code/buffers.js at main · javascript-2020/code · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
      var buffers = {};
      buffers.mem = [];
      buffers.copy = function () {
            var copy = [];
            buffers.mem.forEach(buf => copy.push(structuredClone(buf)));
            return copy;
      }; //copy
      buffers.set = function (copy) {
            buffers.mem.length = 0;
            copy.forEach(buf => buffers.mem.push(structuredClone(buf)));
      }; //set
      buffers.clear = function () {
            buffers.mem.length = 0;
      };
      //buffers.encoder               = new TextEncoder();
      //buffers.decoder               = new TextDecoder();
      buffers.add = function (uint8) {
            [...arguments].forEach(uint8 => buffers.mem.push(uint8));
      }; //add
      buffers.add.arraybuffer = function (buf) {
            [...arguments].forEach((buf, i) => {
                  console.log('buffers.add.arraybuffer', i);
                  var uint8 = new Uint8Array(buf);
                  buffers.mem.push(uint8);
            });
      }; //arraybuffer
      buffers.add.string = function (str) {
            [...arguments].forEach(str => {
                  var uint8 = buffers.encoder.encode(str);
                  buffers.mem.push(uint8);
            });
      }; //string
      buffers.len = function () {
            var size = 0;
            buffers.mem.forEach(buf => (size += buf.byteLength));
            return size;
      }; //len
      buffers.peek = {};
      buffers.peek.rd=function(len){

            var uint8   = buffers.rd(len,false);
            return uint8;

      }//peek.rd
      buffers.peek.slice=function(i1,i2){

            var uint8   = buffers.rd(i2+1,false);
            uint8       = uint8.slice(i1,i2+1);
            return uint8;

      }//peek.slice
      buffers.peek.uint16=function(offset){
            var uint8     = buffers.peek.slice(offset,offset+2);
            var view      = new DataView(uint8.buffer);
            var num       = view.getUint16(0);
            return num;
      }//uint16
      buffers.peek.uint64=function(offset){

            var uint8     = buffers.peek.slice(offset,offset+8);
            var view      = new DataView(uint8.buffer);
            var bigint    = view.getBigUint64(0);
            var num       = Number(bigint);
            return num;

      }//peek.bigint
      buffers.peek.number = function (offset) {
            var uint8 = buffers.rd(offset + 1, false);
            if (!uint8) {
                  return uint8;
            }
            var num = uint8[offset];
            return num;
      }; //peek.number
      buffers.rd = function (len, remove = true) {
            var info = [];
            var t = 0;
            var flag = false;
            var n = buffers.mem.length;
            for (var i = 0; i < n; i++) {
                  var buf2 = buffers.mem[i];
                  if (t + buf2.byteLength > len) {
                        var n1 = len - t;
                        info.push({index: i, num: n1});
                        t += n1;
                  } else {
                        info.push(i);
                        t += buf2.byteLength;
                  }
                  if (t == len) {
                        flag = true;
                        break;
                  }
            } //for

            if (!flag) {
                  return null;
            }

            var t = len;
            var buf = new Uint8Array(len);
            var buf2, buf3;
            var n = info.length;
            for (var j = n - 1; j >= 0; j--) {
                  var o = info[j];
                  if (typeof o == 'number') {
                        buf2 = buffers.mem[o];
                        t -= buf2.byteLength;
                        buf.set(buf2, t);
                  } else {
                        buf2 = buffers.mem[o.index];
                        buf3 = buf2.slice(0, o.num);
                        t -= o.num;
                        buf.set(buf3, t);
                  }
            } //for

            if (remove) {
                  var n = info.length;
                  for (var j = n - 1; j >= 0; j--) {
                        var o = info[j];
                        if (typeof o == 'number') {
                              buffers.mem.splice(o, 1);
                        } else {
                              buf3 = buf2.slice(n1);
                              buffers.mem.splice(o.index, 1, buf3);
                        }
                  } //for
            } //remove

            return buf;
      }; //rd
      buffers.rd.simple = function (len) {
            var copy = buffers.copy();
            var t = 0;
            var n = buffers.mem.length;
            for (var i = 0; i < n; i++) {
                  var buf2 = buffers.mem[i];
                  if (t + buf2.byteLength > len) {
                        var n1 = len - t;
                        var buf3 = buf2.slice(0, n1);
                        buf.set(buf3, t);
                        var buf3 = buf2.slice(n1);
                        buffers.mem.splice(i, 1, buf3);
                        t += n1;
                  } else {
                        buf.set(buf2, t);
                        t += buf2.byteLength;
                        buffers.mem.splice(i, 1);
                        i--;
                        n--;
                  }
                  if (t == len) {
                        return buf;
                  }
            } //for
            buffers.set(copy);
            return null;
      }; //rd.simple
      buffers.rd.string = function (len) {
            var uint8 = buffers.rd(len);
            if (!uint8) {
                  return uint8;
            }
            var str = buffers.decoder.decode(uint8);
            return str;
      }; //string
      buffers.rd.number = function () {
            var uint8 = buffers.rd(1);
            var num = uint8[0];
            return num;
      }; //rd.number
      buffers.display = function (pretty = true) {
            console.log('buffers :', buffers.mem.length);
            buffers.mem.forEach(uint8 => {
                  var n = uint8.length;
                  var str = '';
                  for (var i = 0; i < n; i++) {
                        var b = uint8[i];
                        str += b + ' ';
                  } //for
                  console.log(str);
            });
      }; //display

      return buffers;