Record Extension Protocol Specification

X Consortium Standard

Martha Zimet

   Network Computing Devices, Inc.

Edited by

Stephen Gildea

   X Consortium

   X Version 11, Release 7.7

   Copyright © 1994 Network Computing Devices, Inc.

   Permission to use, copy, modify, distribute, and sell this
   documentation for any purpose is hereby granted without fee,
   provided that the above copyright notice and this permission
   notice appear in all copies. Network Computing Devices, Inc.
   makes no representations about the suitability for any purpose
   of the information in this document. This documentation is
   provided "as is" without express or implied warranty.

   Copyright © 1994, 1995 X Consortium

   Permission is hereby granted, free of charge, to any person
   obtaining a copy of this software and associated documentation
   files (the "Software"), to deal in the Software without
   restriction, including without limitation the rights to use,
   copy, modify, merge, publish, distribute, sublicense, and/or
   sell copies of the Software, and to permit persons to whom the
   Software is furnished to do so, subject to the following
   conditions:

   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE
   FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   THE SOFTWARE.

   Except as contained in this notice, the name of the X
   Consortium and shall not be used in advertising or otherwise to
   promote the sale, use or other dealings in this Software
   without prior written authorization from the X Consortium.

   X Window System is a trademark of The Open Group.
     __________________________________________________________

   Table of Contents

   1. Introduction

        Acknowledgements
        Goals
        Requirements

   2. Design

        Overview

              Data Delivery
              Record Context
              Record Client Connections
              Events
              Timing

        Types
        Errors

   3. Protocol Requests
   4. Encoding

        Types
        Errors
        Requests

Chapter 1. Introduction

   Table of Contents

   Acknowledgements
   Goals
   Requirements

   Several proposals have been written over the past few years
   that address some of the issues surrounding the recording and
   playback of user actions in the X Window System^[1] :
     * Some Proposals for a Minimal X11 Testing Extension, Kieron
       Drake, UniSoft Ltd., April 1991
     * X11 Input Synthesis Extension Proposal, Larry Woestman,
       Hewlett Packard, November 1991
     * XTrap Architecture, Dick Annicchiario, et al, Digital
       Equipment Corporation, July 1991
     * XTest Extension Recording Specification, Yochanan Slonim,
       Mercury Interactive, December 1992

   This document both unifies and extends the previous diverse
   approaches to generate a proposal for an X extension that
   provides support for the recording of all core X protocol and
   arbitrary extension protocol. Input synthesis, or playback, has
   already been implemented in the XTest extension, an X
   Consortium standard. Therefore, this extension is limited to
   recording.

   In order to provide both record and playback functionality, a
   hypothetical record application could use this extension to
   capture both user actions and their consequences. For example,
   a button press (a user action) may cause a window to be mapped
   and a corresponding MapNotify event to be sent (a consequence).
   This information could be stored for later use by a playback
   application.

   The playback application could use the recorded actions as
   input for the XTest extension's XTestFakeInput operation to
   synthesize the appropriate input events. The "consequence" or
   synchronization information is then used as a synchronization
   point during playback. That is, the playback application does
   not generate specific synthesized events until their matching
   synchronization condition occurs. When the condition occurs the
   processing of synthesized events continues. Determination that
   the condition has occurred may be made by capturing the
   consequences of the synthesized events and comparing them to
   the previously recorded synchronization information. For
   example, if a button press was followed by a MapNotify event on
   a particular window in the recorded data, the playback
   application might synthesize the button press then wait for the
   MapNotify event on the appropriate window before proceeding
   with subsequent synthesized input.

   Because it is impossible to predict what synchronization
   information will be required by a particular application, the
   extension provides facilities to record any subset of core X
   protocol and arbitrary extension protocol. As such, this
   extension does not enforce a specific synchronization
   methodology; any method based on information in the X protocol
   stream (e.g., watching for window mapping/unmapping, cursor
   changes, drawing of certain text strings, etc.) can capture the
   information it needs using RECORD facilities.

Acknowledgements

   The document represents the culmination of two years of debate
   and experiments done under the auspices of the X Consortium
   xtest working group. Although this was a group effort, the
   author remains responsible for any errors or omissions. Two
   years ago, Robert Chesler of Absol-puter, Kieron Drake of
   UniSoft Ltd., Marc Evans of Synergytics and Ken Miller of
   Digitial shared the vision of a standard extension for
   recording and were all instrumental in the early protocol
   development. During the last two years, Bob Scheifler of the X
   Consortium and Jim Fulton of NCD continuously provided input to
   the protocol design, as well as encouragement to the author. In
   the last few months, Stephen Gildea and Dave Wiggins, both X
   Consortium staff, have spent considerable time fine tuning the
   protocol design and reviewing the protocol specifications. Most
   recently, Amnon Cohen of Mercury Interactive has assisted in
   clarification of the recorded event policy, and Kent Siefkes of
   Performance Awareness has assisted in clarification of the
   timestamp policy.

Goals

     * To provide a standard for recording, whereby both device
       events and synchronization information in the form of
       device event consequences are recorded.
     * To record contextual information used in synchronized
       playback without prior knowledge of the application that is
       being recorded.
     * To provide the ability to record arbitrary X protocol
       extensions.

Requirements

   The extension should function as follows:
     * It should not be dependent on other clients or extensions
       for its operation.
     * It should not significantly impact performance.
     * It should support the recording of all device input (core
       devices and XInput devices).
     * It should be extendible.
     * It should support the recording of synchronization
       information for user events.
     __________________________________________________________

   ^[1] X Window System is a trademark of The Open Group.

Chapter 2. Design

   Table of Contents

   Overview

        Data Delivery
        Record Context
        Record Client Connections
        Events
        Timing

   Types
   Errors

   This section gives an overview of the RECORD extension and
   discusses its overall operation and data types.

Overview

   The mechanism used by this extension for recording is to
   intercept core X protocol and arbitrary X extension protocol
   entirely within the X server itself. When the extension has
   been requested to intercept specific protocol by one or more
   clients, the protocol data are formatted and returned to the
   recording clients.

   The extension provides a mechanism for capturing all events,
   including input device events that go to no clients, that is
   analogous to a client expressing "interest" in all events in
   all windows, including the root window. Event filtering in the
   extension provides a mechanism for feeding device events to
   recording clients; it does not provide a mechanism for
   in-place, synchronous event substitution, modification, or
   withholding. In addition, the extension does not provide data
   compression before intercepted protocol is returned to the
   recording clients.

Data Delivery

   Because events are limited in size to 32 bytes, using events to
   return intercepted protocol data to recording clients is
   prohibitive in terms of performance. Therefore, intercepted
   protocol data are returned to recording clients through
   multiple replies to the extension request to begin protocol
   interception and reporting. This utilization is consistent with
   ListFontsWithInfo , for example, where a single request has
   multiple replies.

   Individual requests, replies, events or errors intercepted by
   the extension on behalf of recording clients cannot be split
   across reply packets. In order to reduce overhead, multiple
   intercepted requests, replies, events and errors might be
   collected into a single reply. Nevertheless, all data are
   returned to the client in a timely manner.

Record Context

   The extension adds a record context resource (RC) to the set of
   resources managed by the server. All the extension operations
   take an RC as an argument. Although the protocol permits
   sharing of RCs between clients, it is expected that clients
   will use their own RCs. The attributes used in extension
   operations are stored in the RCs, and these attributes include
   the protocol and clients to intercept.

   The terms "register" and "unregister" are used to describe the
   relationship between clients to intercept and the RC. To
   register a client with an RC means the client is added to the
   list of clients to intercept; to unregister a client means the
   client is deleted from the list of clients to intercept. When
   the server is requested to register or unregister clients from
   an RC, it is required to do so immediately. That is, it is not
   permissible for the server to wait until recording is enabled
   to register clients or recording is disabled to unregister
   clients.

Record Client Connections

   The typical communication model for a recording client is to
   open two connections to the server and use one for RC control
   and the other for reading protocol data.

   The "control" connection can execute requests to obtain
   information about the supported protocol version, create and
   destroy RCs, specify protocol types to intercept and clients to
   be recorded, query the current state of an RC, and to stop
   interception and reporting of protocol data. The "data"
   connection can execute a request to enable interception and
   reporting of specified protocol for a particular RC. When the
   "enable" request is issued, intercepted protocol is sent back
   on the same connection, generally in more than one reply
   packet. Until the last reply to the "enable" request is sent by
   the server, signifying that the request execution is complete,
   no other requests will be executed by the server on that
   connection. That is, the connection that data are being
   reported on cannot issue the "disable" request until the last
   reply to the "enable" request is sent by the server. Therefore,
   unless a recording client never has the need to disable the
   interception and reporting of protocol data, two client
   connections are necessary.

Events

   The terms "delivered events" and "device events" are used to
   describe the two event classes recording clients may select for
   interception. These event classes are handled differently by
   the extension. Delivered events are core X events or X
   extension events the server actually delivers to one or more
   clients. Device events are events generated by core X devices
   or extension input devices that the server may or may not
   deliver to any clients. When device events are selected for
   interception by a recording client, the extension guarantees
   each device event is recorded and will be forwarded to the
   recording client in the same order it is generated by the
   device.

   The recording of selected device events is not affected by
   server grabs. Delivered events, on the other hand, can be
   affected by server grabs. If a recording client selects both a
   device event and delivered events that result from that device
   event, the delivered events are recorded after the device
   event. In the absence of grabs, the delivered events for a
   device event precede later device events.

   Requests that have side effects on devices, such as WarpPointer
   and GrabPointer with a confine-to window, will cause RECORD to
   record an associated device event. The XTEST extension request
   XTestFakeInput causes a device event to be recorded; the device
   events are recorded in the same order that the XTestFakeInput
   requests are received by the server.

   If a key autorepeats, multiple KeyPress and KeyRelease device
   events are reported.

Timing

   Requests are recorded just before they are executed; the time
   associated with a request is the server time when it is
   recorded.

Types

   The following new types are used in the request definitions
   that appear in section 3.

   RC: CARD32

   The "RC" type is a resource identifier for a server record
   context.
   RANGE8:   [first, last: CARD8]
   RANGE16:  [first, last: CARD16]
   EXTRANGE: [major:       RANGE8
             minor:        RANGE16]
   RECORDRANGE: [core-requests:   RANGE8
                core-replies:     RANGE8
                ext-requests:     EXTRANGE
                ext-replies:      EXTRANGE
                delivered-events: RANGE8
                device-events:    RANGE8
                errors:           RANGE8
                client-started:   BOOL
                client-died:      BOOL]

   The "RECORDRANGE" structure contains the protocol values to
   intercept. Typically, this structure is sent by recording
   clients over the control connection when creating or modifying
   an RC.
     * Specifies core X protocol requests with an opcode field
       between first and last inclusive. If first is equal to 0
       and last is equal to 0, no core requests are specified by
       this RECORDRANGE. If first is greater than last, a "Value"
       error results.
     * Specifies replies resulting from core X protocol requests
       with an opcode field between first and last inclusive. If
       first is equal to 0 and last is equal to 0, no core replies
       are specified by this RECORDRANGE. If first is greater than
       last, a "Value" error results.
     * Specifies extension protocol requests with a major opcode
       field between major.first and major.last and a minor opcode
       field between minor.first and minor.last inclusive. If
       major.first and major.last are equal to 0, no extension
       protocol requests are specified by this RECORDRANGE. If
       major.first or major.last is less than 128 and greater than
       0, if major.first is greater than major.last, or if
       minor.first is greater than minor.last, a "Value" error
       results.
     * Specifies replies resulting from extension protocol
       requests with a major opcode field between major.first and
       major.last and a minor opcode field between minor.first and
       minor.last inclusive. If major.first and major.last are
       equal to 0, no extension protocol replies are specified by
       this RECORDRANGE. If major.first or major.last is less than
       128 and greater than 0, if major.first is greater than
       major.last, or if minor.first is greater than minor.last, a
       "Value" error results.
     * This is used for both core X protocol events and arbitrary
       extension events. Specifies events that are delivered to at
       least one client that have a code field between first and
       last inclusive. If first is equal to 0 and last is equal to
       0, no events are specified by this RECORDRANGE. Otherwise,
       if first is less than 2 or last is less than 2, or if first
       is greater than last, a "Value" error results.
     * This is used for both core X device events and X extension
       device events that may or may not be delivered to a client.
       Specifies device events that have a code field between
       first and last inclusive. If first is equal to 0 and last
       is equal to 0, no device events are specified by this
       RECORDRANGE. Otherwise, if first is less than 2 or last is
       less than 2, or if first is greater than last, a "Value"
       error results.
     * Because the generated device event may or may not be
       associated with a client, unlike other RECORDRANGE
       components, which select protocol for a specific client,
       selecting for device events in any RECORDRANGE in an RC
       causes the recording client to receive one instance for
       each device event generated that is in the range specified.
     * This is used for both core X protocol errors and arbitrary
       extension errors. Specifies errors that have a code field
       between first and last inclusive. If first is equal to 0
       and last is equal to 0, no errors are specified by this
       RECORDRANGE. If first is greater than last, a "Value" error
       results.
     * Specifies the connection setup reply. If False , the
       connection setup reply is not specified by this
       RECORDRANGE.
     * Specifies notification when a client disconnects. If False
       , notification when a client disconnects is not specified
       by this RECORDRANGE.

   ELEMENT_HEADER: [from-server-time:    BOOL
                   from-client-time:     BOOL
                   from-client-sequence: BOOL]

   The ELEMENT_HEADER structure specifies additional data that
   precedes each protocol element in the data field of a
   RecordEnableContext reply.
     * If from-server-time is True , each intercepted protocol
       element with category FromServer is preceded by the server
       time when the protocol was recorded.
     * If from-client-time is True , each intercepted protocol
       element with category FromClient is preceded by the server
       time when the protocol was recorded.
     * If from-client-sequence is True , each intercepted protocol
       element with category FromClient or ClientDied is preceded
       by the 32-bit sequence number of the recorded client's most
       recent request processed by the server at that time. For
       FromClient , this will be one less than the sequence number
       of the following request. For ClientDied , the sequence
       number will be the only data, because no protocol is
       recorded.

   Note that a reply containing device events is treated the same
   as other replies with category FromServer for purposes of these
   flags. Protocol with category FromServer is never preceded by a
   sequence number because almost all such protocol has a sequence
   number in it anyway.

   If both a server time and a sequence number have been requested
   for a reply, each protocol request is preceded first by the
   time and second by the sequence number.

   XIDBASE: CARD32

   The XIDBASE type is used to identify a particular client. Valid
   values are any existing resource identifier of any connected
   client, in which case the client that created the resource is
   specified, or the resource identifier base sent to the target
   client from the server in the connection setup reply. A value
   of 0 (zero) is valid when the XIDBASE is associated with device
   events that may not have been delivered to a client.

   CLIENTSPEC: XIDBASE or {CurrentClients, FutureClients,
   AllClients}

   The CLIENTSPEC type defines the set of clients the RC
   attributes are associated with. This type is used by recording
   clients when creating an RC or when changing RC attributes.
   XIDBASE specifies that the RC attributes apply to a single
   client only. CurrentClients specifies that the RC attributes
   apply to current client connections; FutureClients specifies
   future client connections; AllClients specifies all client
   connections, which includes current and future.

   The numeric values for CurrentClients , FutureClients and
   AllClients are defined such that there will be no intersection
   with valid XIDBASEs.

   When the context is enabled, the data connection is
   unregistered if it was registered. If the context is enabled,
   CurrentClients and AllClients silently exclude the recording
   data connection. It is an error to explicitly register the data
   connection.
   CLIENT_INFO: [client-resource:     CLIENTSPEC
                intercepted-protocol: LISTofRECORDRANGE]

   This structure specifies an intercepted client and the protocol
   to be intercepted for the client. The client-resource field is
   a resource base that identifies the intercepted client. The
   intercepted-protocol field specifies the protocol to intercept
   for the client-resource.

Errors

   RecordContext
     * This error is returned if the value for an RC argument in a
       request does not name a defined record context.

Chapter 3. Protocol Requests

   RecordQueryVersion
     * major-version, minor-version: CARD16

   ->
     * major-version, minor-version: CARD16

   This request specifies the RECORD extension protocol version
   the client would like to use. When the specified protocol
   version is supported by the extension, the protocol version the
   server expects from the client is returned. Clients must use
   this request before other RECORD extension requests.

   This request also determines whether or not the RECORD
   extension protocol version specified by the client is supported
   by the extension. If the extension supports the version
   specified by the client, this version number should be
   returned. If the client has requested a higher version than is
   supported by the server, the server's highest version should be
   returned. Otherwise, if the client has requested a lower
   version than is supported by the server, the server's lowest
   version should be returned. This document defines major version
   one (1), minor version thirteen (13).

   RecordCreateContext
   context: RC
   element-header: ELEMENT_HEADER
   client-specifiers: LISTofCLIENTSPEC
   ranges: LISTofRECORDRANGE
   Errors: Match , Value , IDChoice , Alloc

   This request creates a new record context within the server and
   assigns the identifier context to it. After the context is
   created, this request registers the set of clients in
   client-specifiers with the context and specifies the protocol
   to intercept for those clients. The recorded protocol elements
   will be preceded by data as specified by element-header.
   Typically, this request is used by a recording client over the
   control connection. Multiple RC objects can exist
   simultaneously, containing overlapping sets of protocol and
   clients to intercept.

   If any of the values in element-header or ranges is invalid, a
   "Value" error results. Duplicate items in the list of
   client-specifiers are ignored. If any item in the
   client-specifiers list is not a valid CLIENTSPEC, a "Match"
   error results. Otherwise, each item in the client-specifiers
   list is processed as follows:
     * If the item is an XIDBASE identifying a particular client,
       the specified client is registered with the context and the
       protocol to intercept for the client is then set to ranges.
     * If the item is CurrentClients , all existing clients are
       registered with the context at this time. The protocol to
       intercept for all clients registered with the context is
       then set to ranges.
     * If the item is FutureClients , all clients that connect to
       the server after this request executes will be
       automatically registered with the context. The protocol to
       intercept for such clients will be set to ranges in the
       context.
     * If the item is AllClients , the effect is as if the actions
       described for FutureClients are performed, followed by the
       actions for CurrentClients .

   The "Alloc" error results when the server is unable to allocate
   the necessary resources.

   RecordRegisterClients
   context: RC
   element-header: ELEMENT_HEADER
   client-specifiers: LISTofCLIENTSPEC
   ranges: LISTofRECORDRANGE
   Errors: Match , Value , RecordContext , Alloc

   This request registers the set of clients in client-specifiers
   with the given context and specifies the protocol to intercept
   for those clients. The header preceding each recorded protocol
   element is set as specified by element-header. These flags
   affect the entire context; their effect is not limited to the
   clients registered by this request. Typically, this request is
   used by a recording client over the control connection.

   If context does not name a valid RC, a "RecordContext" error
   results. If any of the values in element-header or ranges is
   invalid, a "Value" error results. Duplicate items in the list
   of client-specifiers are ignored. If any item in the list of
   client-specifiers is not a valid CLIENTSPEC, a "Match" error
   results. If the context is enabled and the XID of the enabling
   connection is specified, a "Match" error results. Otherwise,
   each item in the client-specifiers list is processed as
   follows:
     * If the item is an XIDBASE identifying a particular client,
       the specified client is registered with the context if it
       is not already registered. The protocol to intercept for
       the client is then set to ranges.
     * If the item is CurrentClients , all existing clients that
       are not already registered with the specified context,
       except the enabling connection if the context is enabled,
       are registered at this time. The protocol to intercept for
       all clients registered with the context is then set to
       ranges.
     * If the item is FutureClients , all clients that connect to
       the server after this request executes will be
       automatically registered with the context. The protocol to
       intercept for such clients will be set to ranges in the
       context. The set of clients that are registered with the
       context and their corresponding sets of protocol to
       intercept are left intact.
     * If the item is AllClients , the effect is as if the actions
       described for FutureClients are performed, followed by the
       actions for CurrentClients .

   The "Alloc" error results when the server is unable to allocate
   the necessary resources.

   RecordUnregisterClients
   context: RC
   client-specifiers: LISTofCLIENTSPEC
   Errors: Match , RecordContext

   This request removes the set of clients in client-specifiers
   from the given context's set of registered clients. Typically,
   this request is used by a recording client over the control
   connection.

   If context does not name a valid RC, a "RecordContext" error
   results. Duplicate items in the list of client-specifiers are
   ignored. If any item in the list is not a valid CLIENTSPEC, a
   "Match" error results. Otherwise, each item in the
   client-specifiers list is processed as follows:
     * If the item is an XIDBASE identifying a particular client,
       and the specified client is currently registered with the
       context, it is unregistered, and the set of protocol to
       intercept for the client is deleted from the context. If
       the specified client is not registered with the context,
       the item has no effect.
     * If the item is CurrentClients , all clients currently
       registered with the context are unregistered from it, and
       their corresponding sets of protocol to intercept are
       deleted from the context.
     * If the item is FutureClients , clients that connect to the
       server after this request executes will not automatically
       be registered with the context. The set of clients that are
       registered with this context and their corresponding sets
       of protocol that will be intercepted are left intact.
     * If the item is AllClients , the effect is as if the actions
       described for FutureClients are performed, followed by the
       actions for CurrentClients .

   A client is unregistered automatically when it disconnects.

   RecordGetContext
   context: RC
   ->
   enabled: BOOL
   element-header: ELEMENT_HEADER
   intercepted-clients: LISTofCLIENT_INFO
   Errors:
   RecordContext

   This request queries the current state of the specified context
   and is typically used by a recording client over the control
   connection. The enabled field specifies the state of data
   transfer between the extension and the recording client, and is
   either enabled ( True ) or disabled ( False ). The initial
   state is disabled. When enabled, all core X protocol and
   extension protocol received from (requests) or sent to
   (replies, errors, events) a particular client, and requested to
   be intercepted by the recording client, is reported to the
   recording client over the data connection. The element-header
   specifies the header that precedes each recorded protocol
   element. The intercepted-clients field specifies the list of
   clients currently being recorded and the protocol associated
   with each client. If future clients will be automatically
   registered with the context, one of the returned CLIENT_INFO
   structures has a client-resource value of FutureClients and an
   intercepted-protocol giving the protocol to intercept for
   future clients. Protocol ranges may be decomposed, coalesced,
   or otherwise modified by the server from how they were
   specified by the client. All CLIENTSPECs registered with the
   server are returned, even if the RECORDRANGE(s) associated with
   them specify no protocol to record.

   When the context argument is not valid, a RecordContext error
   results.

   RecordEnableContext
   context: RC
   ->+
   category: {FromServer, FromClient, ClientStarted, ClientDied,
   StartOfData, EndOfData}
   element-header: ELEMENT_HEADER
   client-swapped: BOOL
   id-base: XIDBASE
   server-time: TIMESTAMP
   recorded-sequence-number: CARD32
   data: LISTofBYTE
   Errors: Match, RecordContext

   This request enables data transfer between the recording client
   and the extension and returns the protocol data the recording
   client has previously expressed interest in. Typically, this
   request is executed by the recording client over the data
   connection.

   If the client is registered on the context, it is unregistered
   before any recording begins.

   Once the server receives this request, it begins intercepting
   and reporting to the recording client all core and extension
   protocol received from or sent to clients registered with the
   RC that the recording client has expressed interest in. All
   intercepted protocol data is returned in the byte-order of the
   recorded client. Therefore, recording clients are responsible
   for all byte swapping, if required. More than one recording
   client cannot enable data transfer on the same RC at the same
   time. Multiple intercepted requests, replies, events and errors
   might be packaged into a single reply before being returned to
   the recording clients.

   The category field determines the possible types of the data.
   When a context is enabled, the server will immediately send a
   reply of category StartOfData to notify the client that
   recording is enabled. A category of FromClient means the data
   are from the client (requests); FromServer means data are from
   the server (replies, errors, events, or device events). For a
   new client, the category is ClientStarted and the data are the
   connection setup reply. When the recorded client connection is
   closed, category is set to the value ClientDied and no protocol
   is included in this reply. When the disable request is made
   over the control connection, a final reply is sent over the
   data connection with category EndOfData and no protocol.

   The element-header field returns the value currently set for
   the context, which tells what header information precedes each
   recorded protocol element in this reply.

   The client-swapped field is True if the byte order of the
   protocol being recorded is swapped relative to the recording
   client; otherwise, client-swapped is False . The recorded
   protocol is in the byte order of the client being recorded;
   device events are in the byte order of the recording client.
   For replies of category StartOfData and EndOfData the
   client-swapped bit is set according to the byte order of the
   server relative to the recording client. The id-base field is
   the resource identifier base sent to the client from the server
   in the connection setup reply, and hence, identifies the client
   being recorded. The id-base field is 0 (zero) when the protocol
   data being returned are device events. The server-time field is
   set to the time of the server when the first protocol element
   in this reply was intercepted. The server-time of reply N+1 is
   greater than or equal to the server-time of reply N, and is
   greater than or equal to the time of the last protocol element
   in reply N.

   The recorded-sequence-number field is set to the sequence
   number of the recorded client's most recent request processed
   by the server.

   The data field contains the raw protocol data being returned to
   the recording client. If requested by the element-header of
   this record context, each protocol element may be preceded by a
   32-bit timestamp and/or a 32-bit sequence number. If present,
   both the timestamp and sequence number are always in the byte
   order of the recording client.

   For the core X events KeyPress , KeyRelease , ButtonPress , and
   ButtonRelease , the fields of a device event that contain valid
   information are time and detail. For the core X event
   MotionNotify , the fields of a device event that contain valid
   information are time, root, root-x and root-y. The time field
   refers to the time the event was generated by the device.

   For the extension input device events DeviceKeyPress ,
   DeviceKeyRelease , DeviceButtonPress , and DeviceButtonRelease
   , the fields of a device event that contain valid information
   are device, time and detail. For DeviceMotionNotify , the valid
   device event fields are device and time. For the extension
   input device events ProximityIn and ProximityOut , the fields
   of a device event that contain valid information are device and
   time. For the extension input device event DeviceValuator , the
   fields of a device event that contain valid information are
   device, num_valuators, first_valuator, and valuators. The time
   field refers to the time the event was generated by the device.

   The error "Match" is returned when data transfer is already
   enabled. When the context argument is not valid, a
   RecordContext error results.

   RecordDisableContext
   context: RC
   Errors: RecordContext

   This request is typically executed by the recording client over
   the control connection. This request directs the extension to
   immediately send any complete protocol elements currently
   buffered, to send a final reply with category EndOfData , and
   to discontinue data transfer between the extension and the
   recording client. Protocol reporting is disabled on the data
   connection that is currently enabled for the given context.
   Once the extension completes processing this request, no
   additional recorded protocol will be reported to the recording
   client. If a data connection is not currently enabled when this
   request is executed, then this request has no affect on the
   state of data transfer. An RC is disabled automatically when
   the connection to the enabling client is closed down.

   When the context argument is not valid, a RecordContext error
   results.

   RecordFreeContext
     * context RC
     * Errors: RecordContext

   This request deletes the association between the resource ID
   and the RC and destroys the RC. If a client has enabled data
   transfer on this context, the actions described in
   RecordDisableContext are performed before the context is freed.

   An RC is destroyed automatically when the connection to the
   creating client is closed down and the close-down mode is
   DestroyAll. When the context argument is not valid, a
   RecordContext error results.

Chapter 4. Encoding

   Table of Contents

   Types
   Errors
   Requests

   Please refer to the X11 Protocol Encoding document as this
   document uses conventions established there.

   The name of this extension is "RECORD".

Types

   RC: CARD32
RANGE8
     1     CARD8          first
     1     CARD8          last

RANGE16
     2     CARD16          first
     2     CARD16          last

EXTRANGE
     2     RANGE8          major
     4     RANGE16         minor

RECORDRANGE
     2     RANGE8          core-requests
     2     RANGE8          core-replies
     6     EXTRANGE        ext-requests
     6     EXTRANGE        ext-replies
     2     RANGE8          delivered-events
     2     RANGE8          device-events
     2     RANGE8          errors
     1     BOOL            client-started
     1     BOOL            client-died

ELEMENT_HEADER
     1     CARD8
          0x01     from-server-time
          0x02     from-client-time
          0x04     from-client-sequence

   XIDBASE: CARD32
CLIENTSPEC
     4    XIDBASE  client-id-base
          1        CurrentClients
          2        FutureClients
          3        AllClients

CLIENT_INFO
     4    CLIENTSPEC          client-resource
     4    CARD32              n, number of record ranges in
                                 intercepted-protocol
     24n  LISTofRECORDRANGE   intercepted-protocol

Errors

RecordContext
     1     0                  Error
     1     CARD8              extension's base error code + 0
     2     CARD16             sequence number
     4     CARD32             invalid record context
     24                       unused

Requests

RecordQueryVersion
     1     CARD8      major opcode
     1     0          minor opcode
     2     2          request length
     2     CARD16     major version
     2     CARD16     minor version
 =>
     1     1          Reply
     1                unused
     2     CARD16     sequence number
     4     0          reply length
     2     CARD16     major version
     2     CARD16     minor version
     20               unused

RecordCreateContext
     1     CARD8                 major opcode
     1     1                     minor opcode
     2     5+m+6n                request length
     4     RC                    context
     1     ELEMENT_HEADER        element-header
     3                           unused
     4     CARD32                m, number of client-specifiers
     4     CARD32                n, number of ranges
     4m    LISTofCLIENTSPEC      client-specifiers
     24n   LISTofRECORDRANGE     ranges

RecordRegisterClients
     1     CARD8                 major opcode
     1     2                     minor opcode
     2     5+m+6n                request length
     4     RC                    context
     1     ELEMENT_HEADER        element-header
     3                           unused
     4     CARD32                m, number of client-specifiers
     4     CARD32                n, number of ranges
     4m    LISTofCLIENTSPEC      client-specifiers
     24n   LISTofRECORDRANGE     ranges

RecordUnregisterClients
     1     CARD8                 major opcode
     1     3                     minor opcode
     2     3+m                   request length
     4     RC                    context
     4     CARD32                m, number of client-specifiers
     4m    LISTofCLIENTSPEC      client-specifiers

RecordGetContext
     1     CARD8                 major opcode
     1     4                     minor opcode
     2     2                     request length
     4     RC                    context
 =>
     1     1                     Reply
     1     BOOL                  enabled
     2     CARD16                sequence number
     4     j                     reply length
     1     ELEMENT_HEADER        element-header
     3                           unused
     4     CARD32                n, number of intercepted-clients
     16                          unused
     4j    LISTofCLIENT_INFO     intercepted-clients

RecordEnableContext
     1     CARD8                 major opcode
     1     5                     minor opcode
     2     2                     request length
     4     RC                    context
 =>+
     1     1                     Reply
     1                           category
           0     FromServer
           1     FromClient
           2     ClientStarted
           3     ClientDied
           4     StartOfData
           5     EndOfData
     2     CARD16                sequence number
     4     n                     reply length
     1     ELEMENT_HEADER        element-header
     1     BOOL                  client-swapped
     2                           unused
     4     XIDBASE               id-base
     4     TIMESTAMP             server-time
     4     CARD32                recorded-sequence-number
     8                           unused
     4n    BYTE                  data

RecordDisableContext
     1     CARD8                 major opcode
     1     6                     minor opcode
     2     2                     request length
     4     RC                    context

RecordFreeContext
     1     CARD8                 major opcode
     1     7                     minor opcode
     2     2                     request length
     4     RC                    context
