sumeru
Version:
A Realtime Javascript RIA Framework For Mobile WebApp
274 lines (240 loc) • 9.64 kB
JavaScript
var runnable =function(fw){
var idField = fw.idField;
var isArray = function(obj) {
if (Array.isArray) {
return Array.isArray(obj);
} else if (Object.prototype.toString.call(obj) == '[object Array]') {
return true;
};
return false;
};
var fdTools = {};
fdTools.insert = function(cnt){return fdTools.createStruct("insert",cnt)};//cnt: {key1:value1,....}
fdTools.update = function(cnt,id){return fdTools.createStruct("update",cnt,id)};//cnt: {key1:value1,....}/value || 这里包括了collection和array的update
fdTools.delete = function(cnt){return fdTools.createStruct("delete",cnt)};//cnt: id
fdTools.append = function(cnt){return fdTools.createStruct("append",cnt)};//cnt: [item1,item2]
fdTools.splice = function(cnt){return fdTools.createStruct("splice",cnt)};//cnt: [start,end]
fdTools.createStruct = function(type,cnt,id){
var struct = {
"type":type,
"cnt":cnt
};
if(typeof id != 'undefined'){
struct.id = id;
}
return struct;
};
fdTools.compareObj = function(A,B){
return JSON.stringify(A)==JSON.stringify(B);
};
//FIXME 这里还是应该跟端上的Collection统一考虑
var findDiff = function(data, snapshot, modelName){
var collectionDiff = function(cur,snap,modelName){
var diffResult = [],
deleteDelta = [],
hasDelete = false,
curIdMap = {} ,snapIdMap = {} ,curLen,snapLen,
_diff = [];
if(typeof cur != 'undefined' && isArray(cur)){
curLen = cur.length;
}else{
cur = [];
curLen = 0;
};
if(typeof snap != 'undefined' && isArray(snap)){
snapLen = snap.length;
}else{
snap = [];
snapLen = 0;
};
if(typeof snap != 'undefined' && isArray(snap)){
for(var i=0;i<snapLen;i++){
snapIdMap[snap[i][idField]] = {
rownum : i,
existed : false
}
}
};
for(var i=0;i<curLen;i++){
if(typeof snapIdMap[cur[i][idField]] != 'undefined'){
_diff = modelDiff(cur[i],
snap[snapIdMap[cur[i][idField]]['rownum']],
modelName);
if(_diff.length>0){
diffResult.push(fdTools.update(_diff,cur[i][idField]));
}
snapIdMap[cur[i][idField]]['existed'] = true;
}else{//insert
diffResult.push(fdTools.insert(cur[i]));
}
}
for(var p in snapIdMap){
if(snapIdMap[p]['existed'] == false){//delete
deleteDelta.push(p);
hasDelete = true;
}
}
if(hasDelete){
diffResult.push(fdTools.delete(deleteDelta));
}
return diffResult;
};
var modelDiff = function(cur,snap,modelName){
var diffResult = [],
insertDelta = {}, updateDelta = {}, deleteDelta = [],
hasInsert = false, hasUpdate = false, hasDelete = false,
_diff = [];
var modelTemp = fw.server_model.getModelTemp(modelName);
for(var p in modelTemp){
var field = modelTemp[p];
if (p == '_id') {
continue;
};
if(typeof field != 'undefined'){
if(typeof cur[p] == 'undefined'){
if(typeof snap[p] != 'undefined'){
deleteDelta.push(p);
hasDelete = true;
}else{
continue;
}
}
if(typeof snap[p] == 'undefined'){
if(typeof cur[p] != 'undefined'){
insertDelta[p] = cur[p];
hasInsert = true;
}else{
continue;
}
}
if(field['type']=='model'){//model比较
if(field['relation']=='many'){
_diff = collectionDiff(cur[p], snap[p],field['model']);
}else{
_diff = modelDiff(cur[p], snap[p],field['model']);
}
if(_diff.length>0){
updateDelta[p] = _diff;
hasUpdate = true;
}
}else if(field['type']=='object'){
_diff = objDiff(cur[p], snap[p]);
if(_diff.length>0){
updateDelta[p] = _diff;
hasUpdate = true;
}
}/* array 的问题在于客户端的提交延迟补差，不能准确判断append
else if(field['type']=='array'){
_diff = arrayDiff(cur[p], snap[p]);
if(_diff.length>0){
updateDelta[p] = _diff;
hasUpdate = true;
}
}*/else{//简单对象比较
if(!fdTools.compareObj(cur[p], snap[p])){
updateDelta[p] = cur[p];
hasUpdate = true;
}
}
}
}
if(hasInsert){
diffResult.push(fdTools.insert(insertDelta));
}
if(hasUpdate){
diffResult.push(fdTools.update(updateDelta));
}
if(hasDelete){
diffResult.push(fdTools.insert(deleteDelta));
}
return diffResult;
}
//亲，obj也有增删改哦,删除的只给出key
var objDiff = function(cur ,snap){
var diffResult = [],
insertDelta = {}, updateDelta = {}, deleteDelta = [],
hasInsert = false, hasUpdate = false, hasDelete = false;
for(var p in snap){//以快照为基准
if(typeof cur[p] != 'undefined'){
if(!fdTools.compareObj(snap[p], cur[p])){
updateDelta[p] = cur[p];
hasUpdate = true;
}
}else{
deleteDelta.push(p);
hasDelete = true;
}
}
for(var p in cur){
if(typeof snap[p] == 'undefined'){
insertDelta[p] = cur[p];
hasInsert = true;
}
}
if(hasInsert){
diffResult.push(fdTools.insert(insertDelta));
}
if(hasUpdate){
diffResult.push(fdTools.update(updateDelta));
}
if(hasDelete){
diffResult.push(fdTools.insert(deleteDelta));
}
return diffResult;
}
var arrayDiff = function(cur,snap){/*,compareObj*/
var diffResult = [],
insertDelta = {}, updateDelta = {}, deleteDelta = [],
hasInsert = false, hasUpdate = false, hasDelete = false,
curLen,snapLen;
if(typeof cur != 'undefined' && isArray(cur)){
curLen = cur.length;
}else{
cur = [];
curLen = 0;
};
if(typeof snap != 'undefined' && isArray(snap)){
snapLen = snap.length;
}else{
snap = [];
snapLen = 0;
};
if(curLen > 0){//有新数据
if(snapLen > 0){//有快照
var compareLen = Math.min(curLen,snapLen);
//比较重叠部分
for(var i=0;i<compareLen;i++){//遍历快照
if(!fdTools.compareObj(cur[i], snap[i])){
diffResult.push(fdTools.update(cur[i],i));
}
}
//需插入
if(curLen>compareLen){
diffResult.push(fdTools.append(cur.splice(compareLen)));
}
//需splice
if(snapLen>compareLen){
diffResult.push(fdTools.splice(compareLen));
}
}else{//无快照，直接append
diffResult.push(fdTools.append(cur));
}
}else{//无新数据，直接splice
diffResult.push(fdTools.splice([0]));
}
return diffResult
}
/**
* 要存储的对象和其上一次保存后的快照比较形成diff
*/
if(modelName){
return collectionDiff(data, snapshot, modelName);
}else{
return objDiff(data, snapshot, modelName);
}
};
return findDiff;
}
if(typeof module !='undefined' && module.exports){
module.exports = runnable;
}