mpv/m_option.h

/*
 * This file is part of MPlayer.
 *
 * MPlayer 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.
 *
 * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef MPLAYER_M_OPTION_H
#define MPLAYER_M_OPTION_H

#include <string.h>
#include <stddef.h>
#include <stdbool.h>

#include "config.h"
#include "bstr.h"

// m_option allows to parse, print and copy data of various types.

typedef struct m_option_type m_option_type_t;
typedef struct m_option m_option_t;
struct m_struct_st;

///////////////////////////// Options types declarations ////////////////////

// Simple types
extern const m_option_type_t m_option_type_flag;
extern const m_option_type_t m_option_type_int;
extern const m_option_type_t m_option_type_int64;
extern const m_option_type_t m_option_type_intpair;
extern const m_option_type_t m_option_type_float;
extern const m_option_type_t m_option_type_double;
extern const m_option_type_t m_option_type_string;
extern const m_option_type_t m_option_type_string_list;
extern const m_option_type_t m_option_type_position;
extern const m_option_type_t m_option_type_time;
extern const m_option_type_t m_option_type_time_size;
extern const m_option_type_t m_option_type_choice;

extern const m_option_type_t m_option_type_print;
extern const m_option_type_t m_option_type_print_indirect;
extern const m_option_type_t m_option_type_print_func;
extern const m_option_type_t m_option_type_subconfig;
extern const m_option_type_t m_option_type_imgfmt;
extern const m_option_type_t m_option_type_afmt;

// Func-based types
extern const m_option_type_t m_option_type_func_param;
extern const m_option_type_t m_option_type_func;

// Callback used to reset func options.
typedef void (*m_opt_default_func_t)(const m_option_t *, const char *);

// Callback used by m_option_type_func_full options.
typedef int (*m_opt_func_full_t)(const m_option_t *, const char *, const char *);

// Callback used by m_option_type_func_param options.
typedef int (*m_opt_func_param_t)(const m_option_t *, const char *);

// Callback used by m_option_type_func options.
typedef int (*m_opt_func_t)(const m_option_t *);

// Backwards compatibility
typedef m_opt_default_func_t cfg_default_func_t;
typedef m_opt_func_full_t cfg_func_arg_param_t;
typedef m_opt_func_param_t cfg_func_param_t;
typedef m_opt_func_t cfg_func_t;

#define END_AT_NONE   0
#define END_AT_TIME   1
#define END_AT_SIZE   2
typedef struct {
    double pos;
    int type;
} m_time_size_t;

// Extra definition needed for \ref m_option_type_obj_settings_list options.
typedef struct {
    // Pointer to an array of pointer to some object type description struct.
    void **list;
    // Offset of the object type name (char*) in the description struct.
    void *name_off;
    // Offset of the object type info string (char*) in the description struct.
    void *info_off;
    // Offset of the object type parameter description (\ref m_struct_st)
    // in the description struct.
    void *desc_off;
} m_obj_list_t;

// The data type used by \ref m_option_type_obj_settings_list.
typedef struct m_obj_settings {
    // Type of the object.
    char *name;
    // NULL terminated array of parameter/value pairs.
    char **attribs;
} m_obj_settings_t;

// A parser to set up a list of objects.
/** It creates a NULL terminated array \ref m_obj_settings. The option priv
 *  field (\ref m_option::priv) must point to a \ref m_obj_list_t describing
 *  the available object types.
 */
extern const m_option_type_t m_option_type_obj_settings_list;

// Extra definition needed for \ref m_option_type_obj_presets options.
typedef struct {
    // Description of the struct holding the presets.
    const struct m_struct_st *in_desc;
    // Description of the struct that should be set by the presets.
    const struct m_struct_st *out_desc;
    // Pointer to an array of structs defining the various presets.
    const void *presets;
    // Offset of the preset's name inside the in_struct.
    void *name_off;
} m_obj_presets_t;

// Set several fields in a struct at once.
/** For this two struct descriptions are used. One for the struct holding the
 *  preset and one for the struct beeing set. Every field present in both
 *  structs will be copied from the preset struct to the destination one.
 *  The option priv field (\ref m_option::priv) must point to a correctly
 *  filled \ref m_obj_presets_t.
 */
extern const m_option_type_t m_option_type_obj_presets;

// Parse an URL into a struct.
/** The option priv field (\ref m_option::priv) must point to a
 *  \ref m_struct_st describing which fields of the URL must be used.
 */
extern const m_option_type_t m_option_type_custom_url;

// Extra definition needed for \ref m_option_type_obj_params options.
typedef struct {
    // Field descriptions.
    const struct m_struct_st *desc;
    // Field separator to use.
    char separator;
} m_obj_params_t;

// Parse a set of parameters.
/** Parameters are separated by the given separator and each one
 *  successively sets a field from the struct. The option priv field
 *  (\ref m_option::priv) must point to a \ref m_obj_params_t.
 */
extern const m_option_type_t m_option_type_obj_params;

typedef struct {
    int start;
    int end;
} m_span_t;
// Ready made settings to parse a \ref m_span_t with a start-end syntax.
extern const m_obj_params_t m_span_params_def;

struct m_opt_choice_alternatives {
    char *name;
    int value;
};


// FIXME: backward compatibility
#define CONF_TYPE_FLAG          (&m_option_type_flag)
#define CONF_TYPE_INT           (&m_option_type_int)
#define CONF_TYPE_INT64         (&m_option_type_int64)
#define CONF_TYPE_FLOAT         (&m_option_type_float)
#define CONF_TYPE_DOUBLE        (&m_option_type_double)
#define CONF_TYPE_STRING        (&m_option_type_string)
#define CONF_TYPE_FUNC          (&m_option_type_func)
#define CONF_TYPE_FUNC_PARAM    (&m_option_type_func_param)
#define CONF_TYPE_PRINT         (&m_option_type_print)
#define CONF_TYPE_PRINT_INDIRECT (&m_option_type_print_indirect)
#define CONF_TYPE_PRINT_FUNC    (&m_option_type_print_func)
#define CONF_TYPE_SUBCONFIG     (&m_option_type_subconfig)
#define CONF_TYPE_STRING_LIST   (&m_option_type_string_list)
#define CONF_TYPE_POSITION      (&m_option_type_position)
#define CONF_TYPE_IMGFMT        (&m_option_type_imgfmt)
#define CONF_TYPE_AFMT          (&m_option_type_afmt)
#define CONF_TYPE_SPAN          (&m_option_type_span)
#define CONF_TYPE_OBJ_SETTINGS_LIST (&m_option_type_obj_settings_list)
#define CONF_TYPE_OBJ_PRESETS   (&m_option_type_obj_presets)
#define CONF_TYPE_CUSTOM_URL    (&m_option_type_custom_url)
#define CONF_TYPE_OBJ_PARAMS    (&m_option_type_obj_params)
#define CONF_TYPE_TIME          (&m_option_type_time)
#define CONF_TYPE_TIME_SIZE     (&m_option_type_time_size)

////////////////////////////////////////////////////////////////////////////

// Option type description
struct m_option_type {
    const char *name;
    // Syntax description, etc
    const char *comments;
    // Size needed for the data.
    unsigned int size;
    // See \ref OptionTypeFlags.
    unsigned int flags;

    // Parse the data from a string.
    /** It is the only required function, all others can be NULL.
     *
     *  \param opt The option that is parsed.
     *  \param name The full option name.
     *  \param param The parameter to parse.
     *  \param ambiguous_param: "param" old cmdline style, "param" may or
     *         may not be an argument meant for this option
     *  \param dst Pointer to the memory where the data should be written.
     *             If NULL the parameter validity should still be checked.
     *  \return On error a negative value is returned, on success the number
     *          of arguments consumed. For details see \ref OptionParserReturn.
     */
    int (*parse)(const m_option_t *opt, struct bstr name, struct bstr param,
                 bool ambiguous_param, void *dst);

    // Print back a value in string form.
    /** \param opt The option to print.
     *  \param val Pointer to the memory holding the data to be printed.
     *  \return An allocated string containing the text value or (void*)-1
     *          on error.
     */
    char *(*print)(const m_option_t *opt, const void *val);

    /** \name
     *  These functions are called to save/set/restore the status of the
     *  variables. The difference between the 3 only matters for types like
     *  \ref m_option_type_func where 'setting' needs to do more than just
     *  copying some data.
     */
    //@{

    // Update a save slot (dst) from the current value in the program (src).
    /** \param opt The option to copy.
     *  \param dst Pointer to the destination memory.
     *  \param src Pointer to the source memory.
     */
    void (*save)(const m_option_t *opt, void *dst, const void *src);

    // Set the value in the program (dst) from a save slot.
    /** \param opt The option to copy.
     *  \param dst Pointer to the destination memory.
     *  \param src Pointer to the source memory.
     */
    void (*set)(const m_option_t *opt, void *dst, const void *src);

    // Copy the data between two save slots. If NULL and size is > 0 a memcpy will be used.
    /** \param opt The option to copy.
     *  \param dst Pointer to the destination memory.
     *  \param src Pointer to the source memory.
     */
    void (*copy)(const m_option_t *opt, void *dst, const void *src);
    //@}

    // Free the data allocated for a save slot.
    /** This is only needed for dynamic types like strings.
     *  \param dst Pointer to the data, usually a pointer that should be freed and
     *             set to NULL.
     */
    void (*free)(void *dst);
};

// Option description
struct m_option {
    // Option name.
    const char *name;

    // Reserved for higher level APIs, it shouldn't be used by parsers.
    /** The suboption parser and func types do use it. They should instead
     *  use the priv field but this was inherited from older versions of the
     *  config code.
     */
    void *p;

    // Option type.
    const m_option_type_t *type;

    // See \ref OptionFlags.
    unsigned int flags;

    // \brief Mostly useful for numeric types, the \ref M_OPT_MIN flags must
    // also be set.
    double min;

    // \brief Mostly useful for numeric types, the \ref M_OPT_MAX flags must
    // also be set.
    double max;

    // Type dependent data (for all kinds of extended settings).
    /** This used to be a function pointer to hold a 'reverse to defaults' func.
     *  Now it can be used to pass any type of extra args needed by the parser.
     *  Passing a 'default func' is still valid for all func based option types.
     */
    void *priv;

    int new;

    int offset;
};


// The option has a minimum set in \ref m_option::min.
#define M_OPT_MIN               (1 << 0)

// The option has a maximum set in \ref m_option::max.
#define M_OPT_MAX               (1 << 1)

// The option has a minimum and maximum in m_option::min and m_option::max.
#define M_OPT_RANGE             (M_OPT_MIN | M_OPT_MAX)

// The option is forbidden in config files.
#define M_OPT_NOCFG             (1 << 2)

// The option is forbidden on the command line.
#define M_OPT_NOCMD             (1 << 3)

// The option is global in the \ref Config.
/** It won't be saved on push and the command line parser will set it when
 *  it's parsed (i.e. it won't be set later)
 *  e.g options : -v, -quiet
 */
#define M_OPT_GLOBAL            (1 << 4)

// The \ref Config won't save this option on push.
/** It won't be saved on push but the command line parser will add it with
 *  its entry (i.e. it may be set later)
 *  e.g options : -include
 */
#define M_OPT_NOSAVE            (1 << 5)

// The option should be set during command line pre-parsing
#define M_OPT_PRE_PARSE         (1 << 6)

// Accept an option without parameter, even if the option type normally requires
// a parameter. The option value will be set to a default value.
// For m_option_type_choice, the first listed choice will be used.
#define M_OPT_IMPLICIT_DEFAULT  (1 << 7)

// These are kept for compatibility with older code.
#define CONF_MIN                M_OPT_MIN
#define CONF_MAX                M_OPT_MAX
#define CONF_RANGE              M_OPT_RANGE
#define CONF_NOCFG              M_OPT_NOCFG
#define CONF_NOCMD              M_OPT_NOCMD
#define CONF_GLOBAL             M_OPT_GLOBAL
#define CONF_NOSAVE             M_OPT_NOSAVE
#define CONF_PRE_PARSE          M_OPT_PRE_PARSE

// These flags are used to describe special parser capabilities or behavior.

// Suboption parser flag.
/** When this flag is set, m_option::p should point to another m_option
 *  array. Only the parse function will be called. If dst is set, it should
 *  create/update an array of char* containg opt/val pairs. The options in
 *  the child array will then be set automatically by the \ref Config.
 *  Also note that suboptions may be directly accessed by using
 *  -option:subopt blah.
 */
#define M_OPT_TYPE_HAS_CHILD            (1 << 0)

// Wildcard matching flag.
/** If set the option type has a use for option names ending with a *
 *  (used for -aa*), this only affects the option name matching.
 */
#define M_OPT_TYPE_ALLOW_WILDCARD       (1 << 1)

// Dynamic data type.
/** This flag indicates that the data is dynamically allocated (m_option::p
 *  points to a pointer). It enables a little hack in the \ref Config wich
 *  replaces the initial value of such variables with a dynamic copy in case
 *  the initial value is statically allocated (pretty common with strings).
 */
#define M_OPT_TYPE_DYNAMIC              (1 << 2)

// Indirect option type.
/** If this is set the parse function doesn't directly return
 *  the wanted thing. Options use this if for some reasons they have to wait
 *  until the set call to be able to correctly set the target var.
 *  So for those types new values must first be parsed, then set to the target
 *  var. If this flag isn't set then new values can be parsed directly to the
 *  target var. It's used by the callback-based options as the callback call
 *  may append later on.
 */
#define M_OPT_TYPE_INDIRECT             (1 << 3)

///////////////////////////// Parser flags /////////////////////////////////

// On success parsers return the number of arguments consumed: 0 or 1.
//
// To indicate that MPlayer should exit without playing anything,
// parsers return M_OPT_EXIT minus the number of parameters they
// consumed: \ref M_OPT_EXIT or \ref M_OPT_EXIT-1.
//
// On error one of the following (negative) error codes is returned:

// For use by higher level APIs when the option name is invalid.
#define M_OPT_UNKNOWN           -1

// Returned when a parameter is needed but wasn't provided.
#define M_OPT_MISSING_PARAM     -2

// Returned when the given parameter couldn't be parsed.
#define M_OPT_INVALID           -3

// Returned if the value is "out of range". The exact meaning may
// vary from type to type.
#define M_OPT_OUT_OF_RANGE      -4

// Returned if the parser failed for any other reason than a bad parameter.
#define M_OPT_PARSER_ERR        -5

// Returned when MPlayer should exit. Used by various help stuff.
/** M_OPT_EXIT must be the lowest number on this list.
 */
#define M_OPT_EXIT              -6

// These are kept for compatibility with older code.
//
#define ERR_NOT_AN_OPTION       M_OPT_UNKNOWN
#define ERR_MISSING_PARAM       M_OPT_MISSING_PARAM
#define ERR_OUT_OF_RANGE        M_OPT_OUT_OF_RANGE
#define ERR_FUNC_ERR            M_OPT_PARSER_ERR

char *m_option_strerror(int code);

// Find the option matching the given name in the list.
/** \ingroup Options
 *  This function takes the possible wildcards into account (see
 *  \ref M_OPT_TYPE_ALLOW_WILDCARD).
 *
 *  \param list Pointer to an array of \ref m_option.
 *  \param name Name of the option.
 *  \return The matching option or NULL.
 */
const m_option_t *m_option_list_find(const m_option_t *list, const char *name);

static inline void *m_option_get_ptr(const struct m_option *opt,
                                     void *optstruct)
{
    return opt->new ? (char *) optstruct + opt->offset : opt->p;
}

// Helper to parse options, see \ref m_option_type::parse.
static inline int m_option_parse(const m_option_t *opt, struct bstr name,
                                 struct bstr param, bool ambiguous_param,
                                 void *dst)
{
    return opt->type->parse(opt, name, param, ambiguous_param, dst);
}

// Helper to print options, see \ref m_option_type::print.
static inline char *m_option_print(const m_option_t *opt, const void *val_ptr)
{
    if (opt->type->print)
        return opt->type->print(opt, val_ptr);
    else
        return NULL;
}

// Helper around \ref m_option_type::copy.
static inline void m_option_copy(const m_option_t *opt, void *dst,
                                 const void *src)
{
    if (opt->type->copy)
        opt->type->copy(opt, dst, src);
    else if (opt->type->size > 0)
        memcpy(dst, src, opt->type->size);
}

// Helper around \ref m_option_type::free.
static inline void m_option_free(const m_option_t *opt, void *dst)
{
    if (opt->type->free)
        opt->type->free(dst);
}

/*@}*/

#define OPTION_LIST_SEPARATOR ','

#if HAVE_DOS_PATHS
#define OPTION_PATH_SEPARATOR ';'
#else
#define OPTION_PATH_SEPARATOR ':'
#endif

// The code will interpret arguments different from 1 as disabled, thus
// CONFIG_FOO etc mean disabled if no such macro is defined.
#define OPT_START_CONDITIONAL(enable, featurename) OPT_START_CONDITIONAL_AFTERMACROEVAL(enable, featurename)
#define OPT_START_CONDITIONAL_AFTERMACROEVAL(enable, featurename) {"conditional functionality: " #enable, .p = featurename}

#define OPT_FLAG_ON(optname, varname, flags) {optname, NULL, &m_option_type_flag, flags, 0, 1, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_FLAG_OFF(optname, varname, flags) {optname, NULL, &m_option_type_flag, flags, 1, 0, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_MAKE_FLAGS(optname, varname, flags) OPT_FLAG_ON(optname, varname, flags), OPT_FLAG_OFF("no" optname, varname, flags)
#define OPT_FLAG_CONSTANTS(optname, varname, flags, offvalue, value) {optname, NULL, &m_option_type_flag, flags, offvalue, value, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_STRINGLIST(optname, varname, flags) {optname, NULL, &m_option_type_string_list, flags, 0, 0, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_PATHLIST(optname, varname, flags) {optname, NULL, &m_option_type_string_list, flags, 0, 0, (void *)&(const char){OPTION_PATH_SEPARATOR}, 1, offsetof(struct MPOpts, varname)}
#define OPT_INT(optname, varname, flags) {optname, NULL, &m_option_type_int, flags, 0, 0, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_INTRANGE(optname, varname, flags, min, max) {optname, NULL, &m_option_type_int, (flags) | CONF_RANGE, min, max, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_INTPAIR(optname, varname, flags) {optname, NULL, &m_option_type_intpair, (flags), 0, 0, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_FLOATRANGE(optname, varname, flags, min, max) {optname, NULL, &m_option_type_float, (flags) | CONF_RANGE, min, max, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_STRING(optname, varname, flags) {optname, NULL, &m_option_type_string, flags, 0, 0, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_SETTINGSLIST(optname, varname, flags, objlist) {optname, NULL, &m_option_type_obj_settings_list, flags, 0, 0, objlist, 1, offsetof(struct MPOpts, varname)}
#define OPT_AUDIOFORMAT(optname, varname, flags) {optname, NULL, &m_option_type_afmt, flags, 0, 0, NULL, 1, offsetof(struct MPOpts, varname)}
#define OPT_HELPER_REMOVEPAREN(...) __VA_ARGS__
#define OPT_CHOICE(optname, varname, flags, choices) {optname, NULL, &m_option_type_choice, flags, 0, 0, (void *)&(const struct m_opt_choice_alternatives[]){OPT_HELPER_REMOVEPAREN choices, {NULL}}, 1, offsetof(struct MPOpts, varname)}
#define OPT_TIME(optname, varname, flags) {optname, NULL, &m_option_type_time, flags, 0, 0, NULL, 1, offsetof(struct MPOpts, varname)}

#endif /* MPLAYER_M_OPTION_H */