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| -rw-r--r-- | doc/messages | 122 |
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diff --git a/doc/messages b/doc/messages deleted file mode 100644 index b9bd825..0000000 --- a/doc/messages +++ /dev/null @@ -1,122 +0,0 @@ -Messages in mds are text based, in UTF-8, with LF for -line separation. - -Each headers is contained to exactly one line. - -All header names are in sentence case. - -A colon followed by a blank space separates the header -name from its associated value. - -One blank line separates the headers from the payload. - -If the message does not have a payload it most still -have a blank line after the headers. It marks the end -of the message. - -The payload of the message may be in binary format. - -A message with a payload must have a ‘Length’ header -that specifies the byte length of the message. Their -most not an additional LF, or any other symbol, after -the payload that is not inside the range specified -by the ‘Length’ header. - - -All clients have an ID that consists of two unsigned -32-bit integers. When a client is created its ID is -automatically 0:0, this is a special ID: it is the -only non-unique ID and client with this ID cannot -get responses. It can however ask for interceptions, -which it would receive. To get a real ID it must -ask the master server (which is the only server that -can communicate with it when it does not have an ID) -for an ID, this can only be done when it does not -have an ID. To do this, it sends an message with -two headers and no payload. One of the headers is -‘Command’ and its value should be ‘assign-id’, -the other header is ‘Message ID’ and its value is -an unsigned 32-bit integer of the index of the -message starting at 0. In response the server sends -a message with two headers and no payload, one of -the headers is ‘ID assignment’ and its value is -two unsigned 32-bit integers joined together -with a colon, for example ‘0:1’, the other header -is ‘In response to’ and its value is the message -ID that the client sent. - - -When a client closes the server multicasts a single -header message with no payload. The header is ‘Client -closed’ with the client's ID. Be aware that the ID -may be 0:0, which is not unique. - - -Multicasts are sent to clients that have ask for -the type of message this is being sent. This technique -is also used to intercept message or receive message -as part of a service that a server provides. Servers -that implement the ability to connect from another -computer are encouraged to reject this type of message -if it could be used for spying. To tell the server -that you want to intercept a type of message the client -sends a message with the header and value -‘Command: intercept’. It can also specify a priority -that is a signed 64-bit integer, the default value is -zero. This is done by using the header ‘Priority’. A -higher priority means that the message is sent earlier. -If the client wishes to be able to modify the message -it most have the header ‘Modifying’ with the value ‘yes’. -If the client wishes to receive all messages it should -not include a payload, otherwise it which send a -LF delimited list of headers that it is interested in. -In this list it is possible to limit to exact values -byte appending a colon and blank space (‘: ’) followed -by the value to the header name. You can also request -that the interception stops by including the header -and value ‘Stop: yes’. - -For ‘Command: intercept’ and all other messages, the -client should include the ‘Message ID’ header. - -A client that as requested to be able to modify -messages will receive the header ‘Modify ID’. This -header may be include even for clients that has -not requested to be able to modify the message. -The ID is only necessary unique for the message -and does not necessary increase when the message -is modified. The client most respond if it has -requested to be able to modify the message. This -is done by sending the header ‘Modify’ and the -header ‘Modify ID’ with the same value as for the -message is is responding to. The value of the -‘Modify’ header should be ‘no’ if the message -is not modified. If the message should be modify -it the value of the ‘Modify’ header should be -‘yes’ and the payload should be the new message -with all the, possibly modified, headers the new -payload. A server may also choose to consume a -message message, this is done by responding -without a payload and include ‘Modify: yes’. -Once a message is consumed it will not be sent -to any additional servers. - - -Unless a client's ID is 0:0 (allowed even if it is -0:0) it should always include the header ‘Client ID’ -and its ID as the headers value. Otherwise it is -assumed that the client's ID is 0:0. - - -Clients automatically receives messages that is -addressed to them with priority zero with a mark that -it will not modify the message. To address a message -to client include the header ‘To’ with the client's -ID [that the message is addressed to] as the value. -Furthermore, client's automatically receives messages -that include the header ‘To: all’ — a broadcast. Since -servers are clients too they will also receive these -messages; there are two exceptions, the kernel and -the master server, neither of which are servers proper, -but rather a dual-layer kernel. - |