pgtclcmds.c

关系型数据库 Postgresql 6.5.2

/*-------------------------------------------------------------------------
 *
 * pgtclCmds.c
 *	  C functions which implement pg_* tcl commands
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /usr/local/cvsroot/pgsql/src/interfaces/libpgtcl/pgtclCmds.c,v 1.44 1999/05/25 22:43:43 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "postgres.h"
#include "pgtclCmds.h"
#include "pgtclId.h"
#include "libpq/libpq-fs.h"		/* large-object interface */

#ifdef TCL_ARRAYS

#define ISOCTAL(c)		(((c) >= '0') && ((c) <= '7'))
#define DIGIT(c)		((c) - '0')

/*
 * translate_escape()
 *
 * This function performs in-place translation of a single C-style
 * escape sequence pointed by p. Curly braces { } and double-quote
 * are left escaped if they appear inside an array.
 * The value returned is the pointer to the last character (the one
 * just before the rest of the buffer).
 */

static inline char *
translate_escape(char *p, int isArray)
{
	char		c,
			   *q,
			   *s;

#ifdef TCL_ARRAYS_DEBUG_ESCAPE
	printf("   escape = '%s'\n", p);
#endif
	/* Address of the first character after the escape sequence */
	s = p + 2;
	switch (c = *(p + 1))
	{
		case '0':
		case '1':
		case '2':
		case '3':
		case '4':
		case '5':
		case '6':
		case '7':
			c = DIGIT(c);
			if (ISOCTAL(*s))
				c = (c << 3) + DIGIT(*s++);
			if (ISOCTAL(*s))
				c = (c << 3) + DIGIT(*s++);
			*p = c;
			break;
		case 'b':
			*p = '\b';
			break;
		case 'f':
			*p = '\f';
			break;
		case 'n':
			*p = '\n';
			break;
		case 'r':
			*p = '\r';
			break;
		case 't':
			*p = '\t';
			break;
		case 'v':
			*p = '\v';
			break;
		case '\\':
		case '{':
		case '}':
		case '"':

			/*
			 * Backslahes, curly braces and double-quotes are left escaped
			 * if they appear inside an array. They will be unescaped by
			 * Tcl in Tcl_AppendElement. The buffer position is advanced
			 * by 1 so that the this character is not processed again by
			 * the caller.
			 */
			if (isArray)
				return p + 1;
			else
				*p = c;
			break;
		case '\0':

			/*
			 * This means a backslash at the end of the string. It should
			 * never happen but in that case replace the \ with a \0 but
			 * don't shift the rest of the buffer so that the caller can
			 * see the end of the string and terminate.
			 */
			*p = c;
			return p;
			break;
		default:

			/*
			 * Default case, store the escaped character over the
			 * backslash and shift the buffer over itself.
			 */
			*p = c;
	}
	/* Shift the rest of the buffer over itself after the current char */
	q = p + 1;
	for (; *s;)
		*q++ = *s++;
	*q = '\0';
#ifdef TCL_ARRAYS_DEBUG_ESCAPE
	printf("   after  = '%s'\n", p);
#endif
	return p;
}

/*
 * tcl_value()
 *
 * This function does in-line conversion of a value returned by libpq
 * into a tcl string or into a tcl list if the value looks like the
 * representation of a postgres array.
 */

static char *
tcl_value(char *value)
{
	int			literal,
				last;
	char	   *p;

	if (!value)
		return (char *) NULL;

#ifdef TCL_ARRAYS_DEBUG
	printf("pq_value  = '%s'\n", value);
#endif
	last = strlen(value) - 1;
	if ((last >= 1) && (value[0] == '{') && (value[last] == '}'))
	{
		/* Looks like an array, replace ',' with spaces */
		/* Remove the outer pair of { }, the last first! */
		value[last] = '\0';
		value++;
		literal = 0;
		for (p = value; *p; p++)
		{
			if (!literal)
			{
				/* We are at the list level, look for ',' and '"' */
				switch (*p)
				{
					case '"':	/* beginning of literal */
						literal = 1;
						break;
					case ',':	/* replace the ',' with space */
						*p = ' ';
						break;
				}
			}
			else
			{
				/* We are inside a C string */
				switch (*p)
				{
					case '"':	/* end of literal */
						literal = 0;
						break;
					case '\\':

						/*
						 * escape sequence, translate it
						 */
						p = translate_escape(p, 1);
						break;
				}
			}
			if (!*p)
				break;
		}
	}
	else
	{
		/* Looks like a normal scalar value */
		for (p = value; *p; p++)
		{
			if (*p == '\\')
			{

				/*
				 * escape sequence, translate it
				 */
				p = translate_escape(p, 0);
			}
			if (!*p)
				break;
		}
	}
#ifdef TCL_ARRAYS_DEBUG
	printf("tcl_value = '%s'\n\n", value);
#endif
	return value;
}

#endif	 /* TCL_ARRAYS */


/**********************************
 * pg_conndefaults

 syntax:
 pg_conndefaults

 the return result is a list describing the possible options and their
 current default values for a call to pg_connect with the new -conninfo
 syntax. Each entry in the list is a sublist of the format:

	 {optname label dispchar dispsize value}

 **********************************/

int
Pg_conndefaults(ClientData cData, Tcl_Interp *interp, int argc, char **argv)
{
	PQconninfoOption *option;
	Tcl_DString result;
	char		ibuf[32];

	Tcl_DStringInit(&result);
	for (option = PQconndefaults(); option->keyword != NULL; option++)
	{
		char	   *val = option->val ? option->val : "";

		sprintf(ibuf, "%d", option->dispsize);
		Tcl_DStringStartSublist(&result);
		Tcl_DStringAppendElement(&result, option->keyword);
		Tcl_DStringAppendElement(&result, option->label);
		Tcl_DStringAppendElement(&result, option->dispchar);
		Tcl_DStringAppendElement(&result, ibuf);
		Tcl_DStringAppendElement(&result, val);
		Tcl_DStringEndSublist(&result);
	}
	Tcl_DStringResult(interp, &result);

	return TCL_OK;
}


/**********************************
 * pg_connect
 make a connection to a backend.

 syntax:
 pg_connect dbName [-host hostName] [-port portNumber] [-tty pqtty]]

 the return result is either an error message or a handle for a database
 connection.  Handles start with the prefix "pgp"

 **********************************/

int
Pg_connect(ClientData cData, Tcl_Interp *interp, int argc, char *argv[])
{
	char	   *pghost = NULL;
	char	   *pgtty = NULL;
	char	   *pgport = NULL;
	char	   *pgoptions = NULL;
	char	   *dbName;
	int			i;
	PGconn	   *conn;

	if (argc == 1)
	{
		Tcl_AppendResult(interp, "pg_connect: database name missing\n", 0);
		Tcl_AppendResult(interp, "pg_connect databaseName [-host hostName] [-port portNumber] [-tty pgtty]]\n", 0);
		Tcl_AppendResult(interp, "pg_connect -conninfo <conninfo-string>", 0);
		return TCL_ERROR;

	}

	if (!strcmp("-conninfo", argv[1]))
	{

		/*
		 * Establish a connection using the new PQconnectdb() interface
		 */
		if (argc != 3)
		{
			Tcl_AppendResult(interp, "pg_connect: syntax error\n", 0);
			Tcl_AppendResult(interp, "pg_connect -conninfo <conninfo-string>", 0);
			return TCL_ERROR;
		}
		conn = PQconnectdb(argv[2]);
	}
	else
	{

		/*
		 * Establish a connection using the old PQsetdb() interface
		 */
		if (argc > 2)
		{
			/* parse for pg environment settings */
			i = 2;
			while (i + 1 < argc)
			{
				if (strcmp(argv[i], "-host") == 0)
				{
					pghost = argv[i + 1];
					i += 2;
				}
				else if (strcmp(argv[i], "-port") == 0)
				{
					pgport = argv[i + 1];
					i += 2;
				}
				else if (strcmp(argv[i], "-tty") == 0)
				{
					pgtty = argv[i + 1];
					i += 2;
				}
				else if (strcmp(argv[i], "-options") == 0)
				{
					pgoptions = argv[i + 1];
					i += 2;
				}
				else
				{
					Tcl_AppendResult(interp, "Bad option to pg_connect : \n",
									 argv[i], 0);
					Tcl_AppendResult(interp, "pg_connect databaseName [-host hostName] [-port portNumber] [-tty pgtty]]", 0);
					return TCL_ERROR;
				}
			}					/* while */
			if ((i % 2 != 0) || i != argc)
			{
				Tcl_AppendResult(interp, "wrong # of arguments to pg_connect\n", argv[i], 0);
				Tcl_AppendResult(interp, "pg_connect databaseName [-host hostName] [-port portNumber] [-tty pgtty]]", 0);
				return TCL_ERROR;
			}
		}
		dbName = argv[1];
		conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
	}

	if (PQstatus(conn) == CONNECTION_OK)
	{
		PgSetConnectionId(interp, conn);
		return TCL_OK;
	}
	else
	{
		Tcl_AppendResult(interp, "Connection to database failed\n",
						 PQerrorMessage(conn), 0);
		PQfinish(conn);
		return TCL_ERROR;
	}
}


/**********************************
 * pg_disconnect
 close a backend connection

 syntax:
 pg_disconnect connection

 The argument passed in must be a connection pointer.

 **********************************/

int
Pg_disconnect(ClientData cData, Tcl_Interp *interp, int argc, char *argv[])
{
	Tcl_Channel conn_chan;

	if (argc != 2)
	{
		Tcl_AppendResult(interp, "Wrong # of arguments\n", "pg_disconnect connection", 0);
		return TCL_ERROR;
	}

	conn_chan = Tcl_GetChannel(interp, argv[1], 0);
	if (conn_chan == NULL)
	{
		Tcl_ResetResult(interp);
		Tcl_AppendResult(interp, argv[1], " is not a valid connection\n", 0);
		return TCL_ERROR;
	}

	return Tcl_UnregisterChannel(interp, conn_chan);
}

/**********************************
 * pg_exec
 send a query string to the backend connection

 syntax:
 pg_exec connection query

 the return result is either an error message or a handle for a query
 result.  Handles start with the prefix "pgp"
 **********************************/

int
Pg_exec(ClientData cData, Tcl_Interp *interp, int argc, char *argv[])
{
	Pg_ConnectionId *connid;
	PGconn	   *conn;
	PGresult   *result;

	if (argc != 3)
	{
		Tcl_AppendResult(interp, "Wrong # of arguments\n",
						 "pg_exec connection queryString", 0);
		return TCL_ERROR;
	}

	conn = PgGetConnectionId(interp, argv[1], &connid);
	if (conn == (PGconn *) NULL)
		return TCL_ERROR;

	if (connid->res_copyStatus != RES_COPY_NONE)
	{
		Tcl_SetResult(interp, "Attempt to query while COPY in progress", TCL_STATIC);
		return TCL_ERROR;
	}

	result = PQexec(conn, argv[2]);

	/* Transfer any notify events from libpq to Tcl event queue. */
	PgNotifyTransferEvents(connid);

	if (result)
	{
		int			rId = PgSetResultId(interp, argv[1], result);

		ExecStatusType rStat = PQresultStatus(result);

		if (rStat == PGRES_COPY_IN || rStat == PGRES_COPY_OUT)
		{
			connid->res_copyStatus = RES_COPY_INPROGRESS;
			connid->res_copy = rId;
		}
		return TCL_OK;
	}
	else
	{
		/* error occurred during the query */
		Tcl_SetResult(interp, PQerrorMessage(conn), TCL_VOLATILE);
		return TCL_ERROR;
	}
}

/**********************************
 * pg_result
 get information about the results of a query

 syntax:

	pg_result result ?option?

 the options are:

	-status		the status of the result

	-error		the error message, if the status indicates error; otherwise
				an empty string

	-conn		the connection that produced the result

	-oid		if command was an INSERT, the OID of the inserted tuple

	-numTuples	the number of tuples in the query

	-numAttrs	returns the number of attributes returned by the query

	-assign arrayName
				assign the results to an array, using subscripts of the form
				(tupno,attributeName)

	-assignbyidx arrayName ?appendstr?
				assign the results to an array using the first field's value
				as a key.
				All but the first field of each tuple are stored, using
				subscripts of the form (field0value,attributeNameappendstr)

	-getTuple tupleNumber
				returns the values of the tuple in a list

	-tupleArray tupleNumber arrayName
				stores the values of the tuple in array arrayName, indexed
				by the attributes returned

	-attributes
				returns a list of the name/type pairs of the tuple attributes

	-lAttributes
				returns a list of the {name type len} entries of the tuple
				attributes

	-clear		clear the result buffer. Do not reuse after this

 **********************************/
int
Pg_result(ClientData cData, Tcl_Interp *interp, int argc, char *argv[])
{
	PGresult   *result;
	char	   *opt;
	int			i;
	int			tupno;