m_struct.h

   1 #ifndef MPLAYER_M_STRUCT_H
   2 #define MPLAYER_M_STRUCT_H
   3
   4 /// \defgroup OptionsStruct Options struct
   5 /// \ingroup Options
   6 /// An API to manipulate structs using m_option.
   7 ///@{
   8
   9 /// \file m_struct.h
  10
  11 struct m_option;
  12
  13 /// Struct definition
  14 typedef struct m_struct_st {
  15   /// For error messages and debugging
  16   const char* name;
  17   /// size of the whole struct
  18   unsigned int size;
  19   /// Pointer to a struct filled with the default settings
  20   const void* defaults;
  21   /// Field list.
  22   /** The p field of the \ref m_option struct must contain the offset
  23    *  of the member in the struct (use M_ST_OFF macro for this).
  24    */
  25   const struct m_option* fields;
  26 } m_struct_t;
  27
  28
  29 // From glib.h (modified ;-)
  30
  31 /// Get the offset of a struct field.
  32 /** \param struct_type Struct type.
  33  *  \param member Name of the field.
  34  *  \return The offset of the field in bytes.
  35  */
  36 #define M_ST_OFF(struct_type, member)    \
  37     ((void*) &((struct_type*) 0)->member)
  38
  39 /// Get a pointer to a struct field.
  40 /** \param struct_p Pointer to the struct.
  41  *  \param struct_offset Offset of the field in the struct.
  42  *  \return Pointer to the struct field.
  43  */
  44 #define M_ST_MB_P(struct_p, struct_offset)   \
  45     ((void *)((char *)(struct_p) + (unsigned long)(struct_offset)))
  46
  47 /// Access a struct field at a given offset.
  48 /** \param member_type Type of the field.
  49  *  \param struct_p Pointer to the struct.
  50  *  \param struct_offset Offset of the field in the struct.
  51  *  \return The struct field at the given offset.
  52  */
  53 #define M_ST_MB(member_type, struct_p, struct_offset)   \
  54     (*(member_type*) M_ST_MB_P ((struct_p), (struct_offset)))
  55
  56
  57
  58 /// Allocate the struct and set it to the defaults.
  59 /** \param st Struct definition.
  60  *  \return The newly allocated object set to default.
  61  */
  62 void*
  63 m_struct_alloc(const m_struct_t* st);
  64
  65 /// Set a field of the struct.
  66 /** \param st Struct definition.
  67  *  \param obj Pointer to the struct to set.
  68  *  \param field Name of the field to set.
  69  *  \param param New value of the field.
  70  *  \return 0 on error, 1 on success.
  71  */
  72 int
  73 m_struct_set(const m_struct_t* st, void* obj, char* field, char* param);
  74
  75 /// Reset a field (or all if field == NULL) to defaults.
  76 /** \param st Struct definition.
  77  *  \param obj Pointer to the struct to set.
  78  *  \param field Name of the field to reset, if NULL all fields are reseted.
  79  */
  80 void
  81 m_struct_reset(const m_struct_t* st, void* obj, const char* field);
  82
  83 /// Create a copy of an existing struct.
  84 /** \param st Struct definition.
  85  *  \param obj Pointer to the struct to copy.
  86  *  \return Newly allocated copy of obj.
  87  */
  88 void*
  89 m_struct_copy(const m_struct_t* st, void* obj);
  90
  91 /// Free an allocated struct.
  92 /** \param st Struct definition.
  93  *  \param obj Pointer to the struct to copy.
  94  */
  95 void
  96 m_struct_free(const m_struct_t* st, void* obj);
  97
  98 /// Get a field description.
  99 /** \param st Struct definition.
 100  *  \param f Name of the field.
 101  *  \return The \ref m_option struct describing the field or NULL if not found.
 102  */
 103 const struct m_option*
 104 m_struct_get_field(const m_struct_t* st,const char* f);
 105
 106 ///@}
 107
 108 #endif /* MPLAYER_M_STRUCT_H */