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toast_internals.h
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1 /*-------------------------------------------------------------------------
2  *
3  * toast_internals.h
4  * Internal definitions for the TOAST system.
5  *
6  * Copyright (c) 2000-2021, PostgreSQL Global Development Group
7  *
8  * src/include/access/toast_internals.h
9  *
10  *-------------------------------------------------------------------------
11  */
12 #ifndef TOAST_INTERNALS_H
13 #define TOAST_INTERNALS_H
14 
16 #include "storage/lockdefs.h"
17 #include "utils/relcache.h"
18 #include "utils/snapshot.h"
19 
20 /*
21  * The information at the start of the compressed toast data.
22  */
23 typedef struct toast_compress_header
24 {
25  int32 vl_len_; /* varlena header (do not touch directly!) */
26  uint32 tcinfo; /* 2 bits for compression method and 30 bits
27  * external size; see va_extinfo */
29 
30 /*
31  * Utilities for manipulation of header information for compressed
32  * toast entries.
33  */
34 #define TOAST_COMPRESS_EXTSIZE(ptr) \
35  (((toast_compress_header *) (ptr))->tcinfo & VARLENA_EXTSIZE_MASK)
36 #define TOAST_COMPRESS_METHOD(ptr) \
37  (((toast_compress_header *) (ptr))->tcinfo >> VARLENA_EXTSIZE_BITS)
38 
39 #define TOAST_COMPRESS_SET_SIZE_AND_COMPRESS_METHOD(ptr, len, cm_method) \
40  do { \
41  Assert((len) > 0 && (len) <= VARLENA_EXTSIZE_MASK); \
42  Assert((cm_method) == TOAST_PGLZ_COMPRESSION_ID || \
43  (cm_method) == TOAST_LZ4_COMPRESSION_ID); \
44  ((toast_compress_header *) (ptr))->tcinfo = \
45  (len) | ((uint32) (cm_method) << VARLENA_EXTSIZE_BITS); \
46  } while (0)
47 
48 extern Datum toast_compress_datum(Datum value, char cmethod);
49 extern Oid toast_get_valid_index(Oid toastoid, LOCKMODE lock);
50 
51 extern void toast_delete_datum(Relation rel, Datum value, bool is_speculative);
53  struct varlena *oldexternal, int options);
54 
55 extern int toast_open_indexes(Relation toastrel,
56  LOCKMODE lock,
57  Relation **toastidxs,
58  int *num_indexes);
59 extern void toast_close_indexes(Relation *toastidxs, int num_indexes,
60  LOCKMODE lock);
61 extern void init_toast_snapshot(Snapshot toast_snapshot);
62 
63 #endif /* TOAST_INTERNALS_H */
void toast_close_indexes(Relation *toastidxs, int num_indexes, LOCKMODE lock)
int LOCKMODE
Definition: lockdefs.h:26
Datum toast_compress_datum(Datum value, char cmethod)
void toast_delete_datum(Relation rel, Datum value, bool is_speculative)
unsigned int Oid
Definition: postgres_ext.h:31
signed int int32
Definition: c.h:429
struct toast_compress_header toast_compress_header
int toast_open_indexes(Relation toastrel, LOCKMODE lock, Relation **toastidxs, int *num_indexes)
Oid toast_get_valid_index(Oid toastoid, LOCKMODE lock)
unsigned int uint32
Definition: c.h:441
uintptr_t Datum
Definition: postgres.h:411
void init_toast_snapshot(Snapshot toast_snapshot)
static struct @143 value
Datum toast_save_datum(Relation rel, Datum value, struct varlena *oldexternal, int options)
Definition: c.h:621