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12 |
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13 | var utils = require('../utils')
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14 | , nodes = require('../nodes')
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15 | , Buffer = require('safer-buffer').Buffer
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16 | , fs = require('fs')
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17 | , path = require('path')
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18 | , sax = require('sax');
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27 |
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28 | var Image = module.exports = function Image(ctx, path) {
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29 | this.ctx = ctx;
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30 | this.path = utils.lookup(path, ctx.paths);
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31 | if (!this.path) throw new Error('failed to locate file ' + path);
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32 | };
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33 |
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34 |
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35 |
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36 |
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37 |
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38 |
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39 |
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40 | Image.prototype.open = function(){
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41 | this.fd = fs.openSync(this.path, 'r');
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42 | this.length = fs.fstatSync(this.fd).size;
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43 | this.extname = path.extname(this.path).slice(1);
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44 | };
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45 |
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46 |
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47 |
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48 |
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49 |
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50 |
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51 |
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52 | Image.prototype.close = function(){
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53 | if (this.fd) fs.closeSync(this.fd);
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54 | };
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55 |
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66 |
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67 |
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68 | Image.prototype.type = function(){
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69 | var type
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70 | , buf = Buffer.alloc(4);
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71 |
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72 | fs.readSync(this.fd, buf, 0, 4, 0);
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73 |
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74 |
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75 | if (0x47 == buf[0] && 0x49 == buf[1] && 0x46 == buf[2]) type = 'gif';
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76 |
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77 |
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78 | else if (0x50 == buf[1] && 0x4E == buf[2] && 0x47 == buf[3]) type = 'png';
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79 |
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80 |
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81 | else if (0xff == buf[0] && 0xd8 == buf[1]) type = 'jpeg';
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82 |
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83 |
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84 | else if ('svg' == this.extname) type = this.extname;
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85 |
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86 | return type;
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87 | };
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88 |
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90 |
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91 |
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93 |
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94 |
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95 |
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96 | Image.prototype.size = function(){
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97 | var type = this.type()
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98 | , width
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99 | , height
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100 | , buf
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101 | , offset
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102 | , blockSize
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103 | , parser;
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104 |
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105 | function uint16(b) { return b[1] << 8 | b[0]; }
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106 | function uint32(b) { return b[0] << 24 | b[1] << 16 | b[2] << 8 | b[3]; }
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107 |
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108 |
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109 | switch (type) {
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110 | case 'jpeg':
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111 | buf = Buffer.alloc(this.length);
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112 | fs.readSync(this.fd, buf, 0, this.length, 0);
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113 | offset = 4;
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114 | blockSize = buf[offset] << 8 | buf[offset + 1];
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115 |
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116 | while (offset < this.length) {
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117 | offset += blockSize;
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118 | if (offset >= this.length || 0xff != buf[offset]) break;
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119 |
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120 | if (0xc0 == buf[offset + 1] || 0xc2 == buf[offset + 1]) {
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121 | height = buf[offset + 5] << 8 | buf[offset + 6];
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122 | width = buf[offset + 7] << 8 | buf[offset + 8];
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123 | } else {
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124 | offset += 2;
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125 | blockSize = buf[offset] << 8 | buf[offset + 1];
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126 | }
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127 | }
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128 | break;
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129 | case 'png':
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130 | buf = Buffer.alloc(8);
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131 |
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132 | fs.readSync(this.fd, buf, 0, 8, 16);
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133 | width = uint32(buf);
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134 | height = uint32(buf.slice(4, 8));
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135 | break;
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136 | case 'gif':
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137 | buf = Buffer.alloc(4);
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138 |
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139 | fs.readSync(this.fd, buf, 0, 4, 6);
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140 | width = uint16(buf);
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141 | height = uint16(buf.slice(2, 4));
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142 | break;
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143 | case 'svg':
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144 | offset = Math.min(this.length, 1024);
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145 | buf = Buffer.alloc(offset);
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146 | fs.readSync(this.fd, buf, 0, offset, 0);
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147 | buf = buf.toString('utf8');
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148 | parser = sax.parser(true);
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149 | parser.onopentag = function(node) {
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150 | if ('svg' == node.name && node.attributes.width && node.attributes.height) {
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151 | width = parseInt(node.attributes.width, 10);
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152 | height = parseInt(node.attributes.height, 10);
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153 | }
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154 | };
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155 | parser.write(buf).close();
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156 | break;
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157 | }
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158 |
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159 | if ('number' != typeof width) throw new Error('failed to find width of "' + this.path + '"');
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160 | if ('number' != typeof height) throw new Error('failed to find height of "' + this.path + '"');
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161 |
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162 | return [width, height];
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163 | };
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