yonote/yjs
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simplify exposed APi

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This commit is contained in:
Kevin Jahns
2019-04-12 20:04:07 +02:00
parent 4582832a71
commit 07a6a0044b
6 changed files with 46 additions and 99 deletions
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10
src/utils/StructStore.js
View File

@@ -263,16 +263,6 @@ export const replaceStruct = (store, struct, newStruct) => {
structs[findIndexSS(structs, struct.id.clock)] = newStruct
}
/**
* @param {StructStore} store
* @param {ID} id
* @return {boolean}
*
* @private
* @function
*/
export const exists = (store, id) => id.clock < getState(store, id.client)
/**
* Read StateMap from Decoder and return as Map
*

108
src/utils/relativePosition.js → src/utils/cursor.js
View File

@@ -1,15 +1,15 @@
/**
* @module RelativePosition
* @module Cursors
*/
import {
find,
exists,
getItem,
getItemType,
createID,
writeID,
readID,
compareIDs,
getState,
findRootTypeKey,
AbstractItem,
ID, StructStore, Y, AbstractType // eslint-disable-line
@@ -20,31 +20,29 @@ import * as decoding from 'lib0/decoding.js'
import * as error from 'lib0/error.js'
/**
* A relative position that is based on the Yjs model. In contrast to an
* absolute position (position by index), the relative position can be
* A Cursor is a relative position that is based on the Yjs model. In contrast to an
* absolute position (position by index), the Cursor can be
* recomputed when remote changes are received. For example:
*
* ```Insert(0, 'x')('a|bc') = 'xa|bc'``` Where | is the cursor position.
*
* A relative cursor position can be obtained with the function
* {@link getRelativePosition} and it can be transformed to an absolute position
* with {@link fromRelativePosition}.
*
* One of the properties must be defined.
*
* @example
* // Current cursor position is at position 10
* let relativePosition = getRelativePosition(yText, 10)
* // modify yText
* yText.insert(0, 'abc')
* yText.delete(3, 10)
* // Compute the cursor position
* let absolutePosition = fromRelativePosition(y, relativePosition)
* absolutePosition.type // => yText
* console.log('cursor location is ' + absolutePosition.offset) // => cursor location is 3
* // Current cursor position is at position 10
* const relativePosition = createCursorFromOffset(yText, 10)
* // modify yText
* yText.insert(0, 'abc')
* yText.delete(3, 10)
* // Compute the cursor position
* const absolutePosition = toAbsolutePosition(y, relativePosition)
* absolutePosition.type === yText // => true
* console.log('cursor location is ' + absolutePosition.offset) // => cursor location is 3
*
*/
export class RelativePosition {
export class Cursor {
/**
* @param {ID|null} type
* @param {string|null} tname
@@ -81,11 +79,11 @@ export class RelativePosition {
/**
* @param {Object} json
* @return {RelativePosition}
* @return {Cursor}
*
* @function
*/
export const createRelativePositionFromJSON = json => new RelativePosition(json.type == null ? null : createID(json.type.client, json.type.clock), json.tname || null, json.item == null ? null : createID(json.item.client, json.item.clock))
export const createCursorFromJSON = json => new Cursor(json.type == null ? null : createID(json.type.client, json.type.clock), json.tname || null, json.item == null ? null : createID(json.item.client, json.item.clock))
export class AbsolutePosition {
/**
@@ -118,7 +116,7 @@ export const createAbsolutePosition = (type, offset) => new AbsolutePosition(typ
*
* @function
*/
export const createRelativePosition = (type, item) => {
export const createCursor = (type, item) => {
let typeid = null
let tname = null
if (type._item === null) {
@@ -126,7 +124,7 @@ export const createRelativePosition = (type, item) => {
} else {
typeid = type._item.id
}
return new RelativePosition(typeid, tname, item)
return new Cursor(typeid, tname, item)
}
/**
@@ -134,32 +132,32 @@ export const createRelativePosition = (type, item) => {
*
* @param {AbstractType<any>} type The base type (e.g. YText or YArray).
* @param {number} offset The absolute position.
* @return {RelativePosition}
* @return {Cursor}
*
* @function
*/
export const createRelativePositionByOffset = (type, offset) => {
export const createCursorFromTypeOffset = (type, offset) => {
let t = type._start
while (t !== null) {
if (!t.deleted && t.countable) {
if (t.length > offset) {
// case 1: found position somewhere in the linked list
return createRelativePosition(type, createID(t.id.client, t.id.clock + offset))
return createCursor(type, createID(t.id.client, t.id.clock + offset))
}
offset -= t.length
}
t = t.right
}
return createRelativePosition(type, null)
return createCursor(type, null)
}
/**
* @param {encoding.Encoder} encoder
* @param {RelativePosition} rpos
* @param {Cursor} rpos
*
* @function
*/
export const writeRelativePosition = (encoder, rpos) => {
export const writeCursor = (encoder, rpos) => {
const { type, tname, item } = rpos
if (item !== null) {
encoding.writeVarUint(encoder, 0)
@@ -182,11 +180,11 @@ export const writeRelativePosition = (encoder, rpos) => {
* @param {decoding.Decoder} decoder
* @param {Y} y
* @param {StructStore} store
* @return {RelativePosition|null}
* @return {Cursor|null}
*
* @function
*/
export const readRelativePosition = (decoder, y, store) => {
export const readCursor = (decoder, y, store) => {
let type = null
let tname = null
let itemID = null
@@ -204,28 +202,28 @@ export const readRelativePosition = (decoder, y, store) => {
type = readID(decoder)
}
}
return new RelativePosition(type, tname, itemID)
return new Cursor(type, tname, itemID)
}
/**
* @param {RelativePosition} rpos
* @param {Cursor} cursor
* @param {Y} y
* @return {AbsolutePosition|null}
*
* @function
*/
export const toAbsolutePosition = (rpos, y) => {
export const createAbsolutePositionFromCursor = (cursor, y) => {
const store = y.store
const rightID = rpos.item
const typeID = rpos.type
const tname = rpos.tname
const rightID = cursor.item
const typeID = cursor.type
const tname = cursor.tname
let type = null
let offset = 0
if (rightID !== null) {
if (!exists(store, rightID)) {
if (getState(store, rightID.client) <= rightID.clock) {
return null
}
const right = find(store, rightID)
const right = getItem(store, rightID)
if (!(right instanceof AbstractItem)) {
return null
}
@@ -255,42 +253,12 @@ export const toAbsolutePosition = (rpos, y) => {
}
/**
* Transforms an absolute to a relative position.
*
* @param {AbsolutePosition} apos The absolute position.
* @param {Y} y The Yjs instance in which to query for the absolute position.
* @return {RelativePosition} The absolute position in the Yjs model
* (type + offset).
* @param {Cursor|null} a
* @param {Cursor|null} b
*
* @function
*/
export const toRelativePosition = (apos, y) => {
const type = apos.type
if (type._length === apos.offset) {
return createRelativePosition(type, null)
} else {
let offset = apos.offset
let n = type._start
while (n !== null) {
if (!n.deleted && n.countable) {
if (n.length > offset) {
return createRelativePosition(type, createID(n.id.client, n.id.clock + offset))
}
offset -= n.length
}
n = n.right
}
}
throw error.unexpectedCase()
}
/**
* @param {RelativePosition|null} a
* @param {RelativePosition|null} b
*
* @function
*/
export const compareRelativePositions = (a, b) => a === b || (
export const compareCursors = (a, b) => a === b || (
a !== null && b !== null && a.tname === b.tname && (
(a.item !== null && b.item !== null && compareIDs(a.item, b.item)) ||
(a.type !== null && b.type !== null && compareIDs(a.type, b.type))

3
src/utils/encoding.js
View File

@@ -5,7 +5,6 @@
import {
findIndexSS,
exists,
GCRef,
ItemBinaryRef,
ItemDeletedRef,
@@ -204,7 +203,7 @@ const resumeStructIntegration = (transaction, store) => {
}
while (m.length > 0) {
const missing = m[m.length - 1]
if (!exists(store, missing)) {
if (getState(store, missing.client) <= missing.clock) {
const client = missing.client
// get the struct reader that has the missing struct
const structRefs = clientsStructRefs.get(client)