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23 | "use strict";
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24 |
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25 | var POINTER_MASK = 0xC0;
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26 |
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27 | var isPointer = function (len) {
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28 | return (len & POINTER_MASK) > 0;
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29 | };
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30 |
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31 | var unpack = function (buff, pos) {
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32 | var hit_label,
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33 | read_size,
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34 | end,
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35 | increaseRead,
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36 | increasePosition,
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37 | readLen,
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38 | parts,
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39 | len;
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40 |
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41 | parts = [];
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42 | read_size = 0;
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43 | hit_label = false;
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44 |
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45 | increaseRead = function (length) {
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46 | if (length === undefined) {
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47 | length = 1;
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48 | }
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49 |
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50 | if (!hit_label) {
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51 | read_size += length;
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52 | }
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53 | };
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54 |
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55 | increasePosition = function (length) {
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56 | if (length === undefined) {
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57 | length = 1;
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58 | }
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59 | increaseRead(length);
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60 | pos += length;
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61 | };
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62 |
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63 | readLen = function () {
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64 | len = buff.readUInt8(pos);
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65 | increasePosition();
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66 | };
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67 |
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68 | readLen();
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69 |
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70 | while (len !== 0) {
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71 | if (isPointer(len)) {
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72 | len -= POINTER_MASK;
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73 | len = len << 8;
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74 | pos = len + buff.readUInt8(pos);
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75 | increaseRead();
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76 | hit_label = true;
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77 | } else {
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78 | end = pos + len;
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79 | parts.push(buff.toString('ascii', pos, end));
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80 | increasePosition(len);
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81 | }
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82 |
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83 | readLen();
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84 | }
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85 |
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86 | return {
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87 | read: read_size,
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88 | value: parts.join('.'),
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89 | };
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90 | };
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91 | exports.unpack = unpack;
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92 |
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93 | function splitMax(str, sep, max) {
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94 | var tmp = str.split(sep, max)
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95 | var txt = tmp.join(sep)
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96 | var rest = str.replace(txt, '').replace(sep, '')
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97 | tmp.push(rest)
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98 | return tmp
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99 | }
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100 |
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101 | var pack = function (str, buff, buf_pos, index) {
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102 | var written = 0,
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103 | found_ptr = false,
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104 | written_parts = [],
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105 | parts, name, left;
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106 |
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107 | var compress = function (s) {
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108 | if (!s) { return false; }
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109 |
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110 | var offset = index[s];
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111 | if (offset) {
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112 | offset = (POINTER_MASK << 8) + offset;
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113 | buff.writeUInt16BE(offset, buf_pos + written);
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114 | written += 2;
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115 | return true;
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116 | }
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117 | return false;
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118 | };
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119 |
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120 | var splitStr = function (s) {
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121 | if (s && s.length) {
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122 | parts = splitMax(s, '.', 1);
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123 | name = parts[0];
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124 | if (parts.length > 1) {
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125 | left = parts[1];
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126 | } else {
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127 | left = undefined;
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128 | }
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129 | } else {
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130 | parts = [];
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131 | name = undefined;
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132 | left = undefined;
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133 | }
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134 | };
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135 |
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136 | found_ptr = compress(str);
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137 | splitStr(str);
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138 |
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139 | while (!found_ptr && parts.length > 0) {
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140 | written_parts.push({
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141 | value: name,
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142 | offset: written + buf_pos,
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143 | });
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144 |
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145 | buff.writeUInt8(name.length, written + buf_pos);
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146 | written += 1;
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147 | buff.write(name, written + buf_pos, name.length);
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148 | written += name.length;
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149 |
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150 | found_ptr = compress(left);
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151 | splitStr(left);
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152 | }
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153 |
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154 | if (!found_ptr) {
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155 | buff.writeUInt8(0, written + buf_pos);
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156 | written += 1;
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157 | }
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158 |
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159 | if (written_parts.length) {
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160 | var i = written_parts.length;
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161 | while (i > 0) {
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162 | var key = written_parts.slice(i-1);
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163 | var names = [];
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164 | key.forEach(function(k) { names.push(k.value); });
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165 | index[names.join('.')] = key[0].offset;
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166 | i -= 1;
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167 | }
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168 | }
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169 |
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170 | return written;
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171 | };
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172 | exports.pack = pack;
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