beginning of mds-clipboard

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

5 files changed, 424 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index a41bc22..f831ba1 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ include mk/config.mk
 LIBOBJ = linked-list client-list hash-table fd-table mds-message util
 
 # Servers and utilities.
-SERVERS = mds mds-respawn mds-server mds-echo mds-registry
+SERVERS = mds mds-respawn mds-server mds-echo mds-registry mds-clipboard
 
 
 
diff --git a/TODO b/TODO
index 1762f29..8236fe4 100644
--- a/TODO
+++ b/TODO
@@ -15,7 +15,6 @@ Missing servers:
 	inet		Network enabled display server
 	remote		Bind to a remote display server
 	fb		Framebuffer presenter
-	clipboard	Clipboard
 	kkbd		Keyboard input from kernel
 	kbd		Keyboard input
 	rat		Rat input
@@ -36,6 +35,7 @@ Missing servers:
 	stack		A simple, reference implementation of a, stack window manager
 	workspace	A simple, reference implementation of a, workspaces
 	vt		VT switcher
+	iclipboard	User-private interdisplay clipboard
 
 Missing commands:
 
@@ -45,7 +45,10 @@ Missing commands:
 Need testing:
 
 	registry
+	clipboard
 
 Fast lanes
-Optimise use of mutexe with shared and exclusive locks
+Optimise use of mutexe by replace them with rwlocks
+Listen for `Command: reregister`
+Register protocols
 
diff --git a/doc/protocols b/doc/protocols
index ee1fd18..e008c28 100644
--- a/doc/protocols
+++ b/doc/protocols
@@ -70,7 +70,7 @@ Command: register
 Required header: Client ID
   Your ID, provided by `ID assignment`
   in response to `Command: assign-id`
-  
+
 Conditionally required header: Length
   Required if: `Action: list`
   Length of the message
@@ -114,3 +114,101 @@ Compulsivity: highly recommended (infrastructure), programs may
 
 ---------------------------------------------------------------------
 
+Command: clipboard
+  Read or manipulate a clipboard
+
+Required header: Level
+  The clipboard level, an [1, 3] integer:
+    1 "primary".    Text copied/pasted using
+      		    the keyboard or a menu item
+    2 "secondary".  Text copied/pasted using the rat
+    3 "tertiary".   Non-text, it is customary for this
+      		    data to begin with a line describing
+		    the data type.
+
+Required header: Action
+  What to do with the clipboard:
+    add)  Write the message to the clipboard
+    read)  Read the clipboard
+    clear)  Clear all entries on the selected level on the clipboard
+    set-size)  Shrink/grow the clipstack
+    get-size)  Read the size of the clipstack
+      In the reply, the server will send:
+	Size: <configured maximum size of the clipstack>
+	Used: <number of elements currently in the clipstack>
+
+Conditionally required header: Length
+  Required if: `Action: add`
+  Length of the message
+
+Conditionally required header: Size
+  Available and optional if: `Action: set-size`
+  The maximum number of elements in the clipstack
+
+Conditionally optional header: Index
+  Available and optional if: `Action: read`
+  The index of the item in the clipstack, starting at 0
+
+Conditionally required header: Client ID
+  Your ID, provided by `ID assignment`
+  in response to `Command: assign-id`.
+  Required if: `Action: add` but not `Time to live: forever`
+
+Conditionally optional header: Time to live
+  Available and optional if: `Action: add`
+  The number of seconds the entry should be available
+  before it is removed by the server, or:
+    until-death: remove entry when the client closes
+    forever: never remove it (default)
+  The server will always remove the entry when:
+    1) it is at the bottom of the clipstack and a new
+       entry is added to the clipstack
+    2) `Action: clear` is issued for the clipstack
+  The entry will also be removed, unless
+  `Time to live: forever`, if the server crashes or is
+  reexecuted.
+  It is up to the implementation to choose when
+  the removal actually takes place. For example,
+  the reference implementation will pop entries
+  that have timed out when a new entry is added,
+  the reading on the clipstack is requested or the
+  server is reexecuted, but another implement may
+  choose to pop entires asynchronously using another
+  thread or an alarm an pop when when SIGARLM is
+  received.
+
+Purpose: Enable the user to duplicate content from one process
+	 into another process without requiring those processes
+	 to be aware of eathother to any extent
+
+Compulsivity: optional
+
+Reference implementation: mds-clipboard
+
+---------------------------------------------------------------------
+
+Command: clipboard-info
+  The clipboard server sends out some information about
+  what it is doing, such as automatically removing entires
+
+Included header: Event
+  pop)  An item in the clipstack has been removed
+    Included headers:
+      Level:   The clipboard level that has been affected
+      Popped:  The index of the item in the clipstack
+      	       that has been removed
+      Size:    Configured maximum size of the clipstack
+      Used:    Number of elements currently in the clipstack
+  crash)  The clipboard has been reset because of a software crash
+
+Purpose: Enable clients to get notification about changes
+	 to the clipboard, that cannot trivially derived
+	 from `Command: clipboard`
+
+Compulsivity: optional, optional add-on to the
+	      clipboard's functionallity
+
+Reference implementation: mds-clipboard
+
+---------------------------------------------------------------------
+
diff --git a/src/mds-clipboard.c b/src/mds-clipboard.c
new file mode 100644
index 0000000..1ea4ee9
--- /dev/null
+++ b/src/mds-clipboard.c
@@ -0,0 +1,275 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "mds-clipboard.h"
+
+#include <libmdsserver/macros.h>
+#include <libmdsserver/util.h>
+#include <libmdsserver/mds-message.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#define reconnect_to_display() -1 /* TODO */
+
+
+
+#define MDS_CLIPBOARD_VARS_VERSION  0
+
+
+
+/**
+ * This variable should declared by the actual server implementation.
+ * It must be configured before `main` is invoked.
+ * 
+ * This tells the server-base how to behave
+ */
+server_characteristics_t server_characteristics =
+  {
+    .require_privileges = 0,
+    .require_display = 1,
+    .require_respawn_info = 1,
+    .sanity_check_argc = 1
+  };
+
+
+
+/**
+ * Value of the ‘Message ID’ header for the next message
+ */
+static int32_t message_id = 1;
+
+/**
+ * Buffer for received messages
+ */
+static mds_message_t received;
+
+/**
+ * Whether the server is connected to the display
+ */
+static int connected = 1;
+
+
+
+/**
+ * This function will be invoked before `initialise_server` (if not re-exec:ing)
+ * or before `unmarshal_server` (if re-exec:ing)
+ * 
+ * @return  Non-zero on error
+ */
+int __attribute__((const)) preinitialise_server(void)
+{
+  return 0;
+}
+
+
+/**
+ * This function should initialise the server,
+ * and it not invoked after a re-exec.
+ * 
+ * @return  Non-zero on error
+ */
+int initialise_server(void)
+{
+  const char* const message =
+    "Command: intercept\n"
+    "Message ID: 0\n"
+    "Length: 19\n"
+    "\n"
+    "Command: clipboard\n";
+  
+  if (full_send(message, strlen(message)))
+    return 1;
+  server_initialised();
+  mds_message_initialise(&received);
+  return 0;
+}
+
+
+/**
+ * This function will be invoked after `initialise_server` (if not re-exec:ing)
+ * or after `unmarshal_server` (if re-exec:ing)
+ * 
+ * @return  Non-zero on error
+ */
+int postinitialise_server(void)
+{
+  if (connected)
+    return 0;
+  
+  if (reconnect_to_display())
+    {
+      mds_message_destroy(&received);
+      return 1;
+    }
+  connected = 1;
+  return 0;
+}
+
+
+/**
+ * Calculate the number of bytes that will be stored by `marshal_server`
+ * 
+ * On failure the program should `abort()` or exit by other means.
+ * However it should not be possible for this function to fail.
+ * 
+ * @return  The number of bytes that will be stored by `marshal_server`
+ */
+size_t marshal_server_size(void)
+{
+  return 2 * sizeof(int) + sizeof(int32_t) + mds_message_marshal_size(&received);
+}
+
+
+/**
+ * Marshal server implementation specific data into a buffer
+ * 
+ * @param   state_buf  The buffer for the marshalled data
+ * @return             Non-zero on error
+ */
+int marshal_server(char* state_buf)
+{
+  buf_set_next(state_buf, int, MDS_CLIPBOARD_VARS_VERSION);
+  buf_set_next(state_buf, int, connected);
+  buf_set_next(state_buf, int32_t, message_id);
+  mds_message_marshal(&received, state_buf);
+  
+  mds_message_destroy(&received);
+  return 0;
+}
+
+
+/**
+ * Unmarshal server implementation specific data and update the servers state accordingly
+ * 
+ * On critical failure the program should `abort()` or exit by other means.
+ * That is, do not let `reexec_failure_recover` run successfully, if it unrecoverable
+ * error has occurred or one severe enough that it is better to simply respawn.
+ * 
+ * @param   state_buf  The marshalled data that as not been read already
+ * @return             Non-zero on error
+ */
+int unmarshal_server(char* state_buf)
+{
+  int r;
+  /* buf_get_next(state_buf, int, MDS_CLIPBOARD_VARS_VERSION); */
+  buf_next(state_buf, int, 1);
+  buf_get_next(state_buf, int, connected);
+  buf_get_next(state_buf, int32_t, message_id);
+  r = mds_message_unmarshal(&received, state_buf);
+  if (r)
+    {
+      xperror(*argv);
+      mds_message_destroy(&received);
+    }
+  return r;
+}
+
+
+/**
+ * Attempt to recover from a re-exec failure that has been
+ * detected after the server successfully updated it execution image
+ * 
+ * @return  Non-zero on error
+ */
+int __attribute__((const)) reexec_failure_recover(void)
+{
+  return -1;
+}
+
+
+/**
+ * Perform the server's mission
+ * 
+ * @return  Non-zero on error
+ */
+int master_loop(void)
+{
+  int rc = 1;
+  
+  while (!reexecing && !terminating)
+    {
+      int r = mds_message_read(&received, socket_fd);
+      if (r == 0)
+	{
+	  r = 0; /* FIXME */
+	  if (r == 0)
+	    continue;
+	}
+      
+      if (r == -2)
+	{
+	  eprint("corrupt message received, aborting.");
+	  goto fail;
+	}
+      else if (errno == EINTR)
+	continue;
+      else if (errno != ECONNRESET)
+	goto pfail;
+      
+      eprint("lost connection to server.");
+      mds_message_destroy(&received);
+      mds_message_initialise(&received);
+      connected = 0;
+      if (reconnect_to_display())
+	goto fail;
+      connected = 1;
+    }
+  
+  rc = 0;
+  goto fail;
+ pfail:
+  xperror(*argv);
+ fail:
+  if (rc || !reexecing)
+    mds_message_destroy(&received);
+  return rc;
+}
+
+
+/**
+ * Send a full message even if interrupted
+ * 
+ * @param   message  The message to send
+ * @param   length   The length of the message
+ * @return           Non-zero on success
+ */
+int full_send(const char* message, size_t length)
+{
+  size_t sent;
+  
+  while (length > 0)
+    {
+      sent = send_message(socket_fd, message, length);
+      if (sent > length)
+	{
+	  eprint("Sent more of a message than exists in the message, aborting.");
+	  return -1;
+	}
+      else if ((sent < length) && (errno != EINTR))
+	{
+	  xperror(*argv);
+	  return -1;
+	}
+      message += sent;
+      length -= sent;
+    }
+  return 0;
+}
+
diff --git a/src/mds-clipboard.h b/src/mds-clipboard.h
new file mode 100644
index 0000000..34a12e9
--- /dev/null
+++ b/src/mds-clipboard.h
@@ -0,0 +1,44 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef MDS_MDS_ECHO_H
+#define MDS_MDS_ECHO_H
+
+
+#include "mds-base.h"
+
+
+/**
+ * Echo the received message payload
+ * 
+ * @return  Zero on success -1 on error or interruption,
+ *          errno will be set accordingly
+ */
+int echo_message(void);
+
+/**
+ * Send a full message even if interrupted
+ * 
+ * @param   message  The message to send
+ * @param   length   The length of the message
+ * @return           Non-zero on success
+ */
+int full_send(const char* message, size_t length);
+
+
+#endif
+