reduce allocations in vidmode

Signed-off-by: Mattias Andrée <maandree@operamail.com>

3 files changed, 56 insertions, 88 deletions

diff --git a/src/blueshift_vidmode.pyx b/src/blueshift_vidmode.pyx
index d3ab99f..7f1810d 100644
--- a/src/blueshift_vidmode.pyx
+++ b/src/blueshift_vidmode.pyx
@@ -20,22 +20,42 @@ from libc.stdlib cimport malloc, free
 
 
 cdef extern int blueshift_vidmode_open(int use_screen)
-cdef extern unsigned short int* blueshift_vidmode_read(int use_crtc)
+cdef extern int blueshift_vidmode_read(int use_crtc,
+                                       unsigned short int* r_curve,
+                                       unsigned short int* g_curve,
+                                       unsigned short int* b_curve)
 cdef extern int blueshift_vidmode_apply(unsigned long long int use_crtcs,
-                                      unsigned short int* r_curve,
-                                      unsigned short int* g_curve,
-                                      unsigned short int* b_curve)
+                                        unsigned short int* r_curve,
+                                        unsigned short int* g_curve,
+                                        unsigned short int* b_curve)
 cdef extern void blueshift_vidmode_close()
 
 
+
+cdef int vidmode_gamma_size
+vidmode_gamma_size = 0
+
+cdef unsigned short int* r_c
+cdef unsigned short int* g_c
+cdef unsigned short int* b_c
+r_c = <unsigned short int*>malloc(256 * 2)
+g_c = <unsigned short int*>malloc(256 * 2)
+b_c = <unsigned short int*>malloc(256 * 2)
+if (r_c is NULL) or (g_c is NULL) or (b_c is NULL):
+    raise MemoryError()
+
+
+
 def vidmode_open(int use_screen):
     '''
     Start stage of colour curve control
     
     @param   use_screen  The screen to use
-    @return              Zero on success
+    @return  :bool       Whether call was successful
     '''
-    return blueshift_vidmode_open(use_screen)
+    global vidmode_gamma_size
+    vidmode_gamma_size = blueshift_vidmode_open(use_screen)
+    return vidmode_gamma_size > 1
 
 
 def vidmode_read(int use_crtc):
@@ -45,19 +65,14 @@ def vidmode_read(int use_crtc):
     @param   use_crtc                                  The CRTC to use
     @return  :(r:list<int>, g:list<int>, b:list<int>)  The current red, green and blue colour curves
     '''
-    cdef unsigned short int* got
-    got = blueshift_vidmode_read(use_crtc)
-    if got is NULL:
+    if not blueshift_vidmode_read(use_crtc, r_c, g_c, b_c) == 0:
         raise Exception()
-    r, g, b, i = [], [], [], 0
-    for c in (r, g, b):
-        s = got[i]
-        i += 1
-        for j in range(s):
-            c.append(got[i + j])
-        i += s
+    r, g, b = [], [], []
+    for i in range(vidmode_gamma_size):
+        r.append(r_c[i])
+        g.append(g_c[i])
+        b.append(b_c[i])
     return (r, g, b)
-    
 
 
 def vidmode_apply(unsigned long long use_crtcs, r_curve, g_curve, b_curve):
@@ -70,28 +85,19 @@ def vidmode_apply(unsigned long long use_crtcs, r_curve, g_curve, b_curve):
     @param   b_curve:list<unsigned short int>  The blue colour curve
     @return                                    Zero on success
     '''
-    cdef unsigned short int* r
-    cdef unsigned short int* g
-    cdef unsigned short int* b
-    r = <unsigned short int*>malloc(256 * 2)
-    g = <unsigned short int*>malloc(256 * 2)
-    b = <unsigned short int*>malloc(256 * 2)
-    if (r is NULL) or (g is NULL) or (b is NULL):
-        raise MemoryError()
     for i in range(256):
-        r[i] = r_curve[i] & 0xFFFF
-        g[i] = g_curve[i] & 0xFFFF
-        b[i] = b_curve[i] & 0xFFFF
-    rc = blueshift_vidmode_apply(use_crtcs, r, g, b)
-    free(r)
-    free(g)
-    free(b)
-    return rc
+        r_c[i] = r_curve[i] & 0xFFFF
+        g_c[i] = g_curve[i] & 0xFFFF
+        b_c[i] = b_curve[i] & 0xFFFF
+    return blueshift_vidmode_apply(use_crtcs, r_c, g_c, b_c)
 
 
 def vidmode_close():
     '''
     Resource freeing stage of colour curve control
     '''
+    free(r_c)
+    free(g_c)
+    free(b_c)
     blueshift_vidmode_close()
 
diff --git a/src/blueshift_vidmode_c.c b/src/blueshift_vidmode_c.c
index fdc73ae..72c8053 100644
--- a/src/blueshift_vidmode_c.c
+++ b/src/blueshift_vidmode_c.c
@@ -44,14 +44,11 @@ static int curve_size;
  * Start stage of colour curve control
  * 
  * @param   use_screen  The screen to use
- * @return              Zero on success
+ * @return              Zero on error, otherwise the size of colours curves
  */
 int blueshift_vidmode_open(int use_screen)
 {
   int _major, _minor;
-  uint16_t* r_gamma;
-  uint16_t* g_gamma;
-  uint16_t* b_gamma;
   
   
   /* Get X display */
@@ -59,7 +56,7 @@ int blueshift_vidmode_open(int use_screen)
   if ((display = XOpenDisplay(NULL)) == NULL)
     {
       fprintf(stderr, "Cannot open X display\n");
-      return 1;
+      return 0;
     }
   
   
@@ -69,7 +66,7 @@ int blueshift_vidmode_open(int use_screen)
     {
       fprintf(stderr, "VidMode version query failed\n");
       XCloseDisplay(display);
-      return 1;
+      return 0;
     }
   
   
@@ -80,37 +77,17 @@ int blueshift_vidmode_open(int use_screen)
     {
       fprintf(stderr, "VidMode gamma size query failed\n");
       XCloseDisplay(display);
-      return 1;
+      return 0;
     }
   
-  if (curve_size < 1)
+  if (curve_size <= 1)
     {
-      fprintf(stderr, "VidMode gamma size query failed\n");
+      fprintf(stderr, "VidMode gamma size query failed, impossible dimension\n");
       XCloseDisplay(display);
-      return 1;
+      return 0;
     }
   
-  
-  /* Acquire curve control */
-  
-  r_gamma = malloc(3 * curve_size * sizeof(uint16_t));
-  if (r_gamma == NULL)
-    {
-      fprintf(stderr, "Out of memory\n");
-      return 1;
-    }
-  g_gamma = r_gamma + curve_size;
-  b_gamma = g_gamma + curve_size;
-  if (XF86VidModeGetGammaRamp(display, screen, curve_size, r_gamma, g_gamma, b_gamma) == 0)
-    {
-      fprintf(stderr, "VidMode gamma query failed\n");
-      free(r_gamma);
-      XCloseDisplay(display);
-      return 1;
-    }
-  free(r_gamma);
-  
-  return 0;
+  return curve_size;
 }
 
 
@@ -118,40 +95,25 @@ int blueshift_vidmode_open(int use_screen)
  * Gets the current colour curves
  * 
  * @param   use_crtc  The CRTC to use
- * @return            {the size of the red curve, *the red curve,
- *                    the size of the green curve, *the green curve,
- *                    the size of the blue curve, *the blue curve},
- *                    needs to be free:d. `NULL` on error.
+ * @param   r_gamma   Storage location for the red colour curve
+ * @param   g_gamma   Storage location for the green colour curve
+ * @param   b_gamma   Storage location for the blue colour curve
+ * @return            Zero on success
  */
-uint16_t* blueshift_vidmode_read(int use_crtc)
+int blueshift_vidmode_read(int use_crtc, uint16_t* r_gamma, uint16_t* g_gamma, uint16_t* b_gamma)
 {
   (void) use_crtc;
   
   /* Read curves */
   
-  uint16_t* r_gamma = malloc((3 + 3 * curve_size) * sizeof(uint16_t));
-  uint16_t* g_gamma = r_gamma + curve_size + 1;
-  uint16_t* b_gamma = g_gamma + curve_size + 1;
-  if (r_gamma == NULL)
-    {
-      fprintf(stderr, "Out of memory\n");
-      XCloseDisplay(display);
-      return NULL;
-    }
-  
-  *r_gamma++ = curve_size;
-  *g_gamma++ = curve_size;
-  *b_gamma++ = curve_size;
-  
   if (XF86VidModeGetGammaRamp(display, screen, curve_size, r_gamma, g_gamma, b_gamma) == 0)
     {
       fprintf(stderr, "VidMode gamma query failed\n");
-      free(r_gamma);
       XCloseDisplay(display);
-      return NULL;
+      return 1;
     }
   
-  return r_gamma - 1;
+  return 0;
 }
 
 
diff --git a/src/monitor.py b/src/monitor.py
index f375156..90ae603 100644
--- a/src/monitor.py
+++ b/src/monitor.py
@@ -122,7 +122,7 @@ def vidmode_get(crtc = 0, screen = 0):
     if (vidmode_opened is None) or not (vidmode_opened == screen):
         if vidmode_opened is not None:
             vidmode_close()
-        if vidmode_open(screen) == 0:
+        if vidmode_open(screen):
             vidmode_opened = screen
         else:
             sys.exit(1)
@@ -186,7 +186,7 @@ def vidmode(*crtcs, screen = 0):
     if (vidmode_opened is None) or not (vidmode_opened == screen):
         if vidmode_opened is not None:
             vidmode_close()
-        if vidmode_open(screen) == 0:
+        if vidmode_open(screen):
             vidmode_opened = screen
         else:
             sys.exit(1)