Source/WebCore/inspector/front-end/CompilerSourceMapping.js

   1 /*
   2  * Copyright (C) 2011 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 /**
  32  * @constructor
  33  */
  34 WebInspector.CompilerSourceMapping = function()
  35 {
  36 }
  37
  38 WebInspector.CompilerSourceMapping.prototype = {
  39     compiledLocationToSourceLocation: function(lineNumber, columnNumber)
  40     {
  41         // Should be implemented by subclasses.
  42     },
  43
  44     sourceLocationToCompiledLocation: function(sourceURL, lineNumber, columnNumber)
  45     {
  46         // Should be implemented by subclasses.
  47     },
  48
  49     sources: function()
  50     {
  51         // Should be implemented by subclasses.
  52     }
  53 }
  54
  55 /**
  56  * Implements Source Map V3 consumer. See http://code.google.com/p/closure-compiler/wiki/SourceMaps
  57  * for format description.
  58  * @extends {WebInspector.CompilerSourceMapping}
  59  * @constructor
  60  */
  61 WebInspector.ClosureCompilerSourceMapping = function(payload)
  62 {
  63     if (!WebInspector.ClosureCompilerSourceMapping.prototype._base64Map) {
  64         base64Digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  65         WebInspector.ClosureCompilerSourceMapping.prototype._base64Map = {};
  66         for (var i = 0; i < base64Digits.length; ++i)
  67             WebInspector.ClosureCompilerSourceMapping.prototype._base64Map[base64Digits.charAt(i)] = i;
  68     }
  69
  70     this._sources = payload.sources;
  71     this._mappings = [];
  72     this._reverseMappingsBySourceURL = {};
  73     for (var i = 0; i < this._sources.length; ++i)
  74         this._reverseMappingsBySourceURL[this._sources[i]] = [];
  75     this._parseMappings(payload.mappings);
  76 }
  77
  78 WebInspector.ClosureCompilerSourceMapping.prototype = {
  79     compiledLocationToSourceLocation: function(lineNumber, columnNumber)
  80     {
  81         var mapping = this._findMapping(lineNumber, columnNumber);
  82         return { sourceURL: mapping[2], lineNumber: mapping[3], columnNumber: mapping[4] };
  83     },
  84
  85     sourceLocationToCompiledLocation: function(sourceURL, lineNumber)
  86     {
  87         var mappings = this._reverseMappingsBySourceURL[sourceURL];
  88         for ( ; lineNumber < mappings.length; ++lineNumber) {
  89             var mapping = mappings[lineNumber];
  90             if (mapping)
  91                 return { lineNumber: mapping[0], columnNumber: mapping[1] };
  92         }
  93     },
  94
  95     sources: function()
  96     {
  97         return this._sources;
  98     },
  99
 100     _findMapping: function(lineNumber, columnNumber)
 101     {
 102         var first = 0;
 103         var count = this._mappings.length;
 104         while (count > 1) {
 105           var step = count >> 1;
 106           var middle = first + step;
 107           var mapping = this._mappings[middle];
 108           if (lineNumber < mapping[0] || (lineNumber == mapping[0] && columnNumber < mapping[1]))
 109               count = step;
 110           else {
 111               first = middle;
 112               count -= step;
 113           }
 114         }
 115         return this._mappings[first];
 116     },
 117
 118     _parseMappings: function(mappingsPayload)
 119     {
 120         var stringCharIterator = new WebInspector.ClosureCompilerSourceMapping.StringCharIterator(mappingsPayload);
 121
 122         var lineNumber = 0;
 123         var columnNumber = 0;
 124         var sourceIndex = 0;
 125         var sourceLineNumber = 0;
 126         var sourceColumnNumber = 0;
 127         var nameIndex = 0;
 128
 129         var sourceURL = this._sources[0];
 130         var reverseMappings = this._reverseMappingsBySourceURL[sourceURL];
 131
 132         do {
 133             columnNumber += this._decodeVLQ(stringCharIterator);
 134             if (this._isSeparator(stringCharIterator.peek()))
 135                 continue;
 136             var sourceIndexDelta = this._decodeVLQ(stringCharIterator);
 137             if (sourceIndexDelta) {
 138                 sourceIndex += sourceIndexDelta;
 139                 sourceURL = this._sources[sourceIndex];
 140                 reverseMappings = this._reverseMappingsBySourceURL[sourceURL];
 141             }
 142             sourceLineNumber += this._decodeVLQ(stringCharIterator);
 143             sourceColumnNumber += this._decodeVLQ(stringCharIterator);
 144             if (!this._isSeparator(stringCharIterator.peek()))
 145                 nameIndex += this._decodeVLQ(stringCharIterator);
 146
 147             this._mappings.push([lineNumber, columnNumber, sourceURL, sourceLineNumber, sourceColumnNumber]);
 148             if (!reverseMappings[sourceLineNumber])
 149                 reverseMappings[sourceLineNumber] = [lineNumber, columnNumber];
 150
 151             if (stringCharIterator.next() === ";") {
 152                 lineNumber += 1;
 153                 columnNumber = 0;
 154             }
 155         } while(stringCharIterator.hasNext());
 156     },
 157
 158     _isSeparator: function(char)
 159     {
 160         return char === "," || char === ";";
 161     },
 162
 163     _decodeVLQ: function(stringCharIterator)
 164     {
 165         // Read unsigned value.
 166         var result = 0;
 167         var shift = 0;
 168         do {
 169             var digit = this._base64Map[stringCharIterator.next()];
 170             result += (digit & this._VLQ_BASE_MASK) << shift;
 171             shift += this._VLQ_BASE_SHIFT;
 172         } while (digit & this._VLQ_CONTINUATION_MASK);
 173
 174         // Fix the sign.
 175         var negative = result & 1;
 176         result >>= 1;
 177         return negative ? -result : result;
 178     },
 179
 180     _VLQ_BASE_SHIFT: 5,
 181     _VLQ_BASE_MASK: (1 << 5) - 1,
 182     _VLQ_CONTINUATION_MASK: 1 << 5
 183 }
 184
 185 /**
 186  * @constructor
 187  */
 188 WebInspector.ClosureCompilerSourceMapping.StringCharIterator = function(string)
 189 {
 190     this._string = string;
 191     this._position = 0;
 192 }
 193
 194 WebInspector.ClosureCompilerSourceMapping.StringCharIterator.prototype = {
 195     next: function()
 196     {
 197         return this._string.charAt(this._position++);
 198     },
 199
 200     peek: function()
 201     {
 202         return this._string.charAt(this._position);
 203     },
 204
 205     hasNext: function()
 206     {
 207         return this._position < this._string.length;
 208     }
 209 }