postgresql/contrib/seg/buffer.c

/* This module defines the parse buffer and routines for setting/reading it */

#include "postgres.h"

static char *PARSE_BUFFER;
static char *PARSE_BUFFER_PTR;
static unsigned int PARSE_BUFFER_SIZE;
static unsigned int SCANNER_POS;

void		set_parse_buffer(char *s);
void		reset_parse_buffer(void);
int			read_parse_buffer(void);
char	   *parse_buffer(void);
char	   *parse_buffer_ptr(void);
unsigned int parse_buffer_curr_char(void);
unsigned int parse_buffer_size(void);
unsigned int parse_buffer_pos(void);

extern void seg_flush_scanner_buffer(void);		/* defined in segscan.l */

void
set_parse_buffer(char *s)
{
	PARSE_BUFFER = s;
	PARSE_BUFFER_SIZE = strlen(s);
	if (PARSE_BUFFER_SIZE == 0)
		ereport(ERROR,
				(errcode(ERRCODE_ZERO_LENGTH_CHARACTER_STRING),
				 errmsg("can't parse an empty string")));
	PARSE_BUFFER_PTR = PARSE_BUFFER;
	SCANNER_POS = 0;
}

void
reset_parse_buffer(void)
{
	PARSE_BUFFER_PTR = PARSE_BUFFER;
	SCANNER_POS = 0;
	seg_flush_scanner_buffer();
}

int
read_parse_buffer(void)
{
	int			c;

	/*
	 * c = *PARSE_BUFFER_PTR++; SCANNER_POS++;
	 */
	c = PARSE_BUFFER[SCANNER_POS];
	if (SCANNER_POS < PARSE_BUFFER_SIZE)
		SCANNER_POS++;
	return c;
}

char *
parse_buffer(void)
{
	return PARSE_BUFFER;
}

unsigned int
parse_buffer_curr_char(void)
{
	return PARSE_BUFFER[SCANNER_POS];
}

char *
parse_buffer_ptr(void)
{
	return PARSE_BUFFER_PTR;
}

unsigned int
parse_buffer_pos(void)
{
	return SCANNER_POS;
}

unsigned int
parse_buffer_size(void)
{
	return PARSE_BUFFER_SIZE;
}