src/libds/buffer.c

   1 #include <assert.h>
   2 #include <stdlib.h>
   3
   4 #include "libds/log.h"
   5 #include "libds/interfaces/buffer.h"
   6
   7 #include "buffer.h"
   8 #include "client_buffer.h"
   9
  10 static struct wl_array buffer_resource_interfaces = {0};
  11
  12 static void buffer_consider_destroy(struct ds_buffer *buffer);
  13 static bool ds_resource_is_buffer(struct wl_resource *resource);
  14 static const struct ds_buffer_resource_interface *
  15 get_buffer_resource_iface(struct wl_resource *resource);
  16
  17 WL_EXPORT void
  18 ds_buffer_init(struct ds_buffer *buffer,
  19         const struct ds_buffer_interface *iface, int width, int height)
  20 {
  21     buffer->iface = iface;
  22     buffer->width = width;
  23     buffer->height = height;
  24
  25     wl_signal_init(&buffer->events.destroy);
  26     wl_signal_init(&buffer->events.release);
  27 }
  28
  29 WL_EXPORT struct ds_buffer *
  30 ds_buffer_from_resource(struct wl_resource *resource)
  31 {
  32     struct ds_buffer *buffer;
  33     const struct ds_buffer_resource_interface *iface;
  34
  35     assert(resource && ds_resource_is_buffer(resource));
  36
  37     if (wl_shm_buffer_get(resource) != NULL) {
  38         struct ds_shm_client_buffer *shm_client_buffer =
  39             ds_shm_client_buffer_get_or_create(resource);
  40         if (!shm_client_buffer) {
  41             ds_err("Failed to create shm client buffer");
  42             return NULL;
  43         }
  44
  45         buffer = ds_buffer_lock(&shm_client_buffer->base);
  46     }
  47     else {
  48         iface = get_buffer_resource_iface(resource);
  49         if (!iface) {
  50             ds_err("Unknown buffer type");
  51             return NULL;
  52         }
  53
  54         buffer = iface->from_resource(resource);
  55         if (!buffer) {
  56             ds_err("Failed to create %s buffer", iface->name);
  57             return NULL;
  58         }
  59
  60         buffer = ds_buffer_lock(buffer);
  61     }
  62
  63     return buffer;
  64 }
  65
  66 WL_EXPORT void
  67 ds_buffer_drop(struct ds_buffer *buffer)
  68 {
  69     assert(!buffer->dropped);
  70     buffer->dropped = true;
  71     ds_dbg("Buffer(%p) dropped: n_locks(%zu)", buffer, buffer->n_locks);
  72     buffer_consider_destroy(buffer);
  73 }
  74
  75 WL_EXPORT struct ds_buffer *
  76 ds_buffer_lock(struct ds_buffer *buffer)
  77 {
  78     buffer->n_locks++;
  79     ds_dbg("Buffer(%p) n_locks(%zu)", buffer, buffer->n_locks);
  80     return buffer;
  81 }
  82
  83 WL_EXPORT void
  84 ds_buffer_unlock(struct ds_buffer *buffer)
  85 {
  86     assert(buffer->n_locks > 0);
  87     buffer->n_locks--;
  88     ds_dbg("Buffer(%p) n_locks(%zu)", buffer, buffer->n_locks);
  89
  90     if (buffer->n_locks == 0)
  91         wl_signal_emit(&buffer->events.release, NULL);
  92
  93     buffer_consider_destroy(buffer);
  94 }
  95
  96 WL_EXPORT bool
  97 ds_buffer_begin_data_ptr_access(struct ds_buffer *buffer, uint32_t flags,
  98         void **data, uint32_t *format, size_t *stride)
  99 {
 100     assert(!buffer->accessing_data_ptr);
 101     if (!buffer->iface->begin_data_ptr_access)
 102         return false;
 103     if (!buffer->iface->begin_data_ptr_access(buffer,
 104                 flags, data, format, stride))
 105         return false;
 106     buffer->accessing_data_ptr = true;
 107     return true;
 108 }
 109
 110 WL_EXPORT void
 111 ds_buffer_end_data_ptr_access(struct ds_buffer *buffer)
 112 {
 113     assert(buffer->accessing_data_ptr);
 114     buffer->iface->end_data_ptr_access(buffer);
 115     buffer->accessing_data_ptr = false;
 116 }
 117
 118 WL_EXPORT void
 119 ds_buffer_add_destroy_listener(struct ds_buffer *buffer,
 120         struct wl_listener *listener)
 121 {
 122     wl_signal_add(&buffer->events.destroy, listener);
 123 }
 124
 125 void
 126 ds_buffer_add_release_listener(struct ds_buffer *buffer,
 127         struct wl_listener *listener)
 128 {
 129     wl_signal_add(&buffer->events.release, listener);
 130 }
 131
 132 WL_EXPORT bool
 133 ds_buffer_get_shm(struct ds_buffer *buffer, struct ds_shm_attributes *attribs)
 134 {
 135     if (!buffer->iface->get_shm)
 136         return false;
 137
 138     return buffer->iface->get_shm(buffer, attribs);
 139 }
 140
 141 WL_EXPORT void
 142 ds_buffer_get_size(struct ds_buffer *buffer, int *out_width, int *out_height)
 143 {
 144     if (out_width)
 145         *out_width = buffer->width;
 146     if (out_height)
 147         *out_height = buffer->height;
 148 }
 149
 150 WL_EXPORT void
 151 ds_buffer_register_resource_interface(
 152         const struct ds_buffer_resource_interface *iface)
 153 {
 154     const struct ds_buffer_resource_interface **iface_ptr;
 155
 156     assert(iface);
 157     assert(iface->is_instance);
 158     assert(iface->from_resource);
 159
 160     wl_array_for_each(iface_ptr, &buffer_resource_interfaces) {
 161         if (*iface_ptr == iface) {
 162             ds_dbg("ds_buffer_resource_interface %s has already "
 163                     "been registered", iface->name);
 164             return;
 165         }
 166     }
 167
 168     iface_ptr = wl_array_add(&buffer_resource_interfaces, sizeof(iface));
 169     *iface_ptr = iface;
 170 }
 171
 172 static void
 173 buffer_consider_destroy(struct ds_buffer *buffer)
 174 {
 175     if (!buffer->dropped || buffer->n_locks > 0)
 176         return;
 177
 178     assert(!buffer->accessing_data_ptr);
 179
 180     wl_signal_emit(&buffer->events.destroy, NULL);
 181     buffer->iface->destroy(buffer);
 182 }
 183
 184 static bool
 185 ds_resource_is_buffer(struct wl_resource *resource)
 186 {
 187     return strcmp(wl_resource_get_class(resource),
 188             wl_buffer_interface.name) == 0;
 189 }
 190
 191 static const struct ds_buffer_resource_interface *
 192 get_buffer_resource_iface(struct wl_resource *resource)
 193 {
 194     struct ds_buffer_resource_interface **iface_ptr;
 195
 196     wl_array_for_each(iface_ptr, &buffer_resource_interfaces) {
 197         if ((*iface_ptr)->is_instance(resource)) {
 198             return *iface_ptr;
 199         }
 200     }
 201
 202     return NULL;
 203 }