diff options
Diffstat (limited to 'src/include/postgres.h')
| -rw-r--r-- | src/include/postgres.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/include/postgres.h b/src/include/postgres.h index be37313fa5a..ccf1605455e 100644 --- a/src/include/postgres.h +++ b/src/include/postgres.h @@ -88,6 +88,23 @@ typedef struct varatt_indirect } varatt_indirect; /* + * struct varatt_expanded is a "TOAST pointer" representing an out-of-line + * Datum that is stored in memory, in some type-specific, not necessarily + * physically contiguous format that is convenient for computation not + * storage. APIs for this, in particular the definition of struct + * ExpandedObjectHeader, are in src/include/utils/expandeddatum.h. + * + * Note that just as for struct varatt_external, this struct is stored + * unaligned within any containing tuple. + */ +typedef struct ExpandedObjectHeader ExpandedObjectHeader; + +typedef struct varatt_expanded +{ + ExpandedObjectHeader *eohptr; +} varatt_expanded; + +/* * Type tag for the various sorts of "TOAST pointer" datums. The peculiar * value for VARTAG_ONDISK comes from a requirement for on-disk compatibility * with a previous notion that the tag field was the pointer datum's length. @@ -95,11 +112,18 @@ typedef struct varatt_indirect typedef enum vartag_external { VARTAG_INDIRECT = 1, + VARTAG_EXPANDED_RO = 2, + VARTAG_EXPANDED_RW = 3, VARTAG_ONDISK = 18 } vartag_external; +/* this test relies on the specific tag values above */ +#define VARTAG_IS_EXPANDED(tag) \ + (((tag) & ~1) == VARTAG_EXPANDED_RO) + #define VARTAG_SIZE(tag) \ ((tag) == VARTAG_INDIRECT ? sizeof(varatt_indirect) : \ + VARTAG_IS_EXPANDED(tag) ? sizeof(varatt_expanded) : \ (tag) == VARTAG_ONDISK ? sizeof(varatt_external) : \ TrapMacro(true, "unrecognized TOAST vartag")) @@ -294,6 +318,12 @@ typedef struct (VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_ONDISK) #define VARATT_IS_EXTERNAL_INDIRECT(PTR) \ (VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_INDIRECT) +#define VARATT_IS_EXTERNAL_EXPANDED_RO(PTR) \ + (VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_EXPANDED_RO) +#define VARATT_IS_EXTERNAL_EXPANDED_RW(PTR) \ + (VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_EXPANDED_RW) +#define VARATT_IS_EXTERNAL_EXPANDED(PTR) \ + (VARATT_IS_EXTERNAL(PTR) && VARTAG_IS_EXPANDED(VARTAG_EXTERNAL(PTR))) #define VARATT_IS_SHORT(PTR) VARATT_IS_1B(PTR) #define VARATT_IS_EXTENDED(PTR) (!VARATT_IS_4B_U(PTR)) |