diff options
Diffstat (limited to 'src/backend/access/common/tupdesc.c')
| -rw-r--r-- | src/backend/access/common/tupdesc.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c index 75b191ba2aa..4436c863617 100644 --- a/src/backend/access/common/tupdesc.c +++ b/src/backend/access/common/tupdesc.c @@ -19,6 +19,7 @@ #include "postgres.h" +#include "access/hash.h" #include "access/htup_details.h" #include "catalog/pg_collation.h" #include "catalog/pg_type.h" @@ -26,6 +27,7 @@ #include "parser/parse_type.h" #include "utils/acl.h" #include "utils/builtins.h" +#include "utils/hashutils.h" #include "utils/resowner_private.h" #include "utils/syscache.h" @@ -444,6 +446,31 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) } /* + * hashTupleDesc + * Compute a hash value for a tuple descriptor. + * + * If two tuple descriptors would be considered equal by equalTupleDescs() + * then their hash value will be equal according to this function. + * + * Note that currently contents of constraint are not hashed - it'd be a bit + * painful to do so, and conflicts just due to constraints are unlikely. + */ +uint32 +hashTupleDesc(TupleDesc desc) +{ + uint32 s; + int i; + + s = hash_combine(0, hash_uint32(desc->natts)); + s = hash_combine(s, hash_uint32(desc->tdtypeid)); + s = hash_combine(s, hash_uint32(desc->tdhasoid)); + for (i = 0; i < desc->natts; ++i) + s = hash_combine(s, hash_uint32(TupleDescAttr(desc, i)->atttypid)); + + return s; +} + +/* * TupleDescInitEntry * This function initializes a single attribute structure in * a previously allocated tuple descriptor. |