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Command: assign-id
Assign new ID to client, or fetch current ID
Purpose: assigning ID to clients so server can respond to that client
Compulsivity: manditory (core infrastructure)
More documentation: doc/messages
Reference implementation: mds-server
---------------------------------------------------------------------
Command: intercept
Sign up for reception of message
Optional header: Stop
Stop reception of messages if `yes`
Optional header: Priority
Signed 64-bit integer of reception priority (reversed of order)
Optional header: Modifying
Send message asynchronously and await modification if `yes`
Optional header: Length
Length of the message
Message: list of headers and header–value-pairs that qualifies
a message for reception, all messages qualifies if this
list is empty
Purpose: filter received message for clients and servers
Purpose: assigned interception order for modification of messages
Compulsivity: manditory (core infrastructure)
More documentation: doc/messages
Reference implementation: mds-server
---------------------------------------------------------------------
Command: echo
Echo back a message
Required header: Client ID
Your ID, provided by `ID assignment`
in response to `Command: assign-id`
Optional header: Length
Length of the message
Message: message to echo
Purpose: debugging and testing
Purpose: network heartbeat
Compulsivity: recommended for network enabled servers
Reference implementation: mds-echo
---------------------------------------------------------------------
Command: register
Register availability of a command for which you implement a service
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
Optional header: Action
Remove availability for registry if `remove`.
Wait until listed commands are available if `wait`,
however if a protocol becomes unavailable during this
wait period it will still be counted as available for
this wait action.
Send a list of availability commands if `list`.
Conditionally optional header: Time to live
Available and optional if: `Action: wait`
The maximum number of seconds to wait.
Message: List of values for the header `Command` that you implement
Purpose: Identify supported display server operations
Purpose: Initialisation process synchronisation
Compulsivity: highly recommended (infrastructure), programs may
stall a bit from time to time without it, or at
initialisation depending on the program's implementation
Reference implementation: mds-registry
---------------------------------------------------------------------
Command: reregister
Request that all servers resends `Command: register` with either
`Action: add` or without the `Action` header (does the same thing)
Purpose: Rebuild registry created with `Command: register` if the
registry server crashes
Compulsivity: highly recommended (infrastructure), programs may
think a protocol is not supported of the registry
server crashes if you do not implement this in your
server
---------------------------------------------------------------------
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
Required if: `Action: set-size`
The maximum number of elements in the clipstack
Conditionally required header: Client ID
Your ID, provided by `ID assignment`
in response to `Command: assign-id`.
Required if: `Action: add` and a header starting with
`Time to live: until-death`
Required if: `Action: read`
Required if: `Action: get-size`
Conditionally optional header: Index
Available and optional if: `Action: read`
The index of the item in the clipstack, starting at 0
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
until-death #: remove entry when the client closes,
or # seconds have elapsed
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
---------------------------------------------------------------------
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