mediawiki-extensions-Visual.../modules/ve/dm/ve.dm.TransactionProcessor.js
Ed Sanders e01e2e045b Always use #getDocumentNode.
Because if you only sometimes use a getter you're just wasting your time!

Change-Id: Idd38976f77b58e322d527cecca9f9c36e3ad9318
2013-12-04 22:55:26 +00:00

500 lines
16 KiB
JavaScript

/*!
* VisualEditor DataModel TransactionProcessor class.
*
* @copyright 2011-2013 VisualEditor Team and others; see AUTHORS.txt
* @license The MIT License (MIT); see LICENSE.txt
*/
/**
* DataModel transaction processor.
*
* This class reads operations from a transaction and applies them one by one. It's not intended
* to be used directly; use {ve.dm.Document#commit} instead.
*
* NOTE: Instances of this class are not recyclable: you can only call .process() on them once.
*
* @class
* @param {ve.dm.Document} doc Document
* @param {ve.dm.Transaction} transaction Transaction
* @constructor
*/
ve.dm.TransactionProcessor = function VeDmTransactionProcessor( doc, transaction ) {
// Properties
this.document = doc;
this.transaction = transaction;
this.operations = transaction.getOperations();
this.synchronizer = new ve.dm.DocumentSynchronizer( doc, transaction );
// Linear model offset that we're currently at. Operations in the transaction are ordered, so
// the cursor only ever moves forward.
this.cursor = 0;
this.metadataCursor = 0;
// Adjustment used to convert between linear model offsets in the original linear model and
// in the half-updated linear model.
this.adjustment = 0;
// Set and clear are sets of annotations which should be added or removed to content being
// inserted or retained.
this.set = new ve.dm.AnnotationSet( this.document.getStore() );
this.clear = new ve.dm.AnnotationSet( this.document.getStore() );
};
/* Static members */
/* See ve.dm.TransactionProcessor.processors */
ve.dm.TransactionProcessor.processors = {};
/* Methods */
/**
* Get the next operation.
*
* @method
*/
ve.dm.TransactionProcessor.prototype.nextOperation = function () {
return this.operations[this.operationIndex++] || false;
};
/**
* Execute an operation.
*
* @method
* @param {Object} op Operation object to execute
* @throws {Error} Operation type is not supported
*/
ve.dm.TransactionProcessor.prototype.executeOperation = function ( op ) {
if ( op.type in ve.dm.TransactionProcessor.processors ) {
ve.dm.TransactionProcessor.processors[op.type].call( this, op );
} else {
throw new Error( 'Invalid operation error. Operation type is not supported: ' + op.type );
}
};
/**
* Advance the main data cursor.
*
* @method
* @param {number} increment Number of positions to increment the cursor by
*/
ve.dm.TransactionProcessor.prototype.advanceCursor = function ( increment ) {
this.cursor += increment;
this.metadataCursor = 0;
};
/**
* Process all operations.
*
* When all operations are done being processed, the document will be synchronized.
*
* @method
*/
ve.dm.TransactionProcessor.prototype.process = function () {
var op;
// This loop is factored this way to allow operations to be skipped over or executed
// from within other operations
this.operationIndex = 0;
while ( ( op = this.nextOperation() ) ) {
this.executeOperation( op );
}
this.synchronizer.synchronize();
// Mark the transaction as committed or rolled back, as appropriate
this.transaction.markAsApplied();
};
/**
* Apply the current annotation stacks.
*
* This will set all annotations in this.set and clear all annotations in `this.clear` on the data
* between the offsets `this.cursor` and `this.cursor + to`.
*
* @method
* @param {number} to Offset to stop annotating at, annotating starts at this.cursor
* @throws {Error} Cannot annotate a branch element
* @throws {Error} Annotation to be set is already set
* @throws {Error} Annotation to be cleared is not set
*/
ve.dm.TransactionProcessor.prototype.applyAnnotations = function ( to ) {
var item, isElement, annotated, annotations, i, range, selection,
store = this.document.getStore();
if ( this.set.isEmpty() && this.clear.isEmpty() ) {
return;
}
for ( i = this.cursor; i < to; i++ ) {
item = this.document.data.getData( i );
isElement = this.document.data.isElementData( i );
if ( isElement ) {
if ( !ve.dm.nodeFactory.isNodeContent( this.document.data.getType( i ) ) ) {
throw new Error( 'Invalid transaction, cannot annotate a non-content element' );
}
if ( this.document.data.isCloseElementData( i ) ) {
// Closing content element, ignore
continue;
}
}
annotated = isElement ? 'annotations' in item : ve.isArray( item );
annotations = annotated ?
new ve.dm.AnnotationSet( store, isElement ? item.annotations : item[1] ) :
new ve.dm.AnnotationSet( store );
// Set and clear annotations
if ( annotations.containsAnyOf( this.set ) ) {
throw new Error( 'Invalid transaction, annotation to be set is already set' );
} else {
annotations.addSet( this.set );
}
if ( !annotations.containsAllOf( this.clear ) ) {
throw new Error( 'Invalid transaction, annotation to be cleared is not set' );
} else {
annotations.removeSet( this.clear );
}
// Store annotation indexes in linear model
this.document.data.setAnnotationsAtOffset( i, annotations );
}
if ( this.cursor < to ) {
range = new ve.Range( this.cursor, to );
selection = this.document.selectNodes(
new ve.Range(
this.cursor - this.adjustment,
to - this.adjustment
),
'leaves'
);
this.synchronizer.pushAnnotation( new ve.Range( this.cursor, to ) );
}
};
/**
* Processing methods.
*
* Each method is specific to a type of action. Methods are called in the context of a transaction
* processor, so they work similar to normal methods on the object.
*
* @class ve.dm.TransactionProcessor.processors
* @singleton
*/
/**
* Execute a retain operation.
*
* This method is called within the context of a transaction processor instance.
*
* This moves the cursor by op.length and applies annotations to the characters that the cursor
* moved over.
*
* @method
* @param {Object} op Operation object:
* @param {number} op.length Number of elements to retain
*/
ve.dm.TransactionProcessor.processors.retain = function ( op ) {
this.applyAnnotations( this.cursor + op.length );
this.advanceCursor( op.length );
};
/**
* Execute a metadata retain operation.
*
* This method is called within the context of a transaction processor instance.
*
* This moves the metadata cursor by op.length.
*
* @method
* @param {Object} op Operation object:
* @param {number} op.length Number of elements to retain
*/
ve.dm.TransactionProcessor.processors.retainMetadata = function ( op ) {
this.metadataCursor += op.length;
};
/**
* Execute an annotate operation.
*
* This method is called within the context of a transaction processor instance.
*
* This will add an annotation to or remove an annotation from `this.set`or `this.clear`.
*
* @method
* @param {Object} op Operation object
* @param {string} op.method Annotation method, either 'set' to add or 'clear' to remove
* @param {string} op.bias End point of marker, either 'start' to begin or 'stop' to end
* @param {string} op.annotation Annotation object to set or clear from content
* @throws {Error} Invalid annotation method
*/
ve.dm.TransactionProcessor.processors.annotate = function ( op ) {
var target;
if ( op.method === 'set' ) {
target = this.set;
} else if ( op.method === 'clear' ) {
target = this.clear;
} else {
throw new Error( 'Invalid annotation method ' + op.method );
}
if ( op.bias === 'start' ) {
target.push( op.annotation );
} else {
target.remove( op.annotation );
}
// Tree sync is done by applyAnnotations()
};
/**
* Execute an attribute operation.
*
* This method is called within the context of a transaction processor instance.
*
* This sets the attribute named `op.key` on the element at `this.cursor` to `op.to`, or unsets it if
* `op.to === undefined`. `op.from `is not checked against the old value, but is used instead of `op.to`
* in reverse mode. So if `op.from` is incorrect, the transaction will commit fine, but won't roll
* back correctly.
*
* @method
* @param {Object} op Operation object
* @param {string} op.key Attribute name
* @param {Mixed} op.from Old attribute value, or undefined if not previously set
* @param {Mixed} op.to New attribute value, or undefined to unset
*/
ve.dm.TransactionProcessor.processors.attribute = function ( op ) {
var element = this.document.data.getData( this.cursor ),
to = op.to,
from = op.from;
if ( element.type === undefined ) {
throw new Error( 'Invalid element error, cannot set attributes on non-element data' );
}
if ( to === undefined ) {
// Clear
if ( element.attributes ) {
delete element.attributes[op.key];
}
} else {
// Automatically initialize attributes object
if ( !element.attributes ) {
element.attributes = {};
}
// Set
element.attributes[op.key] = to;
}
this.synchronizer.pushAttributeChange(
this.document.getDocumentNode().getNodeFromOffset( this.cursor + 1 ),
op.key,
from, to
);
};
/**
* Execute a replace operation.
*
* This method is called within the context of a transaction processor instance.
*
* This replaces a range of linear model data with another at this.cursor, figures out how the model
* tree needs to be synchronized, and queues this in the DocumentSynchronizer.
*
* op.remove isn't checked against the actual data (instead op.remove.length things are removed
* starting at this.cursor), but it's used instead of op.insert in reverse mode. So if
* op.remove is incorrect but of the right length, the transaction will commit fine, but won't roll
* back correctly.
*
* @method
* @param {Object} op Operation object
* @param {Array} op.remove Linear model data to remove
* @param {Array} op.insert Linear model data to insert
*/
ve.dm.TransactionProcessor.processors.replace = function ( op ) {
var node, selection, range,
remove = op.remove,
insert = op.insert,
removeMetadata = op.removeMetadata,
insertMetadata = op.insertMetadata,
removeLinearData = new ve.dm.ElementLinearData( this.document.getStore(), remove ),
insertLinearData = new ve.dm.ElementLinearData( this.document.getStore(), insert ),
removeIsContent = removeLinearData.isContentData(),
insertIsContent = insertLinearData.isContentData(),
removeHasStructure = removeLinearData.containsElementData(),
insertHasStructure = insertLinearData.containsElementData(),
operation = op,
removeLevel = 0,
insertLevel = 0,
i,
type,
prevCursor,
affectedRanges = [],
scope,
minInsertLevel = 0,
coveringRange,
scopeStart,
scopeEnd,
opAdjustment = 0,
opRemove, opInsert, opRemoveMetadata, opInsertMetadata;
if ( removeIsContent && insertIsContent ) {
// Content replacement
// Update the linear model
this.document.data.batchSplice( this.cursor, remove.length, insert );
// Keep the meta linear model in sync
if ( removeMetadata !== undefined ) {
this.document.metadata.batchSplice( this.cursor, removeMetadata.length, insertMetadata );
} else {
this.document.metadata.batchSplice( this.cursor, remove.length, new Array( insert.length ) );
}
this.applyAnnotations( this.cursor + insert.length );
// Get the node containing the replaced content
selection = this.document.selectNodes(
new ve.Range(
this.cursor - this.adjustment,
this.cursor - this.adjustment + remove.length
),
'leaves'
);
node = selection[0].node;
if (
!removeHasStructure && !insertHasStructure &&
selection.length === 1 &&
node && node.getType() === 'text'
) {
// Text-only replacement
// Queue a resize for the text node
this.synchronizer.pushResize( node, insert.length - remove.length );
} else {
// Replacement is not exclusively text
// Rebuild all covered nodes
range = new ve.Range(
selection[0].nodeOuterRange.start,
selection[selection.length - 1].nodeOuterRange.end
);
this.synchronizer.pushRebuild( range,
new ve.Range( range.start + this.adjustment,
range.end + this.adjustment + insert.length - remove.length )
);
}
// Advance the cursor
this.advanceCursor( insert.length );
this.adjustment += insert.length - remove.length;
} else {
// Structural replacement
// It's possible that multiple replace operations are needed before the
// model is back in a consistent state. This loop applies the current
// replace operation to the linear model, then keeps applying subsequent
// operations until the model is consistent. We keep track of the changes
// and queue a single rebuild after the loop finishes.
while ( true ) {
if ( operation.type === 'replace' ) {
opRemove = operation.remove;
opInsert = operation.insert;
opRemoveMetadata = operation.removeMetadata;
opInsertMetadata = operation.insertMetadata;
// Update the linear model
this.document.data.batchSplice( this.cursor, opRemove.length, opInsert );
// Keep the meta linear model in sync
if ( opRemoveMetadata !== undefined ) {
this.document.metadata.batchSplice( this.cursor, opRemoveMetadata.length, opInsertMetadata );
} else {
this.document.metadata.batchSplice( this.cursor, opRemove.length, new Array( opInsert.length ) );
}
affectedRanges.push( new ve.Range(
this.cursor - this.adjustment,
this.cursor - this.adjustment + opRemove.length
) );
prevCursor = this.cursor;
this.advanceCursor( opInsert.length );
// Paint the removed selection, figure out which nodes were
// covered, and add their ranges to the affected ranges list
if ( opRemove.length > 0 ) {
selection = this.document.selectNodes( new ve.Range(
prevCursor - this.adjustment,
prevCursor + opRemove.length - this.adjustment
), 'siblings' );
for ( i = 0; i < selection.length; i++ ) {
affectedRanges.push( selection[i].nodeOuterRange );
}
}
// Walk through the remove and insert data
// and keep track of the element depth change (level)
// for each of these two separately. The model is
// only consistent if both levels are zero.
for ( i = 0; i < opRemove.length; i++ ) {
type = opRemove[i].type;
if ( type !== undefined ) {
if ( type.charAt( 0 ) === '/' ) {
// Closing element
removeLevel--;
} else {
// Opening element
removeLevel++;
}
}
}
// Keep track of the scope of the insertion
// Normally this is the node we're inserting into, except if the
// insertion closes elements it doesn't open (i.e. splits elements),
// in which case it's the affected ancestor
for ( i = 0; i < opInsert.length; i++ ) {
type = opInsert[i].type;
if ( type !== undefined ) {
if ( type.charAt( 0 ) === '/' ) {
// Closing element
insertLevel--;
if ( insertLevel < minInsertLevel ) {
// Closing an unopened element at a higher
// (more negative) level than before
// Lazy-initialize scope
scope = scope || this.document.getNodeFromOffset( prevCursor );
// Push the full range of the old scope as an affected range
scopeStart = scope.getOffset();
scopeEnd = scopeStart + scope.getOuterLength();
affectedRanges.push( new ve.Range( scopeStart, scopeEnd ) );
// Update scope
scope = scope.getParent() || scope;
}
} else {
// Opening element
insertLevel++;
}
}
}
// Update adjustment
this.adjustment += opInsert.length - opRemove.length;
opAdjustment += opInsert.length - opRemove.length;
} else {
// We know that other operations won't cause adjustments, so we
// don't have to update adjustment
this.executeOperation( operation );
}
if ( removeLevel === 0 && insertLevel === 0 ) {
// The model is back in a consistent state, so we're done
break;
}
// Get the next operation
operation = this.nextOperation();
if ( !operation ) {
throw new Error( 'Unbalanced set of replace operations found' );
}
}
// From all the affected ranges we have gathered, compute a range that covers all
// of them, and rebuild that
coveringRange = ve.Range.newCoveringRange( affectedRanges );
this.synchronizer.pushRebuild(
coveringRange,
new ve.Range(
coveringRange.start + this.adjustment - opAdjustment,
coveringRange.end + this.adjustment
)
);
}
};
/**
* Execute a metadata replace operation.
*
* This method is called within the context of a transaction processor instance.
*
* @method
* @param {Object} op Operation object
* @param {Array} op.remove Metadata to remove
* @param {Array} op.insert Metadata to insert
*/
ve.dm.TransactionProcessor.processors.replaceMetadata = function ( op ) {
var remove = op.remove,
insert = op.insert;
this.document.spliceMetadata( this.cursor, this.metadataCursor, remove.length, insert );
this.metadataCursor += insert.length;
};