@ivujs/i-utils
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前端模块化 JavaScript 工具库
532 lines (530 loc) • 19.4 kB
JavaScript
/*
* base64加解密
* 高性能、高健壮性、纯JS实现，兼容Node/浏览器/Worker
*/
// 核心常量定义
const ENCODING_ERROR = "not a UTF-8 string";
const BASE64_ENCODE_CHAR = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".split("");
const BASE64_DECODE_CHAR = {};
for (let i = 0; i < 64; ++i) {
BASE64_DECODE_CHAR[BASE64_ENCODE_CHAR[i]] = i;
}
// 兼容URL安全的Base64
BASE64_DECODE_CHAR["-"] = 62;
BASE64_DECODE_CHAR["_"] = 63;
// ======================== 精简版环境判断（核心场景全覆盖，保留！）========================
const isNodeEnv = typeof process === "object" && process.versions && process.versions.node;
const isBrowserEnv = typeof window === "object" && typeof window.btoa === "function";
const root = isNodeEnv ? global : typeof self === "object" ? self : window;
// ======================== 核心工具函数（全部保留，原生API更快！）========================
/**
* 清理Base64字符串（移除等号、换行符、非法字符）
*/
const cleanBase64Str = function (base64Str) {
return base64Str
.split("=")[0]
.replace(/[\r\n]/g, "")
.replace(/[^A-Za-z0-9+/=_-]/g, ""); // 过滤非法字符
};
/**
* UTF-8字符串转字节数组（性能优化版）
*/
const utf8ToBytes = function (str) {
const len = str.length; // 缓存长度，减少属性访问
const bytes = new Array(len * 4); // 预分配最大可能长度（避免频繁扩容）
let byteIndex = 0;
for (let i = 0; i < len; i++) {
const c = str.charCodeAt(i);
if (c < 0x80) {
bytes[byteIndex++] = c;
}
else if (c < 0x800) {
bytes[byteIndex++] = 0xc0 | (c >> 6);
bytes[byteIndex++] = 0x80 | (c & 0x3f);
}
else if (c < 0xd800 || c >= 0xe000) {
bytes[byteIndex++] = 0xe0 | (c >> 12);
bytes[byteIndex++] = 0x80 | ((c >> 6) & 0x3f);
bytes[byteIndex++] = 0x80 | (c & 0x3f);
}
else {
// 处理代理对
const code = 0x10000 + (((c & 0x3ff) << 10) | (str.charCodeAt(++i) & 0x3ff));
bytes[byteIndex++] = 0xf0 | (code >> 18);
bytes[byteIndex++] = 0x80 | ((code >> 12) & 0x3f);
bytes[byteIndex++] = 0x80 | ((code >> 6) & 0x3f);
bytes[byteIndex++] = 0x80 | (code & 0x3f);
}
}
// 截断数组到实际长度
return bytes.slice(0, byteIndex);
};
/**
* Base64字符串解码为字节数组（性能优化版）
*/
const decodeAsBytes = function (base64Str) {
// 空值快速返回
if (!base64Str)
return [];
base64Str = cleanBase64Str(base64Str);
const len = base64Str.length;
const count = (len >> 2) << 2;
// 预计算最大长度：3/4 * 总字符数，减少数组扩容
const bytes = new Array(Math.floor((len * 3) / 4));
let byteIndex = 0;
let i = 0; // 把i的作用域提升到函数级，确保后续能访问
// 4字符转3字节
for (; i < count;) {
const v1 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
const v2 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
const v3 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
const v4 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
bytes[byteIndex++] = ((v1 << 2) | (v2 >>> 4)) & 255;
bytes[byteIndex++] = ((v2 << 4) | (v3 >>> 2)) & 255;
bytes[byteIndex++] = ((v3 << 6) | v4) & 255;
}
// 处理剩余字符（此时i的作用域有效）
const remain = len - count;
if (remain === 2) {
const v1 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
const v2 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
bytes[byteIndex++] = ((v1 << 2) | (v2 >>> 4)) & 255;
}
else if (remain === 3) {
const v1 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
const v2 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
const v3 = BASE64_DECODE_CHAR[base64Str.charAt(i++)] || 0;
bytes[byteIndex++] = ((v1 << 2) | (v2 >>> 4)) & 255;
bytes[byteIndex++] = ((v2 << 4) | (v3 >>> 2)) & 255;
}
// 截断数组到实际长度
return bytes.slice(0, byteIndex);
};
/**
* 抽离公共逻辑：字节数组转Base64字符（减少代码冗余）
*/
const bytesToBase64Chars = function (bytes) {
const len = bytes.length;
const count = Math.floor(len / 3) * 3;
const base64Str = new Array(Math.ceil((len * 4) / 3)); // 预分配长度
let strIndex = 0;
// 3字节转4字符
for (let i = 0; i < count;) {
const v1 = bytes[i++];
const v2 = bytes[i++];
const v3 = bytes[i++];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[v1 >>> 2];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[((v1 << 4) | (v2 >>> 4)) & 63];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[((v2 << 2) | (v3 >>> 6)) & 63];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[v3 & 63];
}
// 处理剩余字节
const remain = len - count;
if (remain === 1) {
const v1 = bytes[count];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[v1 >>> 2];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[(v1 << 4) & 63];
base64Str[strIndex++] = "=";
base64Str[strIndex++] = "=";
}
else if (remain === 2) {
const v1 = bytes[count];
const v2 = bytes[count + 1];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[v1 >>> 2];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[((v1 << 4) | (v2 >>> 4)) & 63];
base64Str[strIndex++] = BASE64_ENCODE_CHAR[(v2 << 2) & 63];
base64Str[strIndex++] = "=";
}
return base64Str.join("");
};
/**
* 字节数组编码为Base64字符串（复用公共逻辑）
*/
let encodeFromBytes = function (bytes) {
// 空值快速返回
if (!bytes || bytes.length === 0)
return "";
return bytesToBase64Chars(bytes);
};
// ======================== 环境适配的btoa/atob实现（全部保留，原生更快！）=======================
let btoa = root.btoa;
let atob = root.atob;
let utf8Base64Encode;
let utf8Base64Decode;
// 1. Node.js环境（纯JS实现，不使用require）
if (isNodeEnv) {
// 纯JS版btoa（替代Buffer实现）
btoa = function (str) {
if (!str)
return "";
const bytes = Array.from(str).map((c) => c.charCodeAt(0));
return bytesToBase64Chars(bytes);
};
// 纯JS版atob
atob = function (base64Str) {
if (!base64Str)
return "";
const bytes = decodeAsBytes(base64Str);
return String.fromCharCode.apply(null, bytes);
};
// 纯JS版UTF8编码/解码（和浏览器环境保持一致）
utf8Base64Encode = function (str) {
if (!str)
return "";
const bytes = utf8ToBytes(str);
return bytesToBase64Chars(bytes);
};
utf8Base64Decode = function (base64Str) {
if (!base64Str)
return "";
const bytes = decodeAsBytes(base64Str);
const str = [];
const len = bytes.length;
let i = 0;
while (i < len) {
const b = bytes[i++];
if (b <= 0x7f) {
str.push(String.fromCharCode(b));
continue;
}
let c, followingChars;
if (b > 0xbf && b <= 0xdf) {
c = b & 0x1f;
followingChars = 1;
}
else if (b <= 0xef) {
c = b & 0x0f;
followingChars = 2;
}
else if (b <= 0xf7) {
c = b & 0x07;
followingChars = 3;
}
else {
throw new Error(ENCODING_ERROR);
}
// 校验后续字节合法性
for (let j = 0; j < followingChars; ++j) {
const byte = bytes[i++];
if (i > len || byte < 0x80 || byte > 0xbf) {
throw new Error(ENCODING_ERROR);
}
c = (c << 6) + (byte & 0x3f);
}
// 校验Unicode范围
if (c >= 0xd800 && c <= 0xdfff)
throw new Error(ENCODING_ERROR);
if (c > 0x10ffff)
throw new Error(ENCODING_ERROR);
// 转换为字符
if (c <= 0xffff) {
str.push(String.fromCharCode(c));
}
else {
c -= 0x10000;
str.push(String.fromCharCode((c >> 10) + 0xd800), String.fromCharCode((c & 0x3ff) + 0xdc00));
}
}
return str.join("");
};
// 2. 无原生btoa/atob的环境（老旧浏览器/Worker）
}
else if (!isBrowserEnv) {
// 纯JS版btoa（复用公共逻辑）
btoa = function (str) {
if (!str)
return "";
const bytes = Array.from(str).map((c) => c.charCodeAt(0));
return bytesToBase64Chars(bytes);
};
// 纯JS版atob
atob = function (base64Str) {
if (!base64Str)
return "";
const bytes = decodeAsBytes(base64Str);
return String.fromCharCode.apply(null, bytes);
};
// 纯JS版UTF8编码/解码
utf8Base64Encode = function (str) {
if (!str)
return "";
const bytes = utf8ToBytes(str);
return bytesToBase64Chars(bytes);
};
utf8Base64Decode = function (base64Str) {
if (!base64Str)
return "";
const bytes = decodeAsBytes(base64Str);
const str = [];
const len = bytes.length;
let i = 0;
while (i < len) {
const b = bytes[i++];
if (b <= 0x7f) {
str.push(String.fromCharCode(b));
continue;
}
let c, followingChars;
if (b > 0xbf && b <= 0xdf) {
c = b & 0x1f;
followingChars = 1;
}
else if (b <= 0xef) {
c = b & 0x0f;
followingChars = 2;
}
else if (b <= 0xf7) {
c = b & 0x07;
followingChars = 3;
}
else {
throw new Error(ENCODING_ERROR);
}
// 校验后续字节合法性
for (let j = 0; j < followingChars; ++j) {
const byte = bytes[i++];
if (i > len || byte < 0x80 || byte > 0xbf) {
throw new Error(ENCODING_ERROR);
}
c = (c << 6) + (byte & 0x3f);
}
// 校验Unicode范围
if (c >= 0xd800 && c <= 0xdfff)
throw new Error(ENCODING_ERROR);
if (c > 0x10ffff)
throw new Error(ENCODING_ERROR);
// 转换为字符
if (c <= 0xffff) {
str.push(String.fromCharCode(c));
}
else {
c -= 0x10000;
str.push(String.fromCharCode((c >> 10) + 0xd800), String.fromCharCode((c & 0x3ff) + 0xdc00));
}
}
return str.join("");
};
// 3. 浏览器原生支持btoa/atob
}
else {
utf8Base64Encode = function (str) {
if (!str)
return "";
const result = [];
const len = str.length;
for (let i = 0; i < len; i++) {
const charcode = str.charCodeAt(i);
if (charcode < 0x80) {
result.push(String.fromCharCode(charcode));
}
else if (charcode < 0x800) {
result.push(String.fromCharCode(0xc0 | (charcode >> 6)), String.fromCharCode(0x80 | (charcode & 0x3f)));
}
else if (charcode < 0xd800 || charcode >= 0xe000) {
result.push(String.fromCharCode(0xe0 | (charcode >> 12)), String.fromCharCode(0x80 | ((charcode >> 6) & 0x3f)), String.fromCharCode(0x80 | (charcode & 0x3f)));
}
else {
const code = 0x10000 + (((charcode & 0x3ff) << 10) | (str.charCodeAt(++i) & 0x3ff));
result.push(String.fromCharCode(0xf0 | (code >> 18)), String.fromCharCode(0x80 | ((code >> 12) & 0x3f)), String.fromCharCode(0x80 | ((code >> 6) & 0x3f)), String.fromCharCode(0x80 | (code & 0x3f)));
}
}
return btoa(result.join(""));
};
utf8Base64Decode = function (base64Str) {
if (!base64Str)
return "";
const tmpStr = atob(base64Str.replace(/-/g, "+").replace(/_/g, "/"));
// 替换Unicode转义，避免ESLint控制字符警告
// eslint-disable-next-line no-control-regex
if (!/[^\u0000-\u007F]/.test(tmpStr)) {
return tmpStr;
}
const str = [];
const len = tmpStr.length;
let i = 0;
while (i < len) {
const b = tmpStr.charCodeAt(i++);
if (b <= 0x7f) {
str.push(String.fromCharCode(b));
continue;
}
let c, followingChars;
if (b > 0xbf && b <= 0xdf) {
c = b & 0x1f;
followingChars = 1;
}
else if (b <= 0xef) {
c = b & 0x0f;
followingChars = 2;
}
else if (b <= 0xf7) {
c = b & 0x07;
followingChars = 3;
}
else {
throw new Error(ENCODING_ERROR);
}
for (let j = 0; j < followingChars; ++j) {
const byte = tmpStr.charCodeAt(i++);
if (i > len || byte < 0x80 || byte > 0xbf)
throw new Error(ENCODING_ERROR);
c = (c << 6) + (byte & 0x3f);
}
if (c >= 0xd800 && c <= 0xdfff)
throw new Error(ENCODING_ERROR);
if (c > 0x10ffff)
throw new Error(ENCODING_ERROR);
if (c <= 0xffff) {
str.push(String.fromCharCode(c));
}
else {
c -= 0x10000;
str.push(String.fromCharCode((c >> 10) + 0xd800), String.fromCharCode((c & 0x3ff) + 0xdc00));
}
}
return str.join("");
};
}
// ======================== 类型转换工具函数（全部保留）========================
/**
* Uint8Array转Base64字符串
* @param {Uint8Array} uint8Array 字节数组
* @param {boolean} [urlSafe=false] 是否URL安全
* @returns {string} Base64字符串
*/
const fromUint8Array = function (uint8Array, urlSafe = false) {
if (!(uint8Array instanceof Uint8Array)) {
throw new TypeError("fromUint8Array: input must be Uint8Array");
}
const bytes = Array.from(uint8Array);
let result = bytesToBase64Chars(bytes);
if (urlSafe) {
result = result.replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "");
}
return result;
};
/**
* Base64字符串转Uint8Array
* @param {string} base64Str Base64字符串
* @param {boolean} [urlSafe=false] 是否URL安全
* @returns {Uint8Array} 字节数组
*/
const toUint8Array = function (base64Str, urlSafe = false) {
if (typeof base64Str !== "string") {
throw new TypeError("toUint8Array: input must be string");
}
// 处理URL安全字符
if (urlSafe) {
base64Str = base64Str.replace(/-/g, "+").replace(/_/g, "/");
}
const bytes = decodeAsBytes(base64Str);
return new Uint8Array(bytes);
};
/**
* 十六进制字符串转Base64字符串
* @param {string} hexStr 十六进制字符串
* @param {boolean} [urlSafe=false] 是否URL安全
* @returns {string} Base64字符串
*/
const fromHex = function (hexStr, urlSafe = false) {
if (typeof hexStr !== "string" || !/^[0-9a-fA-F]+$/.test(hexStr)) {
throw new TypeError("fromHex: input must be hex string");
}
// 补全偶数长度
const str = hexStr.length % 2 ? `0${hexStr}` : hexStr;
const bytes = new Array(str.length / 2);
for (let i = 0; i < bytes.length; i++) {
bytes[i] = parseInt(str.substr(i * 2, 2), 16);
}
let result = bytesToBase64Chars(bytes);
if (urlSafe) {
result = result.replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "");
}
return result;
};
/**
* Base64字符串转十六进制字符串
* @param {string} base64Str Base64字符串
* @param {boolean} [urlSafe=false] 是否URL安全
* @returns {string} 十六进制字符串
*/
const toHex = function (base64Str, urlSafe = false) {
if (typeof base64Str !== "string") {
throw new TypeError("toHex: input must be string");
}
// 处理URL安全字符
if (urlSafe) {
base64Str = base64Str.replace(/-/g, "+").replace(/_/g, "/");
}
const bytes = decodeAsBytes(base64Str);
return Array.from(bytes)
.map((byte) => byte.toString(16).padStart(2, "0"))
.join("");
};
// ======================== 核心方法（仅删除asciiOnly开关，默认UTF8）========================
/**
* Base64编码（高性能、高健壮性版，默认UTF8）
* @param {string | number[] | Uint8Array | ArrayBuffer} data 待编码数据
* @param {boolean} [urlSafe=false] 是否生成URL安全的Base64
* @returns {string} Base64字符串
*/
const encode = function (data, urlSafe = false) {
// 空值快速返回
if (data == null)
return "";
const notString = typeof data !== "string";
let result = "";
if (notString) {
// 处理ArrayBuffer
if (data.constructor === root.ArrayBuffer) {
data = new Uint8Array(data);
}
// 处理字节数组/Uint8Array
result = encodeFromBytes(data);
}
else {
// 空字符串快速返回
if (data === "")
return "";
// 强制走UTF8编码（删掉asciiOnly判断，直接用utf8Base64Encode）
result = utf8Base64Encode(data);
}
// URL安全处理：替换+->-，/->_，去掉=
if (urlSafe) {
result = result.replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "");
}
return result;
};
/**
* Base64解码（高性能、高健壮性版，默认UTF8）
* @param {string} base64Str 待解码的Base64字符串
* @returns {string} 解码后的UTF8字符串
*/
const decode = function (base64Str) {
// 空值快速返回
if (base64Str == null || base64Str === "")
return "";
// 处理URL安全的Base64
base64Str = base64Str.replace(/-/g, "+").replace(/_/g, "/");
base64Str = cleanBase64Str(base64Str);
// 强制走UTF8解码（删掉asciiOnly判断，直接用utf8Base64Decode）
return utf8Base64Decode(base64Str);
};
// ======================== URL安全专用方法（同步删除asciiOnly开关）========================
/**
* URL安全Base64编码（专用方法，等价于encode(data, true)）
* @param {string | number[] | Uint8Array | ArrayBuffer} data 待编码数据
* @returns {string} URL安全的Base64字符串
*/
const encodeURI = function (data) {
return encode(data, true);
};
/**
* URL安全Base64解码（专用方法，兼容URL安全字符）
* @param {string} base64Str URL安全的Base64字符串
* @returns {string} 解码后的UTF8字符串
*/
const decodeURI = function (base64Str) {
return decode(base64Str);
};
export { decode, decodeURI, encode, encodeURI, fromHex, fromUint8Array, toHex, toUint8Array };