m + do state merge in servers/crtc.c

Signed-off-by: Mattias Andrée <maandree@kth.se>

3 files changed, 96 insertions, 52 deletions

diff --git a/src/coopgammad.c b/src/coopgammad.c
index cd30dbd..f46957e 100644
--- a/src/coopgammad.c
+++ b/src/coopgammad.c
@@ -530,77 +530,42 @@ static size_t unmarshal(const void* restrict buf)
 GCC_ONLY(__attribute__((nonnull)))
 static int unmarshal_and_merge_state(const char* restrict statefile)
 {
-  struct output* restrict new_outputs = outputs;
   struct output* restrict old_outputs = NULL;
-  size_t new_outputs_n = outputs_n;
-  size_t old_outputs_n = 0;
-  size_t i, j, k;
+  size_t i, n, r, old_outputs_n = 0;
   void* marshalled = NULL;
   int fd = -1, saved_errno;
   
-  outputs = NULL;
-  outputs_n = 0;
-  
   fd = open(statefile, O_RDONLY);
   if (fd < 0)
     goto fail;
-  if (!(marshalled = nread(fd, &k)))
+  if (!(marshalled = nread(fd, &n)))
     goto fail;
   close(fd), fd = -1;
   unlink(statefile), statefile = NULL;
   
-  if (unmarshal(marshalled) == 0)
-    goto fail;
-  free(marshalled), marshalled = NULL;
-  
-  old_outputs   = outputs,   outputs   = new_outputs,   new_outputs   = NULL;
-  old_outputs_n = outputs_n, outputs_n = new_outputs_n, new_outputs_n = 0;
-  
-  i = j = new_outputs_n = 0;
-  while ((i < old_outputs_n) && (j < outputs_n))
-    {
-      int cmp = strcmp(old_outputs[i].name, outputs[j].name);
-      if (cmp <= 0)
-	new_outputs_n++;
-      i += cmp >= 0;
-      j += cmp <= 0;
-    }
-  new_outputs_n += outputs_n - j;
+  old_outputs   = outputs;
+  old_outputs_n = outputs_n;
+  outputs   = NULL;
+  outputs_n = 0;
   
-  new_outputs = calloc(new_outputs_n, sizeof(*new_outputs));
-  if (new_outputs == NULL)
+  r = unmarshal(marshalled);
+  if (r == 0)
     goto fail;
-  
-  i = j = k = new_outputs_n = 0;
-  while ((i < old_outputs_n) && (j < outputs_n))
+  if (r != n)
     {
-      int cmp = strcmp(old_outputs[i].name, outputs[j].name);
-      int is_same = 0;
-      if (cmp == 0)
-	is_same = (old_outputs[i].depth      == outputs[j].depth      &&
-		   old_outputs[i].red_size   == outputs[j].red_size   &&
-		   old_outputs[i].green_size == outputs[j].green_size &&
-		   old_outputs[i].blue_size  == outputs[j].blue_size);
-      if (is_same)
-	{
-	  new_outputs[k] = old_outputs[i];
-	  new_outputs[k].crtc = outputs[j].crtc;
-	  output_destroy(outputs + j);
-	  k++;
-	}
-      else if (cmp <= 0)
-	new_outputs[k++] = outputs[j];
-      i += cmp >= 0;
-      j += cmp <= 0;
+      fprintf(stderr, "%s: unmarshalled state file was %s than the unmarshalled state\n",
+	      argv0, n > r ? "larger" : "smaller");
+      errno = 0;
+      goto fail;
     }
-  while (j < outputs_n)
-    new_outputs[k++] = outputs[j++];
+  free(marshalled), marshalled = NULL;
   
-  outputs = new_outputs;
-  outputs_n = new_outputs_n;
+  if (merge_state(old_outputs, old_outputs_n) < 0)
+    goto fail;
   
   for (i = 0; i < old_outputs_n; i++)
     output_destroy(old_outputs + i);
+  free(old_outputs);
   
   return 0;
  fail:
diff --git a/src/servers/crtc.c b/src/servers/crtc.c
index 2e884a8..5b3af43 100644
--- a/src/servers/crtc.c
+++ b/src/servers/crtc.c
@@ -127,3 +127,71 @@ int initialise_crtcs(void)
   return -1;
 }
 
+
+/**
+ * Merge the new state with an old state
+ * 
+ * @param   old_outputs    The old `outputs`
+ * @param   old_outputs_n  The old `outputs_n`
+ * @return                 Zero on success, -1 on error
+ */
+int merge_state(struct output* restrict old_outputs, size_t old_outputs_n)
+{
+  struct output* restrict new_outputs = NULL;
+  size_t new_outputs_n;
+  size_t i, j, k;
+  
+  /* How many outputs does the system now have? */
+  i = j = new_outputs_n = 0;
+  while ((i < old_outputs_n) && (j < outputs_n))
+    {
+      int cmp = strcmp(old_outputs[i].name, outputs[j].name);
+      if (cmp <= 0)
+	new_outputs_n++;
+      i += cmp >= 0;
+      j += cmp <= 0;
+    }
+  new_outputs_n += outputs_n - j;
+  
+  /* Allocate output state array */
+  if (new_outputs_n > 0)
+    {
+      new_outputs = calloc(new_outputs_n, sizeof(*new_outputs));
+      if (new_outputs == NULL)
+	return -1;
+    }
+  
+  /* Merge output states */
+  i = j = k = new_outputs_n = 0;
+  while ((i < old_outputs_n) && (j < outputs_n))
+    {
+      int is_same = 0, cmp = strcmp(old_outputs[i].name, outputs[j].name);
+      if (cmp == 0)
+	is_same = (old_outputs[i].depth      == outputs[j].depth      &&
+		   old_outputs[i].red_size   == outputs[j].red_size   &&
+		   old_outputs[i].green_size == outputs[j].green_size &&
+		   old_outputs[i].blue_size  == outputs[j].blue_size);
+      if (is_same)
+	{
+	  new_outputs[k] = old_outputs[i];
+	  new_outputs[k].crtc = outputs[j].crtc;
+	  memset(old_outputs + i, 0, sizeof(*old_outputs));
+	  outputs[j].crtc = NULL;
+	  output_destroy(outputs + j);
+	  k++;
+	}
+      else if (cmp <= 0)
+	new_outputs[k++] = outputs[j];
+      i += cmp >= 0;
+      j += cmp <= 0;
+    }
+  while (j < outputs_n)
+    new_outputs[k++] = outputs[j++];
+  
+  /* Commit merge */
+  outputs   = new_outputs;
+  outputs_n = new_outputs_n;
+  
+  return 0;
+}
+
diff --git a/src/servers/crtc.h b/src/servers/crtc.h
index 4c96045..1670ee2 100644
--- a/src/servers/crtc.h
+++ b/src/servers/crtc.h
@@ -19,6 +19,8 @@
 #define SERVERS_CRTC_H
 
 
+#include "../types/output.h"
+
 #include <libgamma.h>
 
 
@@ -62,6 +64,15 @@ char* get_crtc_name(const libgamma_crtc_information_t* restrict info,
  */
 int initialise_crtcs(void);
 
+/**
+ * Merge the new state with an old state
+ * 
+ * @param   old_outputs    The old `outputs`
+ * @param   old_outputs_n  The old `outputs_n`
+ * @return                 Zero on success, -1 on error
+ */
+int merge_state(struct output* restrict old_outputs, size_t old_outputs_n);
+
 
 #endif