鸿蒙next教程：压缩与解压_鸿蒙 next 解压zip
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压缩与解压
本文针对常见的几种压缩、解压场景，介绍相关函数的使用方法。
接口说明
以下是示例中使用的主要接口，更多接口及使用方式请见接口文档。
开发步骤
环境准备
在应用沙箱目录下创建一个测试文件data.txt，并写入测试数据。示例代码如下。
import { fileIo as fs} from \'@kit.CoreFileKit\';import { BusinessError, zlib } from \'@kit.BasicServicesKit\';@Entry@Componentstruct Index { @State dataSize: number = 0; build() { Row() { Column() { // 在应用沙箱目录下创建文件data.txt，并写入测试数据 Button(\'创建测试文件data.txt\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; // 创建文件data.txt let inFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); // 写入测试数据 for (let index = 0; index < 100; index++) { fs.writeSync(inFile.fd, index + \': hello world, hello world, hello world, hello world, hello world.\\n\'); } // 获取测试数据原始大小，并保存到dataSize中 let stat = fs.statSync(inFile.path); this.dataSize = stat.size; console.info(\'dataSize: \' + this.dataSize); // 关闭文件 fs.closeSync(inFile); }) } } .height(\'100%\') .width(\'100%\') }}Zip文件的压缩与解压
采用接口zlib.compressFile()将文件data.txt压缩并归档到data.zip中，采用接口zlib.decompressFile()将data.zip解压到应用沙箱目录下，示例代码如下。
import { fileIo as fs} from \'@kit.CoreFileKit\';import { BusinessError, zlib } from \'@kit.BasicServicesKit\';@Entry@Componentstruct Index { build() { Row() { // 示例一：将测试文件data.txt压缩并归档到data.zip中。 Button(\'compressFile\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = path + \'/data.txt\'; let outFile = path + \'/data.zip\'; let options: zlib.Options = {}; zlib.compressFile(inFile, outFile, options).then((data: void) => { console.info(\'compressFile success, data: \' + JSON.stringify(data)); }).catch((errData: BusinessError) => { console.error(`compressFile errCode: ${errData.code}, message: ${errData.message}`); }) }) // 示例二：将data.zip文件解压到应用沙箱目录下。 Button(\'decompressFile\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = path + \'/data.zip\'; let outFile = path; let options: zlib.Options = {}; zlib.decompressFile(inFile, outFile, options).then((data: void) => { console.info(\'decompressFile success, data: \' + JSON.stringify(data)); }).catch((errData: BusinessError) => { console.error(`decompressFile errCode: ${errData.code}, message: ${errData.message}`); }) }) } .height(\'100%\') .width(\'100%\') }}已知大小缓冲区的压缩与解压
针对一个已知大小的缓冲区中的数据，使用接口compress()将其压缩到一个目的缓冲区中，使用接口compressBound()计算压缩目的缓冲区大小的上限值，使用接口uncompress()对存储压缩数据的缓冲区进行解压。由于解压时无法获取解压后原始数据的大小，为了确认解压后目的缓冲区的大小，需要在压缩前获取原始数据的大小并保存，示例代码如下。
import { fileIo as fs} from \'@kit.CoreFileKit\';import { BusinessError, zlib } from \'@kit.BasicServicesKit\';@Entry@Componentstruct Index { @State dataSize: number = 0; //用于保存原始数据的大小 build() { Row() { // 示例一：读取data.txt文件内容并存入一个缓冲区，调用compress接口压缩缓冲区中的数据到目标缓冲区，并将目标缓冲区的内容写入文件data.bin Button(\'compress buffer\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); let outFile = fs.openSync(path + \'/data.bin\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); // 读取data.txt文件的内容，并存入缓冲区inBuf let stat = fs.statSync(inFile.path); let inBuf = new ArrayBuffer(stat.size); let readLen = fs.readSync(inFile.fd, inBuf); console.info(`original size: ${stat.size}, read len: ${readLen}`); // 获取原始数据的大小，并保存 this.dataSize = stat.size; // 创建一个压缩对象实例 let zip = zlib.createZipSync(); // 获取一个目标缓冲区的上限 zip.compressBound(stat.size).then((data) => { console.info(`the max dest buf len is ${data}`); // 目标缓冲区outBuf let outBuf = new ArrayBuffer(data); // 将inBuf中的数据压缩到outBuf中 zip.compress(outBuf, inBuf, readLen).then((zipOutInfo) => { console.info(`compress success, status ${zipOutInfo.status}, destLen ${zipOutInfo.destLen}`); // 将outBuf中的数据写入到data.bin文件 let writeLen = fs.writeSync(outFile.fd, outBuf, { length: zipOutInfo.destLen }); console.info(`write destBuf to data.bin, writeLen ${writeLen}`); // 关闭文件 fs.closeSync(inFile.fd); fs.closeSync(outFile.fd); }).catch((errData: BusinessError) => { console.error(`errData is errCode:${errData.code} message:${errData.message}`); }) }).catch((errData: BusinessError) => { console.error(`errData is errCode:${errData.code} message:${errData.message}`); }) }) // 示例二：读取data.bin文件中的压缩数据并存入一个缓冲区，调用uncompress接口将缓冲区中的数据解压到目标缓冲区，并将目标缓冲区的内容写入文件data.txt Button(\'uncompress buffer\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = fs.openSync(path + \'/data.bin\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); let outFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); // 读取data.bin文件中的压缩数据，并存入缓冲区inBuf let stat = fs.statSync(inFile.path); let inBuf = new ArrayBuffer(stat.size); let readLen = fs.readSync(inFile.fd, inBuf); console.info(`compressed data size: ${stat.size}, read len: ${readLen}`); // 创建一个目标缓冲区，此处的dataSize是我们进行数据压缩前保存的数据的原始大小 let outBuf = new ArrayBuffer(this.dataSize); console.info(`the dest buf size is ${this.dataSize}`); // 创建一个压缩对象实例 let zip = zlib.createZipSync(); // 将inBuf中的数据解压缩outBuf中 zip.uncompress(outBuf, inBuf, readLen).then((zipOutInfo) => { console.info(`uncompress success, status ${zipOutInfo.status}, destLen ${zipOutInfo.destLen}`); // 将outBuf中的数据写入到data.txt文件 let writeLen = fs.writeSync(outFile.fd, outBuf, { length: zipOutInfo.destLen }); console.info(`write destBuf to data.txt, writeLen ${writeLen}`); // 关闭文件 fs.closeSync(inFile.fd); fs.closeSync(outFile.fd); }).catch((errData: BusinessError) => { console.error(`errData is errCode:${errData.code} message:${errData.message}`); }) }) } .height(\'100%\') .width(\'100%\') }}未知大小缓冲区的压缩与解压（zlib格式）
针对一个未知大小的缓冲区中的数据，使用接口deflate()将从一个原始输入流中读取的数据进行压缩，使用接口inflate()将从一个压缩输入流中读取的数据进行解压，示例代码如下。
import { fileIo as fs} from \'@kit.CoreFileKit\';import { BusinessError, zlib } from \'@kit.BasicServicesKit\';@Entry@Componentstruct Index { build() { Row() { // 示例一：从文件中不断读取数据进行压缩 Button(\'deflateFile\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); let outFile = fs.openSync(path + \'/data.bin\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); deflateFile(inFile, outFile).then(() => { console.info(\'deflateFile success\'); fs.closeSync(inFile.fd); fs.closeSync(outFile.fd); }) }) // 示例二：从文件中不断读取压缩数据进行解压 Button(\'inflateFile\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = fs.openSync(path + \'/data.bin\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); let outFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); inflateFile(inFile, outFile).then(() => { console.info(\'deflateFile success\'); fs.closeSync(inFile.fd); fs.closeSync(outFile.fd); }) }) } .height(\'100%\') .width(\'100%\') }}// 从一个文件中，不断的读入数据，进行压缩，并写入到另一个文件中async function deflateFile(src: fs.File, dest: fs.File) { let flush = zlib.CompressFlushMode.NO_FLUSH; let strm: zlib.ZStream = {}; //初始化一个压缩流 const BUFLEN = 4096; let inBuf = new ArrayBuffer(BUFLEN); // 初始化一个输入缓冲区 let outBuf = new ArrayBuffer(BUFLEN); // 初始化一个输出缓冲区 // 创建一个压缩对象实例 let zip = zlib.createZipSync(); // 初始化流的状态 let initStatus = zip.deflateInit(strm, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED); console.info(\'deflateInit ret: \' + (await initStatus).valueOf()); do { // 从文件中读取数据到缓冲区 let readLen = fs.readSync(src.fd, inBuf); console.info(\"readSync readLen: \" + readLen); flush = readLen == 0 ? zlib.CompressFlushMode.FINISH : zlib.CompressFlushMode.NO_FLUSH; // 设置输入缓冲区 strm.availableIn = readLen; strm.nextIn = inBuf; do { // 设置输出缓冲区 strm.availableOut = BUFLEN; strm.nextOut = outBuf; try { // 压缩输入缓冲区中数据到输出缓冲区 let deflateStatus = zip.deflate(strm, flush); console.info(\'deflate ret: \' + (await deflateStatus).valueOf()); // 更新流的状态 let innerStrm = zip.getZStream(); strm.availableIn = (await innerStrm).availableIn; strm.nextIn = (await innerStrm).nextIn; strm.availableOut = (await innerStrm).availableOut; strm.nextOut = (await innerStrm).nextOut; strm.totalIn = (await innerStrm).totalIn; strm.totalOut = (await innerStrm).totalOut; if (strm.availableOut != undefined) { // 将已完成压缩的数据，写入到输出文件中 let have = BUFLEN - strm.availableOut; let writeLen = fs.writeSync(dest.fd, outBuf, { length: have }); console.info(`writeSync writeLen: ${writeLen}`); } } catch (err) { console.error(\'deflate err: \' + JSON.stringify(err)); } } while (strm.availableOut == 0); // 循环压缩输入缓冲区中剩余的数据，直到全部完成压缩 } while (flush != zlib.CompressFlushMode.FINISH); // 循环从文件中读取数据，直到数据全部读取 // 释放资源 zip.deflateEnd(strm);}// 从一个文件中，不断的读入已压缩的数据，进行解压，并写入到另一个文件中async function inflateFile(src: fs.File, dest: fs.File) { let status: zlib.ReturnStatus = zlib.ReturnStatus.OK; let strm: zlib.ZStream = {}; //初始化一个压缩流 const BUFLEN = 4096; let inBuf = new ArrayBuffer(BUFLEN); // 初始化一个输入缓冲区 let outBuf = new ArrayBuffer(BUFLEN); // 初始化一个输出缓冲区 // 创建一个压缩对象实例 let zip = zlib.createZipSync(); // 初始化流的状态 let initStatus = zip.inflateInit(strm); console.info(\'inflateInit ret: \' + (await initStatus).valueOf()); do { // 从文件中读取已压缩的数据到缓冲区 let readLen = fs.readSync(src.fd, inBuf); console.info(\"readSync readLen: \" + readLen); if (readLen == 0) { break; } // 设置输入缓冲区 strm.availableIn = readLen; strm.nextIn = inBuf; do { // 设置输出缓冲区 strm.availableOut = BUFLEN; strm.nextOut = outBuf; try { // 解压输入缓冲区中数据到输出缓冲区 let inflateStatus = zip.inflate(strm, zlib.CompressFlushMode.NO_FLUSH); console.info(\'inflate ret: \' + (await inflateStatus).valueOf()); // 更新流的状态 let innerStrm = zip.getZStream(); strm.availableIn = (await innerStrm).availableIn; strm.nextIn = (await innerStrm).nextIn; strm.availableOut = (await innerStrm).availableOut; strm.nextOut = (await innerStrm).nextOut; strm.totalIn = (await innerStrm).totalIn; strm.totalOut = (await innerStrm).totalOut; if (strm.availableOut != undefined) { // 将已完成解压的数据，写入到输出文件中 let have = BUFLEN - strm.availableOut; let writeLen = fs.writeSync(dest.fd, outBuf, { length: have }); console.info(`writeSync writeLen: ${writeLen}`); } } catch (err) { console.error(\'inflate err: \' + JSON.stringify(err)); } } while (strm.availableOut == 0) // 循环解压输入缓冲区中剩余的数据，直到全部完成解压 } while (status != zlib.ReturnStatus.STREAM_END.valueOf()) // 循环从文件中读取数据，直到数据全部读取 // 释放资源 zip.inflateEnd(strm);}未知大小缓冲区的压缩与解压（gzip格式）
采用gzip格式，针对一个未知大小的缓冲区中的数据，使用接口deflate()将从一个原始输入流中读取的数据进行压缩，使用接口inflate()将从一个压缩输入流中读取的数据进行解压，示例代码如下。
import { fileIo as fs} from \'@kit.CoreFileKit\';import { BusinessError, zlib } from \'@kit.BasicServicesKit\';@Entry@Componentstruct Index { build() { Row() { // 示例一：从文件中不断读取数据进行压缩 Button(\'deflateGzipFile\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); let outFile = fs.openSync(path + \'/data.gz\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); deflateGzipFile(inFile, outFile).then(() => { console.info(\'deflateGzipFile success\'); fs.closeSync(inFile.fd); fs.closeSync(outFile.fd); }) }) // 示例二：从文件中不断读取压缩数据进行解压 Button(\'inflateGzipFile\').onClick(() => { let path = this.getUIContext()?.getHostContext()?.filesDir; let inFile = fs.openSync(path + \'/data.gz\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); let outFile = fs.openSync(path + \'/data.txt\', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); inflateGzipFile(inFile, outFile).then(() => { console.info(\'deflateGzipFile success\'); fs.closeSync(inFile.fd); fs.closeSync(outFile.fd); }) }) } .height(\'100%\') .width(\'100%\') }}// 从一个文件中，不断的读入数据，进行压缩，并写入到另一个文件中async function deflateGzipFile(src: fs.File, dest: fs.File) { let flush = zlib.CompressFlushMode.NO_FLUSH; let strm: zlib.ZStream = {}; //初始化一个压缩流 const BUFLEN = 4096; let inBuf = new ArrayBuffer(BUFLEN); // 初始化一个输入缓冲区 let outBuf = new ArrayBuffer(BUFLEN); // 初始化一个输出缓冲区 // 创建一个压缩对象实例 let zip = zlib.createZipSync(); // 初始化流的状态，windowBits > 15时，启用gzip格式 let windowBits = 15 + 16; let initStatus = zip.deflateInit2(strm, zlib.CompressLevel.COMPRESS_LEVEL_BEST_SPEED, zlib.CompressMethod.DEFLATED, windowBits, zlib.MemLevel.MEM_LEVEL_DEFAULT, zlib.CompressStrategy.COMPRESS_STRATEGY_DEFAULT_STRATEGY); console.info(\'deflateInit2 ret: \' + (await initStatus).valueOf()); do { // 从文件中读取数据到缓冲区 let readLen = fs.readSync(src.fd, inBuf); console.info(\"readSync readLen: \" + readLen); flush = readLen == 0 ? zlib.CompressFlushMode.FINISH : zlib.CompressFlushMode.NO_FLUSH; // 设置输入缓冲区 strm.availableIn = readLen; strm.nextIn = inBuf; do { // 设置输出缓冲区 strm.availableOut = BUFLEN; strm.nextOut = outBuf; try { // 压缩输入缓冲区中数据到输出缓冲区 let deflateStatus = zip.deflate(strm, flush); console.info(\'deflate ret: \' + (await deflateStatus).valueOf()); // 更新流的状态 let innerStrm = zip.getZStream(); strm.availableIn = (await innerStrm).availableIn; strm.nextIn = (await innerStrm).nextIn; strm.availableOut = (await innerStrm).availableOut; strm.nextOut = (await innerStrm).nextOut; strm.totalIn = (await innerStrm).totalIn; strm.totalOut = (await innerStrm).totalOut; if (strm.availableOut != undefined) { // 将已完成压缩的数据，写入到输出文件中 let have = BUFLEN - strm.availableOut; let writeLen = fs.writeSync(dest.fd, outBuf, { length: have }); console.info(`writeSync writeLen: ${writeLen}`); } } catch (err) { console.error(\'deflate err: \' + JSON.stringify(err)); } } while (strm.availableOut == 0); // 循环压缩输入缓冲区中剩余的数据，直到全部完成压缩 } while (flush != zlib.CompressFlushMode.FINISH); // 循环从文件中读取数据，直到数据全部读取 // 释放资源 zip.deflateEnd(strm);}// 从一个文件中，不断的读入已压缩的数据，进行解压，并写入到另一个文件中async function inflateGzipFile(src: fs.File, dest: fs.File) { let status: zlib.ReturnStatus = zlib.ReturnStatus.OK; let strm: zlib.ZStream = {}; //初始化一个压缩流 const BUFLEN = 4096; let inBuf = new ArrayBuffer(BUFLEN); // 初始化一个输入缓冲区 let outBuf = new ArrayBuffer(BUFLEN); // 初始化一个输出缓冲区 // 创建一个压缩对象实例 let zip = zlib.createZipSync(); // 初始化流的状态，windowBits > 15时，启用gzip格式 let windowBits = 15 + 16; let initStatus = zip.inflateInit2(strm, windowBits); console.info(\'inflateInit2 ret: \' + (await initStatus).valueOf()); do { // 从文件中读取已压缩的数据到缓冲区 let readLen = fs.readSync(src.fd, inBuf); console.info(\"readSync readLen: \" + readLen); if (readLen == 0) { break; } // 设置输入缓冲区 strm.availableIn = readLen; strm.nextIn = inBuf; do { // 设置输出缓冲区 strm.availableOut = BUFLEN; strm.nextOut = outBuf; try { // 解压输入缓冲区中数据到输出缓冲区 let inflateStatus = zip.inflate(strm, zlib.CompressFlushMode.NO_FLUSH); console.info(\'inflate ret: \' + (await inflateStatus).valueOf()); // 更新流的状态 let innerStrm = zip.getZStream(); strm.availableIn = (await innerStrm).availableIn; strm.nextIn = (await innerStrm).nextIn; strm.availableOut = (await innerStrm).availableOut; strm.nextOut = (await innerStrm).nextOut; strm.totalIn = (await innerStrm).totalIn; strm.totalOut = (await innerStrm).totalOut; if (strm.availableOut != undefined) { // 将已完成解压的数据，写入到输出文件中 let have = BUFLEN - strm.availableOut; let writeLen = fs.writeSync(dest.fd, outBuf, { length: have }); console.info(`writeSync writeLen: ${writeLen}`); } } catch (err) { console.error(\'inflate err: \' + JSON.stringify(err)); } } while (strm.availableOut == 0) // 循环解压输入缓冲区中剩余的数据，直到全部完成解压 } while (status != zlib.ReturnStatus.STREAM_END.valueOf()) // 循环从文件中读取数据，直到数据全部读取 // 释放资源 zip.inflateEnd(strm);}
