Re: post82.diff

/* TDSPool - Connection pooling for TDS based databases
 * Copyright (C) 2001, 2002, 2003, 2004, 2005  Brian Bruns
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*
 * Name: stream.c
 * Description: Controls the result stream processing.
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */

#include <stdarg.h>
#include <stdio.h>

#if HAVE_STDLIB_H
#include <stdlib.h>
#endif /* HAVE_STDLIB_H */

#if HAVE_STRING_H
#include <string.h>
#endif /* HAVE_STDLIB_H */

#include "pool.h"
#include "tds.h"

TDS_RCSID(var, "$Id: stream.c,v 1.26 2008/07/08 08:47:08 freddy77 Exp $");

int pool_find_end_token(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int len);

struct tmp_col_struct
{
	char *column_name;
	struct tmp_col_struct *next;
};

/*
 *  returns 1 if this end token has the final bit set
 */
static int
is_final_token(const unsigned char *buf)
{
	return buf[1] & 0x01 ? 0 : 1;
}

/*
 *  computes the number of bytes left to be read from the input stream 
 *  after this packet is completely processed.
 *  returns 1 if token overruns the current packet, 0 otherwise.
 */
static int
bytes_left(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int pos, int maxlen, int need)
{
	if (pos + need > maxlen) {
		return 1;
	} else
		return 0;
}

/*
 * attempts to read a fixed length token, returns 1 if successful
 * bytes_read is set to the number of bytes read fromt the input stream.
 */
static int
read_fixed_token(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDS_SMALLINT sz;
	int marker;
	int pos = 0;

	if (bytes_left(pmbr, buf, pos, maxlen, 1)) {
		*bytes_read = maxlen;
		return 0;
	}
	marker = buf[pos++];
	sz = tds_get_token_size(marker);
	if (bytes_left(pmbr, buf, pos, maxlen, sz)) {
		*bytes_read = maxlen;
		return 0;
	} else {
		*bytes_read = sz + 1;
		return 1;
	}
}

static int
read_variable_token(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDS_SMALLINT sz;
	int pos = 0;

	if (bytes_left(pmbr, buf, pos, maxlen, 3)) {
		*bytes_read = maxlen;
		return 0;
	}

	/* memcpy(&sz,&buf[1],2); */
	/* FIX ME -- works only in emul little endian mode on bigend boxen */
	sz = buf[1] + buf[2] * 256;
	pos += 3;
	if (bytes_left(pmbr, buf, pos, maxlen, sz)) {
		*bytes_read = maxlen;
		return 0;
	} else {
		*bytes_read = sz + 3;
		return 1;
	}
}

static int
read_row(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDSCOLUMN *curcol;
	TDSRESULTINFO *info;
	int i, colsize;
	int pos = 1;		/* skip marker */

	info = pmbr->tds->res_info;

	die_if((!info), "Entered read_row() without a res_info structure.");

	for (i = 0; i < info->num_cols; i++) {
		curcol = info->columns[i];
		if (!is_fixed_type(curcol->column_type)) {
			if (bytes_left(pmbr, buf, pos, maxlen, 1)) {
				*bytes_read = maxlen;
				return 0;
			}
			colsize = buf[pos++];
		} else {
			colsize = tds_get_size_by_type(curcol->column_type);
		}
		if (bytes_left(pmbr, buf, pos, maxlen, colsize)) {
			*bytes_read = maxlen;
			return 0;
		}
		pos += colsize;
	}

	*bytes_read = pos;

	return 1;
}

static void
free_col_struct(struct tmp_col_struct *head)
{
	while (head) {
		struct tmp_col_struct *prev = head;
		head = prev->next;
		free(prev->column_name);
		free(prev);
	}
}

static int
read_col_name(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDS_SMALLINT hdrsize;
	int pos = 0;
	int num_cols = 0;
	int namelen;
	struct tmp_col_struct *head = NULL, *cur = NULL, *prev;
	int col;
	TDSCOLUMN *curcol;
	TDSRESULTINFO *info;

	/* header size */
	if (bytes_left(pmbr, buf, pos, maxlen, 3)) {
		*bytes_read = maxlen;
		return 0;
	}
	/* FIXME -- endian */
	hdrsize = buf[1] + buf[2] * 256;
	pos += 3;

	for (;;) {
		prev = cur;
		cur = (struct tmp_col_struct *)
			malloc(sizeof(struct tmp_col_struct));
		cur->next = NULL;
		cur->column_name = NULL;

		if (prev)
			prev->next = cur;
		if (!head)
			head = cur;

		if (bytes_left(pmbr, buf, pos, maxlen, 1)) {
			*bytes_read = maxlen;
			free_col_struct(head);
			return 0;
		}
		namelen = buf[pos++];


		if (bytes_left(pmbr, buf, pos, maxlen, namelen)) {
			*bytes_read = maxlen;
			free_col_struct(head);
			return 0;
		}
		cur->column_name = (char *) malloc(namelen + 1);
		strncpy(cur->column_name, (char *) &buf[pos], namelen);
		cur->column_name[namelen] = '\0';

		pos += namelen;

		num_cols++;

		if (pos >= hdrsize)
			break;
	}

	tds_free_all_results(pmbr->tds);
	pmbr->tds->res_info = tds_alloc_results(num_cols);
	info = pmbr->tds->res_info;

	cur = head;

	for (col = 0; col < info->num_cols; col++) {
		curcol = info->columns[col];
		strncpy(curcol->column_name, cur->column_name, sizeof(curcol->column_name));
		/* FIXME ucs2 client and others */
		curcol->column_name[sizeof(curcol->column_name) - 1] = 0;
		curcol->column_namelen = strlen(curcol->column_name);
		prev = cur;
		cur = cur->next;
		free(prev->column_name);
		free(prev);
	}


	*bytes_read = pos;
	return 1;
}

static int
read_col_info(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDS_SMALLINT hdrsize;
	int pos = 0;
	int col, rest;
	TDSCOLUMN *curcol;
	TDSRESULTINFO *info;
	TDSSOCKET *tds = pmbr->tds;

	/* header size */
	if (bytes_left(pmbr, buf, pos, maxlen, 3)) {
		*bytes_read = maxlen;
		return 0;
	}
	/* FIX ME -- endian */
	hdrsize = buf[1] + buf[2] * 256;
	pos += 3;

	info = tds->res_info;
	for (col = 0; col < info->num_cols; col++) {
		curcol = info->columns[col];
		if (bytes_left(pmbr, buf, pos, maxlen, 5)) {
			*bytes_read = maxlen;
			return 0;
		}
		pos += 4;
		curcol->column_type = buf[pos++];

		/* FIX ME -- blob types */
		if (!is_fixed_type(curcol->column_type)) {
			if (bytes_left(pmbr, buf, pos, maxlen, 1)) {
				*bytes_read = maxlen;
				return 0;
			}
			curcol->column_size = buf[pos++];
		} else {
			curcol->column_size = tds_get_size_by_type(curcol->column_type);
		}
	}

	rest = hdrsize + 3 - pos;
	if (rest > 0) {
		if (bytes_left(pmbr, buf, pos, maxlen, rest)) {
			*bytes_read = maxlen;
			return 0;
		}
		fprintf(stderr, "read_col_info: draining %d bytes\n", rest);
		pos += rest;
	}
	*bytes_read = pos;

	return 1;
}

/*
 * TDS 5 style result sets
 */
static int
read_result(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDS_SMALLINT hdrsize;
	int pos = 0;
	int namelen;
	int col;
	TDSSOCKET *tds = pmbr->tds;
	int num_cols;
	TDSCOLUMN *curcol;
	TDSRESULTINFO *info;

	if (bytes_left(pmbr, buf, pos, maxlen, 3)) {
		*bytes_read = maxlen;
		return 0;
	}
	/* FIX ME -- endian */
	hdrsize = buf[1] + buf[2] * 256;
	pos += 3;

	/* read number of columns and allocate the columns structure */
	num_cols = buf[pos] + buf[pos+1] * 256;
	pos += 2;

	tds_free_all_results(tds);

	tds->res_info = tds_alloc_results(num_cols);
	info = pmbr->tds->res_info;

	/*
	 * loop through the columns populating COLINFO struct from
 	 * server response
	 */

	for (col = 0; col < info->num_cols; col++) {
		curcol = info->columns[col];

		namelen = buf[pos++];

		strncpy(curcol->column_name, (char *) &buf[pos], namelen);
		curcol->column_name[namelen] = '\0';
		pos += namelen;

		curcol->column_namelen = namelen;

		pos++;     /* flags */
		pos += 4;  /* user type */

		tds_set_column_type(tds, curcol, (int)buf[pos]);
		switch(curcol->column_varint_size) {
			/* FIX ME - endian */
			case 2: curcol->column_size = buf[pos] + buf[pos+1]*256; break;
			case 1: curcol->column_size = buf[pos]; break;
			case 0: break;
		}
		pos+=curcol->column_varint_size;
		if (is_numeric_type(curcol->column_type))
			pos+=2;

		/* skip locale information */
		pos += buf[pos];
	}
	return tds_alloc_row(info);
}

/* 
 * is_end_token processes one token and returns 0 for an incomplete token
 * or -1 if this is the END token, and 1 for successful processing of token.  
 * The number of bytes read from the stream is returned in 'bytes_read'.
 */
static int
pool_is_end_token(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int maxlen, int *bytes_read)
{
	TDS_SMALLINT sz;
	int marker;
	int ret;

	if (maxlen == 0)
		return 0;

	marker = buf[0];
	sz = tds_get_token_size(marker);

	if (sz) {
		ret = read_fixed_token(pmbr, buf, maxlen, bytes_read);
	} else if (marker == TDS_ROW_TOKEN) {
		ret = read_row(pmbr, buf, maxlen, bytes_read);
	} else if (marker == TDS_COLNAME_TOKEN) {
		ret = read_col_name(pmbr, buf, maxlen, bytes_read);
	} else if (marker == TDS_COLFMT_TOKEN) {
		ret = read_col_info(pmbr, buf, maxlen, bytes_read);
	} else if (marker == TDS_RESULT_TOKEN) {
		ret = read_result(pmbr, buf, maxlen, bytes_read);
	} else {
		ret = read_variable_token(pmbr, buf, maxlen, bytes_read);
	}

	/* fprintf(stderr,"bytes_read = %d\n",*bytes_read); */
	if (!ret) {
		return 0;
	}

	if (is_end_token(marker)) {
		if (is_final_token(buf)) {
			/* clean up */
			return -1;
		}
	}

	return 1;
}

int
pool_find_end_token(TDS_POOL_MEMBER * pmbr, const unsigned char *buf, int len)
{
	int pos = 0, startpos, ret;
	int bytes_read;
	int stop = 0;
	const unsigned char *curbuf;
	unsigned char tmpbuf[PGSIZ + BLOCKSIZ];
	int totlen;
	static int last_mark;

	/*
	 * if we had part of a token left over, copy to tmpbuf
	 */
	if (pmbr->num_bytes_left) {
		/* fprintf(stderr,"%d bytes left from last packet\n",pmbr->num_bytes_left); */
		if (pmbr->num_bytes_left > 2000) {
			fprintf(stderr, "marker is %d last mark was %d\n", pmbr->fragment[0], last_mark);
		}
		memcpy(tmpbuf, pmbr->fragment, pmbr->num_bytes_left);
		memcpy(&tmpbuf[pmbr->num_bytes_left], buf, len);
		curbuf = tmpbuf;
		totlen = len + pmbr->num_bytes_left;
	} else {
		curbuf = buf;
		totlen = len;
	}

	do {
		startpos = pos;

		ret = pool_is_end_token(pmbr, &curbuf[pos], totlen - pos, &bytes_read);
		if (ret <= 0)
			stop = 1;

		pos += bytes_read;
	} while (!stop);

	if (ret == -1) {
		pmbr->num_bytes_left = 0;
		return 1;	/* found end token */
	} else {
		last_mark = buf[0];
		pmbr->num_bytes_left = totlen - startpos;
		memcpy(pmbr->fragment, &curbuf[startpos], pmbr->num_bytes_left);
		return 0;	/* exhausted the stream */
	}
}