Implement primary selections, and minor improvements elsewhere

* 12to11.c (XLMain): Initialize primary selections.  Transfer
between X and Wayland programs is still incomplete.
* Imakefile (SRCS, OBJS): Add primary selection related objects
and sources.
(primary-selection-unstable-v1.h):
(primary-selection-unstable-v1.c): New targets.
* README: Update what is not supported.
* compositor.h: New prototypes.

* data_device.c (XLDataDeviceSendEnter): Handle resource
allocation failures.
* mime1.awk: Update generated code for changes in target entry
structures.
* seat.c (SetFocusSurface): Handle focus change for primary
selections as well.
(FindSurfaceUnder): Cut off fractional portion instead of
rounding the given coordinates, so the correct surface is found
when the cursor is moved just inside the rightmost pixel.
* surface.c (XLSurfaceRunFrameCallbacks): Handle timestamp
overflow.
* xdata.c (struct _TargetMapping): Rename atom to atom_flag, and
use it to store flags.
(MappingAtom, MappingFlag, MappingIsNextDuplicate, MappingSetFlag)
(MappingUnsetFlag, MappingIs): New macros.
(struct _TargetMappingTable): New structure.
(Duplicate): New definition.
(direct_transfer): Update duplicate types.
(mapping_table): New hash table.
(HashMimeString, SetupMappingTable): New functions.
(FindTranslationForMimeType, Receive): Use the target mapping
table to look up targets instead.
(CheckDuplicate): New function.
(SendOffers): Call CheckDuplicates.
(XLInitXData): Set up duplicate relationship between UTF8_STRING
and is conversion entry, and the targets mapping table.

12to11.c

@@ -155,6 +155,7 @@ XLMain (int argc, char **argv)
   XLInitXData ();
   XLInitXSettings ();
   XLInitIconSurfaces ();
+  XLInitPrimarySelection ();
   /* This has to come after the rest of the initialization.  */
   DetermineServerTime ();
   XLRunCompositor ();

Imakefile

@@ -21,14 +21,16 @@ SRCS = 12to11.c run.c alloc.c fns.c output.c compositor.c       \
   positioner.c xdg_wm.c xdg_surface.c xdg_toplevel.c            \
   frame_clock.c xerror.c ewmh.c timer.c subsurface.c seat.c     \
   data_device.c xdg_popup.c linux-dmabuf-unstable-v1.c dmabuf.c \
-  buffer.c select.c xdata.c xsettings.c dnd.c icon_surface.c
+  buffer.c select.c xdata.c xsettings.c dnd.c icon_surface.c    \
+  primary-selection-unstable-v1.c primary_selection.c
 
 OBJS = 12to11.o run.o alloc.o fns.o output.o compositor.o       \
   xdg-shell.o surface.o region.o shm.o atoms.o subcompositor.o  \
   positioner.o xdg_wm.o xdg_surface.o xdg_toplevel.o            \
   frame_clock.o xerror.o ewmh.o timer.o subsurface.o seat.o     \
   data_device.o xdg_popup.o linux-dmabuf-unstable-v1.o dmabuf.o \
-  buffer.o select.o xdata.o xsettings.o dnd.o icon_surface.o
+  buffer.o select.o xdata.o xsettings.o dnd.o icon_surface.o    \
+  primary-selection-unstable-v1.o primary_selection.o
 
 OPTIMIZE = -O0
 ANALYZE  = -fanalyzer
@@ -53,7 +55,7 @@ CDEBUGFLAGS := -fno-common -Wall -Warith-conversion -Wdate-time \
   $(ANALYZE)
 
 short_types.txt: media_types.txt
-XCOMM	remove all data types starting with application/vnd.
+XCOMM	Remove all data types starting with application/vnd.
 XCOMM	no program really uses them in clipboard data, and they
 XCOMM	waste a lot of space on disk.
 	sed '/application\/vnd/d' media_types.txt > $@
@@ -81,9 +83,17 @@ xdg-shell.h: xdg-shell.xml
 xdg-shell.c: xdg-shell.xml xdg-shell.h
 	$(WAYLAND_SCANNER) private-code $< $@
 
+primary-selection-unstable-v1.h: primary-selection-unstable-v1.xml
+	$(WAYLAND_SCANNER) server-header $< $@
+
+primary-selection-unstable-v1.c: primary-selection-unstable-v1.xml \
+				 primary-selection-unstable-v1.h
+	$(WAYLAND_SCANNER) private-code $< $@
+
 cleandir::
 	$(RM) linux-dmabuf-unstable-v1.c linux-dmabuf-unstable-v1.h   \
-	      xdg-shell.c xdg-shell.h
+	      xdg-shell.c xdg-shell.h primary-selection-unstable-v1.c \
+	      primary-selection-unstable-v1.h
 	$(RM) transfer_atoms.h short_types.txt
 
 /* Undefine _BSD_SOURCE and _SVID_SOURCE, since both are deprecated

README

@@ -42,14 +42,15 @@ complete degree:
   'wl_seat',                                    version:  7
   'wl_data_device_manager',                     version:  3
   'zwp_linux_dmabuf_v1',                        version:  4
+  'zwp_primary_selection_device_manager_v1',    version:  1
 
 With the main caveat being that zwp_linux_dmabuf_v1 has no real
 support for multiple-provider setups (help wanted).
 
-Primary selections and window decorations are also not supported, even
+Window decorations are also not supported, even though they fit in
-though they fit in nicely with X window management.
+nicely with X window management.
 
-It would also be nice to have pinch gesture support in wl_pointer.
+It would also be nice to have pinch gesture support.
 
 This directory is organized as follows:
 

compositor.h

@@ -965,6 +965,11 @@ extern void XLInitIconSurfaces (void);
 extern void XLReleaseIconSurface (IconSurface *);
 extern Bool XLIsWindowIconSurface (Window);
 
+/* Defined in primary_selection.c.  */
+
+extern void XLInitPrimarySelection (void);
+extern void XLPrimarySelectionHandleFocusChange (Seat *);
+
 /* Utility functions that don't belong in a specific file.  */
 
 #define ArrayElements(arr) (sizeof (arr) / sizeof (arr)[0])

data_device.c

@@ -1364,6 +1364,11 @@ XLDataDeviceSendEnter (Seat *seat, Surface *surface, double x, double y,
 	      /* First, create a data offer corresponding to the data
 		 source if it exists.  */
 	      resource = AddDataOffer (client, source);
+
+	      if (!resource)
+		/* Allocation of the resource failed.  */
+		goto next;
+
 	      offer = wl_resource_get_user_data (resource);
 	      offer->dnd_serial = serial;
 	      offer->last_action = -1;
@@ -1397,6 +1402,7 @@ XLDataDeviceSendEnter (Seat *seat, Surface *surface, double x, double y,
 
 	}
 
+    next:
       reference = reference->next;
     }
 }

mime1.awk

@@ -26,7 +26,7 @@ BEGIN {
   match ($0, /  ([a-z]+\/[-+.[:alnum:]]+) /, array)
   name = array[1]
   gsub (/[[:punct:]]/, "_", name) # Convert to a valid atom name
-  printf "	table[%d + start].atom = %s;\\\n", i++, name
+  printf "	table[%d + start].atom_flag = %s;\\\n", i++, name
 }
 
 END {

seat.c

@@ -2625,7 +2625,12 @@ SetFocusSurface (Seat *seat, Surface *focus)
     }
 
   if (!focus)
+    {
+      /* These changes must be handled even if there is no more focus
+	 surface.  */
+      XLPrimarySelectionHandleFocusChange (seat);
       return;
+    }
 
   seat->focus_surface = focus;
   seat->focus_destroy_callback
@@ -2633,6 +2638,8 @@ SetFocusSurface (Seat *seat, Surface *focus)
 
   SendKeyboardEnter (seat, focus);
 
+  XLPrimarySelectionHandleFocusChange (seat);
+
   if (seat->data_device)
     XLDataDeviceHandleFocusChange (seat->data_device);
 }
@@ -2670,8 +2677,10 @@ FindSurfaceUnder (Subcompositor *subcompositor, double x, double y)
   int x_off, y_off;
   View *view;
 
-  view = SubcompositorLookupView (subcompositor, lrint (x),
+  /* Do not round these figures.  Instead, cut off the fractional,
-				  lrint (y), &x_off, &y_off);
+     like the X server does when deciding when to set the cursor.  */
+  view = SubcompositorLookupView (subcompositor, x, y,
+				  &x_off, &y_off);
 
   if (view)
     return ViewGetData (view);

surface.c

@@ -1167,7 +1167,13 @@ XLSurfaceRunFrameCallbacks (Surface *surface, struct timespec time)
   uint32_t ms_time;
   XLList *list;
 
-  ms_time = time.tv_sec * 1000 + time.tv_nsec / 1000000;
+  /* I don't know what else is reasonable in case of overflow.  */
+
+  if (IntMultiplyWrapv (time.tv_sec, 1000, &ms_time))
+    ms_time = UINT32_MAX;
+  else if (IntAddWrapv (ms_time, time.tv_nsec / 1000000,
+			&ms_time))
+    ms_time = UINT32_MAX;
 
   RunFrameCallbacks (&surface->current_state.frame_callbacks,
 		     ms_time);

xdata.c

@@ -42,6 +42,7 @@ typedef struct _ConversionTransferInfo ConversionTransferInfo;
 typedef struct _WriteInfo WriteInfo;
 typedef struct _ConversionWriteInfo ConversionWriteInfo;
 typedef struct _DataConversion DataConversion;
+typedef struct _TargetMappingTable TargetMappingTable;
 
 struct _ReadTargetsData
 {
@@ -54,8 +55,12 @@ struct _ReadTargetsData
 
 struct _TargetMapping
 {
-  /* The atom of the X target.  */
+  /* The atom of the X target.  The top 3 bits of an XID are
-  Atom atom;
+     guaranteed to be 0, so the 31st bit is used to store a flag
+     meaning that the next entry is a duplicate of this one, and the
+     30th bit is used to store a flag containing state used by
+     SendOffers.  */
+  Atom atom_flag;
 
   /* The name of the Wayland MIME type.  */
   const char *mime_type;
@@ -64,6 +69,13 @@ struct _TargetMapping
   void (*translation_func) (Time, Atom, Atom, int);
 };
 
+#define MappingAtom(mapping)		((mapping)->atom_flag & 0x1fffffff)
+#define MappingFlag(mapping)		((mapping)->atom_flag & (1 << 29))
+#define MappingIsNextDuplicate(mapping)	((mapping)->atom_flag & (1 << 30))
+#define MappingSetFlag(mapping)		((mapping)->atom_flag |= (1 << 29))
+#define MappingUnsetFlag(mapping)	((mapping)->atom_flag &= ~(1 << 29))
+#define MappingIs(mapping, atom)	(MappingAtom (mapping) == (atom))
+
 struct _DataConversion
 {
   /* The MIME type of the Wayland offer.  */
@@ -179,20 +191,43 @@ struct _ConversionWriteInfo
   iconv_t cd;
 };
 
+struct _TargetMappingTable
+{
+  /* Array of indices into direct_transfer.  */
+  unsigned short *buckets[32];
+
+  /* Number of elements in each array.  */
+  unsigned short n_elements[32];
+
+  /* Array of indices into direct_transfer.  */
+  unsigned short *atom_buckets[16];
+
+  /* Number of elements in each array.  */
+  unsigned short n_atom_elements[16];
+};
+
 /* Base event code of the Xfixes extension.  */
 static int fixes_event_base;
 
+/* This means the next item in the targets mapping table has the same
+   MIME type as this one.  */
+
+#define Duplicate (1U << 30)
+
 /* Map of targets that can be transferred from X to Wayland clients
    and vice versa.  */
 static TargetMapping direct_transfer[] =
   {
     { XA_STRING,	"text/plain;charset=iso-9889-1"	},
-    { 0,	 "text/plain;charset=utf-8"		},
+    { Duplicate,	"text/plain;charset=utf-8"	},
     { XA_STRING,	"text/plain;charset=utf-8"	},
     /* These mappings are automatically generated.  */
     DirectTransferMappings
   };
 
+/* Lookup table for such mappings.  */
+static TargetMappingTable mapping_table;
+
 /* Map of Wayland offer types to X atoms and data conversion
    functions.  */
 static DataConversion data_conversions[] =
@@ -244,6 +279,53 @@ Accept (struct wl_client *client, struct wl_resource *resource,
   /* Nothing has to be done here yet.  */
 }
 
+static unsigned int
+HashMimeString (const char *string)
+{
+  unsigned int i;
+
+  i = 3323198485ul;
+  for (; *string; ++string)
+    {
+      i ^= *string;
+      i *= 0x5bd1e995;
+      i ^= i >> 15;
+    }
+  return i;
+}
+
+static void
+SetupMappingTable (void)
+{
+  unsigned int idx, i, nelements;
+
+  /* This is needed for the atoms table, since the atom indices are
+     determined by the X server.  */
+  XLAssert (ArrayElements (direct_transfer) <= USHRT_MAX);
+
+  for (i = 0; i < ArrayElements (direct_transfer); ++i)
+    {
+      idx = HashMimeString (direct_transfer[i].mime_type) % 32;
+
+      nelements = ++mapping_table.n_elements[idx];
+      mapping_table.buckets[idx]
+	= XLRealloc (mapping_table.buckets[idx],
+		     nelements * sizeof (unsigned short));
+      mapping_table.buckets[idx][nelements - 1] = i;
+
+      /* Now, set up the lookup table indexed by atoms.  It is faster
+	 to compare atoms than strings, so the table is smaller.  */
+
+      idx = MappingAtom (&direct_transfer[i]) % 16;
+
+      nelements = ++mapping_table.n_atom_elements[idx];
+      mapping_table.atom_buckets[idx]
+	= XLRealloc (mapping_table.atom_buckets[idx],
+		     nelements * sizeof (unsigned short));
+      mapping_table.atom_buckets[idx][nelements - 1] = i;
+    }
+}
+
 static Bool
 HasSelectionTarget (Atom atom)
 {
@@ -261,13 +343,18 @@ HasSelectionTarget (Atom atom)
 static TargetMapping *
 FindTranslationForMimeType (const char *mime_type)
 {
-  int i;
+  unsigned short *buckets, i;
+  unsigned int idx;
 
-  for (i = 0; i < ArrayElements (direct_transfer); ++i)
+  idx = HashMimeString (mime_type) % 32;
+  buckets = mapping_table.buckets[idx];
+
+  for (i = 0; i < mapping_table.n_elements[idx]; ++i)
     {
-      if (!strcmp (direct_transfer[i].mime_type, mime_type)
+      if (!strcmp (direct_transfer[buckets[i]].mime_type,
-	  && HasSelectionTarget (direct_transfer[i].atom))
+		   mime_type)
-	return &direct_transfer[i];
+	  && HasSelectionTarget (MappingAtom (&direct_transfer[buckets[i]])))
+	return &direct_transfer[buckets[i]];
     }
 
   return NULL;
@@ -575,11 +662,13 @@ Receive (struct wl_client *client, struct wl_resource *resource,
     {
       if (!translation->translation_func)
 	/* If a corresponding target exists, ask to receive it.  */
-	PostReceiveDirect (time, CLIPBOARD, translation->atom, fd);
+	PostReceiveDirect (time, CLIPBOARD,
+			   MappingAtom (translation), fd);
       else
 	/* Otherwise, use the translation function.  */
 	translation->translation_func (time, CLIPBOARD,
-				       translation->atom, fd);
+				       MappingAtom (translation),
+				       fd);
     }
   else
     close (fd);
@@ -632,10 +721,55 @@ CreateOffer (struct wl_client *client, Time time)
   return resource;
 }
 
+static Bool
+CheckDuplicate (unsigned short index, Atom a)
+{
+  TargetMapping *start;
+
+  start = &direct_transfer[index];
+
+  /* If the flag is already set, then this type has already been
+     sent.  */
+  if (MappingFlag (start))
+    return False;
+
+  /* Set this entry's duplicate flag.  */
+  MappingSetFlag (start);
+
+  /* As long as the next index still refers to a duplicate of this
+     item, set its duplicate flag.  */
+
+  while (MappingIsNextDuplicate (start))
+    MappingSetFlag (++start);
+
+  /* Do the same backwards.  */
+
+  if (index)
+    {
+      start = &direct_transfer[index - 1];
+
+      while (MappingIsNextDuplicate (start))
+	{
+	  MappingSetFlag (start);
+
+	  /* If this is now the start of the target mapping table,
+	     break.  */
+	  if (start == direct_transfer)
+	    break;
+
+	  start--;
+	}
+    }
+
+  return True;
+}
+
 static void
 SendOffers (struct wl_resource *resource, Time time)
 {
   int i, j;
+  unsigned int idx;
+  unsigned short *buckets;
 
   if (time < last_x_selection_change)
     /* This offer is out of date.  */
@@ -644,16 +778,29 @@ SendOffers (struct wl_resource *resource, Time time)
   for (i = 0; i < num_x_selection_targets; ++i)
     {
       /* Offer each type corresponding to this target.  */
+      idx = x_selection_targets[i] % 16;
 
-      for (j = 0; j < ArrayElements (direct_transfer); ++j)
+      /* N.B. that duplicates do appear in the atom buckets, which
+	 is intentional.  */
+      buckets = mapping_table.atom_buckets[idx];
+
+      for (j = 0; j < mapping_table.n_atom_elements[idx]; ++j)
 	{
-	  if (direct_transfer[j].atom == x_selection_targets[i])
+	  if (MappingIs (&direct_transfer[buckets[j]],
-	    /* If it exists, offer it to the client.  TODO: handle
+			 x_selection_targets[i])
-	       duplicates.  */
+	      && CheckDuplicate (buckets[j],
+				 x_selection_targets[i]))
+	    /* If it exists and was not previously offered, offer it
+	       to the client.  */
 	    wl_data_offer_send_offer (resource,
-				      direct_transfer[j].mime_type);
+				      direct_transfer[buckets[j]].mime_type);
 	}
     }
+
+  /* Clear the duplicate flag of each item in the targets table that
+     was touched.  */
+  for (i = 0; i < ArrayElements (direct_transfer); ++i)
+    MappingUnsetFlag (&direct_transfer[i]);
 }
 
 static void
@@ -1751,10 +1898,13 @@ XLInitXData (void)
   SelectSelectionInput (CLIPBOARD);
 
   /* Initialize atoms used in the direct transfer table.  */
-  direct_transfer[1].atom = UTF8_STRING;
+  direct_transfer[1].atom_flag = UTF8_STRING | Duplicate;
   direct_transfer[2].translation_func = PostReceiveConversion;
   DirectTransferInitializer (direct_transfer, 3);
 
+  /* Set up the direct transfer table.  */
+  SetupMappingTable ();
+
   /* And those used in the data conversions table.  */
   data_conversions[0].atom = UTF8_STRING;
   data_conversions[0].type = UTF8_STRING;