Add enum liftoff_basic_property

This allows fast access to properties the library cares about. Not very useful
yet, but will prove more useful in the future.

Closes: https://github.com/emersion/libliftoff/issues/1

alloc.c

@@ -119,7 +119,7 @@ static void plane_step_init_next(struct alloc_step *step,
 
 	zpos_prop = NULL;
 	if (layer != NULL) {
-		zpos_prop = layer_get_property(layer, "zpos");
+		zpos_prop = layer_get_property(layer, LIFTOFF_PROP_ZPOS);
 	}
 	if (zpos_prop != NULL && plane->type != DRM_PLANE_TYPE_PRIMARY) {
 		step->last_layer_zpos = zpos_prop->value;
@@ -150,7 +150,7 @@ static bool has_composited_layer_over(struct liftoff_output *output,
 	struct liftoff_layer *other_layer;
 	struct liftoff_layer_property *zpos_prop, *other_zpos_prop;
 
-	zpos_prop = layer_get_property(layer, "zpos");
+	zpos_prop = layer_get_property(layer, LIFTOFF_PROP_ZPOS);
 	if (zpos_prop == NULL) {
 		return false;
 	}
@@ -160,7 +160,8 @@ static bool has_composited_layer_over(struct liftoff_output *output,
 			continue;
 		}
 
-		other_zpos_prop = layer_get_property(other_layer, "zpos");
+		other_zpos_prop = layer_get_property(other_layer,
+						     LIFTOFF_PROP_ZPOS);
 		if (other_zpos_prop == NULL) {
 			continue;
 		}
@@ -183,7 +184,7 @@ static bool has_allocated_layer_over(struct liftoff_output *output,
 	struct liftoff_layer *other_layer;
 	struct liftoff_layer_property *zpos_prop, *other_zpos_prop;
 
-	zpos_prop = layer_get_property(layer, "zpos");
+	zpos_prop = layer_get_property(layer, LIFTOFF_PROP_ZPOS);
 	if (zpos_prop == NULL) {
 		return false;
 	}
@@ -203,7 +204,8 @@ static bool has_allocated_layer_over(struct liftoff_output *output,
 			continue;
 		}
 
-		other_zpos_prop = layer_get_property(other_layer, "zpos");
+		other_zpos_prop = layer_get_property(other_layer,
+						     LIFTOFF_PROP_ZPOS);
 		if (other_zpos_prop == NULL) {
 			continue;
 		}
@@ -265,7 +267,7 @@ bool check_layer_plane_compatible(struct alloc_step *step,
 		return false;
 	}
 
-	zpos_prop = layer_get_property(layer, "zpos");
+	zpos_prop = layer_get_property(layer, LIFTOFF_PROP_ZPOS);
 	if (zpos_prop != NULL) {
 		if ((int)zpos_prop->value > step->last_layer_zpos &&
 		    has_allocated_layer_over(output, step, layer)) {

display.c

@@ -4,6 +4,26 @@
 #include "log.h"
 #include "private.h"
 
+ssize_t basic_property_index(const char *name)
+{
+	if (strcmp(name, "FB_ID") == 0) {
+		return LIFTOFF_PROP_FB_ID;
+	} else if (strcmp(name, "CRTC_ID") == 0) {
+		return LIFTOFF_PROP_CRTC_ID;
+	} else if (strcmp(name, "CRTC_X") == 0) {
+		return LIFTOFF_PROP_CRTC_X;
+	} else if (strcmp(name, "CRTC_Y") == 0) {
+		return LIFTOFF_PROP_CRTC_Y;
+	} else if (strcmp(name, "CRTC_W") == 0) {
+		return LIFTOFF_PROP_CRTC_W;
+	} else if (strcmp(name, "CRTC_H") == 0) {
+		return LIFTOFF_PROP_CRTC_H;
+	} else if (strcmp(name, "zpos") == 0) {
+		return LIFTOFF_PROP_ZPOS;
+	}
+	return -1;
+}
+
 struct liftoff_display *liftoff_display_create(int drm_fd)
 {
 	struct liftoff_display *display;

include/private.h

@@ -2,9 +2,21 @@
 #define PRIVATE_H
 
 #include <libliftoff.h>
+#include <sys/types.h>
 #include "list.h"
 #include "log.h"
 
+enum liftoff_basic_property {
+	LIFTOFF_PROP_FB_ID,
+	LIFTOFF_PROP_CRTC_ID,
+	LIFTOFF_PROP_CRTC_X,
+	LIFTOFF_PROP_CRTC_Y,
+	LIFTOFF_PROP_CRTC_W,
+	LIFTOFF_PROP_CRTC_H,
+	LIFTOFF_PROP_ZPOS,
+	LIFTOFF_PROP_LAST, /* keep last */
+};
+
 struct liftoff_display {
 	int drm_fd;
 
@@ -32,6 +44,7 @@ struct liftoff_layer {
 
 	struct liftoff_layer_property *props;
 	size_t props_len;
+	struct liftoff_layer_property *basic_props[LIFTOFF_PROP_LAST];
 
 	struct liftoff_plane *plane;
 };
@@ -52,6 +65,7 @@ struct liftoff_plane {
 
 	struct liftoff_plane_property *props;
 	size_t props_len;
+	struct liftoff_plane_property *basic_props[LIFTOFF_PROP_LAST];
 
 	struct liftoff_layer *layer;
 };
@@ -66,8 +80,10 @@ struct liftoff_rect {
 	int width, height;
 };
 
+ssize_t basic_property_index(const char *name);
+
 struct liftoff_layer_property *layer_get_property(struct liftoff_layer *layer,
-						  const char *name);
+						  enum liftoff_basic_property prop);
 void layer_get_rect(struct liftoff_layer *layer, struct liftoff_rect *rect);
 bool layer_intersects(struct liftoff_layer *a, struct liftoff_layer *b);
 void layer_mark_clean(struct liftoff_layer *layer);

layer.c

@@ -27,16 +27,23 @@ void liftoff_layer_destroy(struct liftoff_layer *layer)
 }
 
 struct liftoff_layer_property *layer_get_property(struct liftoff_layer *layer,
-						  const char *name)
+						  enum liftoff_basic_property prop)
+{
+	return layer->basic_props[prop];
+}
+
+static void layer_invalidate_basic_props(struct liftoff_layer *layer)
 {
 	size_t i;
+	ssize_t basic_prop_idx;
 
+	memset(layer->basic_props, 0, sizeof(layer->basic_props));
 	for (i = 0; i < layer->props_len; i++) {
-		if (strcmp(layer->props[i].name, name) == 0) {
+		basic_prop_idx = basic_property_index(layer->props[i].name);
-			return &layer->props[i];
+		if (basic_prop_idx >= 0) {
+			layer->basic_props[basic_prop_idx] = &layer->props[i];
 		}
 	}
-	return NULL;
 }
 
 void liftoff_layer_set_property(struct liftoff_layer *layer, const char *name,
@@ -44,6 +51,8 @@ void liftoff_layer_set_property(struct liftoff_layer *layer, const char *name,
 {
 	struct liftoff_layer_property *props;
 	struct liftoff_layer_property *prop;
+	ssize_t basic_prop_idx;
+	size_t i;
 
 	/* TODO: better error handling */
 	if (strcmp(name, "CRTC_ID") == 0) {
@@ -52,7 +61,19 @@ void liftoff_layer_set_property(struct liftoff_layer *layer, const char *name,
 		return;
 	}
 
-	prop = layer_get_property(layer, name);
+	basic_prop_idx = basic_property_index(name);
+	if (basic_prop_idx >= 0) {
+		prop = layer_get_property(layer, basic_prop_idx);
+	} else {
+		prop = NULL;
+		for (i = 0; i < layer->props_len; i++) {
+			if (strcmp(layer->props[i].name, name) == 0) {
+				prop = &layer->props[i];
+				break;
+			}
+		}
+	}
+
 	if (prop == NULL) {
 		props = realloc(layer->props, (layer->props_len + 1)
 				* sizeof(struct liftoff_layer_property));
@@ -60,12 +81,21 @@ void liftoff_layer_set_property(struct liftoff_layer *layer, const char *name,
 			liftoff_log_errno(LIFTOFF_ERROR, "realloc");
 			return;
 		}
-		layer->props = props;
+		if (layer->props != props) {
-		layer->props_len++;
+			layer->props = props;
+			layer_invalidate_basic_props(layer);
+		} else {
+			layer->props = props;
+		}
 
-		prop = &layer->props[layer->props_len - 1];
+		prop = &layer->props[layer->props_len];
 		memset(prop, 0, sizeof(*prop));
 		strncpy(prop->name, name, sizeof(prop->name) - 1);
+		layer->props_len++;
+
+		if (basic_prop_idx >= 0) {
+			layer->basic_props[basic_prop_idx] = prop;
+		}
 
 		prop->changed = true;
 	} else {
@@ -87,10 +117,10 @@ void layer_get_rect(struct liftoff_layer *layer, struct liftoff_rect *rect)
 {
 	struct liftoff_layer_property *x_prop, *y_prop, *w_prop, *h_prop;
 
-	x_prop = layer_get_property(layer, "CRTC_X");
+	x_prop = layer_get_property(layer, LIFTOFF_PROP_CRTC_X);
-	y_prop = layer_get_property(layer, "CRTC_Y");
+	y_prop = layer_get_property(layer, LIFTOFF_PROP_CRTC_Y);
-	w_prop = layer_get_property(layer, "CRTC_W");
+	w_prop = layer_get_property(layer, LIFTOFF_PROP_CRTC_W);
-	h_prop = layer_get_property(layer, "CRTC_H");
+	h_prop = layer_get_property(layer, LIFTOFF_PROP_CRTC_H);
 
 	rect->x = x_prop != NULL ? x_prop->value : 0;
 	rect->y = y_prop != NULL ? y_prop->value : 0;

plane.c

@@ -39,6 +39,7 @@ struct liftoff_plane *plane_create(struct liftoff_display *display, uint32_t id)
 	drmModePropertyRes *drm_prop;
 	struct liftoff_plane_property *prop;
 	uint64_t value;
+	ssize_t basic_prop_idx;
 	bool has_type = false, has_zpos = false;
 
 	plane = calloc(1, sizeof(*plane));
@@ -83,6 +84,11 @@ struct liftoff_plane *plane_create(struct liftoff_display *display, uint32_t id)
 		drmModeFreeProperty(drm_prop);
 		plane->props_len++;
 
+		basic_prop_idx = basic_property_index(prop->name);
+		if (basic_prop_idx >= 0) {
+			plane->basic_props[basic_prop_idx] = prop;
+		}
+
 		value = drm_props->prop_values[i];
 		if (strcmp(prop->name, "type") == 0) {
 			plane->type = value;