mediawiki-extensions-Visual.../modules/ve/dm/ve.dm.TransactionProcessor.js
Catrope 1176bf9677 Move .commit()/.rollback() from TransactionProcessor to Document
Previously these were static functions in TransactionProcessor
which instantiated a TP called .process() on it. These are now
methods of ve.dm.Document.

Also moved the emission of the 'transact' event on the document from
TransactionProcessor to Document itself, and moved the tests asserting
double application is protected against from TP to Document (because
the corresponding code moved as well).

Change-Id: I7c9f22a14accaf0ba1f70d5aa4f0573bb7e677d0
2013-03-25 21:03:44 +00:00

596 lines
19 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 the .commit() and .rollback() methods of ve.dm.Document.
*
* NOTE: Instances of this class are not recyclable: you can only call .process() on them once.
*
* @class
* @constructor
*/
ve.dm.TransactionProcessor = function VeDmTransactionProcessor( doc, transaction, reversed ) {
// Properties
this.document = doc;
this.transaction = transaction;
this.operations = transaction.getOperations();
this.synchronizer = new ve.dm.DocumentSynchronizer( doc );
this.reversed = reversed;
// 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.AnnotationSet();
this.clear = new ve.AnnotationSet();
};
/* 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;
if ( this.reversed ) {
// Undo change markers before rolling back the transaction, because the offsets
// are relevant to the post-commit state
this.applyChangeMarkers();
// Unset the change markers we've just undone
this.transaction.clearChangeMarkers();
}
// 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();
if ( !this.reversed ) {
// Apply the change markers we've accumulated while processing the transaction
this.applyChangeMarkers();
}
// Mark the transaction as committed or rolled back, as appropriate
this.transaction.toggleApplied();
};
/**
* 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, element, type, annotated, annotations, i, range, selection, offset;
if ( this.set.isEmpty() && this.clear.isEmpty() ) {
return;
}
for ( i = this.cursor; i < to; i++ ) {
item = this.document.data[i];
element = item.type !== undefined;
if ( element ) {
type = item.type;
if ( item.type.charAt( 0 ) === '/' ) {
type = type.substr( 1 );
}
if ( !ve.dm.nodeFactory.isNodeContent( type ) ) {
throw new Error( 'Invalid transaction, cannot annotate a non-content element' );
}
if ( item.type.charAt( 0 ) === '/' ) {
// Closing content element, ignore
continue;
}
}
annotated = element ? 'annotations' in item : ve.isArray( item );
annotations = annotated ? ( element ? item.annotations : item[1] ) :
new ve.AnnotationSet();
// 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 );
}
// Auto initialize/cleanup
if ( !annotations.isEmpty() && !annotated ) {
if ( element ) {
// Initialize new element annotation
item.annotations = new ve.AnnotationSet( annotations );
} else {
// Initialize new character annotation
this.document.data[i] = [item, new ve.AnnotationSet( annotations )];
}
} else if ( annotations.isEmpty() && annotated ) {
if ( element ) {
// Cleanup empty element annotation
delete item.annotations;
} else {
// Cleanup empty character annotation
this.document.data[i] = item[0];
}
}
}
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'
);
for ( i = 0; i < selection.length; i++ ) {
offset = !selection[i].node.isWrapped() && selection[i].parentOuterRange ?
selection[i].parentOuterRange.start :
selection[i].nodeOuterRange.start;
this.setChangeMarker( offset + this.adjustment, 'annotations' );
}
this.synchronizer.pushAnnotation( new ve.Range( this.cursor, to ) );
}
};
/**
* Set a change marker on the transaction when in commit mode.
*
* This function is a no-op in rollback mode.
*
* @see ve.dm.Transaction#setChangeMarker
*
* @method
* @param {number} offset
* @param {string} type
* @param {boolean} increment
*/
ve.dm.TransactionProcessor.prototype.setChangeMarker = function ( offset, type, increment ) {
// Refuse to set any new change markers while reversing transactions
if ( !this.reversed ) {
this.transaction.setChangeMarker( offset, type, increment );
}
};
/**
* Apply the change markers on this.transaction to this.document.
*
* Change markers are set (incremented) in commit mode, and unset (decremented) in rollback mode.
*
* @method
*/
ve.dm.TransactionProcessor.prototype.applyChangeMarkers = function () {
var offset, type, previousValue, newValue, element,
markers = this.transaction.getChangeMarkers(),
m = this.reversed ? -1 : 1;
for ( offset in markers ) {
for ( type in markers[offset] ) {
offset = Number( offset );
element = this.document.data[offset];
previousValue = ve.getProp( element, 'internal', 'changed', type );
newValue = ( previousValue || 0 ) + m*markers[offset][type];
if ( newValue !== 0 ) {
ve.setProp( element, 'internal', 'changed', type, newValue );
} else if ( previousValue !== undefined ) {
// Value was set but becomes zero, delete the key
delete element.internal.changed[type];
// If that made .changed empty, delete it
if ( ve.isEmptyObject( element.internal.changed ) ) {
delete element.internal.changed;
}
// If that made .internal empty, delete it
if ( ve.isEmptyObject( element.internal ) ) {
delete element.internal;
}
}
}
}
};
/**
* 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.reversed ? this.clear : this.set;
} else if ( op.method === 'clear' ) {
target = this.reversed ? this.set : 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[this.cursor],
to = this.reversed ? op.from : op.to,
from = this.reversed ? op.to : 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.getNodeFromOffset( this.cursor + 1 ),
op.key,
from, to
);
this.setChangeMarker( this.cursor, 'attributes' );
};
/**
* 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, parentOffset,
remove = this.reversed ? op.insert : op.remove,
insert = this.reversed ? op.remove : op.insert,
removeIsContent = ve.dm.Document.isContentData( remove ),
insertIsContent = ve.dm.Document.isContentData( insert ),
removeHasStructure = ve.dm.Document.containsElementData( remove ),
insertHasStructure = ve.dm.Document.containsElementData( insert ),
operation = op,
removeLevel = 0,
insertLevel = 0,
i,
type,
prevCursor,
affectedRanges = [],
scope,
minInsertLevel = 0,
coveringRange,
scopeStart,
scopeEnd,
opAdjustment = 0,
opRemove,
opInsert;
if ( removeIsContent && insertIsContent ) {
// Content replacement
// Update the linear model
this.document.spliceData( this.cursor, remove.length, insert );
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 )
);
}
// Set change markers on the parents of the affected nodes
for ( i = 0; i < selection.length; i++ ) {
parentOffset = ( selection[i].parentOuterRange || selection[i].nodeOuterRange ).start;
this.setChangeMarker( parentOffset + this.adjustment, 'content' );
}
// 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 = this.reversed ? operation.insert : operation.remove;
opInsert = this.reversed ? operation.remove : operation.insert;
// Update the linear model for this insert
this.document.spliceData( this.cursor, opRemove.length, opInsert );
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 );
if (
selection[i].nodeOuterRange.start < prevCursor - this.adjustment &&
selection[i].node.canContainContent()
) {
// The opening element survives, so this
// node will have some of its content
// removed and/or have another node merged
// into it. Mark the node.
// TODO detect special case where closing is replaced
parentOffset = selection[i].nodeOuterRange.start + this.adjustment;
this.setChangeMarker( parentOffset, 'content' );
}
}
}
// 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 =
this.document.getDocumentNode().getOffsetFromNode( scope );
scopeEnd = scopeStart + scope.getOuterLength();
affectedRanges.push( new ve.Range( scopeStart, scopeEnd ) );
// Update scope
scope = scope.getParent() || scope;
// Set change marker
this.transaction.setChangeMarker(
scopeStart + this.adjustment,
'rebuilt'
);
}
} else {
// Opening element
insertLevel++;
// Mark as 'created'
this.setChangeMarker( prevCursor + i, 'created' );
}
}
}
// 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 = this.reversed ? op.insert : op.remove,
insert = this.reversed ? op.remove : op.insert;
this.document.spliceMetadata( this.cursor, this.metadataCursor, remove.length, insert );
};