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Diffstat (limited to 'src/include/nodes/nodes.h')
| -rw-r--r-- | src/include/nodes/nodes.h | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h new file mode 100644 index 0000000..f8e8fe6 --- /dev/null +++ b/src/include/nodes/nodes.h @@ -0,0 +1,446 @@ +/*------------------------------------------------------------------------- + * + * nodes.h + * Definitions for tagged nodes. + * + * + * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/nodes/nodes.h + * + *------------------------------------------------------------------------- + */ +#ifndef NODES_H +#define NODES_H + +/* + * The first field of every node is NodeTag. Each node created (with makeNode) + * will have one of the following tags as the value of its first field. + * + * Note that inserting or deleting node types changes the numbers of other + * node types later in the list. This is no problem during development, since + * the node numbers are never stored on disk. But don't do it in a released + * branch, because that would represent an ABI break for extensions. + */ +typedef enum NodeTag +{ + T_Invalid = 0, + +#include "nodes/nodetags.h" +} NodeTag; + +/* + * pg_node_attr() - Used in node definitions to set extra information for + * gen_node_support.pl + * + * Attributes can be attached to a node as a whole (place the attribute + * specification on the first line after the struct's opening brace) + * or to a specific field (place it at the end of that field's line). The + * argument is a comma-separated list of attributes. Unrecognized attributes + * cause an error. + * + * Valid node attributes: + * + * - abstract: Abstract types are types that cannot be instantiated but that + * can be supertypes of other types. We track their fields, so that + * subtypes can use them, but we don't emit a node tag, so you can't + * instantiate them. + * + * - custom_copy_equal: Has custom implementations in copyfuncs.c and + * equalfuncs.c. + * + * - custom_read_write: Has custom implementations in outfuncs.c and + * readfuncs.c. + * + * - custom_query_jumble: Has custom implementation in queryjumblefuncs.c. + * + * - no_copy: Does not support copyObject() at all. + * + * - no_equal: Does not support equal() at all. + * + * - no_copy_equal: Shorthand for both no_copy and no_equal. + * + * - no_query_jumble: Does not support JumbleQuery() at all. + * + * - no_read: Does not support nodeRead() at all. + * + * - nodetag_only: Does not support copyObject(), equal(), jumbleQuery() + * outNode() or nodeRead(). + * + * - special_read_write: Has special treatment in outNode() and nodeRead(). + * + * - nodetag_number(VALUE): assign the specified nodetag number instead of + * an auto-generated number. Typically this would only be used in stable + * branches, to give a newly-added node type a number without breaking ABI + * by changing the numbers of existing node types. + * + * Node types can be supertypes of other types whether or not they are marked + * abstract: if a node struct appears as the first field of another struct + * type, then it is the supertype of that type. The no_copy, no_equal, + * no_query_jumble and no_read node attributes are automatically inherited + * from the supertype. (Notice that nodetag_only does not inherit, so it's + * not quite equivalent to a combination of other attributes.) + * + * Valid node field attributes: + * + * - array_size(OTHERFIELD): This field is a dynamically allocated array with + * size indicated by the mentioned other field. The other field is either a + * scalar or a list, in which case the length of the list is used. + * + * - copy_as(VALUE): In copyObject(), replace the field's value with VALUE. + * + * - copy_as_scalar: In copyObject(), copy the field as a scalar value + * (e.g. a pointer) even if it is a node-type pointer. + * + * - equal_as_scalar: In equal(), compare the field as a scalar value + * even if it is a node-type pointer. + * + * - equal_ignore: Ignore the field for equality. + * + * - equal_ignore_if_zero: Ignore the field for equality if it is zero. + * (Otherwise, compare normally.) + * + * - query_jumble_ignore: Ignore the field for the query jumbling. Note + * that typmod and collation information are usually irrelevant for the + * query jumbling. + * + * - query_jumble_location: Mark the field as a location to track. This is + * only allowed for integer fields that include "location" in their name. + * + * - read_as(VALUE): In nodeRead(), replace the field's value with VALUE. + * + * - read_write_ignore: Ignore the field for read/write. This is only allowed + * if the node type is marked no_read or read_as() is also specified. + * + * - write_only_relids, write_only_nondefault_pathtarget, write_only_req_outer: + * Special handling for Path struct; see there. + * + */ +#define pg_node_attr(...) + +/* + * The first field of a node of any type is guaranteed to be the NodeTag. + * Hence the type of any node can be gotten by casting it to Node. Declaring + * a variable to be of Node * (instead of void *) can also facilitate + * debugging. + */ +typedef struct Node +{ + NodeTag type; +} Node; + +#define nodeTag(nodeptr) (((const Node*)(nodeptr))->type) + +/* + * newNode - + * create a new node of the specified size and tag the node with the + * specified tag. + * + * !WARNING!: Avoid using newNode directly. You should be using the + * macro makeNode. eg. to create a Query node, use makeNode(Query) + * + * Note: the size argument should always be a compile-time constant, so the + * apparent risk of multiple evaluation doesn't matter in practice. + */ +#ifdef __GNUC__ + +/* With GCC, we can use a compound statement within an expression */ +#define newNode(size, tag) \ +({ Node *_result; \ + AssertMacro((size) >= sizeof(Node)); /* need the tag, at least */ \ + _result = (Node *) palloc0fast(size); \ + _result->type = (tag); \ + _result; \ +}) +#else + +/* + * There is no way to dereference the palloc'ed pointer to assign the + * tag, and also return the pointer itself, so we need a holder variable. + * Fortunately, this macro isn't recursive so we just define + * a global variable for this purpose. + */ +extern PGDLLIMPORT Node *newNodeMacroHolder; + +#define newNode(size, tag) \ +( \ + AssertMacro((size) >= sizeof(Node)), /* need the tag, at least */ \ + newNodeMacroHolder = (Node *) palloc0fast(size), \ + newNodeMacroHolder->type = (tag), \ + newNodeMacroHolder \ +) +#endif /* __GNUC__ */ + + +#define makeNode(_type_) ((_type_ *) newNode(sizeof(_type_),T_##_type_)) +#define NodeSetTag(nodeptr,t) (((Node*)(nodeptr))->type = (t)) + +#define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_) + +/* + * castNode(type, ptr) casts ptr to "type *", and if assertions are enabled, + * verifies that the node has the appropriate type (using its nodeTag()). + * + * Use an inline function when assertions are enabled, to avoid multiple + * evaluations of the ptr argument (which could e.g. be a function call). + */ +#ifdef USE_ASSERT_CHECKING +static inline Node * +castNodeImpl(NodeTag type, void *ptr) +{ + Assert(ptr == NULL || nodeTag(ptr) == type); + return (Node *) ptr; +} +#define castNode(_type_, nodeptr) ((_type_ *) castNodeImpl(T_##_type_, nodeptr)) +#else +#define castNode(_type_, nodeptr) ((_type_ *) (nodeptr)) +#endif /* USE_ASSERT_CHECKING */ + + +/* ---------------------------------------------------------------- + * extern declarations follow + * ---------------------------------------------------------------- + */ + +/* + * nodes/{outfuncs.c,print.c} + */ +struct Bitmapset; /* not to include bitmapset.h here */ +struct StringInfoData; /* not to include stringinfo.h here */ + +extern void outNode(struct StringInfoData *str, const void *obj); +extern void outToken(struct StringInfoData *str, const char *s); +extern void outBitmapset(struct StringInfoData *str, + const struct Bitmapset *bms); +extern void outDatum(struct StringInfoData *str, uintptr_t value, + int typlen, bool typbyval); +extern char *nodeToString(const void *obj); +extern char *bmsToString(const struct Bitmapset *bms); + +/* + * nodes/{readfuncs.c,read.c} + */ +extern void *stringToNode(const char *str); +#ifdef WRITE_READ_PARSE_PLAN_TREES +extern void *stringToNodeWithLocations(const char *str); +#endif +extern struct Bitmapset *readBitmapset(void); +extern uintptr_t readDatum(bool typbyval); +extern bool *readBoolCols(int numCols); +extern int *readIntCols(int numCols); +extern Oid *readOidCols(int numCols); +extern int16 *readAttrNumberCols(int numCols); + +/* + * nodes/copyfuncs.c + */ +extern void *copyObjectImpl(const void *from); + +/* cast result back to argument type, if supported by compiler */ +#ifdef HAVE_TYPEOF +#define copyObject(obj) ((typeof(obj)) copyObjectImpl(obj)) +#else +#define copyObject(obj) copyObjectImpl(obj) +#endif + +/* + * nodes/equalfuncs.c + */ +extern bool equal(const void *a, const void *b); + + +/* + * Typedefs for identifying qualifier selectivities and plan costs as such. + * These are just plain "double"s, but declaring a variable as Selectivity + * or Cost makes the intent more obvious. + * + * These could have gone into plannodes.h or some such, but many files + * depend on them... + */ +typedef double Selectivity; /* fraction of tuples a qualifier will pass */ +typedef double Cost; /* execution cost (in page-access units) */ +typedef double Cardinality; /* (estimated) number of rows or other integer + * count */ + + +/* + * CmdType - + * enums for type of operation represented by a Query or PlannedStmt + * + * This is needed in both parsenodes.h and plannodes.h, so put it here... + */ +typedef enum CmdType +{ + CMD_UNKNOWN, + CMD_SELECT, /* select stmt */ + CMD_UPDATE, /* update stmt */ + CMD_INSERT, /* insert stmt */ + CMD_DELETE, /* delete stmt */ + CMD_MERGE, /* merge stmt */ + CMD_UTILITY, /* cmds like create, destroy, copy, vacuum, + * etc. */ + CMD_NOTHING /* dummy command for instead nothing rules + * with qual */ +} CmdType; + + +/* + * JoinType - + * enums for types of relation joins + * + * JoinType determines the exact semantics of joining two relations using + * a matching qualification. For example, it tells what to do with a tuple + * that has no match in the other relation. + * + * This is needed in both parsenodes.h and plannodes.h, so put it here... + */ +typedef enum JoinType +{ + /* + * The canonical kinds of joins according to the SQL JOIN syntax. Only + * these codes can appear in parser output (e.g., JoinExpr nodes). + */ + JOIN_INNER, /* matching tuple pairs only */ + JOIN_LEFT, /* pairs + unmatched LHS tuples */ + JOIN_FULL, /* pairs + unmatched LHS + unmatched RHS */ + JOIN_RIGHT, /* pairs + unmatched RHS tuples */ + + /* + * Semijoins and anti-semijoins (as defined in relational theory) do not + * appear in the SQL JOIN syntax, but there are standard idioms for + * representing them (e.g., using EXISTS). The planner recognizes these + * cases and converts them to joins. So the planner and executor must + * support these codes. NOTE: in JOIN_SEMI output, it is unspecified + * which matching RHS row is joined to. In JOIN_ANTI output, the row is + * guaranteed to be null-extended. + */ + JOIN_SEMI, /* 1 copy of each LHS row that has match(es) */ + JOIN_ANTI, /* 1 copy of each LHS row that has no match */ + JOIN_RIGHT_ANTI, /* 1 copy of each RHS row that has no match */ + + /* + * These codes are used internally in the planner, but are not supported + * by the executor (nor, indeed, by most of the planner). + */ + JOIN_UNIQUE_OUTER, /* LHS path must be made unique */ + JOIN_UNIQUE_INNER /* RHS path must be made unique */ + + /* + * We might need additional join types someday. + */ +} JoinType; + +/* + * OUTER joins are those for which pushed-down quals must behave differently + * from the join's own quals. This is in fact everything except INNER and + * SEMI joins. However, this macro must also exclude the JOIN_UNIQUE symbols + * since those are temporary proxies for what will eventually be an INNER + * join. + * + * Note: semijoins are a hybrid case, but we choose to treat them as not + * being outer joins. This is okay principally because the SQL syntax makes + * it impossible to have a pushed-down qual that refers to the inner relation + * of a semijoin; so there is no strong need to distinguish join quals from + * pushed-down quals. This is convenient because for almost all purposes, + * quals attached to a semijoin can be treated the same as innerjoin quals. + */ +#define IS_OUTER_JOIN(jointype) \ + (((1 << (jointype)) & \ + ((1 << JOIN_LEFT) | \ + (1 << JOIN_FULL) | \ + (1 << JOIN_RIGHT) | \ + (1 << JOIN_ANTI) | \ + (1 << JOIN_RIGHT_ANTI))) != 0) + +/* + * AggStrategy - + * overall execution strategies for Agg plan nodes + * + * This is needed in both pathnodes.h and plannodes.h, so put it here... + */ +typedef enum AggStrategy +{ + AGG_PLAIN, /* simple agg across all input rows */ + AGG_SORTED, /* grouped agg, input must be sorted */ + AGG_HASHED, /* grouped agg, use internal hashtable */ + AGG_MIXED /* grouped agg, hash and sort both used */ +} AggStrategy; + +/* + * AggSplit - + * splitting (partial aggregation) modes for Agg plan nodes + * + * This is needed in both pathnodes.h and plannodes.h, so put it here... + */ + +/* Primitive options supported by nodeAgg.c: */ +#define AGGSPLITOP_COMBINE 0x01 /* substitute combinefn for transfn */ +#define AGGSPLITOP_SKIPFINAL 0x02 /* skip finalfn, return state as-is */ +#define AGGSPLITOP_SERIALIZE 0x04 /* apply serialfn to output */ +#define AGGSPLITOP_DESERIALIZE 0x08 /* apply deserialfn to input */ + +/* Supported operating modes (i.e., useful combinations of these options): */ +typedef enum AggSplit +{ + /* Basic, non-split aggregation: */ + AGGSPLIT_SIMPLE = 0, + /* Initial phase of partial aggregation, with serialization: */ + AGGSPLIT_INITIAL_SERIAL = AGGSPLITOP_SKIPFINAL | AGGSPLITOP_SERIALIZE, + /* Final phase of partial aggregation, with deserialization: */ + AGGSPLIT_FINAL_DESERIAL = AGGSPLITOP_COMBINE | AGGSPLITOP_DESERIALIZE +} AggSplit; + +/* Test whether an AggSplit value selects each primitive option: */ +#define DO_AGGSPLIT_COMBINE(as) (((as) & AGGSPLITOP_COMBINE) != 0) +#define DO_AGGSPLIT_SKIPFINAL(as) (((as) & AGGSPLITOP_SKIPFINAL) != 0) +#define DO_AGGSPLIT_SERIALIZE(as) (((as) & AGGSPLITOP_SERIALIZE) != 0) +#define DO_AGGSPLIT_DESERIALIZE(as) (((as) & AGGSPLITOP_DESERIALIZE) != 0) + +/* + * SetOpCmd and SetOpStrategy - + * overall semantics and execution strategies for SetOp plan nodes + * + * This is needed in both pathnodes.h and plannodes.h, so put it here... + */ +typedef enum SetOpCmd +{ + SETOPCMD_INTERSECT, + SETOPCMD_INTERSECT_ALL, + SETOPCMD_EXCEPT, + SETOPCMD_EXCEPT_ALL +} SetOpCmd; + +typedef enum SetOpStrategy +{ + SETOP_SORTED, /* input must be sorted */ + SETOP_HASHED /* use internal hashtable */ +} SetOpStrategy; + +/* + * OnConflictAction - + * "ON CONFLICT" clause type of query + * + * This is needed in both parsenodes.h and plannodes.h, so put it here... + */ +typedef enum OnConflictAction +{ + ONCONFLICT_NONE, /* No "ON CONFLICT" clause */ + ONCONFLICT_NOTHING, /* ON CONFLICT ... DO NOTHING */ + ONCONFLICT_UPDATE /* ON CONFLICT ... DO UPDATE */ +} OnConflictAction; + +/* + * LimitOption - + * LIMIT option of query + * + * This is needed in both parsenodes.h and plannodes.h, so put it here... + */ +typedef enum LimitOption +{ + LIMIT_OPTION_COUNT, /* FETCH FIRST... ONLY */ + LIMIT_OPTION_WITH_TIES, /* FETCH FIRST... WITH TIES */ + LIMIT_OPTION_DEFAULT, /* No limit present */ +} LimitOption; + +#endif /* NODES_H */ |