@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $ Header : / cvsroot / pgsql / src / backend / nodes / read . c , v 1.26 2000 / 12 / 03 20 : 45 : 33 tgl Exp $
* $ Header : / cvsroot / pgsql / src / backend / nodes / read . c , v 1.27 2001 / 01 / 07 01 : 08 : 47 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -25,6 +25,11 @@
# include "nodes/pg_list.h"
# include "nodes/readfuncs.h"
/* Static state for pg_strtok */
static char * pg_strtok_ptr = NULL ;
/*
* stringToNode -
* returns a Node with a given legal ASCII representation
@ -32,10 +37,22 @@
void *
stringToNode ( char * str )
{
char * save_strtok ;
void * retval ;
lsptok ( str , NULL ) ; /* set the string used in lsptok */
retval = nodeRead ( true ) ; /* start reading */
/*
* We save and restore the pre - existing state of pg_strtok .
* This makes the world safe for re - entrant invocation of stringToNode ,
* without incurring a lot of notational overhead by having to pass the
* next - character pointer around through all the readfuncs . c code .
*/
save_strtok = pg_strtok_ptr ;
pg_strtok_ptr = str ; /* point pg_strtok at the string to read */
retval = nodeRead ( true ) ; /* do the reading */
pg_strtok_ptr = save_strtok ;
return retval ;
}
@ -47,7 +64,7 @@ stringToNode(char *str)
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* lsp tok- - - retrieve next " token " from a string .
* pg_str tok- - - retrieve next " token " from a string .
*
* Works kinda like strtok , except it never modifies the source string .
* ( Instead of storing nulls into the string , the length of the token
@ -55,9 +72,7 @@ stringToNode(char *str)
* Also , the rules about what is a token are hard - wired rather than being
* configured by passing a set of terminating characters .
*
* The string is initially set by passing a non - NULL " string " value ,
* and subsequent calls with string = = NULL read the previously given value .
* ( Pass length = = NULL to set the string without reading its first token . )
* The string is assumed to have been initialized already by stringToNode .
*
* The rules for tokens are :
* * Whitespace ( space , tab , newline ) always separates tokens .
@ -89,20 +104,12 @@ stringToNode(char *str)
* as a single token .
*/
char *
lsptok ( char * string , int * length )
pg_strtok ( int * length )
{
static char * saved_str = NULL ;
char * local_str ; /* working pointer to string */
char * ret_str ; /* start of token to return */
if ( string ! = NULL )
{
saved_str = string ;
if ( length = = NULL )
return NULL ;
}
local_str = saved_str ;
local_str = pg_strtok_ptr ;
while ( * local_str = = ' ' | | * local_str = = ' \n ' | | * local_str = = ' \t ' )
local_str + + ;
@ -110,7 +117,7 @@ lsptok(char *string, int *length)
if ( * local_str = = ' \0 ' )
{
* length = 0 ;
saved_s tr= local_str ;
pg_strtok_p tr= local_str ;
return NULL ; /* no more tokens */
}
@ -147,7 +154,7 @@ lsptok(char *string, int *length)
if ( * length = = 2 & & ret_str [ 0 ] = = ' < ' & & ret_str [ 1 ] = = ' > ' )
* length = 0 ;
saved_s tr= local_str ;
pg_strtok_p tr= local_str ;
return ret_str ;
}
@ -223,7 +230,7 @@ nodeTokenType(char *token, int length)
}
/*
* these three cases do not need length checks , since lsp tok( ) will
* these three cases do not need length checks , since pg_str tok( ) will
* always treat them as single - byte tokens
*/
else if ( * token = = ' ( ' )
@ -248,12 +255,13 @@ nodeTokenType(char *token, int length)
* Slightly higher - level reader .
*
* This routine applies some semantic knowledge on top of the purely
* lexical tokenizer lsp tok( ) . It can read
* lexical tokenizer pg_str tok( ) . It can read
* * Value token nodes ( integers , floats , or strings ) ;
* * Plan nodes ( via parsePlanString ( ) from readfuncs . c ) ;
* * Lists of the above .
*
* Secrets : He assumes that lsptok already has the string ( see above ) .
* We assume pg_strtok is already initialized with a string to read ( hence
* this should only be invoked from within a stringToNode operation ) .
* Any callers should set read_car_only to true .
*/
void *
@ -266,7 +274,7 @@ nodeRead(bool read_car_only)
* return_value ;
bool make_dotted_pair_cell = false ;
token = lsptok ( NULL , & tok_len ) ;
token = pg_strtok ( & tok_len ) ;
if ( token = = NULL )
return NULL ;
@ -277,8 +285,8 @@ nodeRead(bool read_car_only)
{
case PLAN_SYM :
this_value = parsePlanString ( ) ;
token = lsptok ( NULL , & tok_len ) ;
if ( token [ 0 ] ! = ' } ' )
token = pg_strtok ( & tok_len ) ;
if ( token = = NULL | | token [ 0 ] ! = ' } ' )
elog ( ERROR , " nodeRead: did not find '}' at end of plan node " ) ;
if ( ! read_car_only )
make_dotted_pair_cell = true ;
Tom Lane
25 years ago