plpy_typeio.h

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/*
 * src/pl/plpython/plpy_typeio.h
 */

#ifndef PLPY_TYPEIO_H
#define PLPY_TYPEIO_H

#include "access/htup.h"
#include "access/tupdesc.h"
#include "fmgr.h"
#include "storage/itemptr.h"

/*
 * Conversion from PostgreSQL Datum to a Python object.
 */
struct PLyDatumToOb;
typedef PyObject *(*PLyDatumToObFunc) (struct PLyDatumToOb *arg, Datum val);

typedef struct PLyDatumToOb
{
    PLyDatumToObFunc func;
    FmgrInfo    typfunc;        /* The type's output function */
    FmgrInfo    typtransform;   /* from-SQL transform */
    Oid         typoid;         /* The OID of the type */
    int32       typmod;         /* The typmod of the type */
    Oid         typioparam;
    bool        typbyval;
    int16       typlen;
    char        typalign;
    struct PLyDatumToOb *elm;
} PLyDatumToOb;

typedef struct PLyTupleToOb
{
    PLyDatumToOb *atts;
    int         natts;
} PLyTupleToOb;

typedef union PLyTypeInput
{
    PLyDatumToOb d;
    PLyTupleToOb r;
} PLyTypeInput;

/*
 * Conversion from Python object to a PostgreSQL Datum.
 *
 * The 'inarray' argument to the conversion function is true, if the
 * converted value was in an array (Python list). It is used to give a
 * better error message in some cases.
 */
struct PLyObToDatum;
typedef Datum (*PLyObToDatumFunc) (struct PLyObToDatum *arg, int32 typmod, PyObject *val, bool inarray);

typedef struct PLyObToDatum
{
    PLyObToDatumFunc func;
    FmgrInfo    typfunc;        /* The type's input function */
    FmgrInfo    typtransform;   /* to-SQL transform */
    Oid         typoid;         /* The OID of the type */
    int32       typmod;         /* The typmod of the type */
    Oid         typioparam;
    bool        typbyval;
    int16       typlen;
    char        typalign;
    struct PLyObToDatum *elm;
} PLyObToDatum;

typedef struct PLyObToTuple
{
    PLyObToDatum *atts;
    int         natts;
} PLyObToTuple;

typedef union PLyTypeOutput
{
    PLyObToDatum d;
    PLyObToTuple r;
} PLyTypeOutput;

/* all we need to move PostgreSQL data to Python objects,
 * and vice versa
 */
typedef struct PLyTypeInfo
{
    PLyTypeInput in;
    PLyTypeOutput out;

    /*
     * is_rowtype can be: -1 = not known yet (initial state); 0 = scalar
     * datatype; 1 = rowtype; 2 = rowtype, but I/O functions not set up yet
     */
    int         is_rowtype;
    /* used to check if the type has been modified */
    Oid         typ_relid;
    TransactionId typrel_xmin;
    ItemPointerData typrel_tid;

    /* context for subsidiary data (doesn't belong to this struct though) */
    MemoryContext mcxt;
} PLyTypeInfo;

extern void PLy_typeinfo_init(PLyTypeInfo *arg, MemoryContext mcxt);

extern void PLy_input_datum_func(PLyTypeInfo *arg, Oid typeOid, HeapTuple typeTup, Oid langid, List *trftypes);
extern void PLy_output_datum_func(PLyTypeInfo *arg, HeapTuple typeTup, Oid langid, List *trftypes);

extern void PLy_input_tuple_funcs(PLyTypeInfo *arg, TupleDesc desc);
extern void PLy_output_tuple_funcs(PLyTypeInfo *arg, TupleDesc desc);

extern void PLy_output_record_funcs(PLyTypeInfo *arg, TupleDesc desc);

/* conversion from Python objects to composite Datums */
extern Datum PLyObject_ToCompositeDatum(PLyTypeInfo *info, TupleDesc desc, PyObject *plrv, bool isarray);

/* conversion from heap tuples to Python dictionaries */
extern PyObject *PLyDict_FromTuple(PLyTypeInfo *info, HeapTuple tuple, TupleDesc desc);

/* conversion from Python objects to C strings */
extern char *PLyObject_AsString(PyObject *plrv);

#endif                          /* PLPY_TYPEIO_H */