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https://git.postgresql.org/git/postgresql.git
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1430 lines
34 KiB
C
1430 lines
34 KiB
C
/*
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* dblink.c
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*
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* Functions returning results from a remote database
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*
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* Copyright (c) Joseph Conway <mail@joeconway.com>, 2001, 2002,
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* ALL RIGHTS RESERVED;
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*
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* Permission to use, copy, modify, and distribute this software and its
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* documentation for any purpose, without fee, and without a written agreement
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* is hereby granted, provided that the above copyright notice and this
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* paragraph and the following two paragraphs appear in all copies.
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*
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* IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
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* LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
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* DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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*/
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#include "dblink.h"
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/*
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* Internal declarations
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*/
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static dblink_results *init_dblink_results(MemoryContext fn_mcxt);
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static dblink_array_results *init_dblink_array_results(MemoryContext fn_mcxt);
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static char **get_pkey_attnames(Oid relid, int16 *numatts);
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static char *get_strtok(char *fldtext, char *fldsep, int fldnum);
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static char *get_sql_insert(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals);
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static char *get_sql_delete(Oid relid, int16 *pkattnums, int16 pknumatts, char **tgt_pkattvals);
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static char *get_sql_update(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals);
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static char *quote_literal_cstr(char *rawstr);
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static char *quote_ident_cstr(char *rawstr);
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static int16 get_attnum_pk_pos(int16 *pkattnums, int16 pknumatts, int16 key);
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static HeapTuple get_tuple_of_interest(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals);
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static Oid get_relid_from_relname(text *relname_text);
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static dblink_results *get_res_ptr(int32 res_id_index);
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static void append_res_ptr(dblink_results *results);
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static void remove_res_ptr(dblink_results *results);
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/* Global */
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List *res_id = NIL;
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int res_id_index = 0;
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PG_FUNCTION_INFO_V1(dblink);
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Datum
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dblink(PG_FUNCTION_ARGS)
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{
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PGconn *conn = NULL;
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PGresult *res = NULL;
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dblink_results *results;
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char *optstr;
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char *sqlstatement;
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char *execstatement;
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char *msg;
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int ntuples = 0;
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ReturnSetInfo *rsi;
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if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
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elog(ERROR, "dblink: function called in context that does not accept a set result");
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optstr = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(PG_GETARG_TEXT_P(0))));
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sqlstatement = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(PG_GETARG_TEXT_P(1))));
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if (fcinfo->flinfo->fn_extra == NULL)
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{
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conn = PQconnectdb(optstr);
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if (PQstatus(conn) == CONNECTION_BAD)
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQfinish(conn);
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elog(ERROR, "dblink: connection error: %s", msg);
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}
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execstatement = (char *) palloc(strlen(sqlstatement) + 1);
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if (execstatement != NULL)
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{
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strcpy(execstatement, sqlstatement);
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strcat(execstatement, "\0");
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}
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else
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elog(ERROR, "dblink: insufficient memory");
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res = PQexec(conn, execstatement);
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if (!res || (PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK))
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(conn);
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elog(ERROR, "dblink: sql error: %s", msg);
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}
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else
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{
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/*
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* got results, start fetching them
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*/
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ntuples = PQntuples(res);
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/*
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* increment resource index
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*/
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res_id_index++;
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results = init_dblink_results(fcinfo->flinfo->fn_mcxt);
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results->tup_num = 0;
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results->res_id_index = res_id_index;
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results->res = res;
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/*
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* Append node to res_id to hold pointer to results.
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* Needed by dblink_tok to access the data
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*/
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append_res_ptr(results);
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/*
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* save pointer to results for the next function manager call
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*/
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fcinfo->flinfo->fn_extra = (void *) results;
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/* close the connection to the database and cleanup */
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PQfinish(conn);
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprMultipleResult;
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PG_RETURN_INT32(res_id_index);
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}
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}
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else
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{
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/*
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* check for more results
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*/
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results = fcinfo->flinfo->fn_extra;
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results->tup_num++;
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res_id_index = results->res_id_index;
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ntuples = PQntuples(results->res);
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if (results->tup_num < ntuples)
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{
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/*
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* fetch them if available
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*/
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprMultipleResult;
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PG_RETURN_INT32(res_id_index);
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}
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else
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{
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/*
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* or if no more, clean things up
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*/
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results = fcinfo->flinfo->fn_extra;
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remove_res_ptr(results);
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PQclear(results->res);
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pfree(results);
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fcinfo->flinfo->fn_extra = NULL;
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprEndResult;
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PG_RETURN_NULL();
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}
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}
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PG_RETURN_NULL();
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}
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/*
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* dblink_tok
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* parse dblink output string
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* return fldnum item (0 based)
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* based on provided field separator
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*/
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PG_FUNCTION_INFO_V1(dblink_tok);
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Datum
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dblink_tok(PG_FUNCTION_ARGS)
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{
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dblink_results *results;
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int fldnum;
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text *result_text;
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char *result;
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int nfields = 0;
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int text_len = 0;
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results = get_res_ptr(PG_GETARG_INT32(0));
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if (results == NULL)
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{
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if (res_id != NIL)
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{
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freeList(res_id);
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res_id = NIL;
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res_id_index = 0;
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}
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elog(ERROR, "dblink_tok: function called with invalid resource id");
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}
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fldnum = PG_GETARG_INT32(1);
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if (fldnum < 0)
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elog(ERROR, "dblink_tok: field number < 0 not permitted");
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nfields = PQnfields(results->res);
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if (fldnum > (nfields - 1))
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elog(ERROR, "dblink_tok: field number %d does not exist", fldnum);
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if (PQgetisnull(results->res, results->tup_num, fldnum) == 1)
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PG_RETURN_NULL();
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else
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{
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text_len = PQgetlength(results->res, results->tup_num, fldnum);
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result = (char *) palloc(text_len + 1);
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if (result != NULL)
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{
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strcpy(result, PQgetvalue(results->res, results->tup_num, fldnum));
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strcat(result, "\0");
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}
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else
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elog(ERROR, "dblink: insufficient memory");
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(result)));
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PG_RETURN_TEXT_P(result_text);
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}
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}
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/*
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* dblink_strtok
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* parse input string
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* return ord item (0 based)
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* based on provided field separator
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*/
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PG_FUNCTION_INFO_V1(dblink_strtok);
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Datum
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dblink_strtok(PG_FUNCTION_ARGS)
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{
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char *fldtext;
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char *fldsep;
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int fldnum;
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char *buffer;
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text *result_text;
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fldtext = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(PG_GETARG_TEXT_P(0))));
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fldsep = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(PG_GETARG_TEXT_P(1))));
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fldnum = PG_GETARG_INT32(2);
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if (fldtext[0] == '\0')
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{
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elog(ERROR, "get_strtok: blank list not permitted");
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}
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if (fldsep[0] == '\0')
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{
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elog(ERROR, "get_strtok: blank field separator not permitted");
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}
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buffer = get_strtok(fldtext, fldsep, fldnum);
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pfree(fldtext);
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pfree(fldsep);
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if (buffer == NULL)
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{
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PG_RETURN_NULL();
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}
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else
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{
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(buffer)));
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pfree(buffer);
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PG_RETURN_TEXT_P(result_text);
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}
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}
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/*
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* dblink_get_pkey
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*
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* Return comma delimited list of primary key
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* fields for the supplied relation,
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* or NULL if none exists.
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*/
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PG_FUNCTION_INFO_V1(dblink_get_pkey);
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Datum
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dblink_get_pkey(PG_FUNCTION_ARGS)
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{
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text *relname_text;
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Oid relid;
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char **result;
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text *result_text;
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int16 numatts;
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ReturnSetInfo *rsi;
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dblink_array_results *ret_set;
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if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
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elog(ERROR, "dblink: function called in context that does not accept a set result");
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if (fcinfo->flinfo->fn_extra == NULL)
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{
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relname_text = PG_GETARG_TEXT_P(0);
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/*
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* Convert relname to rel OID.
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*/
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relid = get_relid_from_relname(relname_text);
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if (!OidIsValid(relid))
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elog(ERROR, "dblink_get_pkey: relation does not exist");
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/*
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* get an array of attnums.
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*/
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result = get_pkey_attnames(relid, &numatts);
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if ((result != NULL) && (numatts > 0))
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{
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ret_set = init_dblink_array_results(fcinfo->flinfo->fn_mcxt);
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ret_set->elem_num = 0;
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ret_set->num_elems = numatts;
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ret_set->res = result;
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fcinfo->flinfo->fn_extra = (void *) ret_set;
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprMultipleResult;
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(result[ret_set->elem_num])));
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PG_RETURN_TEXT_P(result_text);
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}
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else
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{
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprEndResult;
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PG_RETURN_NULL();
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}
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}
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else
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{
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/*
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* check for more results
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*/
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ret_set = fcinfo->flinfo->fn_extra;
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ret_set->elem_num++;
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result = ret_set->res;
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if (ret_set->elem_num < ret_set->num_elems)
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{
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/*
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* fetch next one
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*/
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprMultipleResult;
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(result[ret_set->elem_num])));
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PG_RETURN_TEXT_P(result_text);
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}
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else
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{
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int i;
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/*
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* or if no more, clean things up
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*/
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for (i = 0; i < ret_set->num_elems; i++)
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pfree(result[i]);
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pfree(ret_set->res);
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pfree(ret_set);
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rsi = (ReturnSetInfo *) fcinfo->resultinfo;
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rsi->isDone = ExprEndResult;
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PG_RETURN_NULL();
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}
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}
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PG_RETURN_NULL();
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}
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/*
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* dblink_last_oid
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* return last inserted oid
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*/
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PG_FUNCTION_INFO_V1(dblink_last_oid);
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Datum
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dblink_last_oid(PG_FUNCTION_ARGS)
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{
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dblink_results *results;
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results = get_res_ptr(PG_GETARG_INT32(0));
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if (results == NULL)
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{
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if (res_id != NIL)
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{
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freeList(res_id);
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res_id = NIL;
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res_id_index = 0;
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}
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elog(ERROR, "dblink_tok: function called with invalid resource id");
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}
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PG_RETURN_OID(PQoidValue(results->res));
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}
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/*
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* dblink_build_sql_insert
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*
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* Used to generate an SQL insert statement
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* based on an existing tuple in a local relation.
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* This is useful for selectively replicating data
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* to another server via dblink.
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*
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* API:
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* <relname> - name of local table of interest
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* <pkattnums> - an int2vector of attnums which will be used
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* to identify the local tuple of interest
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* <pknumatts> - number of attnums in pkattnums
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* <src_pkattvals_arry> - text array of key values which will be used
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* to identify the local tuple of interest
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* <tgt_pkattvals_arry> - text array of key values which will be used
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* to build the string for execution remotely. These are substituted
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* for their counterparts in src_pkattvals_arry
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*/
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PG_FUNCTION_INFO_V1(dblink_build_sql_insert);
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Datum
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dblink_build_sql_insert(PG_FUNCTION_ARGS)
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{
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Oid relid;
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text *relname_text;
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int16 *pkattnums;
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int16 pknumatts;
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char **src_pkattvals;
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char **tgt_pkattvals;
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ArrayType *src_pkattvals_arry;
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ArrayType *tgt_pkattvals_arry;
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int src_ndim;
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int *src_dim;
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int src_nitems;
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int tgt_ndim;
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int *tgt_dim;
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int tgt_nitems;
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int i;
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char *ptr;
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char *sql;
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text *sql_text;
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relname_text = PG_GETARG_TEXT_P(0);
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/*
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* Convert relname to rel OID.
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*/
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relid = get_relid_from_relname(relname_text);
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if (!OidIsValid(relid))
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elog(ERROR, "dblink_build_sql_insert: relation does not exist");
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pkattnums = (int16 *) PG_GETARG_POINTER(1);
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pknumatts = PG_GETARG_INT16(2);
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/*
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* There should be at least one key attribute
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*/
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if (pknumatts == 0)
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elog(ERROR, "dblink_build_sql_insert: number of key attributes must be > 0.");
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src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
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tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
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/*
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* Source array is made up of key values that will be used to
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* locate the tuple of interest from the local system.
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*/
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src_ndim = ARR_NDIM(src_pkattvals_arry);
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src_dim = ARR_DIMS(src_pkattvals_arry);
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src_nitems = ArrayGetNItems(src_ndim, src_dim);
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/*
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* There should be one source array key value for each key attnum
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*/
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if (src_nitems != pknumatts)
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elog(ERROR, "dblink_build_sql_insert: source key array length does not match number of key attributes.");
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/*
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* get array of pointers to c-strings from the input source array
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*/
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src_pkattvals = (char **) palloc(src_nitems * sizeof(char *));
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ptr = ARR_DATA_PTR(src_pkattvals_arry);
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for (i = 0; i < src_nitems; i++)
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{
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src_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
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ptr += INTALIGN(*(int32 *) ptr);
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}
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/*
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* Target array is made up of key values that will be used to
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* build the SQL string for use on the remote system.
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*/
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tgt_ndim = ARR_NDIM(tgt_pkattvals_arry);
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tgt_dim = ARR_DIMS(tgt_pkattvals_arry);
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tgt_nitems = ArrayGetNItems(tgt_ndim, tgt_dim);
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/*
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* There should be one target array key value for each key attnum
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*/
|
|
if (tgt_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: target key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input target array
|
|
*/
|
|
tgt_pkattvals = (char **) palloc(tgt_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(tgt_pkattvals_arry);
|
|
for (i = 0; i < tgt_nitems; i++)
|
|
{
|
|
tgt_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr += INTALIGN(*(int32 *) ptr);
|
|
}
|
|
|
|
/*
|
|
* Prep work is finally done. Go get the SQL string.
|
|
*/
|
|
sql = get_sql_insert(relid, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);
|
|
|
|
/*
|
|
* Make it into TEXT for return to the client
|
|
*/
|
|
sql_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql)));
|
|
|
|
/*
|
|
* And send it
|
|
*/
|
|
PG_RETURN_TEXT_P(sql_text);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_delete
|
|
*
|
|
* Used to generate an SQL delete statement.
|
|
* This is useful for selectively replicating a
|
|
* delete to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of remote table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the remote tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_delete);
|
|
Datum
|
|
dblink_build_sql_delete(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid relid;
|
|
text *relname_text;
|
|
int16 *pkattnums;
|
|
int16 pknumatts;
|
|
char **tgt_pkattvals;
|
|
ArrayType *tgt_pkattvals_arry;
|
|
int tgt_ndim;
|
|
int *tgt_dim;
|
|
int tgt_nitems;
|
|
int i;
|
|
char *ptr;
|
|
char *sql;
|
|
text *sql_text;
|
|
|
|
relname_text = PG_GETARG_TEXT_P(0);
|
|
|
|
/*
|
|
* Convert relname to rel OID.
|
|
*/
|
|
relid = get_relid_from_relname(relname_text);
|
|
if (!OidIsValid(relid))
|
|
elog(ERROR, "dblink_build_sql_delete: relation does not exist");
|
|
|
|
pkattnums = (int16 *) PG_GETARG_POINTER(1);
|
|
pknumatts = PG_GETARG_INT16(2);
|
|
/*
|
|
* There should be at least one key attribute
|
|
*/
|
|
if (pknumatts == 0)
|
|
elog(ERROR, "dblink_build_sql_insert: number of key attributes must be > 0.");
|
|
|
|
tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
|
|
|
|
/*
|
|
* Target array is made up of key values that will be used to
|
|
* build the SQL string for use on the remote system.
|
|
*/
|
|
tgt_ndim = ARR_NDIM(tgt_pkattvals_arry);
|
|
tgt_dim = ARR_DIMS(tgt_pkattvals_arry);
|
|
tgt_nitems = ArrayGetNItems(tgt_ndim, tgt_dim);
|
|
|
|
/*
|
|
* There should be one target array key value for each key attnum
|
|
*/
|
|
if (tgt_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: target key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input target array
|
|
*/
|
|
tgt_pkattvals = (char **) palloc(tgt_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(tgt_pkattvals_arry);
|
|
for (i = 0; i < tgt_nitems; i++)
|
|
{
|
|
tgt_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr += INTALIGN(*(int32 *) ptr);
|
|
}
|
|
|
|
/*
|
|
* Prep work is finally done. Go get the SQL string.
|
|
*/
|
|
sql = get_sql_delete(relid, pkattnums, pknumatts, tgt_pkattvals);
|
|
|
|
/*
|
|
* Make it into TEXT for return to the client
|
|
*/
|
|
sql_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql)));
|
|
|
|
/*
|
|
* And send it
|
|
*/
|
|
PG_RETURN_TEXT_P(sql_text);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_update
|
|
*
|
|
* Used to generate an SQL update statement
|
|
* based on an existing tuple in a local relation.
|
|
* This is useful for selectively replicating data
|
|
* to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of local table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the local tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <src_pkattvals_arry> - text array of key values which will be used
|
|
* to identify the local tuple of interest
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely. These are substituted
|
|
* for their counterparts in src_pkattvals_arry
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_update);
|
|
Datum
|
|
dblink_build_sql_update(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid relid;
|
|
text *relname_text;
|
|
int16 *pkattnums;
|
|
int16 pknumatts;
|
|
char **src_pkattvals;
|
|
char **tgt_pkattvals;
|
|
ArrayType *src_pkattvals_arry;
|
|
ArrayType *tgt_pkattvals_arry;
|
|
int src_ndim;
|
|
int *src_dim;
|
|
int src_nitems;
|
|
int tgt_ndim;
|
|
int *tgt_dim;
|
|
int tgt_nitems;
|
|
int i;
|
|
char *ptr;
|
|
char *sql;
|
|
text *sql_text;
|
|
|
|
relname_text = PG_GETARG_TEXT_P(0);
|
|
|
|
/*
|
|
* Convert relname to rel OID.
|
|
*/
|
|
relid = get_relid_from_relname(relname_text);
|
|
if (!OidIsValid(relid))
|
|
elog(ERROR, "dblink_build_sql_update: relation does not exist");
|
|
|
|
pkattnums = (int16 *) PG_GETARG_POINTER(1);
|
|
pknumatts = PG_GETARG_INT16(2);
|
|
/*
|
|
* There should be one source array key values for each key attnum
|
|
*/
|
|
if (pknumatts == 0)
|
|
elog(ERROR, "dblink_build_sql_insert: number of key attributes must be > 0.");
|
|
|
|
src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
|
|
tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
|
|
|
|
/*
|
|
* Source array is made up of key values that will be used to
|
|
* locate the tuple of interest from the local system.
|
|
*/
|
|
src_ndim = ARR_NDIM(src_pkattvals_arry);
|
|
src_dim = ARR_DIMS(src_pkattvals_arry);
|
|
src_nitems = ArrayGetNItems(src_ndim, src_dim);
|
|
|
|
/*
|
|
* There should be one source array key value for each key attnum
|
|
*/
|
|
if (src_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: source key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input source array
|
|
*/
|
|
src_pkattvals = (char **) palloc(src_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(src_pkattvals_arry);
|
|
for (i = 0; i < src_nitems; i++)
|
|
{
|
|
src_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr += INTALIGN(*(int32 *) ptr);
|
|
}
|
|
|
|
/*
|
|
* Target array is made up of key values that will be used to
|
|
* build the SQL string for use on the remote system.
|
|
*/
|
|
tgt_ndim = ARR_NDIM(tgt_pkattvals_arry);
|
|
tgt_dim = ARR_DIMS(tgt_pkattvals_arry);
|
|
tgt_nitems = ArrayGetNItems(tgt_ndim, tgt_dim);
|
|
|
|
/*
|
|
* There should be one target array key value for each key attnum
|
|
*/
|
|
if (tgt_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: target key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input target array
|
|
*/
|
|
tgt_pkattvals = (char **) palloc(tgt_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(tgt_pkattvals_arry);
|
|
for (i = 0; i < tgt_nitems; i++)
|
|
{
|
|
tgt_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr += INTALIGN(*(int32 *) ptr);
|
|
}
|
|
|
|
/*
|
|
* Prep work is finally done. Go get the SQL string.
|
|
*/
|
|
sql = get_sql_update(relid, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);
|
|
|
|
/*
|
|
* Make it into TEXT for return to the client
|
|
*/
|
|
sql_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql)));
|
|
|
|
/*
|
|
* And send it
|
|
*/
|
|
PG_RETURN_TEXT_P(sql_text);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_current_query
|
|
* return the current query string
|
|
* to allow its use in (among other things)
|
|
* rewrite rules
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_current_query);
|
|
Datum
|
|
dblink_current_query(PG_FUNCTION_ARGS)
|
|
{
|
|
text *result_text;
|
|
|
|
result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(debug_query_string)));
|
|
PG_RETURN_TEXT_P(result_text);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_replace_text
|
|
* replace all occurences of 'old_sub_str' in 'orig_str'
|
|
* with 'new_sub_str' to form 'new_str'
|
|
*
|
|
* returns 'orig_str' if 'old_sub_str' == '' or 'orig_str' == ''
|
|
* otherwise returns 'new_str'
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_replace_text);
|
|
Datum
|
|
dblink_replace_text(PG_FUNCTION_ARGS)
|
|
{
|
|
text *left_text;
|
|
text *right_text;
|
|
text *buf_text;
|
|
text *ret_text;
|
|
char *ret_str;
|
|
int curr_posn;
|
|
text *src_text = PG_GETARG_TEXT_P(0);
|
|
int src_text_len = DatumGetInt32(DirectFunctionCall1(textlen, PointerGetDatum(src_text)));
|
|
text *from_sub_text = PG_GETARG_TEXT_P(1);
|
|
int from_sub_text_len = DatumGetInt32(DirectFunctionCall1(textlen, PointerGetDatum(from_sub_text)));
|
|
text *to_sub_text = PG_GETARG_TEXT_P(2);
|
|
char *to_sub_str = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(to_sub_text)));
|
|
StringInfo str = makeStringInfo();
|
|
|
|
if (src_text_len == 0 || from_sub_text_len == 0)
|
|
PG_RETURN_TEXT_P(src_text);
|
|
|
|
buf_text = DatumGetTextPCopy(PointerGetDatum(src_text));
|
|
curr_posn = DatumGetInt32(DirectFunctionCall2(textpos, PointerGetDatum(buf_text), PointerGetDatum(from_sub_text)));
|
|
|
|
while (curr_posn > 0)
|
|
{
|
|
left_text = DatumGetTextP(DirectFunctionCall3(text_substr, PointerGetDatum(buf_text), 1, DatumGetInt32(DirectFunctionCall2(textpos, PointerGetDatum(buf_text), PointerGetDatum(from_sub_text))) - 1));
|
|
right_text = DatumGetTextP(DirectFunctionCall3(text_substr, PointerGetDatum(buf_text), DatumGetInt32(DirectFunctionCall2(textpos, PointerGetDatum(buf_text), PointerGetDatum(from_sub_text))) + from_sub_text_len, -1));
|
|
|
|
appendStringInfo(str, DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(left_text))));
|
|
appendStringInfo(str, to_sub_str);
|
|
|
|
pfree(buf_text);
|
|
pfree(left_text);
|
|
buf_text = right_text;
|
|
curr_posn = DatumGetInt32(DirectFunctionCall2(textpos, PointerGetDatum(buf_text), PointerGetDatum(from_sub_text)));
|
|
}
|
|
|
|
appendStringInfo(str, DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(buf_text))));
|
|
pfree(buf_text);
|
|
|
|
ret_str = pstrdup(str->data);
|
|
ret_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(ret_str)));
|
|
|
|
PG_RETURN_TEXT_P(ret_text);
|
|
}
|
|
|
|
|
|
/*************************************************************
|
|
* internal functions
|
|
*/
|
|
|
|
|
|
/*
|
|
* init_dblink_results
|
|
* - create an empty dblink_results data structure
|
|
*/
|
|
static dblink_results *
|
|
init_dblink_results(MemoryContext fn_mcxt)
|
|
{
|
|
MemoryContext oldcontext;
|
|
dblink_results *retval;
|
|
|
|
oldcontext = MemoryContextSwitchTo(fn_mcxt);
|
|
|
|
retval = (dblink_results *) palloc(sizeof(dblink_results));
|
|
MemSet(retval, 0, sizeof(dblink_results));
|
|
|
|
retval->tup_num = -1;
|
|
retval->res_id_index =-1;
|
|
retval->res = NULL;
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
/*
|
|
* init_dblink_array_results
|
|
* - create an empty dblink_array_results data structure
|
|
*/
|
|
static dblink_array_results *
|
|
init_dblink_array_results(MemoryContext fn_mcxt)
|
|
{
|
|
MemoryContext oldcontext;
|
|
dblink_array_results *retval;
|
|
|
|
oldcontext = MemoryContextSwitchTo(fn_mcxt);
|
|
|
|
retval = (dblink_array_results *) palloc(sizeof(dblink_array_results));
|
|
MemSet(retval, 0, sizeof(dblink_array_results));
|
|
|
|
retval->elem_num = -1;
|
|
retval->num_elems = 0;
|
|
retval->res = NULL;
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* get_pkey_attnames
|
|
*
|
|
* Get the primary key attnames for the given relation.
|
|
* Return NULL, and set numatts = 0, if no primary key exists.
|
|
*/
|
|
static char **
|
|
get_pkey_attnames(Oid relid, int16 *numatts)
|
|
{
|
|
Relation indexRelation;
|
|
ScanKeyData entry;
|
|
HeapScanDesc scan;
|
|
HeapTuple indexTuple;
|
|
int i;
|
|
char **result = NULL;
|
|
Relation rel;
|
|
TupleDesc tupdesc;
|
|
|
|
/*
|
|
* Open relation using relid, get tupdesc
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
tupdesc = rel->rd_att;
|
|
|
|
/*
|
|
* Initialize numatts to 0 in case no primary key
|
|
* exists
|
|
*/
|
|
*numatts = 0;
|
|
|
|
/*
|
|
* Use relid to get all related indexes
|
|
*/
|
|
indexRelation = heap_openr(IndexRelationName, AccessShareLock);
|
|
ScanKeyEntryInitialize(&entry, 0, Anum_pg_index_indrelid,
|
|
F_OIDEQ, ObjectIdGetDatum(relid));
|
|
scan = heap_beginscan(indexRelation, SnapshotNow, 1, &entry);
|
|
|
|
while ((indexTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
|
|
{
|
|
Form_pg_index index = (Form_pg_index) GETSTRUCT(indexTuple);
|
|
|
|
/*
|
|
* We're only interested if it is the primary key
|
|
*/
|
|
if (index->indisprimary == TRUE)
|
|
{
|
|
i = 0;
|
|
while (index->indkey[i++] != 0)
|
|
(*numatts)++;
|
|
|
|
if (*numatts > 0)
|
|
{
|
|
result = (char **) palloc(*numatts * sizeof(char *));
|
|
for (i = 0; i < *numatts; i++)
|
|
result[i] = SPI_fname(tupdesc, index->indkey[i]);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
heap_endscan(scan);
|
|
heap_close(indexRelation, AccessShareLock);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/*
|
|
* get_strtok
|
|
*
|
|
* parse input string
|
|
* return ord item (0 based)
|
|
* based on provided field separator
|
|
*/
|
|
static char *
|
|
get_strtok(char *fldtext, char *fldsep, int fldnum)
|
|
{
|
|
int j = 0;
|
|
char *result;
|
|
|
|
if (fldnum < 0)
|
|
{
|
|
elog(ERROR, "get_strtok: field number < 0 not permitted");
|
|
}
|
|
|
|
if (fldsep[0] == '\0')
|
|
{
|
|
elog(ERROR, "get_strtok: blank field separator not permitted");
|
|
}
|
|
|
|
result = strtok(fldtext, fldsep);
|
|
for (j = 1; j < fldnum + 1; j++)
|
|
{
|
|
result = strtok(NULL, fldsep);
|
|
if (result == NULL)
|
|
return NULL;
|
|
}
|
|
|
|
return pstrdup(result);
|
|
}
|
|
|
|
static char *
|
|
get_sql_insert(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
HeapTuple tuple;
|
|
TupleDesc tupdesc;
|
|
int natts;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql = NULL;
|
|
char *val = NULL;
|
|
int16 key;
|
|
unsigned int i;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
natts = tupdesc->natts;
|
|
|
|
tuple = get_tuple_of_interest(relid, pkattnums, pknumatts, src_pkattvals);
|
|
|
|
appendStringInfo(str, "INSERT INTO %s(", quote_ident_cstr(relname));
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (i > 0)
|
|
appendStringInfo(str, ",");
|
|
|
|
appendStringInfo(str, NameStr(tupdesc->attrs[i]->attname));
|
|
}
|
|
|
|
appendStringInfo(str, ") VALUES(");
|
|
|
|
/*
|
|
* remember attvals are 1 based
|
|
*/
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (i > 0)
|
|
appendStringInfo(str, ",");
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
key = get_attnum_pk_pos(pkattnums, pknumatts, i + 1);
|
|
else
|
|
key = -1;
|
|
|
|
if (key > -1)
|
|
val = pstrdup(tgt_pkattvals[key]);
|
|
else
|
|
val = SPI_getvalue(tuple, tupdesc, i + 1);
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "NULL");
|
|
}
|
|
appendStringInfo(str, ")");
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return (sql);
|
|
}
|
|
|
|
static char *
|
|
get_sql_delete(Oid relid, int16 *pkattnums, int16 pknumatts, char **tgt_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
TupleDesc tupdesc;
|
|
int natts;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql = NULL;
|
|
char *val = NULL;
|
|
unsigned int i;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
natts = tupdesc->natts;
|
|
|
|
appendStringInfo(str, "DELETE FROM %s WHERE ", quote_ident_cstr(relname));
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int16 pkattnum = pkattnums[i];
|
|
|
|
if (i > 0)
|
|
appendStringInfo(str, " AND ");
|
|
|
|
appendStringInfo(str, NameStr(tupdesc->attrs[pkattnum - 1]->attname));
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
val = pstrdup(tgt_pkattvals[i]);
|
|
else
|
|
elog(ERROR, "Target key array must not be NULL");
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, "=");
|
|
appendStringInfo(str, quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "IS NULL");
|
|
}
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return (sql);
|
|
}
|
|
|
|
static char *
|
|
get_sql_update(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
HeapTuple tuple;
|
|
TupleDesc tupdesc;
|
|
int natts;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql = NULL;
|
|
char *val = NULL;
|
|
int16 key;
|
|
int i;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
natts = tupdesc->natts;
|
|
|
|
tuple = get_tuple_of_interest(relid, pkattnums, pknumatts, src_pkattvals);
|
|
|
|
appendStringInfo(str, "UPDATE %s SET ", quote_ident_cstr(relname));
|
|
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (i > 0)
|
|
appendStringInfo(str, ",");
|
|
|
|
appendStringInfo(str, NameStr(tupdesc->attrs[i]->attname));
|
|
appendStringInfo(str, "=");
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
key = get_attnum_pk_pos(pkattnums, pknumatts, i + 1);
|
|
else
|
|
key = -1;
|
|
|
|
if (key > -1)
|
|
val = pstrdup(tgt_pkattvals[key]);
|
|
else
|
|
val = SPI_getvalue(tuple, tupdesc, i + 1);
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "NULL");
|
|
}
|
|
|
|
appendStringInfo(str, " WHERE ");
|
|
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int16 pkattnum = pkattnums[i];
|
|
|
|
if (i > 0)
|
|
appendStringInfo(str, " AND ");
|
|
|
|
appendStringInfo(str, NameStr(tupdesc->attrs[pkattnum - 1]->attname));
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
val = pstrdup(tgt_pkattvals[i]);
|
|
else
|
|
val = SPI_getvalue(tuple, tupdesc, pkattnum);
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, "=");
|
|
appendStringInfo(str, quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "IS NULL");
|
|
}
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return (sql);
|
|
}
|
|
|
|
/*
|
|
* Return a properly quoted literal value.
|
|
* Uses quote_literal in quote.c
|
|
*/
|
|
static char *
|
|
quote_literal_cstr(char *rawstr)
|
|
{
|
|
text *rawstr_text;
|
|
text *result_text;
|
|
char *result;
|
|
|
|
rawstr_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(rawstr)));
|
|
result_text = DatumGetTextP(DirectFunctionCall1(quote_literal, PointerGetDatum(rawstr_text)));
|
|
result = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(result_text)));
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Return a properly quoted identifier.
|
|
* Uses quote_ident in quote.c
|
|
*/
|
|
static char *
|
|
quote_ident_cstr(char *rawstr)
|
|
{
|
|
text *rawstr_text;
|
|
text *result_text;
|
|
char *result;
|
|
|
|
rawstr_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(rawstr)));
|
|
result_text = DatumGetTextP(DirectFunctionCall1(quote_ident, PointerGetDatum(rawstr_text)));
|
|
result = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(result_text)));
|
|
|
|
return result;
|
|
}
|
|
|
|
static int16
|
|
get_attnum_pk_pos(int16 *pkattnums, int16 pknumatts, int16 key)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Not likely a long list anyway, so just scan for
|
|
* the value
|
|
*/
|
|
for (i = 0; i < pknumatts; i++)
|
|
if (key == pkattnums[i])
|
|
return i;
|
|
|
|
return -1;
|
|
}
|
|
|
|
static HeapTuple
|
|
get_tuple_of_interest(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
TupleDesc tupdesc;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql = NULL;
|
|
int ret;
|
|
HeapTuple tuple;
|
|
int i;
|
|
char *val = NULL;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
|
|
/*
|
|
* Connect to SPI manager
|
|
*/
|
|
if ((ret = SPI_connect()) < 0)
|
|
elog(ERROR, "get_tuple_of_interest: SPI_connect returned %d", ret);
|
|
|
|
/*
|
|
* Build sql statement to look up tuple of interest
|
|
* Use src_pkattvals as the criteria.
|
|
*/
|
|
appendStringInfo(str, "SELECT * from %s WHERE ", relname);
|
|
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int16 pkattnum = pkattnums[i];
|
|
|
|
if (i > 0)
|
|
appendStringInfo(str, " AND ");
|
|
|
|
appendStringInfo(str, NameStr(tupdesc->attrs[pkattnum - 1]->attname));
|
|
|
|
val = pstrdup(src_pkattvals[i]);
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, "=");
|
|
appendStringInfo(str, quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "IS NULL");
|
|
}
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
/*
|
|
* Retrieve the desired tuple
|
|
*/
|
|
ret = SPI_exec(sql, 0);
|
|
pfree(sql);
|
|
|
|
/*
|
|
* Only allow one qualifying tuple
|
|
*/
|
|
if ((ret == SPI_OK_SELECT) && (SPI_processed > 1))
|
|
{
|
|
elog(ERROR, "get_tuple_of_interest: Source criteria may not match more than one record.");
|
|
}
|
|
else if (ret == SPI_OK_SELECT && SPI_processed == 1)
|
|
{
|
|
SPITupleTable *tuptable = SPI_tuptable;
|
|
tuple = SPI_copytuple(tuptable->vals[0]);
|
|
|
|
return tuple;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* no qualifying tuples
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* never reached, but keep compiler quiet
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
static Oid
|
|
get_relid_from_relname(text *relname_text)
|
|
{
|
|
#ifdef NamespaceRelationName
|
|
RangeVar *relvar;
|
|
Relation rel;
|
|
Oid relid;
|
|
|
|
relvar = makeRangeVarFromNameList(textToQualifiedNameList(relname_text, "get_relid_from_relname"));
|
|
rel = heap_openrv(relvar, AccessShareLock);
|
|
relid = RelationGetRelid(rel);
|
|
relation_close(rel, AccessShareLock);
|
|
#else
|
|
char *relname;
|
|
Relation rel;
|
|
Oid relid;
|
|
|
|
relname = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(relname_text)));
|
|
rel = relation_openr(relname, AccessShareLock);
|
|
relid = RelationGetRelid(rel);
|
|
relation_close(rel, AccessShareLock);
|
|
#endif /* NamespaceRelationName */
|
|
|
|
return relid;
|
|
}
|
|
|
|
static dblink_results *
|
|
get_res_ptr(int32 res_id_index)
|
|
{
|
|
List *ptr;
|
|
|
|
/*
|
|
* short circuit empty list
|
|
*/
|
|
if(res_id == NIL)
|
|
return NULL;
|
|
|
|
/*
|
|
* OK, should be good to go
|
|
*/
|
|
foreach(ptr, res_id)
|
|
{
|
|
dblink_results *this_res_id = (dblink_results *) lfirst(ptr);
|
|
if (this_res_id->res_id_index == res_id_index)
|
|
return this_res_id;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Add node to global List res_id
|
|
*/
|
|
static void
|
|
append_res_ptr(dblink_results *results)
|
|
{
|
|
res_id = lappend(res_id, results);
|
|
}
|
|
|
|
/*
|
|
* Remove node from global List
|
|
* using res_id_index
|
|
*/
|
|
static void
|
|
remove_res_ptr(dblink_results *results)
|
|
{
|
|
res_id = lremove(results, res_id);
|
|
|
|
if (res_id == NIL)
|
|
res_id_index = 0;
|
|
}
|
|
|