{"id":30969,"date":"2024-11-25T12:33:18","date_gmt":"2024-11-25T04:33:18","guid":{"rendered":"https:\/\/fwq.ai\/blog\/30969\/"},"modified":"2024-11-25T12:33:18","modified_gmt":"2024-11-25T04:33:18","slug":"%e5%be%ae%e4%bf%a1%e5%b0%8f%e7%a8%8b%e5%ba%8f%e4%b8%ad%e5%85%b3%e4%ba%8ebuffer%e7%bc%93%e5%86%b2%e5%8c%ba%e7%9a%84%e5%ae%9e%e4%be%8b%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/30969\/","title":{"rendered":"\u5fae\u4fe1\u5c0f\u7a0b\u5e8f\u4e2d\u5173\u4e8eBuffer\u7f13\u51b2\u533a\u7684\u5b9e\u4f8b\u8be6\u89e3"},"content":{"rendered":"

\u8fd9\u7bc7\u6587\u7ae0\u4e3b\u8981\u4ecb\u7ecd\u4e86 \u5fae\u4fe1\u5c0f\u7a0b\u5e8f buffer\u7f13\u51b2\u533a\u7684\u8be6\u89e3\u7684\u76f8\u5173\u8d44\u6599,\u9700\u8981\u7684\u670b\u53cb\u53ef\u4ee5\u53c2\u8003\u4e0b<\/p>\n

 \u5fae\u4fe1\u5c0f\u7a0b\u5e8f Buffer\u7f13\u51b2\u533a\u7684\u8be6\u89e3<\/strong><\/p>\n

JavaScript \u8bed\u8a00\u81ea\u8eab\u53ea\u6709\u5b57\u7b26\u4e32\u6570\u636e\u7c7b\u578b\uff0c\u6ca1\u6709\u4e8c\u8fdb\u5236\u6570\u636e\u7c7b\u578b\u3002 <\/p>\n

\u4f46\u5728\u5904\u7406\u50cfTCP\u6d41\u6216\u6587\u4ef6\u6d41\u65f6\uff0c\u5fc5\u987b\u4f7f\u7528\u5230\u4e8c\u8fdb\u5236\u6570\u636e\u3002\u56e0\u6b64\u5728 Node.js\u4e2d\uff0c\u5b9a\u4e49\u4e86\u4e00\u4e2a Buffer \u7c7b\uff0c\u8be5\u7c7b\u7528\u6765\u521b\u5efa\u4e00\u4e2a\u4e13\u95e8\u5b58\u653e\u4e8c\u8fdb\u5236\u6570\u636e\u7684\u7f13\u5b58\u533a\u3002 <\/p>\n

\u5728 node.js \u4e2d\uff0cBuffer \u7c7b\u662f\u968f Node \u5185\u6838\u4e00\u8d77\u53d1\u5e03\u7684\u6838\u5fc3\u5e93\u3002Buffer \u5e93\u4e3a Node.js \u5e26\u6765\u4e86\u4e00\u79cd\u5b58\u50a8\u539f\u59cb\u6570\u636e\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u8ba9 Node.js \u5904\u7406\u4e8c\u8fdb\u5236\u6570\u636e\uff0c\u6bcf\u5f53\u9700\u8981\u5728 Node.js \u4e2d\u5904\u7406I\/O\u64cd\u4f5c\u4e2d\u79fb\u52a8\u7684\u6570\u636e\u65f6\uff0c\u5c31\u6709\u53ef\u80fd\u4f7f\u7528 Buffer \u5e93\u3002\u539f\u59cb\u6570\u636e\u5b58\u50a8\u5728 Buffer \u7c7b\u7684\u5b9e\u4f8b\u4e2d\u3002\u4e00\u4e2a Buffer \u7c7b\u4f3c\u4e8e\u4e00\u4e2a\u6574\u6570\u6570\u7ec4\uff0c\u4f46\u5b83\u5bf9\u5e94\u4e8e V8 \u5806\u5185\u5b58\u4e4b\u5916\u7684\u4e00\u5757\u539f\u59cb\u5185\u5b58\u3002<\/p>\n

\u521b\u5efaBuffer<\/strong><\/p>\n

<\/p>\n

1.\u957f\u5ea6\u4e3a10\u7684\u5b9e\u4f8b\r\nvar buf = new Buffer(10)\r\n2.\u901a\u8fc7\u7ed9\u5b9a\u7684\u6570\u7ec4\u521b\u5efa\r\nvar buf = new Buffer([10,20,30,40,50])\r\n3.\u901a\u8fc7\u5b57\u7b26\u4e32\u521b\u5efa\r\nvar buf = new Buffer(\"www.csdn.net\",\"utf-8\")\r\nutf-8 \u662f\u9ed8\u8ba4\u7684\u7f16\u7801\u65b9\u5f0f\r\n\u652f\u6301\u4ee5\u4e0b\u7f16\u7801\uff1a\"ascii\", \"utf8\", \"utf16le\", \"ucs2\", \"base64\" \u548c \"hex\"\u3002<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u5199\u5165\u7f13\u5b58\u533a.write()<\/strong><\/p>\n
<\/p>\n
var buf = new Buffer(200)\r\nvar len = buf.write(\"www.csdn.net\")\r\nconsole.log(\"\u5199\u5165\u5b57\u8282\u6570\uff1a\" + len)<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
    \n
  • \n
    string – \u5199\u5165\u7f13\u51b2\u533a\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n<\/li>\n
  • \n
    offset – \u7f13\u51b2\u533a\u5f00\u59cb\u5199\u5165\u7684\u7d22\u5f15\u503c\uff0c\u9ed8\u8ba4\u4e3a 0 \u3002<\/p>\n<\/li>\n
  • \n
    length – \u5199\u5165\u7684\u5b57\u8282\u6570\uff0c\u9ed8\u8ba4\u4e3a buffer.length<\/p>\n<\/li>\n
  • \n
    encoding – \u4f7f\u7528\u7684\u7f16\u7801\u3002\u9ed8\u8ba4\u4e3a \u2018utf8′ \u3002<\/p>\n<\/li>\n<\/ul>\n
    \u7f13\u5b58\u533a\u8bfb\u53d6.toString()<\/strong><\/p>\n
    <\/p>\n
    buf = new Buffer(26);\r\nfor (var i = 0 ; i <ol class=\" list-paddingleft-2\">\n<li><p>encoding - \u4f7f\u7528\u7684\u7f16\u7801\u3002\u9ed8\u8ba4\u4e3a \u2018utf8' \u3002<\/p><\/li>\n<li><p>start - \u6307\u5b9a\u5f00\u59cb\u8bfb\u53d6\u7684\u7d22\u5f15\u4f4d\u7f6e\uff0c\u9ed8\u8ba4\u4e3a 0\u3002<\/p><\/li>\n<li><p>end - \u7ed3\u675f\u4f4d\u7f6e\uff0c\u9ed8\u8ba4\u4e3a\u7f13\u51b2\u533a\u7684\u672b\u5c3e\u3002<\/p><\/li>\n<\/ol><p><strong>Buffer\u8f6cJSON<\/strong><\/p><p class=\"jb51code\"><br><\/p><pre class=\"brush:js;\">var buf = new Buffer('www.runoob.com');\r\nvar json = buf.toJSON(buf);\r\nconsole.log(json);<\/pre>\n
      \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
    \u5408\u5e76 Buffer.concat([,])<\/strong><\/p>\n
    <\/p>\n
    var buf = new Buffer(\"\u5317\u4eac\")\r\nvar buf1 = new Buffer(\"\u4e0a\u6d77\")\r\nvar buf2 = Buffer.concat([buf,buf1],12)\r\nconsole.log(buf2.toString())<\/pre>\n
      \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
      \n
    • \n
      list\u7528\u4e8e\u5408\u5e76\u7684 Buffer \u5bf9\u8c61\u6570\u7ec4\u5217\u8868\u3002<\/p>\n<\/li>\n
    • \n
      totalLength\u6307\u5b9a\u5408\u5e76\u540eBuffer\u5bf9\u8c61\u7684\u603b\u957f\u5ea6\u3002<\/p>\n<\/li>\n<\/ul>\n
      \u6bd4\u8f83 .compare(otherBuffer)<\/strong><\/p>\n
      \u5728 Node.js v0.12.2 \u7248\u672c\u5f15\u5165<\/p>\n
      <\/p>\n
      var buffer1 = new Buffer(\"AVCX\")\r\nvar buffer2 = new Buffer(\"ACVV\")\r\n\r\nvar result = buffer1.compare(buffer2)\r\n\r\nif(result <p><strong>\u62f7\u8d1d .compare(buffer2)<\/strong><\/p><p class=\"jb51code\"><br><\/p><pre class=\"brush:js;\">buf.copy(targetBuffer[, targetStart[, sourceStart[, sourceEnd]]])<\/pre>\n
        \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
        \n
      1. \n
        targetBuffer – \u8981\u62f7\u8d1d\u7684 Buffer \u5bf9\u8c61\u3002<\/p>\n<\/li>\n
      2. \n
        targetStart – \u6570\u5b57, \u53ef\u9009, \u9ed8\u8ba4: 0<\/p>\n<\/li>\n
      3. \n
        sourceStart – \u6570\u5b57, \u53ef\u9009, \u9ed8\u8ba4: 0<\/p>\n<\/li>\n
      4. \n
        sourceEnd – \u6570\u5b57, \u53ef\u9009, \u9ed8\u8ba4: buffer.length<\/p>\n<\/li>\n<\/ol>\n
        <\/p>\n
        var buf1 = new Buffer(\"beiJing\")\r\nvar buf2 = new Buffer(8)\r\nbuf1.copy(buf2)\r\nconsole.log(\"buf2 content:\"+buf2.toString())<\/pre>\n
          \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
        \u526a\u88c1 .slice(buffer2)<\/strong><\/p>\n
        <\/p>\n
        buf.slice([start[, end]])<\/pre>\n
          \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
          \n
        1. \n
          start – \u6570\u5b57, \u53ef\u9009, \u9ed8\u8ba4: 0<\/p>\n<\/li>\n
        2. \n
          end – \u6570\u5b57, \u53ef\u9009, \u9ed8\u8ba4: buffer.length<\/p>\n<\/li>\n<\/ol>\n
          \u8fd4\u56de\u503c <\/strong><\/p>\n
          \u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u7f13\u51b2\u533a\uff0c\u5b83\u548c\u65e7\u7f13\u51b2\u533a\u6307\u5411\u540c\u4e00\u5757\u5185\u5b58\uff0c\u4f46\u662f\u4ece\u7d22\u5f15 start \u5230 end \u7684\u4f4d\u7f6e\u526a\u5207\u3002<\/p>\n
          <\/p>\n
          var buf1 = new Buffer(\"beiJing\")\r\nvar buf2 = buf1.slice(0,8)\r\nconsole.log(\"buf2 content:\"+buf2)\r\n\/\/ beiJing<\/pre>\n
            \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
          \u957f\u5ea6 .length<\/strong><\/p>\n
          <\/p>\n
          buf.length;<\/pre>\n
            \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
          \/\/\u8fd4\u56de\u8fd9\u4e2a buffer \u7684 bytes \u6570\u3002\u6ce8\u610f\u8fd9\u672a\u5fc5\u662f buffer \u91cc\u9762\u5185\u5bb9\u7684\u5927\u5c0f\u3002length \u662f buffer \u5bf9\u8c61\u6240\u5206\u914d\u7684\u5185\u5b58\u6570\uff0c\u5b83\u4e0d\u4f1a\u968f\u7740\u8fd9\u4e2a buffer \u5bf9\u8c61\u5185\u5bb9\u7684\u6539\u53d8\u800c\u6539\u53d8\u3002<\/p>\n
          \u4ee5\u4e0a\u5c31\u662f\u5fae\u4fe1\u5c0f\u7a0b\u5e8f\u4e2d\u5173\u4e8eBuffer\u7f13\u51b2\u533a\u7684\u5b9e\u4f8b\u8be6\u89e3\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
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