codekingpro/portable-devtools

1/*-------------------------------------------------------------------------2 *3 * toast_helper.h4 *	  Helper functions for table AMs implementing compressed or5 *    out-of-line storage of varlena attributes.6 *7 * Copyright (c) 2000-2023, PostgreSQL Global Development Group8 *9 * src/include/access/toast_helper.h10 *11 *-------------------------------------------------------------------------12 */13 14#ifndef TOAST_HELPER_H15#define TOAST_HELPER_H16 17#include "utils/rel.h"18 19/*20 * Information about one column of a tuple being toasted.21 *22 * NOTE: toast_action[i] can have these values:23 *		' '						default handling24 *		TYPSTORAGE_PLAIN		already processed --- don't touch it25 *		TYPSTORAGE_EXTENDED		incompressible, but OK to move off26 *27 * NOTE: toast_attr[i].tai_size is only made valid for varlena attributes with28 * toast_action[i] different from TYPSTORAGE_PLAIN.29 */30typedef struct31{32	struct varlena *tai_oldexternal;33	int32		tai_size;34	uint8		tai_colflags;35	char		tai_compression;36} ToastAttrInfo;37 38/*39 * Information about one tuple being toasted.40 */41typedef struct42{43	/*44	 * Before calling toast_tuple_init, the caller must initialize the45	 * following fields.  Each array must have a length equal to46	 * ttc_rel->rd_att->natts.  The ttc_oldvalues and ttc_oldisnull fields47	 * should be NULL in the case of an insert.48	 */49	Relation	ttc_rel;		/* the relation that contains the tuple */50	Datum	   *ttc_values;		/* values from the tuple columns */51	bool	   *ttc_isnull;		/* null flags for the tuple columns */52	Datum	   *ttc_oldvalues;	/* values from previous tuple */53	bool	   *ttc_oldisnull;	/* null flags from previous tuple */54 55	/*56	 * Before calling toast_tuple_init, the caller should set ttc_attr to57	 * point to an array of ToastAttrInfo structures of a length equal to58	 * ttc_rel->rd_att->natts.  The contents of the array need not be59	 * initialized.  ttc_flags also does not need to be initialized.60	 */61	uint8		ttc_flags;62	ToastAttrInfo *ttc_attr;63} ToastTupleContext;64 65/*66 * Flags indicating the overall state of a TOAST operation.67 *68 * TOAST_NEEDS_DELETE_OLD indicates that one or more old TOAST datums need69 * to be deleted.70 *71 * TOAST_NEEDS_FREE indicates that one or more TOAST values need to be freed.72 *73 * TOAST_HAS_NULLS indicates that nulls were found in the tuple being toasted.74 *75 * TOAST_NEEDS_CHANGE indicates that a new tuple needs to built; in other76 * words, the toaster did something.77 */78#define TOAST_NEEDS_DELETE_OLD				0x000179#define TOAST_NEEDS_FREE					0x000280#define TOAST_HAS_NULLS						0x000481#define TOAST_NEEDS_CHANGE					0x000882 83/*84 * Flags indicating the status of a TOAST operation with respect to a85 * particular column.86 *87 * TOASTCOL_NEEDS_DELETE_OLD indicates that the old TOAST datums for this88 * column need to be deleted.89 *90 * TOASTCOL_NEEDS_FREE indicates that the value for this column needs to91 * be freed.92 *93 * TOASTCOL_IGNORE indicates that the toaster should not further process94 * this column.95 *96 * TOASTCOL_INCOMPRESSIBLE indicates that this column has been found to97 * be incompressible, but could be moved out-of-line.98 */99#define TOASTCOL_NEEDS_DELETE_OLD			TOAST_NEEDS_DELETE_OLD100#define TOASTCOL_NEEDS_FREE					TOAST_NEEDS_FREE101#define TOASTCOL_IGNORE						0x0010102#define TOASTCOL_INCOMPRESSIBLE				0x0020103 104extern void toast_tuple_init(ToastTupleContext *ttc);105extern int	toast_tuple_find_biggest_attribute(ToastTupleContext *ttc,106											   bool for_compression,107											   bool check_main);108extern void toast_tuple_try_compression(ToastTupleContext *ttc, int attribute);109extern void toast_tuple_externalize(ToastTupleContext *ttc, int attribute,110									int options);111extern void toast_tuple_cleanup(ToastTupleContext *ttc);112 113extern void toast_delete_external(Relation rel, Datum *values, bool *isnull,114								  bool is_speculative);115 116#endif117