feat: 支持base64

lib/downloader.js

@@ -3,6 +3,7 @@
  * 详细设计文档可查看 https://juejin.im/post/5b42d3ede51d4519277b6ce3
  */
 const util = require('./util');
+const sha1 = require('./sha1');
 
 const SAVED_FILES_KEY = 'savedFiles';
 const KEY_TOTAL_SIZE = 'totalSize';
@@ -40,25 +41,34 @@ export default class Dowloader {
         resolve(url);
         return;
       }
+      const fileName = getFileName(url);
       if (!lru) {
         // 无 lru 情况下直接判断 临时文件是否存在，不存在重新下载
         wx.getFileInfo({
-          filePath: url,
+          filePath: fileName,
           success: () => {
             resolve(url);
           },
           fail: () => {
-            downloadFile(url, lru).then((path) => {
+            if (util.isOnlineUrl(url)) {
-              resolve(path);
+              downloadFile(url, lru).then((path) => {
-            }, () => {
+                resolve(path);
-              reject();
+              }, () => {
-            });
+                reject();
+              });
+            } else if (util.isDataUrl(url)) {
+              transformBase64File(url, lru).then(path => {
+                resolve(path);
+              }, () => {
+                reject();
+              });
+            }
           },
         })
         return
       }
 
-      const file = getFile(url);
+      const file = getFile(fileName);
 
       if (file) {
         // 检查文件是否正常，不正常需要重新下载
@@ -77,16 +87,71 @@ export default class Dowloader {
           },
         });
       } else {
-        downloadFile(url, lru).then((path) => {
+        if (util.isOnlineUrl(url)) {
-          resolve(path);
+          downloadFile(url, lru).then((path) => {
-        }, () => {
+            resolve(path);
-          reject();
+          }, () => {
-        });
+            reject();
+          });
+        } else if (util.isDataUrl(url)) {
+          transformBase64File(url, lru).then(path => {
+            resolve(path);
+          }, () => {
+            reject();
+          });
+        }
       }
     });
   }
 }
 
+function getFileName(url) {
+  if (util.isDataUrl(url)) { 
+    const [, format, bodyData] = /data:image\/(\w+);base64,(.*)/.exec(base64data) || [];
+    const fileName = `${sha1.hex_sha1(bodyData)}.${format}`;
+    return fileName;
+  } else {
+    return url;
+  }
+}
+
+function transformBase64File(base64data, lru) {
+  return new Promise((resolve, reject) => {
+    const [, format, bodyData] = /data:image\/(\w+);base64,(.*)/.exec(base64data) || [];
+    if (!format) {
+      console.error('base parse failed');
+      reject();
+      return;
+    }
+    const fileName = `${sha1.hex_sha1(bodyData)}.${format}`;
+    const path = `${wx.env.USER_DATA_PATH}/${fileName}`;
+    const buffer = wx.base64ToArrayBuffer(bodyData.replace(/[\r\n]/g, ""));
+    const result = wx.getFileSystemManager().writeFileSync(path, buffer, 'binary');
+    if (!result) {
+      wx.getFileInfo({
+        filePath: path,
+        success: (tmpRes) => {
+          const newFileSize = tmpRes.size;
+          lru ? doLru(newFileSize).then(() => {
+            saveFile(fileName, newFileSize, path).then((filePath) => {
+              resolve(filePath);
+            });
+          }, () => {
+            resolve(path);
+          }) : resolve(path);
+        },
+        fail: (error) => {
+        // 文件大小信息获取失败，则此文件也不要进行存储
+          console.error(`getFileInfo ${path} failed, ${JSON.stringify(error)}`);
+          resolve(path);
+        },
+      });
+    } else {
+      reject()
+    }
+  });  
+}
+
 function downloadFile(url, lru) {
   return new Promise((resolve, reject) => {
     wx.downloadFile({

lib/sha1.js

@@ -0,0 +1,97 @@
+var hexcase = 0;
+var chrsz = 8;
+
+function hex_sha1(s) {
+  return binb2hex(core_sha1(str2binb(s), s.length * chrsz));
+}
+
+function core_sha1(x, len) {
+  x[len >> 5] |= 0x80 << (24 - (len % 32));
+  x[(((len + 64) >> 9) << 4) + 15] = len;
+
+  var w = Array(80);
+  var a = 1732584193;
+  var b = -271733879;
+  var c = -1732584194;
+  var d = 271733878;
+  var e = -1009589776;
+
+  for (var i = 0; i < x.length; i += 16) {
+    var olda = a;
+    var oldb = b;
+    var oldc = c;
+    var oldd = d;
+    var olde = e;
+
+    for (var j = 0; j < 80; j++) {
+      if (j < 16) w[j] = x[i + j];
+      else w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
+      var t = safe_add(
+        safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
+        safe_add(safe_add(e, w[j]), sha1_kt(j))
+      );
+      e = d;
+      d = c;
+      c = rol(b, 30);
+      b = a;
+      a = t;
+    }
+
+    a = safe_add(a, olda);
+    b = safe_add(b, oldb);
+    c = safe_add(c, oldc);
+    d = safe_add(d, oldd);
+    e = safe_add(e, olde);
+  }
+  return Array(a, b, c, d, e);
+}
+
+function sha1_ft(t, b, c, d) {
+  if (t < 20) return (b & c) | (~b & d);
+  if (t < 40) return b ^ c ^ d;
+  if (t < 60) return (b & c) | (b & d) | (c & d);
+  return b ^ c ^ d;
+}
+
+function sha1_kt(t) {
+  return t < 20
+    ? 1518500249
+    : t < 40
+    ? 1859775393
+    : t < 60
+    ? -1894007588
+    : -899497514;
+}
+
+function safe_add(x, y) {
+  var lsw = (x & 0xffff) + (y & 0xffff);
+  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
+  return (msw << 16) | (lsw & 0xffff);
+}
+
+function rol(num, cnt) {
+  return (num << cnt) | (num >>> (32 - cnt));
+}
+
+function str2binb(str) {
+  var bin = Array();
+  var mask = (1 << chrsz) - 1;
+  for (var i = 0; i < str.length * chrsz; i += chrsz)
+    bin[i >> 5] |= (str.charCodeAt(i / chrsz) & mask) << (24 - (i % 32));
+  return bin;
+}
+
+function binb2hex(binarray) {
+  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
+  var str = "";
+  for (var i = 0; i < binarray.length * 4; i++) {
+    str +=
+      hex_tab.charAt((binarray[i >> 2] >> ((3 - (i % 4)) * 8 + 4)) & 0xf) +
+      hex_tab.charAt((binarray[i >> 2] >> ((3 - (i % 4)) * 8)) & 0xf);
+  }
+  return str;
+}
+
+module.exports = {
+  hex_sha1,
+}

lib/util.js

@@ -1,6 +1,14 @@
 
 function isValidUrl(url) {
-  return /(ht|f)tp(s?):\/\/([^ \\/]*\.)+[^ \\/]*(:[0-9]+)?\/?/.test(url);
+  return isOnlineUrl(url) || isDataUrl(url);
+}
+
+function isOnlineUrl(url) {
+  return /(ht|f)tp(s?):\/\/([^ \\/]*\.)+[^ \\/]*(:[0-9]+)?\/?/.test(url)
+}
+
+function isDataUrl(url) {
+  return /data:image\/(\w+);base64,(.*)/.test(url);
 }
 
 /**
@@ -63,6 +71,8 @@ function equal(a, b) {
 
 module.exports = {
   isValidUrl,
+  isOnlineUrl,
+  isDataUrl,
   equal
 };