The Tor Browser: tools/profiler/JSStreamWriter.cpp@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #include "JSStreamWriter.h"

     8 #include "mozilla/ArrayUtils.h" // for ArrayLength

     9 #include "nsDataHashtable.h"

    10 #include "nsString.h"

    11 #include "nsTArray.h"

    12 #include "nsUTF8Utils.h"

    14 #if _MSC_VER

    15  #define snprintf _snprintf

    16 #endif

    18 #define ARRAY (void*)1

    19 #define OBJECT (void*)2

    21 // Escape a UTF8 string to a stream. When an illegal encoding

    22 // is found it will insert "INVALID" and the function will return.

    23 static void EscapeToStream(std::ostream& stream, const char* str) {

    24   stream << "\"";

    26   size_t len = strlen(str);

    27   const char* end = &str[len];

    28   while (str < end) {

    29     bool err;

    30     const char* utf8CharStart = str;

    31     uint32_t ucs4Char = UTF8CharEnumerator::NextChar(&str, end, &err);

    33     if (err) {

    34       // Encoding error

    35       stream << "INVALID\"";

    36       return;

    37     }

    39     // See http://www.ietf.org/rfc/rfc4627.txt?number=4627

    40     // characters that must be escaped: quotation mark,

    41     // reverse solidus, and the control characters

    42     // (U+0000 through U+001F).

    43     if (ucs4Char == '\"') {

    44       stream << "\\\"";

    45     } else if (ucs4Char == '\\') {

    46       stream << "\\\\";

    47     } else if (ucs4Char > 0xFF) {

    48       char16_t chr[2];

    49       ConvertUTF8toUTF16 encoder(chr);

    50       encoder.write(utf8CharStart, uint32_t(str-utf8CharStart));

    51       char escChar[13];

    52       snprintf(escChar, mozilla::ArrayLength(escChar), "\\u%04X\\u%04X", chr[0], chr[1]);

    53       stream << escChar;

    54     } else if (ucs4Char < 0x1F || ucs4Char > 0xFF) {

    55       char escChar[7];

    56       snprintf(escChar, mozilla::ArrayLength(escChar), "\\u%04X", ucs4Char);

    57       stream << escChar;

    58     } else {

    59       stream << char(ucs4Char);

    60     }

    61   }

    62   stream << "\"";

    63 }

    65 JSStreamWriter::JSStreamWriter(std::ostream& aStream)

    66   : mStream(aStream)

    67   , mNeedsComma(false)

    68   , mNeedsName(false)

    69 { }

    71 JSStreamWriter::~JSStreamWriter()

    72 {

    73   MOZ_ASSERT(mStack.GetSize() == 0);

    74 }

    76 void

    77 JSStreamWriter::BeginObject()

    78 {

    79   MOZ_ASSERT(!mNeedsName);

    80   if (mNeedsComma && mStack.Peek() == ARRAY) {

    81     mStream << ",";

    82   }

    83   mStream << "{";

    84   mNeedsComma = false;

    85   mNeedsName = true;

    86   mStack.Push(OBJECT);

    87 }

    89 void

    90 JSStreamWriter::EndObject()

    91 {

    92   MOZ_ASSERT(mStack.Peek() == OBJECT);

    93   mStream << "}";

    94   mNeedsComma = true;

    95   mNeedsName = false;

    96   mStack.Pop();

    97   if (mStack.GetSize() > 0 && mStack.Peek() == OBJECT) {

    98     mNeedsName = true;

    99   }

   100 }

   102 void

   103 JSStreamWriter::BeginArray()

   104 {

   105   MOZ_ASSERT(!mNeedsName);

   106   if (mNeedsComma && mStack.Peek() == ARRAY) {

   107     mStream << ",";

   108   }

   109   mStream << "[";

   110   mNeedsComma = false;

   111   mStack.Push(ARRAY);

   112 }

   114 void

   115 JSStreamWriter::EndArray()

   116 {

   117   MOZ_ASSERT(!mNeedsName);

   118   MOZ_ASSERT(mStack.Peek() == ARRAY);

   119   mStream << "]";

   120   mNeedsComma = true;

   121   mStack.Pop();

   122   if (mStack.GetSize() > 0 && mStack.Peek() == OBJECT) {

   123     mNeedsName = true;

   124   }

   125 }

   127 void

   128 JSStreamWriter::Name(const char *aName)

   129 {

   130   MOZ_ASSERT(mNeedsName);

   131   if (mNeedsComma && mStack.Peek() == OBJECT) {

   132     mStream << ",";

   133   }

   134   EscapeToStream(mStream, aName);

   135   mStream << ":";

   136   mNeedsName = false;

   137 }

   139 void

   140 JSStreamWriter::Value(int aValue)

   141 {

   142   MOZ_ASSERT(!mNeedsName);

   143   if (mNeedsComma && mStack.Peek() == ARRAY) {

   144     mStream << ",";

   145   }

   146   mStream << aValue;

   147   mNeedsComma = true;

   148   if (mStack.Peek() == OBJECT) {

   149     mNeedsName = true;

   150   }

   151 }

   153 void

   154 JSStreamWriter::Value(double aValue)

   155 {

   156   MOZ_ASSERT(!mNeedsName);

   157   if (mNeedsComma && mStack.Peek() == ARRAY) {

   158     mStream << ",";

   159   }

   160   mStream.precision(18);

   161   mStream << aValue;

   162   mNeedsComma = true;

   163   if (mStack.Peek() == OBJECT) {

   164     mNeedsName = true;

   165   }

   166 }

   168 void

   169 JSStreamWriter::Value(const char *aValue)

   170 {

   171   MOZ_ASSERT(!mNeedsName);

   172   if (mNeedsComma && mStack.Peek() == ARRAY) {

   173     mStream << ",";

   174   }

   175   EscapeToStream(mStream, aValue);

   176   mNeedsComma = true;

   177   if (mStack.Peek() == OBJECT) {

   178     mNeedsName = true;

   179   }

   180 }

The Tor Browser / file revision

tools/profiler/JSStreamWriter.cpp@97036ab72558

tools/profiler/JSStreamWriter.cpp