php-src/ext/pdo/php_pdo_driver.h

/*
  +----------------------------------------------------------------------+
  | 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: Wez Furlong <wez@php.net>                                    |
  +----------------------------------------------------------------------+
*/

/* $Id$ */

#ifndef PHP_PDO_DRIVER_H
#define PHP_PDO_DRIVER_H

#include "php_pdo.h"

/* forward declarations */
typedef struct _pdo_dbh_t 	pdo_dbh_t;
typedef struct _pdo_stmt_t	pdo_stmt_t;
struct pdo_bound_param_data;

#ifndef TRUE
# define TRUE 1
#endif
#ifndef FALSE
# define FALSE 0
#endif

#define PDO_DRIVER_API	20050120

enum pdo_param_type {
	PDO_PARAM_NULL,
	PDO_PARAM_INT,	/* int as in long, the php native int type */
	PDO_PARAM_STR,
	PDO_PARAM_LOB,
	PDO_PARAM_STMT, /* hierarchical result set */
	PDO_PARAM_BOOL
};

enum pdo_fetch_type {
	PDO_FETCH_USE_DEFAULT,
	PDO_FETCH_LAZY,
	PDO_FETCH_ASSOC,
	PDO_FETCH_NUM,
	PDO_FETCH_BOTH,
	PDO_FETCH_OBJ,
	PDO_FETCH_BOUND, /* return true/false only; rely on bound columns */
	PDO_FETCH_COLUMN,	/* fetch a numbered column only */
	PDO_FETCH_CLASS,	/* create an instance of named class, call ctor and set properties */
	PDO_FETCH_INTO,		/* fetch row into an existing object */
	PDO_FETCH__MAX /* must be last */
};

/* fetch orientation for scrollable cursors */
enum pdo_fetch_orientation {
	PDO_FETCH_ORI_NEXT,		/* default: fetch the next available row */
	PDO_FETCH_ORI_PRIOR,	/* scroll back to prior row and fetch that */
	PDO_FETCH_ORI_FIRST,	/* scroll to the first row and fetch that */
	PDO_FETCH_ORI_LAST,		/* scroll to the last row and fetch that */
	PDO_FETCH_ORI_ABS,		/* scroll to an absolute numbered row and fetch that */
	PDO_FETCH_ORI_REL,		/* scroll relative to the current row, and fetch that */
};

enum pdo_attribute_type {
	PDO_ATTR_AUTOCOMMIT,	/* use to turn on or off auto-commit mode */
	PDO_ATTR_PREFETCH,		/* configure the prefetch size for drivers that support it. Size is in KB */
	PDO_ATTR_TIMEOUT,		/* connection timeout in seconds */
	PDO_ATTR_ERRMODE,		/* control how errors are handled */
	PDO_ATTR_SERVER_VERSION,	/* database server version */
	PDO_ATTR_CLIENT_VERSION,	/* client library version */
	PDO_ATTR_SERVER_INFO,		/* server information */
	PDO_ATTR_CONNECTION_STATUS,	/* connection status */
	PDO_ATTR_CASE,				/* control case folding for portability */
	PDO_ATTR_CURSOR_NAME,		/* name a cursor for use in "WHERE CURRENT OF <name>" */
	PDO_ATTR_CURSOR,			/* cursor type */
	PDO_ATTR_ORACLE_NULLS,		/* convert empty strings to NULL */
	PDO_ATTR_PERSISTENT,		/* pconnect style connection */

	/* this defines the start of the range for driver specific options.
	 * Drivers should define their own attribute constants beginning with this
	 * value. */
	PDO_ATTR_DRIVER_SPECIFIC = 1000
};

enum pdo_cursor_type {
	PDO_CURSOR_FWDONLY,		/* forward only cursor (default) */
	PDO_CURSOR_SCROLL,		/* scrollable cursor */
};

/* SQL-92 SQLSTATE error codes.

The character string value returned for an SQLSTATE consists of a two-character
class value followed by a three-character subclass value. A class value of 01
indicates a warning and is accompanied by a return code of
SQL_SUCCESS_WITH_INFO.

Class values other than '01', except for the class 'IM',
indicate an error and are accompanied by a return code of SQL_ERROR. The class
'IM' is specific to warnings and errors that derive from the implementation of
ODBC itself.

The subclass value '000' in any class indicates that there is no
subclass for that SQLSTATE. The assignment of class and subclass values is
defined by SQL-92.
*/

typedef char pdo_error_type[6]; /* SQLSTATE */


#define PDO_ERR_NONE				"00000"
#if 0
/* generic error code values.
 * Don't want to go overboard with these.
 * */
#define	PDO_ERR_SYNTAX				"42000"		
#define	PDO_ERR_CONSTRAINT			"23000"
#define	PDO_ERR_NOT_FOUND			""
#define	PDO_ERR_ALREADY_EXISTS,
#define	PDO_ERR_NOT_IMPLEMENTED,
#define	PDO_ERR_MISMATCH,
#define	PDO_ERR_TRUNCATED,
#define	PDO_ERR_DISCONNECTED,
#define	PDO_ERR_NO_PERM,

	PDO_ERR_CANT_MAP,		/* no way to map native error to the generic
							 * codes; consult the native error for more info */
};
#endif

enum pdo_error_mode {
	PDO_ERRMODE_SILENT,		/* just set error codes */
	PDO_ERRMODE_WARNING,	/* raise E_WARNING */
	PDO_ERRMODE_EXCEPTION,	/* throw exceptions */
};

enum pdo_case_conversion {
	PDO_CASE_NATURAL,
	PDO_CASE_UPPER,
	PDO_CASE_LOWER
};

/* {{{ utils for reading attributes set as driver_options */
static inline long pdo_attr_lval(zval *options, enum pdo_fetch_type option_name, long defval TSRMLS_DC)
{
	zval **v;

	if (options && SUCCESS == zend_hash_index_find(Z_ARRVAL_P(options), option_name, (void**)&v)) {
		convert_to_long_ex(v);
		return Z_LVAL_PP(v);
	}
	return defval;
}
/* }}} */

/* This structure is registered with PDO when a PDO driver extension is
 * initialized */
typedef struct {
	const char		*driver_name;
	unsigned long	driver_name_len;
	unsigned long	api_version; /* needs to be compatible with PDO */

#define PDO_DRIVER_HEADER(name)	\
	#name, sizeof(#name)-1, \
	PDO_DRIVER_API
	
	/* create driver specific portion of the database handle and stash it into
	 * the dbh.  dbh contains the data source string and flags for this
	 * instance.  You MUST respect dbh->is_persistent and pass that flag to
	 * pemalloc() for all allocations that are stored in the dbh or your instance
	 * data in the db, otherwise you will crash PHP when persistent connections
	 * are used.
	 */
	int (*db_handle_factory)(pdo_dbh_t *dbh, zval *driver_options TSRMLS_DC);

} pdo_driver_t;

/* {{{ methods for a database handle */

/* close or otherwise disconnect the database */
typedef int (*pdo_dbh_close_func)(pdo_dbh_t *dbh TSRMLS_DC);

/* prepare a statement and stash driver specific portion into stmt */
typedef int (*pdo_dbh_prepare_func)(pdo_dbh_t *dbh, const char *sql, long sql_len, pdo_stmt_t *stmt, zval *driver_options TSRMLS_DC);

/* execute a statement (that does not return a result set) */
typedef long (*pdo_dbh_do_func)(pdo_dbh_t *dbh, const char *sql, long sql_len TSRMLS_DC);

/* quote a string */
typedef int (*pdo_dbh_quote_func)(pdo_dbh_t *dbh, const char *unquoted, int unquotedlen, char **quoted, int *quotedlen TSRMLS_DC);

/* transaction related */
typedef int (*pdo_dbh_txn_func)(pdo_dbh_t *dbh TSRMLS_DC);

/* setting of attributes */
typedef int (*pdo_dbh_set_attr_func)(pdo_dbh_t *dbh, long attr, zval *val TSRMLS_DC);

/* return last insert id */
typedef long (*pdo_dbh_last_id_func)(pdo_dbh_t *dbh TSRMLS_DC);

/* fetch error information.  if stmt is not null, fetch information pertaining
 * to the statement, otherwise fetch global error information.  The driver
 * should add the following information to the array "info" in this order:
 * - native error code
 * - string representation of the error code ... any other optional driver
 *   specific data ...  */
typedef	int (*pdo_dbh_fetch_error_func)(pdo_dbh_t *dbh, pdo_stmt_t *stmt, zval *info TSRMLS_DC);

/* fetching of attributes */
typedef int (*pdo_dbh_get_attr_func)(pdo_dbh_t *dbh, long attr, zval *val TSRMLS_DC);

/* checking/pinging persistent connections; return SUCCESS if the connection
 * is still alive and ready to be used, FAILURE otherwise.
 * You may set this handler to NULL, which is equivalent to returning SUCCESS. */
typedef int (*pdo_dbh_check_liveness_func)(pdo_dbh_t *dbh TSRMLS_DC);

/* for adding methods to the dbh or stmt objects 
pointer to a list of driver specific functions. The convention is
to prefix the function names using the PDO driver name; this will
reduce the chance of collisions with future functionality in the
PDO class or in user code (they can extend the PDO object).
*/
enum {
	PDO_DBH_DRIVER_METHOD_KIND_DBH = 0,
	PDO_DBH_DRIVER_METHOD_KIND_STMT,
	PDO_DBH_DRIVER_METHOD_KIND__MAX
};

typedef function_entry *(*pdo_dbh_get_driver_methods_func)(pdo_dbh_t *dbh, int kind TSRMLS_DC);

struct pdo_dbh_methods {
	pdo_dbh_close_func		closer;
	pdo_dbh_prepare_func	preparer;
	pdo_dbh_do_func			doer;
	pdo_dbh_quote_func		quoter;
	pdo_dbh_txn_func		begin;
	pdo_dbh_txn_func		commit;
	pdo_dbh_txn_func		rollback;
	pdo_dbh_set_attr_func	set_attribute;
	pdo_dbh_last_id_func		last_id;
	pdo_dbh_fetch_error_func	fetch_err;
	pdo_dbh_get_attr_func   	get_attribute;
	pdo_dbh_check_liveness_func	check_liveness;
	pdo_dbh_get_driver_methods_func get_driver_methods;
};

/* }}} */

/* {{{ methods for a statement handle */

/* free the statement handle */
typedef int (*pdo_stmt_dtor_func)(pdo_stmt_t *stmt TSRMLS_DC);

/* start the query */
typedef int (*pdo_stmt_execute_func)(pdo_stmt_t *stmt TSRMLS_DC);

/* causes the next row in the set to be fetched; indicates if there are no
 * more rows.  The ori and offset params modify which row should be returned,
 * if the stmt represents a scrollable cursor */
typedef int (*pdo_stmt_fetch_func)(pdo_stmt_t *stmt, 
	enum pdo_fetch_orientation ori, long offset TSRMLS_DC);

/* queries information about the type of a column, by index (0 based).
 * Driver should populate stmt->columns[colno] with appropriate info */
typedef int (*pdo_stmt_describe_col_func)(pdo_stmt_t *stmt, int colno TSRMLS_DC);

/* retrieves pointer and size of the value for a column.
 * Note that PDO expects the driver to manage the lifetime of this data;
 * it will copy the value into a zval on behalf of the script.
 */
typedef int (*pdo_stmt_get_col_data_func)(pdo_stmt_t *stmt, int colno, char **ptr, unsigned long *len TSRMLS_DC);

/* hook for bound params */
enum pdo_param_event {
	PDO_PARAM_EVT_ALLOC,
	PDO_PARAM_EVT_FREE,
	PDO_PARAM_EVT_EXEC_PRE,
	PDO_PARAM_EVT_EXEC_POST,
	PDO_PARAM_EVT_FETCH_PRE,
	PDO_PARAM_EVT_FETCH_POST,
};

typedef int (*pdo_stmt_param_hook_func)(pdo_stmt_t *stmt, struct pdo_bound_param_data *param, enum pdo_param_event event_type TSRMLS_DC);

/* setting of attributes */
typedef int (*pdo_stmt_set_attr_func)(pdo_stmt_t *stmt, long attr, zval *val TSRMLS_DC);

/* fetching of attributes */
typedef int (*pdo_stmt_get_attr_func)(pdo_stmt_t *stmt, long attr, zval *val TSRMLS_DC);

/* retrieves meta data for a numbered column.
 * Returns SUCCESS/FAILURE.
 * On SUCCESS, fill in return_value with an array with the following fields.
 * If a particular field is not supported, then the driver simply does not add it to
 * the array, so that scripts can use isset() to check for it.
 *
 * ### this is just a rough first cut, and subject to change ###
 *
 * these are added by PDO itself, based on data from the describe handler:
 *   name => the column name
 *   len => the length/size of the column
 *   precision => precision of the column
 *   pdo_type => an integer, one of the PDO_PARAM_XXX values
 *
 *   scale => the floating point scale
 *   table => the table for that column
 *   type => a string representation of the type, mapped to the PHP equivalent type name
 *   native_type => a string representation of the type, native style, if different from
 *                  the mapped name.
 *   flags => an array of flags including zero or more of the following:
 *            primary_key, not_null, unique_key, multiple_key, unsigned, auto_increment, blob
 *
 * Any driver specific data should be returned using a prefixed key or value.
 * Eg: custom data for the mysql driver would use either
 *   'mysql:foobar' => 'some data' // to add a new key to the array
 * or
 *   'flags' => array('not_null', 'mysql:some_flag'); // to add data to an existing key
 */
typedef int (*pdo_stmt_get_column_meta_func)(pdo_stmt_t *stmt, long colno, zval *return_value TSRMLS_DC);

/* advances the statement to the next rowset of the batch.
 * If it returns 1, PDO will tear down its idea of columns
 * and meta data.  If it returns 0, PDO will indicate an error
 * to the caller. */
typedef int (*pdo_stmt_next_rowset_func)(pdo_stmt_t *stmt TSRMLS_DC);

struct pdo_stmt_methods {
	pdo_stmt_dtor_func			dtor;
	pdo_stmt_execute_func		executer;
	pdo_stmt_fetch_func			fetcher;
	pdo_stmt_describe_col_func	describer;
	pdo_stmt_get_col_data_func	get_col;
	pdo_stmt_param_hook_func	param_hook;
	pdo_stmt_set_attr_func		set_attribute;
	pdo_stmt_get_attr_func		get_attribute;
	pdo_stmt_get_column_meta_func get_column_meta;
	pdo_stmt_next_rowset_func		next_rowset;
};

/* }}} */

enum pdo_placeholder_support {
	PDO_PLACEHOLDER_NONE=0,
	PDO_PLACEHOLDER_NAMED=1,
	PDO_PLACEHOLDER_POSITIONAL=2
};

/* represents a connection to a database */
struct _pdo_dbh_t {
	/* these items mst appear in this order at the beginning of the
       struct so that this can be cast as a zend_object.  we need this
       to allow the extending class to escape all the custom handlers
	   that PDO declares.
    */
	zend_class_entry *ce; 
	HashTable *properties;
	unsigned int in_get:1;
	unsigned int in_set:1;

	/* driver specific methods */
	struct pdo_dbh_methods *methods;
	/* driver specific data */
	void *driver_data;

	/* credentials */
	char *username, *password;
	
	/* if true, then data stored and pointed at by this handle must all be
	 * persistently allocated */
	unsigned is_persistent:1;

	/* if true, driver should act as though a COMMIT were executed between
	 * each executed statement; otherwise, COMMIT must be carried out manually
	 * */
	unsigned auto_commit:1;

	/* if true, the handle has been closed and will not function anymore */
	unsigned is_closed:1;

	/* if true, the driver requires that memory be allocated explicitly for
	 * the columns that are returned */
	unsigned alloc_own_columns:1;

	/* if true, commit or rollBack is allowed to be called */
	unsigned in_txn:1;

	/* max length a single character can become after correct quoting */
	unsigned max_escaped_char_length:3;

	/* when set, convert empty strings to NULL */
	unsigned oracle_nulls:1;

	/* the sum of the number of bits here and the bit fields preceeding should
	 * equal 32 */
	unsigned _reserved_flags:23;

	/* data source string used to open this handle */
	const char *data_source;
	unsigned long data_source_len;

	/* the global error code. */
	pdo_error_type error_code;

	enum pdo_error_mode error_mode;

	enum pdo_case_conversion native_case, desired_case;

	/* persistent hash key associated with this handle */
	const char *persistent_id;
	int persistent_id_len;
	unsigned int refcount;

	/* driver specific "class" methods for the dbh and stmt */
	HashTable *cls_methods[PDO_DBH_DRIVER_METHOD_KIND__MAX];
};

/* describes a column */
struct pdo_column_data {
	char *name;
	long namelen;
	unsigned long maxlen;
	enum pdo_param_type param_type;
	unsigned long precision;
};

/* describes a bound parameter */
struct pdo_bound_param_data {
	long paramno; /* if -1, then it has a name, and we don't know the index *yet* */
	char *name;
	long namelen;

	long max_value_len;	/* as a hint for pre-allocation */
	
	zval *parameter;				/* the variable itself */
	enum pdo_param_type param_type; /* desired or suggested type */

	zval *driver_params;			/* optional parameter(s) for the driver */
	void *driver_data;

	pdo_stmt_t *stmt;	/* for convenience in dtor */
	int is_param;		/* parameter or column ? */
};

/* represents a prepared statement */
struct _pdo_stmt_t {
	/* driver specifics */
	struct pdo_stmt_methods *methods;
	void *driver_data;

	/* if true, we've already successfully executed this statement at least
	 * once */
	unsigned executed:1;
	/* if true, the statement supports placeholders and can implement
	 * bindParam() for its prepared statements, if false, PDO should
	 * emulate prepare and bind on its behalf */
	unsigned supports_placeholders:2;

	unsigned _reserved:29;

	/* the number of columns in the result set; not valid until after
	 * the statement has been executed at least once.  In some cases, might
	 * not be valid until fetch (at the driver level) has been called at least once.
	 * */
	int column_count;
	struct pdo_column_data *columns;
	
	/* we want to keep the dbh alive while we live, so we own a reference */
	zval database_object_handle;
	pdo_dbh_t *dbh;

	/* keep track of bound input parameters.  Some drivers support
	 * input/output parameters, but you can't rely on that working */
	HashTable *bound_params;
	/* keep track of PHP variables bound to named (or positional) columns
	 * in the result set */
	HashTable *bound_columns;

	/* not always meaningful */
	long row_count;

	/* used to hold the statement's current query */
	char *query_string;
	int query_stringlen;

	/* the copy of the query with expanded binds ONLY for emulated-prepare drivers */
	char *active_query_string;
	int active_query_stringlen;

	/* the cursor specific error code. */
	pdo_error_type error_code;

	/* for lazy fetches, we always return the same lazy object handle.
	 * Let's keep it here. */
	zval lazy_object_ref;
	unsigned long refcount;

	/* defaults for fetches */
	enum pdo_fetch_type default_fetch_type;
	union {
		int column;
		struct {
			zend_class_entry *ce;	
			zval *ctor_args;
		} cls;
		zval *into;
	} fetch;
};

/* call this in MINIT to register your PDO driver */
PDO_API int php_pdo_register_driver(pdo_driver_t *driver);
/* call this in MSHUTDOWN to unregister your PDO driver */
PDO_API void php_pdo_unregister_driver(pdo_driver_t *driver);

/* For the convenience of drivers, this function will parse a data source
 * string, of the form "name=value; name2=value2" and populate variables
 * according to the data you pass in and array of pdo_data_src_parser structures */
struct pdo_data_src_parser {
	const char *optname;
	char *optval;
	int freeme;
};

PDO_API int php_pdo_parse_data_source(const char *data_source,
		unsigned long data_source_len, struct pdo_data_src_parser *parsed,
		int nparams);

PDO_API zend_class_entry *php_pdo_get_exception(void);

PDO_API int pdo_parse_params(pdo_stmt_t *stmt, char *inquery, int inquery_len, 
	char **outquery, int *outquery_len TSRMLS_DC);

#endif /* PHP_PDO_DRIVER_H */
/*
 * 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
 */