source/includes/lv2/urid.h

   1 /*
   2   Copyright 2008-2016 David Robillard <http://drobilla.net>
   3   Copyright 2011 Gabriel M. Beddingfield <gabrbedd@gmail.com>
   4
   5   Permission to use, copy, modify, and/or distribute this software for any
   6   purpose with or without fee is hereby granted, provided that the above
   7   copyright notice and this permission notice appear in all copies.
   8
   9   THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16 */
  17
  18 /**
  19    @defgroup urid URID
  20
  21    Features for mapping URIs to and from integers, see
  22    <http://lv2plug.in/ns/ext/urid> for details.
  23
  24    @{
  25 */
  26
  27 #ifndef LV2_URID_H
  28 #define LV2_URID_H
  29
  30 #define LV2_URID_URI    "http://lv2plug.in/ns/ext/urid"  ///< http://lv2plug.in/ns/ext/urid
  31 #define LV2_URID_PREFIX LV2_URID_URI "#"                 ///< http://lv2plug.in/ns/ext/urid#
  32
  33 #define LV2_URID__map   LV2_URID_PREFIX "map"    ///< http://lv2plug.in/ns/ext/urid#map
  34 #define LV2_URID__unmap LV2_URID_PREFIX "unmap"  ///< http://lv2plug.in/ns/ext/urid#unmap
  35
  36 #define LV2_URID_MAP_URI   LV2_URID__map    ///< Legacy
  37 #define LV2_URID_UNMAP_URI LV2_URID__unmap  ///< Legacy
  38
  39 #include <stdint.h>
  40
  41 #ifdef __cplusplus
  42 extern "C" {
  43 #endif
  44
  45 /**
  46    Opaque pointer to host data for LV2_URID_Map.
  47 */
  48 typedef void* LV2_URID_Map_Handle;
  49
  50 /**
  51    Opaque pointer to host data for LV2_URID_Unmap.
  52 */
  53 typedef void* LV2_URID_Unmap_Handle;
  54
  55 /**
  56    URI mapped to an integer.
  57 */
  58 typedef uint32_t LV2_URID;
  59
  60 /**
  61    URID Map Feature (LV2_URID__map)
  62 */
  63 typedef struct _LV2_URID_Map {
  64         /**
  65            Opaque pointer to host data.
  66
  67            This MUST be passed to map_uri() whenever it is called.
  68            Otherwise, it must not be interpreted in any way.
  69         */
  70         LV2_URID_Map_Handle handle;
  71
  72         /**
  73            Get the numeric ID of a URI.
  74
  75            If the ID does not already exist, it will be created.
  76
  77            This function is referentially transparent; any number of calls with the
  78            same arguments is guaranteed to return the same value over the life of a
  79            plugin instance.  Note, however, that several URIs MAY resolve to the
  80            same ID if the host considers those URIs equivalent.
  81
  82            This function is not necessarily very fast or RT-safe: plugins SHOULD
  83            cache any IDs they might need in performance critical situations.
  84
  85            The return value 0 is reserved and indicates that an ID for that URI
  86            could not be created for whatever reason.  However, hosts SHOULD NOT
  87            return 0 from this function in non-exceptional circumstances (i.e. the
  88            URI map SHOULD be dynamic).
  89
  90            @param handle Must be the callback_data member of this struct.
  91            @param uri The URI to be mapped to an integer ID.
  92         */
  93         LV2_URID (*map)(LV2_URID_Map_Handle handle,
  94                         const char*         uri);
  95 } LV2_URID_Map;
  96
  97 /**
  98    URI Unmap Feature (LV2_URID__unmap)
  99 */
 100 typedef struct _LV2_URID_Unmap {
 101         /**
 102            Opaque pointer to host data.
 103
 104            This MUST be passed to unmap() whenever it is called.
 105            Otherwise, it must not be interpreted in any way.
 106         */
 107         LV2_URID_Unmap_Handle handle;
 108
 109         /**
 110            Get the URI for a previously mapped numeric ID.
 111
 112            Returns NULL if `urid` is not yet mapped.  Otherwise, the corresponding
 113            URI is returned in a canonical form.  This MAY not be the exact same
 114            string that was originally passed to LV2_URID_Map::map(), but it MUST be
 115            an identical URI according to the URI syntax specification (RFC3986).  A
 116            non-NULL return for a given `urid` will always be the same for the life
 117            of the plugin.  Plugins that intend to perform string comparison on
 118            unmapped URIs SHOULD first canonicalise URI strings with a call to
 119            map_uri() followed by a call to unmap_uri().
 120
 121            @param handle Must be the callback_data member of this struct.
 122            @param urid The ID to be mapped back to the URI string.
 123         */
 124         const char* (*unmap)(LV2_URID_Unmap_Handle handle,
 125                              LV2_URID              urid);
 126 } LV2_URID_Unmap;
 127
 128 #ifdef __cplusplus
 129 }  /* extern "C" */
 130 #endif
 131
 132 #endif /* LV2_URID_H */
 133
 134 /**
 135    @}
 136 */