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Diffstat (limited to 'contrib/hstore/hstore.h')
| -rw-r--r-- | contrib/hstore/hstore.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/contrib/hstore/hstore.h b/contrib/hstore/hstore.h new file mode 100644 index 0000000..bf4a565 --- /dev/null +++ b/contrib/hstore/hstore.h @@ -0,0 +1,205 @@ +/* + * contrib/hstore/hstore.h + */ +#ifndef __HSTORE_H__ +#define __HSTORE_H__ + +#include "fmgr.h" +#include "utils/array.h" + + +/* + * HEntry: there is one of these for each key _and_ value in an hstore + * + * the position offset points to the _end_ so that we can get the length + * by subtraction from the previous entry. the ISFIRST flag lets us tell + * whether there is a previous entry. + */ +typedef struct +{ + uint32 entry; +} HEntry; + +#define HENTRY_ISFIRST 0x80000000 +#define HENTRY_ISNULL 0x40000000 +#define HENTRY_POSMASK 0x3FFFFFFF + +/* note possible multiple evaluations, also access to prior array element */ +#define HSE_ISFIRST(he_) (((he_).entry & HENTRY_ISFIRST) != 0) +#define HSE_ISNULL(he_) (((he_).entry & HENTRY_ISNULL) != 0) +#define HSE_ENDPOS(he_) ((he_).entry & HENTRY_POSMASK) +#define HSE_OFF(he_) (HSE_ISFIRST(he_) ? 0 : HSE_ENDPOS((&(he_))[-1])) +#define HSE_LEN(he_) (HSE_ISFIRST(he_) \ + ? HSE_ENDPOS(he_) \ + : HSE_ENDPOS(he_) - HSE_ENDPOS((&(he_))[-1])) + +/* + * determined by the size of "endpos" (ie HENTRY_POSMASK), though this is a + * bit academic since currently varlenas (and hence both the input and the + * whole hstore) have the same limit + */ +#define HSTORE_MAX_KEY_LEN 0x3FFFFFFF +#define HSTORE_MAX_VALUE_LEN 0x3FFFFFFF + +typedef struct +{ + int32 vl_len_; /* varlena header (do not touch directly!) */ + uint32 size_; /* flags and number of items in hstore */ + /* array of HEntry follows */ +} HStore; + +/* + * It's not possible to get more than 2^28 items into an hstore, so we reserve + * the top few bits of the size field. See hstore_compat.c for one reason + * why. Some bits are left for future use here. MaxAllocSize makes the + * practical count limit slightly more than 2^28 / 3, or INT_MAX / 24, the + * limit for an hstore full of 4-byte keys and null values. Therefore, we + * don't explicitly check the format-imposed limit. + */ +#define HS_FLAG_NEWVERSION 0x80000000 + +#define HS_COUNT(hsp_) ((hsp_)->size_ & 0x0FFFFFFF) +#define HS_SETCOUNT(hsp_,c_) ((hsp_)->size_ = (c_) | HS_FLAG_NEWVERSION) + + +/* + * "x" comes from an existing HS_COUNT() (as discussed, <= INT_MAX/24) or a + * Pairs array length (due to MaxAllocSize, <= INT_MAX/40). "lenstr" is no + * more than INT_MAX, that extreme case arising in hstore_from_arrays(). + * Therefore, this calculation is limited to about INT_MAX / 5 + INT_MAX. + */ +#define HSHRDSIZE (sizeof(HStore)) +#define CALCDATASIZE(x, lenstr) ( (x) * 2 * sizeof(HEntry) + HSHRDSIZE + (lenstr) ) + +/* note multiple evaluations of x */ +#define ARRPTR(x) ( (HEntry*) ( (HStore*)(x) + 1 ) ) +#define STRPTR(x) ( (char*)(ARRPTR(x) + HS_COUNT((HStore*)(x)) * 2) ) + +/* note multiple/non evaluations */ +#define HSTORE_KEY(arr_,str_,i_) ((str_) + HSE_OFF((arr_)[2*(i_)])) +#define HSTORE_VAL(arr_,str_,i_) ((str_) + HSE_OFF((arr_)[2*(i_)+1])) +#define HSTORE_KEYLEN(arr_,i_) (HSE_LEN((arr_)[2*(i_)])) +#define HSTORE_VALLEN(arr_,i_) (HSE_LEN((arr_)[2*(i_)+1])) +#define HSTORE_VALISNULL(arr_,i_) (HSE_ISNULL((arr_)[2*(i_)+1])) + +/* + * currently, these following macros are the _only_ places that rely + * on internal knowledge of HEntry. Everything else should be using + * the above macros. Exception: the in-place upgrade in hstore_compat.c + * messes with entries directly. + */ + +/* + * copy one key/value pair (which must be contiguous starting at + * sptr_) into an under-construction hstore; dent_ is an HEntry*, + * dbuf_ is the destination's string buffer, dptr_ is the current + * position in the destination. lots of modification and multiple + * evaluation here. + */ +#define HS_COPYITEM(dent_,dbuf_,dptr_,sptr_,klen_,vlen_,vnull_) \ + do { \ + memcpy((dptr_), (sptr_), (klen_)+(vlen_)); \ + (dptr_) += (klen_)+(vlen_); \ + (dent_)++->entry = ((dptr_) - (dbuf_) - (vlen_)) & HENTRY_POSMASK; \ + (dent_)++->entry = ((((dptr_) - (dbuf_)) & HENTRY_POSMASK) \ + | ((vnull_) ? HENTRY_ISNULL : 0)); \ + } while(0) + +/* + * add one key/item pair, from a Pairs structure, into an + * under-construction hstore + */ +#define HS_ADDITEM(dent_,dbuf_,dptr_,pair_) \ + do { \ + memcpy((dptr_), (pair_).key, (pair_).keylen); \ + (dptr_) += (pair_).keylen; \ + (dent_)++->entry = ((dptr_) - (dbuf_)) & HENTRY_POSMASK; \ + if ((pair_).isnull) \ + (dent_)++->entry = ((((dptr_) - (dbuf_)) & HENTRY_POSMASK) \ + | HENTRY_ISNULL); \ + else \ + { \ + memcpy((dptr_), (pair_).val, (pair_).vallen); \ + (dptr_) += (pair_).vallen; \ + (dent_)++->entry = ((dptr_) - (dbuf_)) & HENTRY_POSMASK; \ + } \ + } while (0) + +/* finalize a newly-constructed hstore */ +#define HS_FINALIZE(hsp_,count_,buf_,ptr_) \ + do { \ + int buflen = (ptr_) - (buf_); \ + if ((count_)) \ + ARRPTR(hsp_)[0].entry |= HENTRY_ISFIRST; \ + if ((count_) != HS_COUNT((hsp_))) \ + { \ + HS_SETCOUNT((hsp_),(count_)); \ + memmove(STRPTR(hsp_), (buf_), buflen); \ + } \ + SET_VARSIZE((hsp_), CALCDATASIZE((count_), buflen)); \ + } while (0) + +/* ensure the varlena size of an existing hstore is correct */ +#define HS_FIXSIZE(hsp_,count_) \ + do { \ + int bl = (count_) ? HSE_ENDPOS(ARRPTR(hsp_)[2*(count_)-1]) : 0; \ + SET_VARSIZE((hsp_), CALCDATASIZE((count_),bl)); \ + } while (0) + +/* DatumGetHStoreP includes support for reading old-format hstore values */ +extern HStore *hstoreUpgrade(Datum orig); + +#define DatumGetHStoreP(d) hstoreUpgrade(d) + +#define PG_GETARG_HSTORE_P(x) DatumGetHStoreP(PG_GETARG_DATUM(x)) + + +/* + * Pairs is a "decompressed" representation of one key/value pair. + * The two strings are not necessarily null-terminated. + */ +typedef struct +{ + char *key; + char *val; + size_t keylen; + size_t vallen; + bool isnull; /* value is null? */ + bool needfree; /* need to pfree the value? */ +} Pairs; + +extern int hstoreUniquePairs(Pairs *a, int32 l, int32 *buflen); +extern HStore *hstorePairs(Pairs *pairs, int32 pcount, int32 buflen); + +extern size_t hstoreCheckKeyLen(size_t len); +extern size_t hstoreCheckValLen(size_t len); + +extern int hstoreFindKey(HStore *hs, int *lowbound, char *key, int keylen); +extern Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs); + +#define HStoreContainsStrategyNumber 7 +#define HStoreExistsStrategyNumber 9 +#define HStoreExistsAnyStrategyNumber 10 +#define HStoreExistsAllStrategyNumber 11 +#define HStoreOldContainsStrategyNumber 13 /* backwards compatibility */ + +/* + * defining HSTORE_POLLUTE_NAMESPACE=0 will prevent use of old function names; + * for now, we default to on for the benefit of people restoring old dumps + */ +#ifndef HSTORE_POLLUTE_NAMESPACE +#define HSTORE_POLLUTE_NAMESPACE 1 +#endif + +#if HSTORE_POLLUTE_NAMESPACE +#define HSTORE_POLLUTE(newname_,oldname_) \ + PG_FUNCTION_INFO_V1(oldname_); \ + Datum newname_(PG_FUNCTION_ARGS); \ + Datum oldname_(PG_FUNCTION_ARGS) { return newname_(fcinfo); } \ + extern int no_such_variable +#else +#define HSTORE_POLLUTE(newname_,oldname_) \ + extern int no_such_variable +#endif + +#endif /* __HSTORE_H__ */ |