@silver-zepp/easy-storage/dist/async-storage.js

The Easy Storage library offers a suite of storage solutions designed for ZeppOS applications, providing a range of data persistence strategies to accommodate different data management needs.

/** @about Easy Storage @min_zeppos 2.0 @author: Silver, Zepp Health. @license: MIT */
import{O_CREAT,O_TRUNC,O_WRONLY,writeSync,closeSync}from"@zos/fs";import{openFile,readFile,removeFile,writeFile,str2ab,debugLog}from"./core/core";let asyncQueue=null;const TOK={T:"type",A:"__arrays",D:"data",M:"meta"};const REV={type:"T",__arrays:"A",data:"D",meta:"M"};const RESERVED_MSET={type:1,__arrays:1,data:1,meta:1,T:1,A:1,D:1,M:1};function nd_tokenEncode(rec){const out={};for(const k in rec){const tk=REV[k]||k;out[tk]=rec[k]}return JSON.stringify(out)}export function nd_tokenDecode(obj){for(const k in obj){const nk=TOK[k];if(nk&&nk!==k){obj[nk]=obj[k];delete obj[k]}}return obj}function safeCopyToMetadata(metadata,key,val,arr_data){if(key in RESERVED_MSET){if(!metadata._u)metadata._u={};metadata._u[key]=val;return}if(val&&typeof val==="object"&&val.length>>>0===val.length&&val.length){metadata[key]=val.length;if(!metadata.__arrays)metadata.__arrays=[];metadata.__arrays.push(key);arr_data[key]=val}else{metadata[key]=val}}function nd_streamJsonWrite(file,data,cb){asyncQueue.startOperation();setTimeout(()=>{let fd;let arr_data={};let metadata={type:"meta"};try{fd=openFile(file,O_WRONLY|O_CREAT|O_TRUNC)}catch(e){debugLog(1,`[ASYNC] Error opening file: ${file}`,e);asyncQueue.endOperation();if(cb)cb(e,false);return}const data_keys=Object.keys(data);let key_index=0;(function processMetadataChunk(){let done=0;const chunk_start=Date.now();while(key_index<data_keys.length&&Date.now()-chunk_start<2&&done<3){const key=data_keys[key_index++];const val=data[key];safeCopyToMetadata(metadata,key,val,arr_data);done++}if(key_index<data_keys.length){setTimeout(processMetadataChunk,2)}else{setTimeout(()=>{const out_meta={};for(const k in metadata)out_meta[REV[k]||k]=metadata[k];const metaline=JSON.stringify(out_meta)+"\n";writeSync({fd:fd,buffer:str2ab(metaline)});setTimeout(()=>buildItemsAsync(fd,arr_data,cb),2)},2)}})()},2)}function buildItemsAsync(fd,arr_data,cb){const WRITE_CHUNK=512;const keys=Object.keys(arr_data);let k=0,i=0;(function pump(){const t0=Date.now();let block="";while(k<keys.length&&Date.now()-t0<1){const key=keys[k];const arr=arr_data[key];if(i<arr.length){block+=nd_tokenEncode({type:key,data:arr[i++]})+"\n";if(block.length>=WRITE_CHUNK){writeSync({fd:fd,buffer:str2ab(block)});block=""}}else{k++;i=0}}if(block)writeSync({fd:fd,buffer:str2ab(block)});k<keys.length?setTimeout(pump,1):finalizeBuild(fd,cb)})()}function finalizeBuild(fd,cb){closeSync({fd:fd});asyncQueue.endOperation();debugLog(3,`[ASYNC] Stream write complete`);if(cb)cb(null,true)}function nd_streamJsonRead(file,cb){setTimeout(()=>{try{const cont=readFile(file);if(!cont){if(cb)cb(new Error("Empty file"),null);return}const lines=cont.trim().split("\n");if(lines.length>0){try{const first_line=nd_tokenDecode(JSON.parse(lines[0]));if(first_line.type==="meta"){nd_parseJsonAsync(lines,cb);return}}catch(e){}}const data=JSON.parse(cont);if(cb)cb(null,data)}catch(e){if(cb)cb(e,null)}},0)}function nd_parseJsonAsync(lines,cb){let idx=0;const res={};const arr_cache={};(function parseSlice(){const t0=Date.now();let done=0;while(idx<lines.length&&Date.now()-t0<1&&done<5){try{const txt=lines[idx++].trim();if(!txt)continue;const obj=nd_tokenDecode(JSON.parse(txt));if(obj.type==="meta"){const lookup={};const af=obj.__arrays||[];for(let j=0;j<af.length;j++)lookup[af[j]]=1;for(const k in obj){if(k==="type"||k==="__arrays")continue;const v=obj[k];if(lookup[k]){arr_cache[k]=[];res[k]=arr_cache[k]}else{res[k]=v}}}else{const akey=obj.type;if(!arr_cache[akey]){arr_cache[akey]=[];res[akey]=arr_cache[akey]}arr_cache[akey].push(obj.data)}done++}catch(e){debugLog(1,`[ASYNC] Parse error at line ${idx}:`,e)}}idx<lines.length?setTimeout(parseSlice,6):(debugLog(3,`[ASYNC] Parse complete: ${lines.length} lines`),cb&&cb(null,res))})()}class AsyncOperationQueue{constructor(){this.queue_arr=[];this.is_running=false;this.active_ops=0}isBusy(){return this.is_running&&(this.queue_arr.length>=4||this.active_ops>0)}getInfo(){return{running:this.is_running,queued:this.queue_arr.length,active:this.active_ops}}startOperation(){this.active_ops++}endOperation(){this.active_ops--}enqueue(operation){this.queue_arr.push(operation);this.process()}process(){if(this.is_running||this.queue_arr.length===0)return;this.is_running=true;this.processNext()}processNext(){if(this.queue_arr.length===0){this.is_running=false;return}const op=this.queue_arr.shift();op(()=>{const delay=Math.min(100+this.queue_arr.length*25,300);setTimeout(()=>this.processNext(),delay)})}emergencyStop(){debugLog(3,`[QUEUE] Emergency stop - clearing ${this.queue_arr.length} operations`);this.queue_arr=[];this.is_running=false}reset(){this.queue_arr=[];this.is_running=false;this.active_ops=0}}asyncQueue=new AsyncOperationQueue;export class AsyncStorage{static pend_writes_map=new Map;static WriteJson(filename,json,callback){this.pend_writes_map.set(filename,json);asyncQueue.enqueue(on_complete=>{nd_streamJsonWrite(filename,json,(err,success)=>{this.pend_writes_map.delete(filename);if(callback)callback(err,success);on_complete()})})}static ReadJson(filename,callback){asyncQueue.enqueue(on_complete=>{nd_streamJsonRead(filename,(err,data)=>{if(callback)callback(err,data);on_complete()})})}static RemoveFile(filename,callback){setTimeout(()=>{try{removeFile(filename);if(callback)callback(null,true)}catch(e){if(callback)callback(e,false)}},0)}static IsBusy(){return asyncQueue.isBusy()}static SaveAndQuit(){let saved_count=0;for(const[fname,data]of this.pend_writes_map.entries()){try{writeFile(fname,JSON.stringify(data));saved_count++}catch(e){debugLog(1,`Save failed: ${fname}`,e)}}this.pend_writes_map.clear();asyncQueue.reset();return{saved:saved_count}}}