/*-------------------------------------------------------------------------
*
* execExpr.h
* Low level infrastructure related to expression evaluation
*
*
* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/executor/execExpr.h
*
*-------------------------------------------------------------------------
*/
#ifndef EXEC_EXPR_H
#define EXEC_EXPR_H
#include "executor/nodeAgg.h"
#include "nodes/execnodes.h"
/* forward references to avoid circularity */
struct ExprEvalStep;
struct ArrayRefState;
/* Bits in ExprState->flags (see also execnodes.h for public flag bits): */
/* expression's interpreter has been initialized */
#define EEO_FLAG_INTERPRETER_INITIALIZED (1 << 1)
/* jump-threading is in use */
#define EEO_FLAG_DIRECT_THREADED (1 << 2)
/* Typical API for out-of-line evaluation subroutines */
typedef void (*ExecEvalSubroutine) (ExprState *state,
struct ExprEvalStep *op,
ExprContext *econtext);
/* ExprEvalSteps that cache a composite type's tupdesc need one of these */
/* (it fits in-line in some step types, otherwise allocate out-of-line) */
typedef struct ExprEvalRowtypeCache
{
/*
* cacheptr points to composite type's TypeCacheEntry if tupdesc_id is not
* 0; or for an anonymous RECORD type, it points directly at the cached
* tupdesc for the type, and tupdesc_id is 0. (We'd use separate fields
* if space were not at a premium.) Initial state is cacheptr == NULL.
*/
void *cacheptr;
uint64 tupdesc_id; /* last-seen tupdesc identifier, or 0 */
} ExprEvalRowtypeCache;
/*
* Discriminator for ExprEvalSteps.
*
* Identifies the operation to be executed and which member in the
* ExprEvalStep->d union is valid.
*
* The order of entries needs to be kept in sync with the dispatch_table[]
* array in execExprInterp.c:ExecInterpExpr().
*/
typedef enum ExprEvalOp
{
/* entire expression has been evaluated completely, return */
EEOP_DONE,
/* apply slot_getsomeattrs on corresponding tuple slot */
EEOP_INNER_FETCHSOME,
EEOP_OUTER_FETCHSOME,
EEOP_SCAN_FETCHSOME,
/* compute non-system Var value */
EEOP_INNER_VAR,
EEOP_OUTER_VAR,
EEOP_SCAN_VAR,
/* compute system Var value */
EEOP_INNER_SYSVAR,
EEOP_OUTER_SYSVAR,
EEOP_SCAN_SYSVAR,
/* compute wholerow Var */
EEOP_WHOLEROW,
/*
* Compute non-system Var value, assign it into ExprState's resultslot.
* These are not used if a CheckVarSlotCompatibility() check would be
* needed.
*/
EEOP_ASSIGN_INNER_VAR,
EEOP_ASSIGN_OUTER_VAR,
EEOP_ASSIGN_SCAN_VAR,
/* assign ExprState's resvalue/resnull to a column of its resultslot */
EEOP_ASSIGN_TMP,
/* ditto, applying MakeExpandedObjectReadOnly() */
EEOP_ASSIGN_TMP_MAKE_RO,
/* evaluate Const value */
EEOP_CONST,
/*
* Evaluate function call (including OpExprs etc). For speed, we
* distinguish in the opcode whether the function is strict and/or
* requires usage stats tracking.
*/
EEOP_FUNCEXPR,
EEOP_FUNCEXPR_STRICT,
EEOP_FUNCEXPR_FUSAGE,
EEOP_FUNCEXPR_STRICT_FUSAGE,
/*
* Evaluate boolean AND expression, one step per subexpression. FIRST/LAST
* subexpressions are special-cased for performance. Since AND always has
* at least two subexpressions, FIRST and LAST never apply to the same
* subexpression.
*/
EEOP_BOOL_AND_STEP_FIRST,
EEOP_BOOL_AND_STEP,
EEOP_BOOL_AND_STEP_LAST,
/* similarly for boolean OR expression */
EEOP_BOOL_OR_STEP_FIRST,
EEOP_BOOL_OR_STEP,
EEOP_BOOL_OR_STEP_LAST,
/* evaluate boolean NOT expression */
EEOP_BOOL_NOT_STEP,
/* simplified version of BOOL_AND_STEP for use by ExecQual() */
EEOP_QUAL,
/* unconditional jump to another step */
EEOP_JUMP,
/* conditional jumps based on current result value */
EEOP_JUMP_IF_NULL,
EEOP_JUMP_IF_NOT_NULL,
EEOP_JUMP_IF_NOT_TRUE,
/* perform NULL tests for scalar values */
EEOP_NULLTEST_ISNULL,
EEOP_NULLTEST_ISNOTNULL,
/* perform NULL tests for row values */
EEOP_NULLTEST_ROWISNULL,
EEOP_NULLTEST_ROWISNOTNULL,
/* evaluate a BooleanTest expression */
EEOP_BOOLTEST_IS_TRUE,
EEOP_BOOLTEST_IS_NOT_TRUE,
EEOP_BOOLTEST_IS_FALSE,
EEOP_BOOLTEST_IS_NOT_FALSE,
/* evaluate PARAM_EXEC/EXTERN parameters */
EEOP_PARAM_EXEC,
EEOP_PARAM_EXTERN,
EEOP_PARAM_CALLBACK,
/* return CaseTestExpr value */
EEOP_CASE_TESTVAL,
/* apply MakeExpandedObjectReadOnly() to target value */
EEOP_MAKE_READONLY,
/* evaluate assorted special-purpose expression types */
EEOP_IOCOERCE,
EEOP_DISTINCT,
EEOP_NOT_DISTINCT,
EEOP_NULLIF,
EEOP_SQLVALUEFUNCTION,
EEOP_CURRENTOFEXPR,
EEOP_NEXTVALUEEXPR,
EEOP_ARRAYEXPR,
EEOP_ARRAYCOERCE,
EEOP_ROW,
/*
* Compare two individual elements of each of two compared ROW()
* expressions. Skip to ROWCOMPARE_FINAL if elements are not equal.
*/
EEOP_ROWCOMPARE_STEP,
/* evaluate boolean value based on previous ROWCOMPARE_STEP operations */
EEOP_ROWCOMPARE_FINAL,
/* evaluate GREATEST() or LEAST() */
EEOP_MINMAX,
/* evaluate FieldSelect expression */
EEOP_FIELDSELECT,
/*
* Deform tuple before evaluating new values for individual fields in a
* FieldStore expression.
*/
EEOP_FIELDSTORE_DEFORM,
/*
* Form the new tuple for a FieldStore expression. Individual fields will
* have been evaluated into columns of the tuple deformed by the preceding
* DEFORM step.
*/
EEOP_FIELDSTORE_FORM,
/* Process an array subscript; short-circuit expression to NULL if NULL */
EEOP_ARRAYREF_SUBSCRIPT,
/*
* Compute old array element/slice when an ArrayRef assignment expression
* contains ArrayRef/FieldStore subexpressions. Value is accessed using
* the CaseTest mechanism.
*/
EEOP_ARRAYREF_OLD,
/* compute new value for ArrayRef assignment expression */
EEOP_ARRAYREF_ASSIGN,
/* compute element/slice for ArrayRef fetch expression */
EEOP_ARRAYREF_FETCH,
/* evaluate value for CoerceToDomainValue */
EEOP_DOMAIN_TESTVAL,
/* evaluate a domain's NOT NULL constraint */
EEOP_DOMAIN_NOTNULL,
/* evaluate a single domain CHECK constraint */
EEOP_DOMAIN_CHECK,
/* evaluate assorted special-purpose expression types */
EEOP_CONVERT_ROWTYPE,
EEOP_SCALARARRAYOP,
EEOP_XMLEXPR,
EEOP_AGGREF,
EEOP_GROUPING_FUNC,
EEOP_WINDOW_FUNC,
EEOP_SUBPLAN,
EEOP_ALTERNATIVE_SUBPLAN,
/* aggregation related nodes */
EEOP_AGG_STRICT_DESERIALIZE,
EEOP_AGG_DESERIALIZE,
EEOP_AGG_STRICT_INPUT_CHECK,
EEOP_AGG_INIT_TRANS,
EEOP_AGG_STRICT_TRANS_CHECK,
EEOP_AGG_PLAIN_TRANS_BYVAL,
EEOP_AGG_PLAIN_TRANS,
EEOP_AGG_ORDERED_TRANS_DATUM,
EEOP_AGG_ORDERED_TRANS_TUPLE,
/* non-existent operation, used e.g. to check array lengths */
EEOP_LAST
} ExprEvalOp;
typedef struct ExprEvalStep
{
/*
* Instruction to be executed. During instruction preparation this is an
* enum ExprEvalOp, but later it can be changed to some other type, e.g. a
* pointer for computed goto (that's why it's an intptr_t).
*/
intptr_t opcode;
/* where to store the result of this step */
Datum *resvalue;
bool *resnull;
/*
* Inline data for the operation. Inline data is faster to access, but
* also bloats the size of all instructions. The union should be kept to
* no more than 40 bytes on 64-bit systems (so that the entire struct is
* no more than 64 bytes, a single cacheline on common systems).
*/
union
{
/* for EEOP_INNER/OUTER/SCAN_FETCHSOME */
struct
{
/* attribute number up to which to fetch (inclusive) */
int last_var;
TupleDesc known_desc;
} fetch;
/* for EEOP_INNER/OUTER/SCAN_[SYS]VAR[_FIRST] */
struct
{
/* attnum is attr number - 1 for regular VAR ... */
/* but it's just the normal (negative) attr number for SYSVAR */
int attnum;
Oid vartype; /* type OID of variable */
} var;
/* for EEOP_WHOLEROW */
struct
{
Var *var; /* original Var node in plan tree */
bool first; /* first time through, need to initialize? */
bool slow; /* need runtime check for nulls? */
TupleDesc tupdesc; /* descriptor for resulting tuples */
JunkFilter *junkFilter; /* JunkFilter to remove resjunk cols */
} wholerow;
/* for EEOP_ASSIGN_*_VAR */
struct
{
/* target index in ExprState->resultslot->tts_values/nulls */
int resultnum;
/* source attribute number - 1 */
int attnum;
} assign_var;
/* for EEOP_ASSIGN_TMP[_MAKE_RO] */
struct
{
/* target index in ExprState->resultslot->tts_values/nulls */
int resultnum;
} assign_tmp;
/* for EEOP_CONST */
struct
{
/* constant's value */
Datum value;
bool isnull;
} constval;
/* for EEOP_FUNCEXPR_* / NULLIF / DISTINCT */
struct
{
FmgrInfo *finfo; /* function's lookup data */
FunctionCallInfo fcinfo_data; /* arguments etc */
/* faster to access without additional indirection: */
PGFunction fn_addr; /* actual call address */
int nargs; /* number of arguments */
} func;
/* for EEOP_BOOL_*_STEP */
struct
{
bool *anynull; /* track if any input was NULL */
int jumpdone; /* jump here if result determined */
} boolexpr;
/* for EEOP_QUAL */
struct
{
int jumpdone; /* jump here on false or null */
} qualexpr;
/* for EEOP_JUMP[_CONDITION] */
struct
{
int jumpdone; /* target instruction's index */
} jump;
/* for EEOP_NULLTEST_ROWIS[NOT]NULL */
struct
{
/* cached descriptor for composite type - filled at runtime */
ExprEvalRowtypeCache rowcache;
} nulltest_row;
/* for EEOP_PARAM_EXEC/EXTERN */
struct
{
int paramid; /* numeric ID for parameter */
Oid paramtype; /* OID of parameter's datatype */
} param;
/* for EEOP_PARAM_CALLBACK */
struct
{
ExecEvalSubroutine paramfunc; /* add-on evaluation subroutine */
void *paramarg; /* private data for same */
int paramid; /* numeric ID for parameter */
Oid paramtype; /* OID of parameter's datatype */
} cparam;
/* for EEOP_CASE_TESTVAL/DOMAIN_TESTVAL */
struct
{
Datum *value; /* value to return */
bool *isnull;
} casetest;
/* for EEOP_MAKE_READONLY */
struct
{
Datum *value; /* value to coerce to read-only */
bool *isnull;
} make_readonly;
/* for EEOP_IOCOERCE */
struct
{
/* lookup and call info for source type's output function */
FmgrInfo *finfo_out;
FunctionCallInfo fcinfo_data_out;
/* lookup and call info for result type's input function */
FmgrInfo *finfo_in;
FunctionCallInfo fcinfo_data_in;
} iocoerce;
/* for EEOP_SQLVALUEFUNCTION */
struct
{
SQLValueFunction *svf;
} sqlvaluefunction;
/* for EEOP_NEXTVALUEEXPR */
struct
{
Oid seqid;
Oid seqtypid;
} nextvalueexpr;
/* for EEOP_ARRAYEXPR */
struct
{
Datum *elemvalues; /* element values get stored here */
bool *elemnulls;
int nelems; /* length of the above arrays */
Oid elemtype; /* array element type */
int16 elemlength; /* typlen of the array element type */
bool elembyval; /* is the element type pass-by-value? */
char elemalign; /* typalign of the element type */
bool multidims; /* is array expression multi-D? */
} arrayexpr;
/* for EEOP_ARRAYCOERCE */
struct
{
ExprState *elemexprstate; /* null if no per-element work */
Oid resultelemtype; /* element type of result array */
struct ArrayMapState *amstate; /* workspace for array_map */
} arraycoerce;
/* for EEOP_ROW */
struct
{
TupleDesc tupdesc; /* descriptor for result tuples */
/* workspace for the values constituting the row: */
Datum *elemvalues;
bool *elemnulls;
} row;
/* for EEOP_ROWCOMPARE_STEP */
struct
{
/* lookup and call data for column comparison function */
FmgrInfo *finfo;
FunctionCallInfo fcinfo_data;
PGFunction fn_addr;
/* target for comparison resulting in NULL */
int jumpnull;
/* target for comparison yielding inequality */
int jumpdone;
} rowcompare_step;
/* for EEOP_ROWCOMPARE_FINAL */
struct
{
RowCompareType rctype;
} rowcompare_final;
/* for EEOP_MINMAX */
struct
{
/* workspace for argument values */
Datum *values;
bool *nulls;
int nelems;
/* is it GREATEST or LEAST? */
MinMaxOp op;
/* lookup and call data for comparison function */
FmgrInfo *finfo;
FunctionCallInfo fcinfo_data;
} minmax;
/* for EEOP_FIELDSELECT */
struct
{
AttrNumber fieldnum; /* field number to extract */
Oid resulttype; /* field's type */
/* cached descriptor for composite type - filled at runtime */
ExprEvalRowtypeCache rowcache;
} fieldselect;
/* for EEOP_FIELDSTORE_DEFORM / FIELDSTORE_FORM */
struct
{
/* original expression node */
FieldStore *fstore;
/* cached descriptor for composite type - filled at runtime */
/* note that a DEFORM and FORM pair share the same cache */
ExprEvalRowtypeCache *rowcache;
/* workspace for column values */
Datum *values;
bool *nulls;
int ncolumns;
} fieldstore;
/* for EEOP_ARRAYREF_SUBSCRIPT */
struct
{
/* too big to have inline */
struct ArrayRefState *state;
int off; /* 0-based index of this subscript */
bool isupper; /* is it upper or lower subscript? */
int jumpdone; /* jump here on null */
} arrayref_subscript;
/* for EEOP_ARRAYREF_OLD / ASSIGN / FETCH */
struct
{
/* too big to have inline */
struct ArrayRefState *state;
} arrayref;
/* for EEOP_DOMAIN_NOTNULL / DOMAIN_CHECK */
struct
{
/* name of constraint */
char *constraintname;
/* where the result of a CHECK constraint will be stored */
Datum *checkvalue;
bool *checknull;
/* OID of domain type */
Oid resulttype;
} domaincheck;
/* for EEOP_CONVERT_ROWTYPE */
struct
{
Oid inputtype; /* input composite type */
Oid outputtype; /* output composite type */
/* these three fields are filled at runtime: */
ExprEvalRowtypeCache *incache; /* cache for input type */
ExprEvalRowtypeCache *outcache; /* cache for output type */
TupleConversionMap *map; /* column mapping */
} convert_rowtype;
/* for EEOP_SCALARARRAYOP */
struct
{
/* element_type/typlen/typbyval/typalign are filled at runtime */
Oid element_type; /* InvalidOid if not yet filled */
bool useOr; /* use OR or AND semantics? */
int16 typlen; /* array element type storage info */
bool typbyval;
char typalign;
FmgrInfo *finfo; /* function's lookup data */
FunctionCallInfo fcinfo_data; /* arguments etc */
/* faster to access without additional indirection: */
PGFunction fn_addr; /* actual call address */
} scalararrayop;
/* for EEOP_XMLEXPR */
struct
{
XmlExpr *xexpr; /* original expression node */
/* workspace for evaluating named args, if any */
Datum *named_argvalue;
bool *named_argnull;
/* workspace for evaluating unnamed args, if any */
Datum *argvalue;
bool *argnull;
} xmlexpr;
/* for EEOP_AGGREF */
struct
{
/* out-of-line state, modified by nodeAgg.c */
AggrefExprState *astate;
} aggref;
/* for EEOP_GROUPING_FUNC */
struct
{
AggState *parent; /* parent Agg */
List *clauses; /* integer list of column numbers */
} grouping_func;
/* for EEOP_WINDOW_FUNC */
struct
{
/* out-of-line state, modified by nodeWindowFunc.c */
WindowFuncExprState *wfstate;
} window_func;
/* for EEOP_SUBPLAN */
struct
{
/* out-of-line state, created by nodeSubplan.c */
SubPlanState *sstate;
} subplan;
/* for EEOP_ALTERNATIVE_SUBPLAN */
struct
{
/* out-of-line state, created by nodeSubplan.c */
AlternativeSubPlanState *asstate;
} alternative_subplan;
/* for EEOP_AGG_*DESERIALIZE */
struct
{
AggState *aggstate;
FunctionCallInfo fcinfo_data;
int jumpnull;
} agg_deserialize;
/* for EEOP_AGG_STRICT_INPUT_CHECK */
struct
{
bool *nulls;
int nargs;
int jumpnull;
} agg_strict_input_check;
/* for EEOP_AGG_INIT_TRANS */
struct
{
AggState *aggstate;
AggStatePerTrans pertrans;
ExprContext *aggcontext;
int setno;
int transno;
int setoff;
int jumpnull;
} agg_init_trans;
/* for EEOP_AGG_STRICT_TRANS_CHECK */
struct
{
AggState *aggstate;
int setno;
int transno;
int setoff;
int jumpnull;
} agg_strict_trans_check;
/* for EEOP_AGG_{PLAIN,ORDERED}_TRANS* */
struct
{
AggState *aggstate;
AggStatePerTrans pertrans;
ExprContext *aggcontext;
int setno;
int transno;
int setoff;
} agg_trans;
} d;
} ExprEvalStep;
/* Non-inline data for array operations */
typedef struct ArrayRefState
{
bool isassignment; /* is it assignment, or just fetch? */
Oid refelemtype; /* OID of the array element type */
int16 refattrlength; /* typlen of array type */
int16 refelemlength; /* typlen of the array element type */
bool refelembyval; /* is the element type pass-by-value? */
char refelemalign; /* typalign of the element type */
/* numupper and upperprovided[] are filled at compile time */
/* at runtime, extracted subscript datums get stored in upperindex[] */
int numupper;
bool upperprovided[MAXDIM];
int upperindex[MAXDIM];
/* similarly for lower indexes, if any */
int numlower;
bool lowerprovided[MAXDIM];
int lowerindex[MAXDIM];
/* subscript expressions get evaluated into here */
Datum subscriptvalue;
bool subscriptnull;
/* for assignment, new value to assign is evaluated into here */
Datum replacevalue;
bool replacenull;
/* if we have a nested assignment, ARRAYREF_OLD puts old value here */
Datum prevvalue;
bool prevnull;
} ArrayRefState;
/* functions in execExpr.c */
extern void ExprEvalPushStep(ExprState *es, const ExprEvalStep *s);
/* functions in execExprInterp.c */
extern void ExecReadyInterpretedExpr(ExprState *state);
extern ExprEvalOp ExecEvalStepOp(ExprState *state, ExprEvalStep *op);
extern Datum ExecInterpExprStillValid(ExprState *state, ExprContext *econtext, bool *isNull);
extern void CheckExprStillValid(ExprState *state, ExprContext *econtext);
/*
* Non fast-path execution functions. These are externs instead of statics in
* execExprInterp.c, because that allows them to be used by other methods of
* expression evaluation, reducing code duplication.
*/
extern void ExecEvalFuncExprFusage(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalFuncExprStrictFusage(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalParamExec(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op);
extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op);
extern void ExecEvalNextValueExpr(ExprState *state, ExprEvalStep *op);
extern void ExecEvalRowNull(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalRowNotNull(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalArrayExpr(ExprState *state, ExprEvalStep *op);
extern void ExecEvalArrayCoerce(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalRow(ExprState *state, ExprEvalStep *op);
extern void ExecEvalMinMax(ExprState *state, ExprEvalStep *op);
extern void ExecEvalFieldSelect(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalFieldStoreDeForm(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalFieldStoreForm(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern bool ExecEvalArrayRefSubscript(ExprState *state, ExprEvalStep *op);
extern void ExecEvalArrayRefFetch(ExprState *state, ExprEvalStep *op);
extern void ExecEvalArrayRefOld(ExprState *state, ExprEvalStep *op);
extern void ExecEvalArrayRefAssign(ExprState *state, ExprEvalStep *op);
extern void ExecEvalConvertRowtype(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalScalarArrayOp(ExprState *state, ExprEvalStep *op);
extern void ExecEvalConstraintNotNull(ExprState *state, ExprEvalStep *op);
extern void ExecEvalConstraintCheck(ExprState *state, ExprEvalStep *op);
extern void ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op);
extern void ExecEvalGroupingFunc(ExprState *state, ExprEvalStep *op);
extern void ExecEvalSubPlan(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalAlternativeSubPlan(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecAggInitGroup(AggState *aggstate, AggStatePerTrans pertrans, AggStatePerGroup pergroup);
extern Datum ExecAggTransReparent(AggState *aggstate, AggStatePerTrans pertrans,
Datum newValue, bool newValueIsNull,
Datum oldValue, bool oldValueIsNull);
extern void ExecEvalAggOrderedTransDatum(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalAggOrderedTransTuple(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
#endif /* EXEC_EXPR_H */