toasted value
* from compression or external storage.
* ----------
*/
varattrib *
heap_tuple_untoast_attr_slice(varattrib *attr, int32 sliceoffset, int32 slicelength)
{
varattrib *preslice;
varattrib *result;
int32 attrsize;
if (VARATT_IS_COMPRESSED(attr))
{
varattrib *tmp;
if (VARATT_IS_EXTERNAL(attr))
tmp = toast_fetch_datum(attr);
else
{
tmp = attr; /* compressed in main tuple */
}
preslice = (varattrib *) palloc(attr->va_content.va_external.va_rawsize
+ VARHDRSZ);
VARATT_SIZEP(preslice) = attr->va_content.va_external.va_rawsize + VARHDRSZ;
pglz_decompress((PGLZ_Header *) tmp, VARATT_DATA(preslice));
if (tmp != attr)
pfree(tmp);
}
else
{
/* Plain value */
if (VARATT_IS_EXTERNAL(attr))
{
/* fast path */
return (toast_fetch_datum_slice(attr, sliceoffset, slicelength));
}
else
preslice = attr;
}
/* slicing of datum for compressed cases and plain value */
attrsize = VARSIZE(preslice) - VARHDRSZ;
if (sliceoffset >= attrsize)
{
sliceoffset = 0;
slicelength = 0;
}
if (((sliceoffset + slicelength) > attrsize) || slicelength < 0)
slicelength = attrsize - sliceoffset;
result = (varattrib *) palloc(slicelength + VARHDRSZ);
VARATT_SIZEP(result) = slicelength + VARHDRSZ;
memcpy(VARDATA(result), VARDATA(preslice) + sliceoffset, slicelength);
if (preslice != attr)
pfree(preslice);
return result;
}
/**
* If this function is changed then update varattrib_untoast_len as well
*/
void varattrib_untoast_ptr_len(Datum d, char **datastart, int *len, void **tofree)
{
if (DatumGetPointer(d) == NULL)
{
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg(" Unable to detoast datum "),
errprintstack(true)));
}
struct varlena *va = (struct varlena *) DatumGetPointer(d);
varattrib *attr = (varattrib *) va;
*len = -1;
*tofree = NULL;
if(VARATT_IS_EXTENDED(attr))
{
if(VARATT_IS_EXTERNAL(attr))
{
attr = (varattrib *)toast_fetch_datum((struct varlena *)attr);
/* toast_fetch_datum will palloc, so set it up for free */
*tofree = attr;
}
if(VARATT_IS_COMPRESSED(attr))
{
PGLZ_Header *tmp = (PGLZ_Header *) attr;
attr = (varattrib *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
pglz_decompress(tmp, VARDATA(attr));
/* If tofree is set, that is, we get it from toast_fetch_datum.
* We need to free it here
*/
if(*tofree)
pfree(*tofree);
*tofree = attr;
}
else if(VARATT_IS_SHORT(attr))
{
/* Warning! Return unaligned pointer! */
*len = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
*datastart = VARDATA_SHORT(attr);
attr = NULL;
}
}
if(*len == -1)
{
*datastart = VARDATA(attr);
*len = VARSIZE(attr) - VARHDRSZ;
}
Assert(*len >= 0);
}
/* ----------
* heap_tuple_untoast_attr -
*
* Public entry point to get back a toasted value from compression
* or external storage.
* ----------
*/
struct varlena *
heap_tuple_untoast_attr(struct varlena * attr)
{
if (VARATT_IS_EXTERNAL(attr))
{
/*
* This is an externally stored datum --- fetch it back from there
*/
attr = toast_fetch_datum(attr);
/* If it's compressed, decompress it */
if (VARATT_IS_COMPRESSED(attr))
{
PGLZ_Header *tmp = (PGLZ_Header *) attr;
attr = (struct varlena *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
pglz_decompress(tmp, VARDATA(attr));
pfree(tmp);
}
}
else if (VARATT_IS_COMPRESSED(attr))
{
/*
* This is a compressed value inside of the main tuple
*/
PGLZ_Header *tmp = (PGLZ_Header *) attr;
attr = (struct varlena *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
pglz_decompress(tmp, VARDATA(attr));
}
else if (VARATT_IS_SHORT(attr))
{
/*
* This is a short-header varlena --- convert to 4-byte header format
*/
Size data_size = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
Size new_size = data_size + VARHDRSZ;
struct varlena *new_attr;
new_attr = (struct varlena *) palloc(new_size);
SET_VARSIZE(new_attr, new_size);
memcpy(VARDATA(new_attr), VARDATA_SHORT(attr), data_size);
attr = new_attr;
}
return attr;
}
/**
* If this function is changed then update varattrib_untoast_ptr_len as well
*/
int varattrib_untoast_len(Datum d)
{
if (DatumGetPointer(d) == NULL)
{
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg(" Unable to detoast datum "),
errprintstack(true)));
}
struct varlena *va = (struct varlena *) DatumGetPointer(d);
varattrib *attr = (varattrib *) va;
int len = -1;
void *toFree = NULL;
if(VARATT_IS_EXTENDED(attr))
{
if(VARATT_IS_EXTERNAL(attr))
{
attr = (varattrib *)toast_fetch_datum((struct varlena *)attr);
/* toast_fetch_datum will palloc, so set it up for free */
toFree = attr;
}
if(VARATT_IS_COMPRESSED(attr))
{
PGLZ_Header *tmp = (PGLZ_Header *) attr;
len = PGLZ_RAW_SIZE(tmp);
}
else if(VARATT_IS_SHORT(attr))
{
len = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
}
}
if(len == -1)
{
len = VARSIZE(attr) - VARHDRSZ;
}
if ( toFree)
pfree(toFree);
Assert(len >= 0);
return len;
}
/* ----------
* heap_tuple_untoast_attr -
*
* Public entry point to get back a toasted value from compression
* or external storage.
* ----------
*/
struct varlena *
heap_tuple_untoast_attr(struct varlena *attr)
{
if (VARATT_IS_EXTERNAL(attr))
{
/*
* This is an externally stored datum --- fetch it back from there
*/
attr = toast_fetch_datum(attr);
/* fall through to IS_COMPRESSED if it's a compressed external datum */
}
if (VARATT_IS_COMPRESSED(attr))
{
/*
* This is a compressed value inside of the main tuple
*/
PGLZ_Header *tmp = (PGLZ_Header *) attr;
attr = (struct varlena *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
pglz_decompress(tmp, VARDATA(attr));
}
else if (VARATT_IS_SHORT(attr))
{
/*
* This is a short-header varlena --- convert to 4-byte header format
*/
Size data_size = VARSIZE_SHORT(attr);
Size new_size = data_size - VARHDRSZ_SHORT + VARHDRSZ;
varattrib *tmp = (varattrib *)attr;
/* This is a "short" varlena header but is otherwise a normal varlena */
attr = (struct varlena *) palloc(new_size);
SET_VARSIZE(attr, new_size);
memcpy(VARDATA(attr), VARDATA_SHORT(tmp), data_size - VARHDRSZ_SHORT);
}
return attr;
}
/* ----------
* heap_tuple_fetch_attr -
*
* Public entry point to get back a toasted value from
* external storage (possibly still in compressed format).
*
* This will return a datum that contains all the data internally, ie, not
* relying on external storage, but it can still be compressed or have a short
* header.
----------
*/
struct varlena *
heap_tuple_fetch_attr(struct varlena * attr)
{
struct varlena *result;
if (VARATT_IS_EXTERNAL(attr))
{
/*
* This is an external stored plain value
*/
result = toast_fetch_datum(attr);
}
else
{
/*
* This is a plain value inside of the main tuple - why am I called?
*/
result = attr;
}
return result;
}
/* ----------
* heap_tuple_untoast_attr_slice -
*
* Public entry point to get back part of a toasted value
* from compression or external storage.
* ----------
*/
struct varlena *
heap_tuple_untoast_attr_slice(struct varlena * attr,
int32 sliceoffset, int32 slicelength)
{
struct varlena *preslice;
struct varlena *result;
char *attrdata;
int32 attrsize;
if (VARATT_IS_EXTERNAL(attr))
{
struct varatt_external toast_pointer;
VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
/* fast path for non-compressed external datums */
if (!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
return toast_fetch_datum_slice(attr, sliceoffset, slicelength);
/* fetch it back (compressed marker will get set automatically) */
preslice = toast_fetch_datum(attr);
}
else
preslice = attr;
if (VARATT_IS_COMPRESSED(preslice))
{
PGLZ_Header *tmp = (PGLZ_Header *) preslice;
Size size = PGLZ_RAW_SIZE(tmp) + VARHDRSZ;
preslice = (struct varlena *) palloc(size);
SET_VARSIZE(preslice, size);
pglz_decompress(tmp, VARDATA(preslice));
if (tmp != (PGLZ_Header *) attr)
pfree(tmp);
}
if (VARATT_IS_SHORT(preslice))
{
attrdata = VARDATA_SHORT(preslice);
attrsize = VARSIZE_SHORT(preslice) - VARHDRSZ_SHORT;
}
else
{
attrdata = VARDATA(preslice);
attrsize = VARSIZE(preslice) - VARHDRSZ;
}
/* slicing of datum for compressed cases and plain value */
if (sliceoffset >= attrsize)
{
sliceoffset = 0;
slicelength = 0;
}
if (((sliceoffset + slicelength) > attrsize) || slicelength < 0)
slicelength = attrsize - sliceoffset;
result = (struct varlena *) palloc(slicelength + VARHDRSZ);
SET_VARSIZE(result, slicelength + VARHDRSZ);
memcpy(VARDATA(result), attrdata + sliceoffset, slicelength);
if (preslice != attr)
pfree(preslice);
return result;
}
/* ----------
* heap_tuple_untoast_attr_slice -
*
* Public entry point to get back part of a toasted value
* from compression or external storage.
* ----------
*/
struct varlena *
heap_tuple_untoast_attr_slice(struct varlena * attr,
int32 sliceoffset, int32 slicelength)
{
varattrib *preslice;
varattrib *result;
char *attrdata;
int32 attrsize;
if (VARATT_IS_EXTERNAL(attr))
{
/* fast path for non-compressed external datums */
if (!VARATT_EXTERNAL_IS_COMPRESSED(attr))
return toast_fetch_datum_slice(attr, sliceoffset, slicelength);
/* this automatically sets the compressed flag if appropriate */
preslice = (varattrib *)toast_fetch_datum(attr);
}
else
preslice = (varattrib *)attr;
if (VARATT_IS_COMPRESSED(preslice))
{
unsigned size;
PGLZ_Header *tmp;
tmp = (PGLZ_Header *) preslice;
size = PGLZ_RAW_SIZE(tmp) + VARHDRSZ;
preslice = (varattrib *) palloc(size);
SET_VARSIZE(preslice, size);
pglz_decompress(tmp, VARDATA(preslice));
if (tmp != (PGLZ_Header *) attr)
pfree(tmp);
}
if (VARATT_IS_SHORT(preslice))
{
attrdata = VARDATA_SHORT(preslice);
attrsize = VARSIZE_SHORT(preslice) - VARHDRSZ_SHORT;
}
else
{
attrdata = VARDATA(preslice);
attrsize = VARSIZE(preslice) - VARHDRSZ;
}
/* slicing of datum for compressed cases and plain value */
if (sliceoffset >= attrsize)
{
sliceoffset = 0;
slicelength = 0;
}
if (((sliceoffset + slicelength) > attrsize) || slicelength < 0)
slicelength = attrsize - sliceoffset;
result = (varattrib *) palloc(slicelength + VARHDRSZ);
SET_VARSIZE(result, slicelength + VARHDRSZ);
memcpy(VARDATA(result), attrdata + sliceoffset, slicelength);
if ((struct varlena *)preslice != (struct varlena *)attr)
pfree(preslice);
return (struct varlena *)result;
}