comparison base64.js @ 35:3faa4e3eedac

Fix object structure for process input in perf test

+'use strict'
+
+if (typeof document === "undefined") {
+    exports.byteLength = byteLength
+    exports.toByteArray = toByteArray
+    exports.fromByteArray = fromByteArray
+}
+
+var lookup = []
+var revLookup = []
+var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array
+
+var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
+for (var i = 0, len = code.length; i < len; ++i) {
+  lookup[i] = code[i]
+  revLookup[code.charCodeAt(i)] = i
+}
+
+revLookup['-'.charCodeAt(0)] = 62
+revLookup['_'.charCodeAt(0)] = 63
+
+function placeHoldersCount (b64) {
+  var len = b64.length
+  if (len % 4 > 0) {
+    throw new Error('Invalid string. Length must be a multiple of 4')
+  }
+
+  // the number of equal signs (place holders)
+  // if there are two placeholders, than the two characters before it
+  // represent one byte
+  // if there is only one, then the three characters before it represent 2 bytes
+  // this is just a cheap hack to not do indexOf twice
+  return b64[len - 2] === '=' ? 2 : b64[len - 1] === '=' ? 1 : 0
+}
+
+function byteLength (b64) {
+  // base64 is 4/3 + up to two characters of the original data
+  return b64.length * 3 / 4 - placeHoldersCount(b64)
+}
+
+function toByteArray (b64) {
+  var i, j, l, tmp, placeHolders, arr
+  var len = b64.length
+  placeHolders = placeHoldersCount(b64)
+
+  arr = new Arr(len * 3 / 4 - placeHolders)
+
+  // if there are placeholders, only get up to the last complete 4 chars
+  l = placeHolders > 0 ? len - 4 : len
+
+  var L = 0
+
+  for (i = 0, j = 0; i < l; i += 4, j += 3) {
+    tmp = (revLookup[b64.charCodeAt(i)] << 18) | (revLookup[b64.charCodeAt(i + 1)] << 12) | (revLookup[b64.charCodeAt(i + 2)] << 6) | revLookup[b64.charCodeAt(i + 3)]
+    arr[L++] = (tmp >> 16) & 0xFF
+    arr[L++] = (tmp >> 8) & 0xFF
+    arr[L++] = tmp & 0xFF
+  }
+
+  if (placeHolders === 2) {
+    tmp = (revLookup[b64.charCodeAt(i)] << 2) | (revLookup[b64.charCodeAt(i + 1)] >> 4)
+    arr[L++] = tmp & 0xFF
+  } else if (placeHolders === 1) {
+    tmp = (revLookup[b64.charCodeAt(i)] << 10) | (revLookup[b64.charCodeAt(i + 1)] << 4) | (revLookup[b64.charCodeAt(i + 2)] >> 2)
+    arr[L++] = (tmp >> 8) & 0xFF
+    arr[L++] = tmp & 0xFF
+  }
+
+  return arr
+}
+
+function tripletToBase64 (num) {
+  return lookup[num >> 18 & 0x3F] + lookup[num >> 12 & 0x3F] + lookup[num >> 6 & 0x3F] + lookup[num & 0x3F]
+}
+
+function encodeChunk (uint8, start, end) {
+  var tmp
+  var output = []
+  for (var i = start; i < end; i += 3) {
+    tmp = (uint8[i] << 16) + (uint8[i + 1] << 8) + (uint8[i + 2])
+    output.push(tripletToBase64(tmp))
+  }
+  return output.join('')
+}
+
+function fromByteArray (uint8) {
+  var tmp
+  var len = uint8.length
+  var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
+  var output = ''
+  var parts = []
+  var maxChunkLength = 16383 // must be multiple of 3
+
+  // go through the array every three bytes, we'll deal with trailing stuff later
+  for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
+    parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)))
+  }
+
+  // pad the end with zeros, but make sure to not forget the extra bytes
+  if (extraBytes === 1) {
+    tmp = uint8[len - 1]
+    output += lookup[tmp >> 2]
+    output += lookup[(tmp << 4) & 0x3F]
+    output += '=='
+  } else if (extraBytes === 2) {
+    tmp = (uint8[len - 2] << 8) + (uint8[len - 1])
+    output += lookup[tmp >> 10]
+    output += lookup[(tmp >> 4) & 0x3F]
+    output += lookup[(tmp << 2) & 0x3F]
+    output += '='
+  }
+
+  parts.push(output)
+
+  return parts.join('')
+}