mediawiki-extensions-Visual.../modules/parser/mediawiki.TokenTransformManager.js

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/**
* Token transformation managers with a (mostly) abstract
* TokenTransformManager base class and AsyncTokenTransformManager and
* SyncTokenTransformManager implementation subclasses. Individual
* transformations register for the token types they are interested in and are
* called on each matching token.
*
* Async token transformations are supported by the TokenAccumulator class,
* that manages as-early-as-possible and in-order return of tokens including
* buffering.
*
* See
* https://www.mediawiki.org/wiki/Future/Parser_development/Token_stream_transformations
* for more documentation.
*
* @author Gabriel Wicke <gwicke@wikimedia.org>
*/
var events = require('events');
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/**
* Base class for token transform managers
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*
* @class
* @constructor
* @param {Function} callback, a callback function accepting a token list as
* its only argument.
*/
function TokenTransformManager( ) {
// Separate the constructor, so that we can call it from subclasses.
this._construct();
}
// Inherit from EventEmitter
TokenTransformManager.prototype = new events.EventEmitter();
TokenTransformManager.prototype.constructor = TokenTransformManager;
TokenTransformManager.prototype._construct = function () {
this.transformers = {
tag: {}, // for TAG, ENDTAG, SELFCLOSINGTAG, keyed on name
text: [],
newline: [],
comment: [],
end: [], // eof
martian: [], // none of the above (unknown token type)
any: [] // all tokens, before more specific handlers are run
};
};
/**
* Register to a token source, normally the tokenizer.
* The event emitter emits a 'chunk' event with a chunk of tokens,
* and signals the end of tokens by triggering the 'end' event.
* XXX: Perform registration directly in the constructor?
*
* @method
* @param {Object} EventEmitter token even emitter.
*/
TokenTransformManager.prototype.listenForTokensFrom = function ( tokenEmitter ) {
tokenEmitter.addListener('chunk', this.onChunk.bind( this ) );
tokenEmitter.addListener('end', this.onEndEvent.bind( this ) );
};
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/**
* Add a transform registration.
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*
* @method
* @param {Function} transform.
* @param {Number} rank, [0,3) with [0,1) in-order on input token stream,
* [1,2) out-of-order and [2,3) in-order on output token stream
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* @param {String} type, one of 'tag', 'text', 'newline', 'comment', 'end',
* 'martian' (unknown token), 'any' (any token, matched before other matches).
* @param {String} tag name for tags, omitted for non-tags
*/
TokenTransformManager.prototype.addTransform = function ( transformation, rank, type, name ) {
var transArr,
transformer = {
transform: transformation,
rank: rank
};
if ( type === 'tag' ) {
name = name.toLowerCase();
transArr = this.transformers.tag[name];
if ( ! transArr ) {
transArr = this.transformers.tag[name] = [];
}
} else {
transArr = this.transformers[type];
}
transArr.push(transformer);
// sort ascending by rank
transArr.sort( this._cmpTransformations );
};
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/**
* Remove a transform registration
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*
* @method
* @param {Function} transform.
* @param {Number} rank, [0,3) with [0,1) in-order on input token stream,
* [1,2) out-of-order and [2,3) in-order on output token stream
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* @param {String} type, one of 'tag', 'text', 'newline', 'comment', 'end',
* 'martian' (unknown token), 'any' (any token, matched before other matches).
* @param {String} tag name for tags, omitted for non-tags
*/
TokenTransformManager.prototype.removeTransform = function ( rank, type, name ) {
var i = -1,
ts;
function rankUnEqual ( i ) {
return i.rank !== rank;
}
if ( type === 'tag' ) {
name = name.toLowerCase();
var maybeTransArr = this.transformers.tag.name;
if ( maybeTransArr ) {
this.transformers.tag.name = maybeTransArr.filter( rankUnEqual );
}
} else {
this.transformers[type] = this.transformers[type].filter( rankUnEqual ) ;
}
};
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/**
* Enforce separation between phases when token types or tag names have
* changed, or when multiple tokens were returned. Processing will restart
* with the new rank.
*
* XXX: This should also be moved to the subclass (actually partially implicit if
* _transformTagToken and _transformToken are subclassed and set the rank when
* fully processed). The token type change case still needs to be covered
* though.
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*/
TokenTransformManager.prototype._resetTokenRank = function ( res, transformer ) {
if ( res.token ) {
// reset rank after type or name change
// Convert String literal to String object
if ( res.token.constructor === String && res.token.rank === undefined ) {
res.token = new String( res.token );
}
if ( transformer.rank < 1 ) {
res.token.rank = 0;
} else {
res.token.rank = 1;
}
} else if ( res.tokens && transformer.rank > 2 ) {
for ( var i = 0; i < res.tokens.length; i++ ) {
var token = res.tokens[i];
// convert string literal to string object
if ( token.constructor === String && token.rank === undefined ) {
res.tokens[i] = new String( token );
}
if ( res.tokens[i].rank === undefined ) {
// Do not run phase 0 on newly created tokens from
// phase 1.
res.tokens[i].rank = 2;
}
}
}
};
TokenTransformManager.prototype.setTokensRank = function ( tokens, rank ) {
for ( var i = 0, l = tokens.length; i < l; i++ ) {
var token = tokens[i];
// convert string literal to string object
if ( token.constructor === String && token.rank === undefined ) {
tokens[i] = new String( token );
token = tokens[i];
}
token.rank = rank;
}
};
/**
* Comparison for sorting transformations by ascending rank.
*/
TokenTransformManager.prototype._cmpTransformations = function ( a, b ) {
return a.rank - b.rank;
};
/* Call all transformers on a tag.
* XXX: Move to subclasses and use a different signature?
*
* @method
* @param {Object} The current token.
* @param {Function} Completion callback for async processing.
* @param {Number} Rank of phase end, both key for transforms and rank for
* processed tokens.
* @returns {Object} Token(s) and async indication.
*/
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TokenTransformManager.prototype._transformTagToken = function ( token, phaseEndRank, cbOrPrevToken ) {
// prepend 'any' transformers
var ts = this.transformers.any,
res = { token: token },
transform,
l, i,
aborted = false,
tName = token.name.toLowerCase(),
tagts = this.transformers.tag[tName];
if ( tagts && tagts.length ) {
// could cache this per tag type to avoid re-sorting each time
ts = ts.concat(tagts);
ts.sort( this._cmpTransformations );
}
//console.warn(JSON.stringify(ts, null, 2));
if ( ts ) {
for ( i = 0, l = ts.length; i < l; i++ ) {
transformer = ts[i];
if ( res.token.rank && transformer.rank < res.token.rank ) {
//console.warn( 'SKIPPING' + JSON.stringify( token, null, 2 ) +
// '\ntransform:\n' + JSON.stringify( transformer, null, 2 ) );
// skip transformation, was already applied.
continue;
}
// Transform token with side effects
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res = transformer.transform( res.token, this, cbOrPrevToken );
// XXX: Sync transform:
// res = transformer.transform( res.token, this, this.prevToken );
// XXX: Async transform:
// res = transformer.transform( res.token, this, cb );
// if multiple tokens or null token: process returned tokens (in parent)
if ( !res.token || // async implies tokens instead of token, so no
// need to check explicitly
res.token.type !== token.type ||
res.token.name !== token.name ) {
this._resetTokenRank ( res, transformer );
aborted = true;
break;
}
// track progress on token
if ( res.token.rank === undefined && res.token.constructor === String ) {
res.token = new String ( res.token );
}
res.token.rank = transformer.rank;
}
if ( ! aborted ) {
// Mark token as fully processed.
if ( res.token.rank === undefined && res.token.constructor === String ) {
res.token = new String ( res.token );
}
res.token.rank = phaseEndRank;
}
}
return res;
};
/* Call all transformers on non-tag token types.
* XXX: different signature for sync vs. async, move to subclass?
*
* @method
* @param {Object} The current token.
* @param {Function} Completion callback for async processing.
* @param {Number} Rank of phase end, both key for transforms and rank for
* processed tokens.
* @param {Array} ts List of token transformers for this token type.
* @returns {Object} Token(s) and async indication.
*/
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TokenTransformManager.prototype._transformToken = function ( token, phaseEndRank, ts, cbOrPrevToken ) {
// prepend 'any' transformers
//this.env.dp('_transformToken', token);
var anyTrans = this.transformers.any;
if ( anyTrans.length ) {
ts = this.transformers.any.concat(ts);
ts.sort( this._cmpTransformations );
}
var transformer,
res = { token: token },
aborted = false;
if ( ts ) {
for (var i = 0, l = ts.length; i < l; i++ ) {
transformer = ts[i];
if ( res.token.rank && transformer.rank <= res.token.rank ) {
// skip transformation, was already applied.
//console.warn( 'skipping transform');
continue;
}
// Transform the token.
// XXX: consider moving the rank out of the token itself to avoid
// transformations messing with it in broken ways. Not sure if
// some transformations need to manipulate it though. gwicke
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res = transformer.transform( res.token, this, cbOrPrevToken );
if ( !res.token ||
res.token.type !== token.type ) {
this._resetTokenRank ( res, transformer );
aborted = true;
break;
}
// XXX: factor the conversion to String out into a generic _setRank
// method? Would need to add to the string prototype for that..
if ( res.token.rank === undefined && res.token.constructor === String ) {
res.token = new String ( res.token );
}
res.token.rank = transformer.rank;
}
if ( ! aborted ) {
// mark token as completely processed
if ( res.token.rank === undefined && res.token.constructor === String ) {
res.token = new String ( res.token );
}
res.token.rank = phaseEndRank; // need phase passed in!
}
//else {
// this.env.dp( '_transformToken aborted', res );
//}
}
return res;
};
/******************** Async token transforms: Phase 2 **********************/
/**
* Asynchronous and potentially out-of-order token transformations, used in phase 2.
*
* return protocol for individual transforms:
* { tokens: [tokens], async: true }: async expansion -> outstanding++ in parent
* { tokens: [tokens] }: fully expanded, tokens will be reprocessed
* { token: token }: single-token return
*
* @class
* @constructor
* @param {Function} childFactory: A function that can be used to create a
* new, nested transform manager:
* nestedAsyncTokenTransformManager = manager.newChildPipeline( inputType, args );
* @param {Object} args, the argument map for templates
* @param {Object} env, the environment.
*/
function AsyncTokenTransformManager ( childFactories, args, env, inputType ) {
// Factory function for new AsyncTokenTransformManager creation with
// default transforms enabled
// Also sets up a tokenizer and phase-1-transform depending on the input format
// nestedAsyncTokenTransformManager = manager.newChildPipeline( inputType, args );
this.inputType = inputType;
this.childFactories = childFactories;
this._construct();
this._reset( args, env );
// FIXME: pass actual title?
this.loopAndDepthCheck = new LoopAndDepthCheck( null );
}
// Inherit from TokenTransformManager, and thus also from EventEmitter.
AsyncTokenTransformManager.prototype = new TokenTransformManager();
AsyncTokenTransformManager.prototype.constructor = AsyncTokenTransformManager;
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/**
* Create a new child pipeline.
*
* @method
* @param {String} Input type, currently only support 'text/wiki'.
* @param {Object} Template arguments
* @returns {Object} Pipeline, which is an object with 'first' pointing to the
* first stage of the pipeline, and 'last' pointing to the last stage.
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*/
AsyncTokenTransformManager.prototype.newChildPipeline = function ( inputType, args, title ) {
//console.warn( 'newChildPipeline: ' + JSON.stringify( args ) );
var pipe = this.childFactories.input( inputType, args );
// now set up a few things on the child AsyncTokenTransformManager.
var child = pipe.last;
// We assume that the title was already checked against this.loopAndDepthCheck
// before!
child.loopAndDepthCheck = new LoopAndDepthCheck (
this.loopAndDepthCheck,
this.env.normalizeTitle( this.env.tokensToString ( title ) )
);
child.title = title;
return pipe;
};
/**
* Create a pipeline for attribute transformations.
*
* @method
* @param {String} Input type, currently only support 'text/wiki'.
* @param {Object} Template arguments
* @returns {Object} Pipeline, which is an object with 'first' pointing to the
* first stage of the pipeline, and 'last' pointing to the last stage.
*/
AsyncTokenTransformManager.prototype.getAttributePipeline = function ( inputType, args ) {
var pipe = this.childFactories.attributes( inputType, args );
var child = pipe.last;
child.title = this.title;
child.loopAndDepthCheck = new LoopAndDepthCheck ( this.loopAndDepthCheck, '' );
return pipe;
};
/**
* Reset the internal token and outstanding-callback state of the
* TokenTransformManager, but keep registrations untouched.
*
* @method
* @param {Object} args, template arguments
* @param {Object} The environment.
*/
AsyncTokenTransformManager.prototype._reset = function ( args, env ) {
// Note: Much of this is frame-like.
this.tailAccumulator = undefined;
// eventize: bend to event emitter callback
this.tokenCB = this._returnTokens.bind( this );
this.prevToken = undefined;
//console.warn( 'AsyncTokenTransformManager args ' + JSON.stringify( args ) );
if ( ! args ) {
this.args = {}; // no arguments at the top level
} else {
this.args = args;
}
if ( ! env ) {
if ( !this.env ) {
throw "AsyncTokenTransformManager: environment needed!" + env;
}
} else {
this.env = env;
}
};
/**
* Simplified wrapper that processes all tokens passed in
*/
AsyncTokenTransformManager.prototype.process = function ( tokens ) {
if ( ! $.isArray ( tokens ) ) {
tokens = [tokens];
}
this.onChunk( tokens );
this.onEndEvent();
};
/**
* Transform and expand tokens. Transformed token chunks will be emitted in
* the 'chunk' event.
*
* @method
* @param {Array} chunk of tokens
*/
AsyncTokenTransformManager.prototype.onChunk = function ( tokens ) {
// Set top-level callback to next transform phase
var res = this.transformTokens ( tokens, this.tokenCB );
this.env.dp( 'AsyncTokenTransformManager onChunk res.async=',
res.async, ' tokens=', tokens );
if ( ! this.tailAccumulator ) {
this.emit( 'chunk', res.tokens );
} else {
this.tailAccumulator.append( res.tokens );
}
if ( res.async ) {
this.tailAccumulator = res.async;
this.tokenCB = res.async.getParentCB ( 'sibling' );
}
//this.phase2TailCB( tokens, true );
// The next processed chunk should call back as a sibling to last
// accumulator, if any.
if ( res.async ) {
}
};
/**
* Run transformations from phases 0 and 1. This includes starting and
* managing asynchronous transformations.
*
*/
AsyncTokenTransformManager.prototype.transformTokens = function ( tokens, parentCB ) {
//console.warn('AsyncTokenTransformManager.transformTokens: ' + JSON.stringify(tokens) );
var res,
phaseEndRank = 2, // XXX: parametrize!
// Prepare a new accumulator, to be used by async children (if any)
localAccum = [],
accum = new TokenAccumulator( this, parentCB ),
cb = accum.getParentCB( 'child' ),
activeAccum = null,
tokensLength = tokens.length,
token,
ts = this.transformers;
for ( var i = 0; i < tokensLength; i++ ) {
token = tokens[i];
switch ( token.constructor ) {
case String:
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res = this._transformToken( token, phaseEndRank, ts.text, cb );
break;
case NlTk:
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res = this._transformToken( token, phaseEndRank, ts.newline, cb );
break;
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case TagTk:
case EndTagTk:
case SelfclosingTagTk:
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res = this._transformTagToken( token, phaseEndRank, cb );
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break;
default:
switch( token.type ) {
case 'COMMENT':
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res = this._transformToken( token, phaseEndRank, ts.comment, cb );
break;
case 'END':
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res = this._transformToken( token, phaseEndRank, ts.end, cb );
break;
default:
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res = this._transformToken( token, phaseEndRank, ts.martian, cb );
break;
}
break;
}
if( res.tokens ) {
// Splice in the returned tokens (while replacing the original
// token), and process them next.
[].splice.apply( tokens, [i, 1].concat(res.tokens) );
tokensLength = tokens.length;
i--; // continue at first inserted token
} else if ( res.token ) {
if ( res.token.rank === 2 ) {
// token is done.
if ( activeAccum ) {
// push to accumulator
activeAccum.push( res.token );
} else {
// If there is no accumulator yet, then directly return the
// token to the parent. Collect them in localAccum for this
// purpose.
localAccum.push( res.token );
}
} else {
// re-process token.
tokens[i] = res.token;
i--;
}
} else if ( res.async ) {
//console.warn( 'tokens returned' );
// The child now switched to activeAccum, we have to create a new
// accumulator for the next potential child.
activeAccum = accum;
accum = new TokenAccumulator( this, activeAccum.getParentCB( 'sibling' ) );
cb = accum.getParentCB( 'child' );
}
}
// Return finished tokens directly to caller, and indicate if further
// async actions are outstanding. The caller needs to point a sibling to
// the returned accumulator, or call .siblingDone() to mark the end of a
// chain.
return { tokens: localAccum, async: activeAccum };
};
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/**
* Callback from tokens fully processed for phase 0 and 1, which are now ready
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* for synchronous and globally in-order phase 2 processing. Thus each async
* transform is responsible for fully processing its returned tokens to the
* end of phase2.
*
* @method
* @param {Array} chunk of tokens
* @param {Mixed} Either a falsy value if this is the last callback
* (everything is done), or a truish value if not yet done.
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*/
AsyncTokenTransformManager.prototype._returnTokens = function ( tokens, notYetDone ) {
//tokens = this._transformPhase2( this.frame, tokens, this.parentCB );
//if ( tokens.length && tokens[tokens.length - 1].type === 'END' ) {
// this.env.dp( 'AsyncTokenTransformManager, stripping end ' );
// tokens.pop();
//}
this.env.dp( 'AsyncTokenTransformManager._returnTokens, emitting chunk: ',
tokens );
this.emit( 'chunk', tokens );
if ( ! notYetDone ) {
//console.warn('AsyncTokenTransformManager._returnTokens done. tokens:' +
// JSON.stringify( tokens, null, 2 ) + ', listeners: ' +
// JSON.stringify( this.listeners( 'chunk' ), null, 2 ) );
// signal our done-ness to consumers.
//if ( this.atTopLevel ) {
// this.emit( 'chunk', [{type: 'END'}]);
//}
this.emit( 'end' );
// and reset internal state.
this._reset();
}
};
/**
* Callback for the end event emitted from the tokenizer.
* Either signals the end of input to the tail of an ongoing asynchronous
* processing pipeline, or directly emits 'end' if the processing was fully
* synchronous.
*/
AsyncTokenTransformManager.prototype.onEndEvent = function () {
if ( this.tailAccumulator ) {
this.env.dp( 'AsyncTokenTransformManager.onEndEvent: calling siblingDone',
this.loopAndDepthCheck );
this.tailAccumulator.siblingDone();
} else {
// nothing was asynchronous, so we'll have to emit end here.
this.env.dp( 'AsyncTokenTransformManager.onEndEvent: synchronous done',
this.loopAndDepthCheck );
this.emit('end');
this._reset();
}
};
/*************** In-order, synchronous transformer (phase 1 and 3) ***************/
/**
* Subclass for phase 3, in-order and synchronous processing.
*
* @class
* @constructor
* @param {Object} environment.
*/
function SyncTokenTransformManager ( env, phaseEndRank, inputType ) {
// both inherited
this._construct();
this.phaseEndRank = phaseEndRank;
this.args = {}; // no arguments at the top level
this.env = env;
this.inputType = inputType;
}
// Inherit from TokenTransformManager, and thus also from EventEmitter.
SyncTokenTransformManager.prototype = new TokenTransformManager();
SyncTokenTransformManager.prototype.constructor = SyncTokenTransformManager;
SyncTokenTransformManager.prototype.process = function ( tokens ) {
if ( ! $.isArray ( tokens ) ) {
tokens = [tokens];
}
this.onChunk( tokens );
this.onEndEvent();
};
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/**
* Global in-order and synchronous traversal on token stream. Emits
* transformed chunks of tokens in the 'chunk' event.
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*
* @method
* @param {Array} Token chunk.
*/
SyncTokenTransformManager.prototype.onChunk = function ( tokens ) {
this.env.dp( 'SyncTokenTransformManager.onChunk, input: ', tokens );
var res,
localAccum = [],
localAccumLength = 0,
tokensLength = tokens.length,
cb, // XXX: not meaningful for purely synchronous processing!
token,
// Top-level frame only in phase 3, as everything is already expanded.
ts = this.transformers;
for ( var i = 0; i < tokensLength; i++ ) {
token = tokens[i];
switch( token.constructor ) {
case String:
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res = this._transformToken( token, this.phaseEndRank,
ts.text, this.prevToken );
break;
case NlTk:
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res = this._transformToken( token, this.phaseEndRank, ts.newline, this.prevToken );
break;
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case TagTk:
case EndTagTk:
case SelfclosingTagTk:
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res = this._transformTagToken( token, this.phaseEndRank, this.prevToken );
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break;
default:
switch( token.type ) {
case 'COMMENT':
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res = this._transformToken( token, this.phaseEndRank, ts.comment, this.prevToken );
break;
case 'END':
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res = this._transformToken( token, this.phaseEndRank, ts.end, this.prevToken );
break;
default:
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res = this._transformToken( token, this.phaseEndRank, ts.martian, this.prevToken );
break;
}
}
if( res.tokens ) {
// Splice in the returned tokens (while replacing the original
// token), and process them next.
[].splice.apply( tokens, [i, 1].concat(res.tokens) );
tokensLength = tokens.length;
i--; // continue at first inserted token
} else if ( res.token ) {
if ( res.token.rank === this.phaseEndRank ) {
// token is done.
localAccum.push(res.token);
this.prevToken = res.token;
} else {
// re-process token.
tokens[i] = res.token;
i--;
}
}
}
this.env.dp( 'SyncTokenTransformManager.onChunk: emitting ', localAccum );
this.emit( 'chunk', localAccum );
};
/**
* Callback for the end event emitted from the tokenizer.
* Either signals the end of input to the tail of an ongoing asynchronous
* processing pipeline, or directly emits 'end' if the processing was fully
* synchronous.
*/
SyncTokenTransformManager.prototype.onEndEvent = function () {
// This phase is fully synchronous, so just pass the end along and prepare
// for the next round.
this.emit('end');
};
/********************** AttributeTransformManager *************************/
/**
* Utility transformation manager for attributes, using an attribute
* transformation pipeline (normally phase1 SyncTokenTransformManager and
* phase2 AsyncTokenTransformManager). This pipeline needs to be independent
* of the containing TokenTransformManager to isolate transforms from each
* other. The AttributeTransformManager returns its result by calling the
* supplied callback.
*
* @class
* @constructor
* @param {Object} Containing TokenTransformManager
*/
function AttributeTransformManager ( manager, callback ) {
this.manager = manager;
this.callback = callback;
this.outstanding = 1;
this.kvs = [];
//this.pipe = manager.getAttributePipeline( manager.args );
}
AttributeTransformManager.prototype.process = function ( attributes ) {
// Potentially need to use multiple pipelines to support concurrent async expansion
//this.pipe.process(
var pipe,
ref;
//console.warn( 'AttributeTransformManager.process: ' + JSON.stringify( attributes ) );
// transform each argument (key and value), and handle asynchronous returns
for ( var i = 0, l = attributes.length; i < l; i++ ) {
var kv = { key: [], value: [] };
this.kvs.push( kv );
var cur = attributes[i];
if ( ! cur ) {
console.warn( JSON.stringify( attributes ) );
console.trace();
continue;
}
if ( cur.k.constructor !== String ) {
// Assume that the return is async, will be decremented in callback
this.outstanding++;
// transform the key
pipe = this.manager.getAttributePipeline( this.manager.inputType,
this.manager.args );
pipe.addListener( 'chunk',
this.onChunk.bind( this, this._returnAttributeKey.bind( this, i ) )
);
pipe.addListener( 'end',
this.onEnd.bind( this, this._returnAttributeKey.bind( this, i ) )
);
pipe.process( attributes[i].k.concat([{type:'END'}]) );
} else {
kv.key = cur.k;
}
if ( cur.v.constructor !== String ) {
// Assume that the return is async, will be decremented in callback
this.outstanding++;
// transform the value
pipe = this.manager.getAttributePipeline( this.manager.inputType,
this.manager.args );
pipe.addListener( 'chunk',
this.onChunk.bind( this, this._returnAttributeValue.bind( this, i ) )
);
pipe.addListener( 'end',
this.onEnd.bind( this, this._returnAttributeValue.bind( this, i ) )
);
//console.warn('starting attribute transform of ' + JSON.stringify( attributes[i].v ) );
pipe.process( cur.v.concat([{type:'END'}]) );
} else {
kv.value = cur.v;
}
}
this.outstanding--;
if ( this.outstanding === 0 ) {
this._returnAttributes();
// synchronous / done
return true;
} else {
// async, will call back
this.async = true;
return false;
}
};
AttributeTransformManager.prototype._returnAttributes = function ( ) {
// convert attributes
var out = [];
for ( var i = 0, l = this.kvs.length; i < l; i++ ) {
var kv = this.kvs[i];
out.push( new KV( kv.key, kv.value ) );
}
// and call the callback with the result
//this.manager.env.dp('AttributeTransformManager._returnAttributes: ' +
// JSON.stringify( out ) );
this.callback( out, this.async );
};
/**
* Collect chunks returned from the pipeline
*/
AttributeTransformManager.prototype.onChunk = function ( cb, chunk ) {
if ( chunk.length && chunk[chunk.length - 1].type === 'END' ) {
chunk.pop();
}
cb( chunk, true );
};
/**
* Empty the pipeline by returning to the parent
*/
AttributeTransformManager.prototype.onEnd = function ( cb ) {
cb( [], false );
};
/**
* Callback for async argument value expansions
*/
AttributeTransformManager.prototype._returnAttributeValue = function ( ref, tokens, notYetDone ) {
//console.warn( 'check _returnAttributeValue: ' + JSON.stringify( tokens ) +
// ' notYetDone:' + notYetDone );
this.kvs[ref].value = this.kvs[ref].value.concat( tokens );
if ( ! notYetDone ) {
this.outstanding--;
if ( this.outstanding === 0 ) {
// this calls back to frame.cb, so no return here.
this._returnAttributes();
}
}
};
/**
* Callback for async argument key expansions
*/
AttributeTransformManager.prototype._returnAttributeKey = function ( ref, tokens, notYetDone ) {
//console.warn( 'check _returnAttributeKey: ' + JSON.stringify( tokens ) +
// ' notYetDone:' + notYetDone );
this.kvs[ref].key = this.kvs[ref].key.concat( tokens );
if ( ! notYetDone ) {
this.outstanding--;
if ( this.outstanding === 0 ) {
// this calls back to frame.cb, so no return here.
this._returnAttributes();
}
}
};
/******************************* TokenAccumulator *************************/
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/**
* Token accumulators buffer tokens between asynchronous processing points,
* and return fully processed token chunks in-order and as soon as possible.
* They support the AsyncTokenTransformManager.
2011-12-13 20:13:09 +00:00
*
* @class
* @constructor
* @param {Object} next TokenAccumulator to link to
* @param {Array} (optional) tokens, init accumulator with tokens or []
*/
function TokenAccumulator ( manager, parentCB ) {
this.manager = manager;
this.parentCB = parentCB;
this.accum = [];
// Wait for child and sibling by default
// Note: Need to decrement outstanding on last accum
// in a chain.
this.outstanding = 2;
}
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/**
* Curry a parentCB with the object and reference.
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*
* @method
* @param {Object} TokenAccumulator
* @param {misc} Reference / key for callback
* @returns {Function}
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*/
TokenAccumulator.prototype.getParentCB = function ( reference ) {
return this._returnTokens.bind( this, reference );
};
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/**
* Pass tokens to an accumulator
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*
* @method
* @param {Object} token
*/
TokenAccumulator.prototype._returnTokens = function ( reference, tokens, notYetDone ) {
var res,
cb,
returnTokens = [];
if ( ! notYetDone ) {
this.outstanding--;
}
//console.warn( 'TokenAccumulator._returnTokens' );
if ( reference === 'child' ) {
tokens = tokens.concat( this.accum );
this.manager.env.dp( 'TokenAccumulator._returnTokens child: ',
tokens, ' outstanding: ', this.outstanding );
this.accum = [];
this.parentCB( tokens, this.outstanding );
return null;
} else {
// sibling
if ( this.outstanding === 0 ) {
tokens = this.accum.concat( tokens );
// A sibling will transform tokens, so we don't have to do this
// again.
this.manager.env.dp( 'TokenAccumulator._returnTokens: ',
'sibling done and parentCB ',
tokens );
this.parentCB( tokens, false );
return null;
} else if ( this.outstanding === 1 && notYetDone ) {
this.manager.env.dp( 'TokenAccumulator._returnTokens: ',
'sibling done and parentCB but notYetDone ',
tokens );
// Sibling is not yet done, but child is. Return own parentCB to
// allow the sibling to go direct, and call back parent with
// tokens. The internal accumulator is empty at this stage, as its
// tokens are passed to the parent when the child is done.
return this.parentCB( tokens, true);
} else {
this.accum = this.accum.concat( tokens );
this.manager.env.dp( 'TokenAccumulator._returnTokens: sibling done, but not overall. notYetDone=',
notYetDone, ', this.outstanding=', this.outstanding,
', this.accum=', this.accum, ' manager.title=', this.manager.title );
}
}
};
/**
* Mark the sibling as done (normally at the tail of a chain).
2011-12-13 20:13:09 +00:00
*/
TokenAccumulator.prototype.siblingDone = function () {
//console.warn( 'TokenAccumulator.siblingDone: ' );
this._returnTokens ( 'sibling', [], false );
};
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/**
* Push a token into the accumulator
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*
* @method
* @param {Object} token
2011-12-13 20:13:09 +00:00
*/
TokenAccumulator.prototype.push = function ( token ) {
return this.accum.push(token);
};
/**
* Append tokens to an accumulator
*
* @method
* @param {Object} token
*/
TokenAccumulator.prototype.append = function ( token ) {
this.accum = this.accum.concat( token );
};
/**
* Loop check helper class for AsyncTokenTransformManager.
*
* We use a bottom-up linked list to allow sharing of paths between async
* expansions.
*
* @class
* @constructor
*/
function LoopAndDepthCheck ( parent, title ) {
if ( parent ) {
this.depth = parent.depth + 1;
this.parent = parent;
} else {
this.depth = 0;
this.parent = null;
}
this.title = title;
}
/**
* Check if expanding <title> would lead to a loop.
*
* @method
* @param {String} Title to check.
*/
LoopAndDepthCheck.prototype.check = function ( title, maxDepth ) {
// XXX: set limit really low for testing!
if ( this.depth > maxDepth ) {
// too deep
//console.warn( 'Loopcheck: ' + JSON.stringify( this, null, 2 ) );
return 'Error: Expansion depth limit exceeded at ';
}
var elem = this;
do {
//console.warn( 'loop check: ' + title + ' vs ' + elem.title );
if ( elem.title === title ) {
// Loop detected
return 'Error: Expansion loop detected at ';
}
elem = elem.parent;
} while ( elem );
// No loop detected.
return false;
};
if (typeof module == "object") {
module.exports.AsyncTokenTransformManager = AsyncTokenTransformManager;
module.exports.SyncTokenTransformManager = SyncTokenTransformManager;
module.exports.AttributeTransformManager = AttributeTransformManager;
}