print.c

Go to the documentation of this file.

/*-------------------------------------------------------------------------
 *
 * print.c
 *    various print routines (used mostly for debugging)
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/nodes/print.c
 *
 * HISTORY
 *    AUTHOR            DATE            MAJOR EVENT
 *    Andrew Yu         Oct 26, 1994    file creation
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include "access/printtup.h"
#include "lib/stringinfo.h"
#include "nodes/nodeFuncs.h"
#include "nodes/pathnodes.h"
#include "nodes/print.h"
#include "parser/parsetree.h"
#include "utils/lsyscache.h"


/*
 * print
 *    print contents of Node to stdout
 */
void
print(const void *obj)
{
    char       *s;
    char       *f;

    s = nodeToString(obj);
    f = format_node_dump(s);
    pfree(s);
    printf("%s\n", f);
    fflush(stdout);
    pfree(f);
}

/*
 * pprint
 *    pretty-print contents of Node to stdout
 */
void
pprint(const void *obj)
{
    char       *s;
    char       *f;

    s = nodeToString(obj);
    f = pretty_format_node_dump(s);
    pfree(s);
    printf("%s\n", f);
    fflush(stdout);
    pfree(f);
}

/*
 * elog_node_display
 *    send pretty-printed contents of Node to postmaster log
 */
void
elog_node_display(int lev, const char *title, const void *obj, bool pretty)
{
    char       *s;
    char       *f;

    s = nodeToString(obj);
    if (pretty)
        f = pretty_format_node_dump(s);
    else
        f = format_node_dump(s);
    pfree(s);
    ereport(lev,
            (errmsg_internal("%s:", title),
             errdetail_internal("%s", f)));
    pfree(f);
}

/*
 * Format a nodeToString output for display on a terminal.
 *
 * The result is a palloc'd string.
 *
 * This version just tries to break at whitespace.
 */
char *
format_node_dump(const char *dump)
{
#define LINELEN     78
    char        line[LINELEN + 1];
    StringInfoData str;
    int         i;
    int         j;
    int         k;

    initStringInfo(&str);
    i = 0;
    for (;;)
    {
        for (j = 0; j < LINELEN && dump[i] != '\0'; i++, j++)
            line[j] = dump[i];
        if (dump[i] == '\0')
            break;
        if (dump[i] == ' ')
        {
            /* ok to break at adjacent space */
            i++;
        }
        else
        {
            for (k = j - 1; k > 0; k--)
                if (line[k] == ' ')
                    break;
            if (k > 0)
            {
                /* back up; will reprint all after space */
                i -= (j - k - 1);
                j = k;
            }
        }
        line[j] = '\0';
        appendStringInfo(&str, "%s\n", line);
    }
    if (j > 0)
    {
        line[j] = '\0';
        appendStringInfo(&str, "%s\n", line);
    }
    return str.data;
#undef LINELEN
}

/*
 * Format a nodeToString output for display on a terminal.
 *
 * The result is a palloc'd string.
 *
 * This version tries to indent intelligently.
 */
char *
pretty_format_node_dump(const char *dump)
{
#define INDENTSTOP  3
#define MAXINDENT   60
#define LINELEN     78
    char        line[LINELEN + 1];
    StringInfoData str;
    int         indentLev;
    int         indentDist;
    int         i;
    int         j;

    initStringInfo(&str);
    indentLev = 0;              /* logical indent level */
    indentDist = 0;             /* physical indent distance */
    i = 0;
    for (;;)
    {
        for (j = 0; j < indentDist; j++)
            line[j] = ' ';
        for (; j < LINELEN && dump[i] != '\0'; i++, j++)
        {
            line[j] = dump[i];
            switch (line[j])
            {
                case '}':
                    if (j != indentDist)
                    {
                        /* print data before the } */
                        line[j] = '\0';
                        appendStringInfo(&str, "%s\n", line);
                    }
                    /* print the } at indentDist */
                    line[indentDist] = '}';
                    line[indentDist + 1] = '\0';
                    appendStringInfo(&str, "%s\n", line);
                    /* outdent */
                    if (indentLev > 0)
                    {
                        indentLev--;
                        indentDist = Min(indentLev * INDENTSTOP, MAXINDENT);
                    }
                    j = indentDist - 1;
                    /* j will equal indentDist on next loop iteration */
                    /* suppress whitespace just after } */
                    while (dump[i + 1] == ' ')
                        i++;
                    break;
                case ')':
                    /* force line break after ), unless another ) follows */
                    if (dump[i + 1] != ')')
                    {
                        line[j + 1] = '\0';
                        appendStringInfo(&str, "%s\n", line);
                        j = indentDist - 1;
                        while (dump[i + 1] == ' ')
                            i++;
                    }
                    break;
                case '{':
                    /* force line break before { */
                    if (j != indentDist)
                    {
                        line[j] = '\0';
                        appendStringInfo(&str, "%s\n", line);
                    }
                    /* indent */
                    indentLev++;
                    indentDist = Min(indentLev * INDENTSTOP, MAXINDENT);
                    for (j = 0; j < indentDist; j++)
                        line[j] = ' ';
                    line[j] = dump[i];
                    break;
                case ':':
                    /* force line break before : */
                    if (j != indentDist)
                    {
                        line[j] = '\0';
                        appendStringInfo(&str, "%s\n", line);
                    }
                    j = indentDist;
                    line[j] = dump[i];
                    break;
            }
        }
        line[j] = '\0';
        if (dump[i] == '\0')
            break;
        appendStringInfo(&str, "%s\n", line);
    }
    if (j > 0)
        appendStringInfo(&str, "%s\n", line);
    return str.data;
#undef INDENTSTOP
#undef MAXINDENT
#undef LINELEN
}

/*
 * print_rt
 *    print contents of range table
 */
void
print_rt(const List *rtable)
{
    const ListCell *l;
    int         i = 1;

    printf("resno\trefname  \trelid\tinFromCl\n");
    printf("-----\t---------\t-----\t--------\n");
    foreach(l, rtable)
    {
        RangeTblEntry *rte = lfirst(l);

        switch (rte->rtekind)
        {
            case RTE_RELATION:
                printf("%d\t%s\t%u\t%c",
                       i, rte->eref->aliasname, rte->relid, rte->relkind);
                break;
            case RTE_SUBQUERY:
                printf("%d\t%s\t[subquery]",
                       i, rte->eref->aliasname);
                break;
            case RTE_JOIN:
                printf("%d\t%s\t[join]",
                       i, rte->eref->aliasname);
                break;
            case RTE_FUNCTION:
                printf("%d\t%s\t[rangefunction]",
                       i, rte->eref->aliasname);
                break;
            case RTE_TABLEFUNC:
                printf("%d\t%s\t[table function]",
                       i, rte->eref->aliasname);
                break;
            case RTE_VALUES:
                printf("%d\t%s\t[values list]",
                       i, rte->eref->aliasname);
                break;
            case RTE_CTE:
                printf("%d\t%s\t[cte]",
                       i, rte->eref->aliasname);
                break;
            case RTE_NAMEDTUPLESTORE:
                printf("%d\t%s\t[tuplestore]",
                       i, rte->eref->aliasname);
                break;
            case RTE_RESULT:
                printf("%d\t%s\t[result]",
                       i, rte->eref->aliasname);
                break;
            default:
                printf("%d\t%s\t[unknown rtekind]",
                       i, rte->eref->aliasname);
        }

        printf("\t%s\t%s\n",
               (rte->inh ? "inh" : ""),
               (rte->inFromCl ? "inFromCl" : ""));
        i++;
    }
}


/*
 * print_expr
 *    print an expression
 */
void
print_expr(const Node *expr, const List *rtable)
{
    if (expr == NULL)
    {
        printf("<>");
        return;
    }

    if (IsA(expr, Var))
    {
        const Var  *var = (const Var *) expr;
        char       *relname,
                   *attname;

        switch (var->varno)
        {
            case INNER_VAR:
                relname = "INNER";
                attname = "?";
                break;
            case OUTER_VAR:
                relname = "OUTER";
                attname = "?";
                break;
            case INDEX_VAR:
                relname = "INDEX";
                attname = "?";
                break;
            default:
                {
                    RangeTblEntry *rte;

                    Assert(var->varno > 0 &&
                           (int) var->varno <= list_length(rtable));
                    rte = rt_fetch(var->varno, rtable);
                    relname = rte->eref->aliasname;
                    attname = get_rte_attribute_name(rte, var->varattno);
                }
                break;
        }
        printf("%s.%s", relname, attname);
    }
    else if (IsA(expr, Const))
    {
        const Const *c = (const Const *) expr;
        Oid         typoutput;
        bool        typIsVarlena;
        char       *outputstr;

        if (c->constisnull)
        {
            printf("NULL");
            return;
        }

        getTypeOutputInfo(c->consttype,
                          &typoutput, &typIsVarlena);

        outputstr = OidOutputFunctionCall(typoutput, c->constvalue);
        printf("%s", outputstr);
        pfree(outputstr);
    }
    else if (IsA(expr, OpExpr))
    {
        const OpExpr *e = (const OpExpr *) expr;
        char       *opname;

        opname = get_opname(e->opno);
        if (list_length(e->args) > 1)
        {
            print_expr(get_leftop((const Expr *) e), rtable);
            printf(" %s ", ((opname != NULL) ? opname : "(invalid operator)"));
            print_expr(get_rightop((const Expr *) e), rtable);
        }
        else
        {
            /* we print prefix and postfix ops the same... */
            printf("%s ", ((opname != NULL) ? opname : "(invalid operator)"));
            print_expr(get_leftop((const Expr *) e), rtable);
        }
    }
    else if (IsA(expr, FuncExpr))
    {
        const FuncExpr *e = (const FuncExpr *) expr;
        char       *funcname;
        ListCell   *l;

        funcname = get_func_name(e->funcid);
        printf("%s(", ((funcname != NULL) ? funcname : "(invalid function)"));
        foreach(l, e->args)
        {
            print_expr(lfirst(l), rtable);
            if (lnext(e->args, l))
                printf(",");
        }
        printf(")");
    }
    else
        printf("unknown expr");
}

/*
 * print_pathkeys -
 *    pathkeys list of PathKeys
 */
void
print_pathkeys(const List *pathkeys, const List *rtable)
{
    const ListCell *i;

    printf("(");
    foreach(i, pathkeys)
    {
        PathKey    *pathkey = (PathKey *) lfirst(i);
        EquivalenceClass *eclass;
        ListCell   *k;
        bool        first = true;

        eclass = pathkey->pk_eclass;
        /* chase up, in case pathkey is non-canonical */
        while (eclass->ec_merged)
            eclass = eclass->ec_merged;

        printf("(");
        foreach(k, eclass->ec_members)
        {
            EquivalenceMember *mem = (EquivalenceMember *) lfirst(k);

            if (first)
                first = false;
            else
                printf(", ");
            print_expr((Node *) mem->em_expr, rtable);
        }
        printf(")");
        if (lnext(pathkeys, i))
            printf(", ");
    }
    printf(")\n");
}

/*
 * print_tl
 *    print targetlist in a more legible way.
 */
void
print_tl(const List *tlist, const List *rtable)
{
    const ListCell *tl;

    printf("(\n");
    foreach(tl, tlist)
    {
        TargetEntry *tle = (TargetEntry *) lfirst(tl);

        printf("\t%d %s\t", tle->resno,
               tle->resname ? tle->resname : "<null>");
        if (tle->ressortgroupref != 0)
            printf("(%u):\t", tle->ressortgroupref);
        else
            printf("    :\t");
        print_expr((Node *) tle->expr, rtable);
        printf("\n");
    }
    printf(")\n");
}

/*
 * print_slot
 *    print out the tuple with the given TupleTableSlot
 */
void
print_slot(TupleTableSlot *slot)
{
    if (TupIsNull(slot))
    {
        printf("tuple is null.\n");
        return;
    }
    if (!slot->tts_tupleDescriptor)
    {
        printf("no tuple descriptor.\n");
        return;
    }

    debugtup(slot, NULL);
}