Rewrite render thread as request based system

ZathuraRenderer is a thread pool rendering the pages. Every page widget holds a
ZathuraRenderRequest instance to request its page to be rendered. This object
can also be used to abort the request in case the page is not visible anymore.
Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

commands.c

@@ -381,9 +381,9 @@ cmd_search(girara_session_t* session, const char* input, girara_argument_t* argu
     GtkWidget* page_widget = zathura_page_get_widget(zathura, page);
     g_object_set(page_widget, "draw-links", FALSE, NULL);
 
-    render_lock(zathura->sync.render_thread);
+    zathura_renderer_lock(zathura->sync.render_thread);
     girara_list_t* result = zathura_page_search_text(page, input, &error);
-    render_unlock(zathura->sync.render_thread);
+    zathura_renderer_unlock(zathura->sync.render_thread);
 
     if (result == NULL || girara_list_size(result) == 0) {
       girara_list_free(result);

page-widget.c

@@ -15,6 +15,7 @@
 #include "utils.h"
 #include "shortcuts.h"
 #include "synctex.h"
+#include "zathura.h"
 
 G_DEFINE_TYPE(ZathuraPage, zathura_page_widget, GTK_TYPE_DRAWING_AREA)
 
@@ -22,6 +23,7 @@ typedef struct zathura_page_widget_private_s {
   zathura_page_t* page; /**< Page object */
   zathura_t* zathura; /**< Zathura object */
   cairo_surface_t* surface; /**< Cairo surface */
+  ZathuraRenderRequest* render_request; /* Request object */
   bool render_requested; /**< No surface and rendering has been requested */
   gint64 last_view; /**< Last time the page has been viewed */
   mutex lock; /**< Lock */
@@ -144,6 +146,7 @@ zathura_page_widget_init(ZathuraPage* widget)
   priv->page             = NULL;
   priv->surface          = NULL;
   priv->render_requested = false;
+  priv->render_request   = NULL;
   priv->last_view        = g_get_real_time();
 
   priv->links.list      = NULL;
@@ -177,7 +180,18 @@ zathura_page_widget_new(zathura_t* zathura, zathura_page_t* page)
 {
   g_return_val_if_fail(page != NULL, NULL);
 
-  return g_object_new(ZATHURA_TYPE_PAGE, "page", page, "zathura", zathura, NULL);
+  GObject* ret = g_object_new(ZATHURA_TYPE_PAGE, "page", page, "zathura", zathura, NULL);
+  if (ret == NULL) {
+    return NULL;
+  }
+
+  ZathuraPage* widget = ZATHURA_PAGE(ret);
+  zathura_page_widget_private_t* priv = ZATHURA_PAGE_GET_PRIVATE(widget);
+  priv->render_request = zathura_render_request_new(zathura->sync.render_thread, page);
+  g_signal_connect_object(priv->render_request, "completed",
+      G_CALLBACK(zathura_page_widget_update_surface), widget, G_CONNECT_SWAPPED);
+
+  return GTK_WIDGET(ret);
 }
 
 static void
@@ -190,6 +204,10 @@ zathura_page_widget_finalize(GObject* object)
     cairo_surface_destroy(priv->surface);
   }
 
+  if (priv->render_request != NULL) {
+    g_object_unref(priv->render_request);
+  }
+
   if (priv->search.list != NULL) {
     girara_list_free(priv->search.list);
   }
@@ -485,7 +503,7 @@ zathura_page_widget_draw(GtkWidget* widget, cairo_t* cairo)
     /* render real page */
     if (priv->render_requested == false) {
       priv->render_requested = true;
-      render_page(priv->zathura->sync.render_thread, priv->page);
+      zathura_render_request(priv->render_request);
     }
   }
   mutex_unlock(&(priv->lock));

print.c

@@ -109,9 +109,9 @@ cb_print_draw_page(GtkPrintOperation* print_operation, GtkPrintContext*
   /* Try to render the page without a temporary surface. This only works with
    * plugins that support rendering to any surface.  */
   girara_debug("printing page %d ...", page_number);
-  render_lock(zathura->sync.render_thread);
+  zathura_renderer_lock(zathura->sync.render_thread);
   int err = zathura_page_render(page, cairo, true);
-  render_unlock(zathura->sync.render_thread);
+  zathura_renderer_unlock(zathura->sync.render_thread);
   if (err == ZATHURA_ERROR_OK) {
     return;
   }
@@ -144,9 +144,9 @@ cb_print_draw_page(GtkPrintOperation* print_operation, GtkPrintContext*
 
   /* Render the page to the temporary surface */
   girara_debug("printing page %d ...", page_number);
-  render_lock(zathura->sync.render_thread);
+  zathura_renderer_lock(zathura->sync.render_thread);
   err = zathura_page_render(page, temp_cairo, true);
-  render_unlock(zathura->sync.render_thread);
+  zathura_renderer_unlock(zathura->sync.render_thread);
   if (err != ZATHURA_ERROR_OK) {
     cairo_destroy(temp_cairo);
     cairo_surface_destroy(surface);

render.c

@@ -5,7 +5,6 @@
 #include <girara/utils.h>
 #include <girara/session.h>
 #include <girara/settings.h>
-
 #include "glib-compat.h"
 #include "render.h"
 #include "zathura.h"
@@ -14,81 +13,299 @@
 #include "page-widget.h"
 #include "utils.h"
 
+/* define the two types */
+G_DEFINE_TYPE(ZathuraRenderer, zathura_renderer, G_TYPE_OBJECT)
+G_DEFINE_TYPE(ZathuraRenderRequest, zathura_render_request, G_TYPE_OBJECT)
+
+/* private methods for ZathuraRenderer  */
+static void zathura_renderer_finalize(GObject* object);
+/* private methods for ZathuraRenderRequest */
+static void zathura_render_request_finalize(GObject* object);
+
 static void render_job(void* data, void* user_data);
-static bool render(zathura_t* zathura, zathura_page_t* page);
+static bool render(ZathuraRenderRequest* request, ZathuraRenderer* renderer);
 static gint render_thread_sort(gconstpointer a, gconstpointer b, gpointer data);
+static void color2double(GdkColor* col, double* v);
 
-struct render_thread_s {
+
+/* private data for ZathuraRenderer */
+typedef struct private_s {
   GThreadPool* pool; /**< Pool of threads */
   mutex mutex; /**< Render lock */
-  bool about_to_close; /**< Render thread is to be freed */
-};
+  volatile bool about_to_close; /**< Render thread is to be freed */
+
+  /* recolor information */
+  struct {
+    bool enabled;
+    bool hue;
+
+    double light[3];
+    double dark[3];
+  } recolor;
+} private_t;
+
+/* private data for ZathuraRenderRequest */
+typedef struct request_private_s {
+  ZathuraRenderer* renderer;
+  zathura_page_t* page;
+  bool requested;
+  bool aborted;
+} request_private_t;
+
+#define GET_PRIVATE(obj) \
+  (G_TYPE_INSTANCE_GET_PRIVATE((obj), ZATHURA_TYPE_RENDERER, private_t))
+#define REQUEST_GET_PRIVATE(obj) \
+  (G_TYPE_INSTANCE_GET_PRIVATE((obj), ZATHURA_TYPE_RENDER_REQUEST, \
+                               request_private_t))
+
+/* init, new and free for ZathuraRenderer */
 
 static void
-render_job(void* data, void* user_data)
+zathura_renderer_class_init(ZathuraRendererClass* class)
 {
-  zathura_page_t* page = data;
-  zathura_t* zathura = user_data;
-  if (page == NULL || zathura == NULL) {
-    return;
+  /* add private members */
+  g_type_class_add_private(class, sizeof(private_t));
+
+  /* overwrite methods */
+  GObjectClass* object_class = G_OBJECT_CLASS(class);
+  object_class->finalize     = zathura_renderer_finalize;
+//  object_class->set_property = zathura_page_widget_set_property;
+//  object_class->get_property = zathura_page_widget_get_property;
+}
+
+static void
+zathura_renderer_init(ZathuraRenderer* renderer)
+{
+  private_t* priv = GET_PRIVATE(renderer);
+  priv->pool = g_thread_pool_new(render_job, renderer, 1, TRUE, NULL);
+  priv->about_to_close = false;
+  g_thread_pool_set_sort_function(priv->pool, render_thread_sort, NULL);
+  mutex_init(&priv->mutex);
+
+  priv->recolor.enabled = false;
+  priv->recolor.hue = true;
+  priv->recolor.light[0] = priv->recolor.light[1] = priv->recolor.light[2] = 1;
+  priv->recolor.dark[0] = priv->recolor.dark[1] = priv->recolor.dark[2] = 1;
+}
+
+ZathuraRenderer*
+zathura_renderer_new(zathura_t* zathura)
+{
+  g_return_val_if_fail(zathura != NULL, NULL);
+
+  return g_object_new(ZATHURA_TYPE_RENDERER, /*"page", page, "zathura", zathura, */ NULL);
+}
+
+static void
+zathura_renderer_finalize(GObject* object)
+{
+  ZathuraRenderer* renderer = ZATHURA_RENDERER(object);
+  private_t* priv = GET_PRIVATE(renderer);
+
+  zathura_renderer_stop(renderer);
+  if (priv->pool) {
+    g_thread_pool_free(priv->pool, TRUE, TRUE);
   }
+  mutex_free(&(priv->mutex));
+}
+
+/* init, new and free for ZathuraRenderRequest */
 
-  girara_debug("rendering page %d ...", zathura_page_get_index(page) + 1);
-  if (render(zathura, page) != true) {
-    girara_error("Rendering failed (page %d)\n", zathura_page_get_index(page) + 1);
+enum {
+  REQUEST_COMPLETED,
+  REQUEST_LAST_SIGNAL
+};
+
+static guint request_signals[REQUEST_LAST_SIGNAL] = { 0 };
+
+static void
+zathura_render_request_class_init(ZathuraRenderRequestClass* class)
+{
+  /* add private members */
+  g_type_class_add_private(class, sizeof(request_private_t));
+
+  /* overwrite methods */
+  GObjectClass* object_class = G_OBJECT_CLASS(class);
+  object_class->finalize     = zathura_render_request_finalize;
+//  object_class->set_property = zathura_page_widget_set_property;
+//  object_class->get_property = zathura_page_widget_get_property;
+
+  request_signals[REQUEST_COMPLETED] = g_signal_new("completed",
+      ZATHURA_TYPE_RENDER_REQUEST,
+      G_SIGNAL_RUN_LAST,
+      0,
+      NULL,
+      NULL,
+      g_cclosure_marshal_generic,
+      G_TYPE_NONE,
+      1,
+      G_TYPE_POINTER);
+}
+
+static void
+zathura_render_request_init(ZathuraRenderRequest* request)
+{
+  request_private_t* priv = REQUEST_GET_PRIVATE(request);
+  priv->renderer = NULL;
+  priv->page = NULL;
+}
+
+ZathuraRenderRequest*
+zathura_render_request_new(ZathuraRenderer* renderer, zathura_page_t* page)
+{
+  g_return_val_if_fail(renderer != NULL && page != NULL, NULL);
+
+  GObject* obj = g_object_new(ZATHURA_TYPE_RENDER_REQUEST, NULL);
+  if (obj == NULL) {
+    return NULL;
   }
+
+  ZathuraRenderRequest* request = ZATHURA_RENDER_REQUEST(obj);
+  request_private_t* priv = REQUEST_GET_PRIVATE(request);
+  /* we want to make sure that renderer lives long enough */
+  priv->renderer = g_object_ref(renderer);
+  priv->page = page;
+  priv->aborted = false;
+  priv->requested = false;
+
+  return request;
 }
 
-render_thread_t*
-render_init(zathura_t* zathura)
+static void
+zathura_render_request_finalize(GObject* object)
 {
-  render_thread_t* render_thread = g_malloc0(sizeof(render_thread_t));
+  ZathuraRenderRequest* request = ZATHURA_RENDER_REQUEST(object);
+  request_private_t* priv = REQUEST_GET_PRIVATE(request);
 
-  /* setup */
-  render_thread->pool = g_thread_pool_new(render_job, zathura, 1, TRUE, NULL);
-  if (render_thread->pool == NULL) {
-    goto error_free;
+  if (priv->renderer) {
+    g_object_unref(priv->renderer);
   }
+}
 
-  render_thread->about_to_close = false;
-  g_thread_pool_set_sort_function(render_thread->pool, render_thread_sort, zathura);
-  mutex_init(&render_thread->mutex);
+/* renderer methods */
 
-  return render_thread;
+bool
+zathura_renderer_recolor_enabled(ZathuraRenderer* renderer)
+{
+  g_return_val_if_fail(ZATHURA_IS_RENDERER(renderer), false);
 
-error_free:
+  return GET_PRIVATE(renderer)->recolor.enabled;
+}
 
-  render_free(render_thread);
-  return NULL;
+void
+zathura_renderer_enable_recolor(ZathuraRenderer* renderer, bool enable)
+{
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+
+  GET_PRIVATE(renderer)->recolor.enabled = enable;
+}
+
+bool
+zathura_renderer_recolor_hue_enabled(ZathuraRenderer* renderer)
+{
+  g_return_val_if_fail(ZATHURA_IS_RENDERER(renderer), false);
+
+  return GET_PRIVATE(renderer)->recolor.hue;
 }
 
 void
-render_free(render_thread_t* render_thread)
+zathura_renderer_enable_recolor_hue(ZathuraRenderer* renderer, bool enable)
 {
-  if (render_thread == NULL) {
-    return;
-  }
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+
+  GET_PRIVATE(renderer)->recolor.hue = enable;
+}
+
+void zathura_renderer_set_recolor_colors(ZathuraRenderer* renderer,
+    GdkColor* light, GdkColor* dark)
+{
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+  g_return_if_fail(light != NULL && dark != NULL);
+
+  private_t* priv = GET_PRIVATE(renderer);
+  color2double(light, priv->recolor.light);
+  color2double(dark, priv->recolor.dark);
+}
+
+void
+zathura_renderer_lock(ZathuraRenderer* renderer)
+{
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+
+  private_t* priv = GET_PRIVATE(renderer);
+  mutex_lock(&priv->mutex);
+}
+
+void
+zathura_renderer_unlock(ZathuraRenderer* renderer)
+{
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+
+  private_t* priv = GET_PRIVATE(renderer);
+  mutex_unlock(&priv->mutex);
+}
+
+void
+zathura_renderer_stop(ZathuraRenderer* renderer)
+{
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+  GET_PRIVATE(renderer)->about_to_close = true;
+}
+
+
+/* ZathuraRenderRequest methods */
 
-  render_thread->about_to_close = true;
-  if (render_thread->pool) {
-    g_thread_pool_free(render_thread->pool, TRUE, TRUE);
+void
+zathura_render_request(ZathuraRenderRequest* request)
+{
+  g_return_if_fail(ZATHURA_IS_RENDER_REQUEST(request));
+
+  request_private_t* request_priv = REQUEST_GET_PRIVATE(request);
+  private_t* priv = GET_PRIVATE(request_priv->renderer);
+  if (request_priv->requested == false) {
+    request_priv->requested = true;
+    request_priv->aborted = false;
+
+    g_thread_pool_push(priv->pool, request, NULL);
   }
+}
+
+void
+zathura_render_request_abort(ZathuraRenderRequest* request)
+{
+  g_return_if_fail(ZATHURA_IS_RENDER_REQUEST(request));
 
-  mutex_free(&(render_thread->mutex));
-  g_free(render_thread);
+  request_private_t* request_priv = REQUEST_GET_PRIVATE(request);
+  if (request_priv->requested == true) {
+    request_priv->aborted = true;
+  }
 }
 
-bool
-render_page(render_thread_t* render_thread, zathura_page_t* page)
+
+static void
+render_job(void* data, void* user_data)
 {
-  if (render_thread == NULL || page == NULL || render_thread->pool == NULL || render_thread->about_to_close == true) {
-    return false;
+  ZathuraRenderRequest* request = data;
+  ZathuraRenderer* renderer = user_data;
+  g_return_if_fail(ZATHURA_IS_RENDER_REQUEST(request));
+  g_return_if_fail(ZATHURA_IS_RENDERER(renderer));
+
+  private_t* priv = GET_PRIVATE(renderer);
+  request_private_t* request_priv = REQUEST_GET_PRIVATE(request);
+  if (priv->about_to_close == true || request_priv->aborted == true) {
+    /* back out early */
+    request_priv->requested = false;
+    return;
   }
 
-  g_thread_pool_push(render_thread->pool, page, NULL);
-  return true;
+  girara_debug("Rendering page %d ...", zathura_page_get_index(request_priv->page) + 1);
+  if (render(request, renderer) != true) {
+    girara_error("Rendering failed (page %d)\n", zathura_page_get_index(request_priv->page) + 1);
+  }
+  request_priv->requested = false;
 }
 
+
 static void
 color2double(GdkColor* col, double* v)
 {
@@ -101,7 +318,7 @@ color2double(GdkColor* col, double* v)
    Assumes that l is in the interval l1, l2 and corrects the value to
    force u=0 on l1 and l2 */
 static double
-colorumax(double* h, double l, double l1, double l2)
+colorumax(const double* h, double l, double l1, double l2)
 {
   double u, uu, v, vv, lv;
   if (h[0] == 0 && h[1] == 0 && h[2] == 0) {
@@ -143,11 +360,11 @@ colorumax(double* h, double l, double l1, double l2)
 
 
 static bool
-render(zathura_t* zathura, zathura_page_t* page)
+render(ZathuraRenderRequest* request, ZathuraRenderer* renderer)
 {
-  if (zathura == NULL || page == NULL || zathura->sync.render_thread->about_to_close == true) {
-    return false;
-  }
+  private_t* priv = GET_PRIVATE(renderer);
+  request_private_t* request_priv = REQUEST_GET_PRIVATE(request);
+  zathura_page_t* page = request_priv->page;
 
   /* create cairo surface */
   unsigned int page_width  = 0;
@@ -155,13 +372,11 @@ render(zathura_t* zathura, zathura_page_t* page)
   const double real_scale = page_calc_height_width(page, &page_height, &page_width, false);
 
   cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, page_width, page_height);
-
   if (surface == NULL) {
     return false;
   }
 
   cairo_t* cairo = cairo_create(surface);
-
   if (cairo == NULL) {
     cairo_surface_destroy(surface);
     return false;
@@ -178,20 +393,24 @@ render(zathura_t* zathura, zathura_page_t* page)
     cairo_scale(cairo, real_scale, real_scale);
   }
 
-  render_lock(zathura->sync.render_thread);
+  zathura_renderer_lock(renderer);
   if (zathura_page_render(page, cairo, false) != ZATHURA_ERROR_OK) {
-    render_unlock(zathura->sync.render_thread);
+    zathura_renderer_unlock(renderer);
     cairo_destroy(cairo);
     cairo_surface_destroy(surface);
     return false;
   }
 
-  render_unlock(zathura->sync.render_thread);
+  zathura_renderer_unlock(renderer);
   cairo_restore(cairo);
   cairo_destroy(cairo);
 
-  const int rowstride  = cairo_image_surface_get_stride(surface);
-  unsigned char* image = cairo_image_surface_get_data(surface);
+  /* before recoloring, check if we've been aborted */
+  if (priv->about_to_close == true || request_priv->aborted == true) {
+    cairo_surface_destroy(surface);
+    return true;
+  }
+
 
   /* recolor */
   /* uses a representation of a rgb color as follows:
@@ -199,72 +418,84 @@ render(zathura_t* zathura, zathura_page_t* page)
      - a hue vector, which indicates a radian direction from the grey axis, inside the equal lightness plane.
      - a saturation scalar between 0,1. It is 0 when grey, 1 when the color is in the boundary of the rgb cube.
   */
-  if (zathura->global.recolor == true) {
-    /* RGB weights for computing lightness. Must sum to one */
-    double a[] = {0.30, 0.59, 0.11};
-
-    double l1, l2, l, s, u, t;
-    double h[3];
-    double rgb1[3], rgb2[3], rgb[3];
+  if (priv->recolor.enabled == true) {
+    const int rowstride  = cairo_image_surface_get_stride(surface);
+    unsigned char* image = cairo_image_surface_get_data(surface);
 
-    color2double(&zathura->ui.colors.recolor_dark_color, rgb1);
-    color2double(&zathura->ui.colors.recolor_light_color, rgb2);
+    /* RGB weights for computing lightness. Must sum to one */
+    static const double a[] = {0.30, 0.59, 0.11};
 
-    l1 = (a[0]*rgb1[0] + a[1]*rgb1[1] + a[2]*rgb1[2]);
-    l2 = (a[0]*rgb2[0] + a[1]*rgb2[1] + a[2]*rgb2[2]);
+#define rgb1 priv->recolor.dark
+#define rgb2 priv->recolor.light
+    const double l1 = (a[0]*rgb1[0] + a[1]*rgb1[1] + a[2]*rgb1[2]);
+    const double l2 = (a[0]*rgb2[0] + a[1]*rgb2[1] + a[2]*rgb2[2]);
 
     for (unsigned int y = 0; y < page_height; y++) {
       unsigned char* data = image + y * rowstride;
 
-      for (unsigned int x = 0; x < page_width; x++) {
+      for (unsigned int x = 0; x < page_width; x++, data += 4) {
         /* Careful. data color components blue, green, red. */
-        rgb[0] = (double) data[2] / 256.;
-        rgb[1] = (double) data[1] / 256.;
-        rgb[2] = (double) data[0] / 256.;
+        const double rgb[3] = {
+          (double) data[2] / 256.,
+          (double) data[1] / 256.,
+          (double) data[0] / 256.
+        };
 
         /* compute h, s, l data   */
-        l = a[0]*rgb[0] + a[1]*rgb[1] + a[2]*rgb[2];
-
-        h[0] = rgb[0] - l;
-        h[1] = rgb[1] - l;
-        h[2] = rgb[2] - l;
-
-        /* u is the maximum possible saturation for given h and l. s is a rescaled saturation between 0 and 1 */
-        u = colorumax(h, l, 0, 1);
+        double l = a[0]*rgb[0] + a[1]*rgb[1] + a[2]*rgb[2];
+
+        const double h[3] = {
+          rgb[0] - l,
+          rgb[1] - l,
+          rgb[2] - l
+        };
+
+        /* u is the maximum possible saturation for given h and l. s is a
+         * rescaled saturation between 0 and 1 */
+        double u = colorumax(h, l, 0, 1);
+        double s;
         if (u == 0) {
           s = 0;
         } else {
           s = 1/u;
         }
 
-        /* Interpolates lightness between light and dark colors. white goes to light, and black goes to dark. */
-        t = l;
+        /* Interpolates lightness between light and dark colors. white goes to
+         * light, and black goes to dark. */
+        const double t = l;
         l = t * (l2 - l1) + l1;
 
-        if (zathura->global.recolor_keep_hue == true) {
-          /* adjusting lightness keeping hue of current color. white and black go to grays of same ligtness
-             as light and dark colors. */
+        if (priv->recolor.hue == true) {
+          /* adjusting lightness keeping hue of current color. white and black
+           * go to grays of same ligtness as light and dark colors. */
           u = colorumax(h, l, l1, l2);
           data[2] = (unsigned char)round(255.*(l + s*u * h[0]));
           data[1] = (unsigned char)round(255.*(l + s*u * h[1]));
           data[0] = (unsigned char)round(255.*(l + s*u * h[2]));
         } else {
-          /* Linear interpolation between dark and light with color ligtness as a parameter */
+          /* linear interpolation between dark and light with color ligtness as
+           * a parameter */
           data[2] = (unsigned char)round(255.*(t * (rgb2[0] - rgb1[0]) + rgb1[0]));
           data[1] = (unsigned char)round(255.*(t * (rgb2[1] - rgb1[1]) + rgb1[1]));
           data[0] = (unsigned char)round(255.*(t * (rgb2[2] - rgb1[2]) + rgb1[2]));
         }
-
-        data += 4;
       }
     }
+
+#undef rgb1
+#undef rgb2
   }
 
-  if (zathura->sync.render_thread->about_to_close == false) {