php/ext/pdo_pgsql/pgsql_statement.c

/*
  +----------------------------------------------------------------------+
  | PHP Version 5                                                        |
  +----------------------------------------------------------------------+
  | Copyright (c) 1997-2005 The PHP Group                                |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.0 of the PHP license,       |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.php.net/license/3_0.txt.                                  |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: Edin Kadribasic <edink@emini.dk>                             |
  +----------------------------------------------------------------------+
*/

/* $Id$ */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"
#include "php_ini.h"
#include "ext/standard/info.h"
#include "pdo/php_pdo.h"
#include "pdo/php_pdo_driver.h"
#include "php_pdo_pgsql.h"
#include "php_pdo_pgsql_int.h"

/* from postgresql/src/include/catalog/pg_type.h */
#define BOOLOID     16
#define BYTEAOID    17
#define INT8OID     20
#define INT2OID     21
#define INT4OID     23
#define OIDOID      26


static int pgsql_stmt_dtor(pdo_stmt_t *stmt TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;

	if (S->result) {
		/* free the resource */
		PQclear(S->result);
		S->result = NULL;
	}

#if HAVE_PQPREPARE
	if (S->stmt_name) {
		pdo_pgsql_db_handle *H = S->H;
		char *q = NULL;
		PGresult *res;

		spprintf(&q, 0, "DEALLOCATE %s", S->stmt_name);
		res = PQexec(H->server, q);
		efree(q);
		if (res) PQclear(res);
		efree(S->stmt_name);
		S->stmt_name = NULL;
	}
	if (S->param_lengths) {
		efree(S->param_lengths);
		S->param_lengths = NULL;
	}
	if (S->param_values) {
		efree(S->param_values);
		S->param_values = NULL;
	}
	if (S->param_formats) {
		efree(S->param_formats);
		S->param_formats = NULL;
	}

#endif

	if (S->cursor_name) {
		pdo_pgsql_db_handle *H = S->H;
		char *q = NULL;
		PGresult *res;

		spprintf(&q, 0, "CLOSE %s", S->cursor_name);
		res = PQexec(H->server, q);
		efree(q);
		if (res) PQclear(res);
		efree(S->cursor_name);
		S->cursor_name = NULL;
	}
	
	if(S->cols) {
		efree(S->cols);
		S->cols = NULL;
	}
	efree(S);
	stmt->driver_data = NULL;
	return 1;
}

static int pgsql_stmt_execute(pdo_stmt_t *stmt TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;
	pdo_pgsql_db_handle *H = S->H;
	ExecStatusType status;

	if (stmt->executed) {
		/* ensure that we free any previous unfetched results */
		if(S->result) {
			PQclear(S->result);
			S->result = NULL;
		}
	}
	
	S->current_row = 0;

#if HAVE_PQPREPARE
	if (S->stmt_name) {
		/* using a prepared statement */

		S->result = PQexecPrepared(H->server, S->stmt_name,
				stmt->bound_params ?
					zend_hash_num_elements(stmt->bound_params) :
					0,
				(const char**)S->param_values,
				S->param_lengths,
				NULL,
				0);
	} else
#endif
	if (S->cursor_name) {
		char *q = NULL;
		spprintf(&q, 0, "DECLARE %s CURSOR FOR %s", S->cursor_name, stmt->active_query_string);
		S->result = PQexec(H->server, q);
		efree(q);
	} else {
		S->result = PQexec(H->server, stmt->active_query_string);
	}
	status = PQresultStatus(S->result);

	if (status != PGRES_COMMAND_OK && status != PGRES_TUPLES_OK) {
		pdo_pgsql_error_stmt(stmt, status, pdo_pgsql_sqlstate(S->result));
		return 0;
	}

	if(!stmt->executed) {
		stmt->column_count = (int) PQnfields(S->result);
		S->cols = ecalloc(stmt->column_count, sizeof(pdo_pgsql_column));
	}

	if (status == PGRES_COMMAND_OK) {
		stmt->row_count = (long)atoi(PQcmdTuples(S->result));
		H->pgoid = PQoidValue(S->result);
	} else {
		stmt->row_count = (long)PQntuples(S->result);
	}

	return 1;
}

static int pgsql_stmt_param_hook(pdo_stmt_t *stmt, struct pdo_bound_param_data *param,
		enum pdo_param_event event_type TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;
#if HAVE_PQPREPARE
	if (S->stmt_name && param->is_param) {
		switch (event_type) {
			case PDO_PARAM_EVT_ALLOC:
				/* decode name from $1, $2 into 0, 1 etc. */
				if (param->name) {
					if (param->name[0] == '$') {
						param->paramno = atoi(param->name + 1);
					} else {
						/* resolve parameter name to rewritten name */
						char *nameptr;
						if (SUCCESS == zend_hash_find(stmt->bound_param_map,
								param->name, param->namelen + 1, (void**)&nameptr)) {
							param->paramno = atoi(nameptr + 1) - 1;
						} else {
							pdo_pgsql_error_stmt(stmt, PGRES_FATAL_ERROR, "HY093");
							return 0;
						}
					}
				}
				break;

			case PDO_PARAM_EVT_EXEC_PRE:
				if (!S->param_values) {
					S->param_values = ecalloc(
							zend_hash_num_elements(stmt->bound_params),
							sizeof(char*));
					S->param_lengths = ecalloc(
							zend_hash_num_elements(stmt->bound_params),
							sizeof(int));
					S->param_formats = ecalloc(
							zend_hash_num_elements(stmt->bound_params),
							sizeof(int));

				}
				if (PDO_PARAM_TYPE(param->param_type) == PDO_PARAM_NULL ||
						Z_TYPE_P(param->parameter) == IS_NULL) {
					S->param_values[param->paramno] = NULL;
					S->param_lengths[param->paramno] = 0;
				} else {
					convert_to_string(param->parameter);
					S->param_values[param->paramno] = Z_STRVAL_P(param->parameter);
					S->param_lengths[param->paramno] = Z_STRLEN_P(param->parameter);
					S->param_formats[param->paramno] = 1;
				}
				break;
		}
	}
#endif	
	return 1;
}

static int pgsql_stmt_fetch(pdo_stmt_t *stmt,
	enum pdo_fetch_orientation ori, long offset TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;

	if (S->cursor_name) {
		char *ori_str;
		char *q = NULL;
		ExecStatusType status;

		switch (ori) {
			case PDO_FETCH_ORI_NEXT: 	ori_str = "FORWARD"; break;
			case PDO_FETCH_ORI_PRIOR:	ori_str = "BACKWARD"; break;
			case PDO_FETCH_ORI_REL:		ori_str = "RELATIVE"; break;
			default:
				return 0;
		}
		
		spprintf(&q, 0, "FETCH %s %ld FROM %s", ori_str, offset, S->cursor_name);
		S->result = PQexec(S->H->server, q);
		status = PQresultStatus(S->result);

		if (status != PGRES_COMMAND_OK && status != PGRES_TUPLES_OK) {
			pdo_pgsql_error_stmt(stmt, status, pdo_pgsql_sqlstate(S->result));
			return 0;
		}

		S->current_row = 1;
		return 1;	
		
	} else {
		if (S->current_row < stmt->row_count) {
			S->current_row++;
			return 1;
		} else {
			return 0;
		}
	}
}

static int pgsql_stmt_describe(pdo_stmt_t *stmt, int colno TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;
	struct pdo_column_data *cols = stmt->columns;
	
	if (!S->result) {
		return 0;
	}

	cols[colno].name = estrdup(PQfname(S->result, colno));
	cols[colno].namelen = strlen(cols[colno].name);
	cols[colno].maxlen = PQfsize(S->result, colno);
	cols[colno].precision = PQfmod(S->result, colno);
	S->cols[colno].pgsql_type = PQftype(S->result, colno);
	
	switch(S->cols[colno].pgsql_type) {

		case BOOLOID:
			cols[colno].param_type = PDO_PARAM_BOOL;
			break;

		case INT2OID:
		case INT4OID:
		case OIDOID:
			cols[colno].param_type = PDO_PARAM_INT;
			break;

		case INT8OID:
			if (sizeof(long)>=8) {
				cols[colno].param_type = PDO_PARAM_INT;
			} else {
				cols[colno].param_type = PDO_PARAM_STR;
			}
			break;

		case BYTEAOID:
			cols[colno].param_type = PDO_PARAM_LOB;
			break;

		default:
			cols[colno].param_type = PDO_PARAM_STR;
	}

	return 1;
}

/* PQunescapeBytea() from PostgreSQL 7.3 to provide bytea unescape feature to 7.2 users.
   Renamed to php_pdo_pgsql_unescape_bytea() */
/*
 *		PQunescapeBytea - converts the null terminated string representation
 *		of a bytea, strtext, into binary, filling a buffer. It returns a
 *		pointer to the buffer which is NULL on error, and the size of the
 *		buffer in retbuflen. The pointer may subsequently be used as an
 *		argument to the function free(3). It is the reverse of PQescapeBytea.
 *
 *		The following transformations are reversed:
 *		'\0' == ASCII  0 == \000
 *		'\'' == ASCII 39 == \'
 *		'\\' == ASCII 92 == \\
 *
 *		States:
 *		0	normal		0->1->2->3->4
 *		1	\			   1->5
 *		2	\0			   1->6
 *		3	\00
 *		4	\000
 *		5	\'
 *		6	\\
 */
static unsigned char *php_pdo_pgsql_unescape_bytea(unsigned char *strtext, size_t *retbuflen)
{
	size_t		buflen;
	unsigned char *buffer,
			   *sp,
			   *bp;
	unsigned int state = 0;

	if (strtext == NULL)
		return NULL;
	buflen = strlen(strtext);	/* will shrink, also we discover if
								 * strtext */
	buffer = (unsigned char *) emalloc(buflen);	/* isn't NULL terminated */
	for (bp = buffer, sp = strtext; *sp != '\0'; bp++, sp++)
	{
		switch (state)
		{
			case 0:
				if (*sp == '\\')
					state = 1;
				*bp = *sp;
				break;
			case 1:
				if (*sp == '\'')	/* state=5 */
				{				/* replace \' with 39 */
					bp--;
					*bp = '\'';
					buflen--;
					state = 0;
				}
				else if (*sp == '\\')	/* state=6 */
				{				/* replace \\ with 92 */
					bp--;
					*bp = '\\';
					buflen--;
					state = 0;
				}
				else
				{
					if (isdigit(*sp))
						state = 2;
					else
						state = 0;
					*bp = *sp;
				}
				break;
			case 2:
				if (isdigit(*sp))
					state = 3;
				else
					state = 0;
				*bp = *sp;
				break;
			case 3:
				if (isdigit(*sp))		/* state=4 */
				{
					unsigned char *start, *end, buf[4]; /* 000 + '\0' */
					
					bp -= 3;
					memcpy(buf, sp-2, 3);
					buf[3] = '\0';
					start = buf;
 					*bp = (unsigned char)strtoul(start, (char **)&end, 8);
					buflen -= 3;
					state = 0;
				}
				else
				{
					*bp = *sp;
					state = 0;
				}
				break;
		}
	}
	buffer = erealloc(buffer, buflen+1);
	buffer[buflen] = '\0';

	*retbuflen = buflen;
	return buffer;
}

static int pgsql_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr, unsigned long *len, int *caller_frees  TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;
	struct pdo_column_data *cols = stmt->columns;
	size_t tmp_len;

	if (!S->result) {
		return 0;
	}

	/* We have already increased count by 1 in pgsql_stmt_fetch() */
	if (PQgetisnull(S->result, S->current_row - 1, colno)) { /* Check if we got NULL */
		*ptr = NULL;
		*len = 0;
	} else {
		*ptr = PQgetvalue(S->result, S->current_row - 1, colno);
		*len = PQgetlength(S->result, S->current_row - 1, colno);
		
		switch(cols[colno].param_type) {

			case PDO_PARAM_INT:
				S->cols[colno].intval = atol(*ptr);
				*ptr = (char *) &(S->cols[colno].intval);
				*len = sizeof(long);
				break;

			case PDO_PARAM_BOOL:
				S->cols[colno].boolval = **ptr == 't' ? 1: 0;
				*ptr = (char *) &(S->cols[colno].boolval);
				*len = sizeof(zend_bool);
				break;
				
			case PDO_PARAM_LOB:
				*ptr = php_pdo_pgsql_unescape_bytea(*ptr, &tmp_len);
				*len = tmp_len;
				*caller_frees = 1;
				break;
			case PDO_PARAM_NULL:
			case PDO_PARAM_STR:
			case PDO_PARAM_STMT:
			case PDO_PARAM_INPUT_OUTPUT:
				break;
		}
	}

	return 1;
}

static int pgsql_stmt_get_column_meta(pdo_stmt_t *stmt, long colno, zval *return_value TSRMLS_DC)
{
	pdo_pgsql_stmt *S = (pdo_pgsql_stmt*)stmt->driver_data;
	PGresult *res;
	char *q=NULL;
	ExecStatusType status;
	
	if (!S->result) {
		return FAILURE;
	}
	
	if (colno >= stmt->column_count) {
		return FAILURE;
	}
	
	array_init(return_value);
	add_assoc_long(return_value, "pgsql:oid", S->cols[colno].pgsql_type);

	/* Fetch metadata from Postgres system catalogue */
	spprintf(&q, 0, "SELECT TYPNAME FROM PG_TYPE WHERE OID=%d", S->cols[colno].pgsql_type);
	res = PQexec(S->H->server, q);
	efree(q);
	
	status = PQresultStatus(res);
	
	if (status != PGRES_TUPLES_OK) {
		/* Failed to get system catalogue, but return success
		 * with the data we have collected so far
		 */
		PQclear(res);
		return 1;
	}

	/* We want exactly one row returned */
	if (1 != PQntuples(res)) {
		PQclear(res);
		return 1;
	}

	add_assoc_string(return_value, "native_type", PQgetvalue(res, 0, 0), 1);

	PQclear(res);		
	return 1;
}

static int pdo_pgsql_stmt_cursor_closer(pdo_stmt_t *stmt TSRMLS_DC)
{
	return 1;
}

struct pdo_stmt_methods pgsql_stmt_methods = {
	pgsql_stmt_dtor,
	pgsql_stmt_execute,
	pgsql_stmt_fetch,
	pgsql_stmt_describe,
	pgsql_stmt_get_col,
	pgsql_stmt_param_hook,
	NULL, /* set_attr */
	NULL, /* get_attr */
	pgsql_stmt_get_column_meta,
	NULL,  /* next_rowset */
	pdo_pgsql_stmt_cursor_closer
};

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */