mozjs_sys 0.67.1

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "util/StringBuffer.h"

#include "mozilla/Range.h"
#include "mozilla/Unused.h"

#include "vm/JSObject-inl.h"
#include "vm/StringType-inl.h"

using namespace js;

template <typename CharT, class Buffer>
static CharT* ExtractWellSized(JSContext* cx, Buffer& cb) {
  size_t capacity = cb.capacity();
  size_t length = cb.length();

  CharT* buf = cb.extractOrCopyRawBuffer();
  if (!buf) {
    return nullptr;
  }

  /* For medium/big buffers, avoid wasting more than 1/4 of the memory. */
  MOZ_ASSERT(capacity >= length);
  if (length > Buffer::sMaxInlineStorage && capacity - length > length / 4) {
    CharT* tmp = cx->pod_realloc<CharT>(buf, capacity, length + 1);
    if (!tmp) {
      js_free(buf);
      return nullptr;
    }
    buf = tmp;
  }

  return buf;
}

char16_t* StringBuffer::stealChars() {
  if (isLatin1() && !inflateChars()) {
    return nullptr;
  }

  return ExtractWellSized<char16_t>(cx, twoByteChars());
}

bool StringBuffer::inflateChars() {
  MOZ_ASSERT(isLatin1());

  TwoByteCharBuffer twoByte(cx);

  /*
   * Note: we don't use Vector::capacity() because it always returns a
   * value >= sInlineCapacity. Since Latin1CharBuffer::sInlineCapacity >
   * TwoByteCharBuffer::sInlineCapacitychars, we'd always malloc here.
   */
  size_t capacity = Max(reserved_, latin1Chars().length());
  if (!twoByte.reserve(capacity)) {
    return false;
  }

  twoByte.infallibleAppend(latin1Chars().begin(), latin1Chars().length());

  cb.destroy();
  cb.construct<TwoByteCharBuffer>(std::move(twoByte));
  return true;
}

template <typename CharT, class Buffer>
static JSFlatString* FinishStringFlat(JSContext* cx, StringBuffer& sb,
                                      Buffer& cb) {
  size_t len = sb.length();
  if (!sb.append('\0')) {
    return nullptr;
  }

  UniquePtr<CharT[], JS::FreePolicy> buf(ExtractWellSized<CharT>(cx, cb));
  if (!buf) {
    return nullptr;
  }

  JSFlatString* str = NewStringDontDeflate<CanGC>(cx, std::move(buf), len);
  if (!str) {
    return nullptr;
  }

  /*
   * The allocation was made on a TempAllocPolicy, so account for the string
   * data on the string's zone.
   */
  cx->updateMallocCounter(sizeof(CharT) * len);

  return str;
}

JSFlatString* StringBuffer::finishString() {
  size_t len = length();
  if (len == 0) {
    return cx->names().empty;
  }

  if (!JSString::validateLength(cx, len)) {
    return nullptr;
  }

  JS_STATIC_ASSERT(JSFatInlineString::MAX_LENGTH_TWO_BYTE <
                   TwoByteCharBuffer::InlineLength);
  JS_STATIC_ASSERT(JSFatInlineString::MAX_LENGTH_LATIN1 <
                   Latin1CharBuffer::InlineLength);

  if (isLatin1()) {
    if (JSInlineString::lengthFits<Latin1Char>(len)) {
      mozilla::Range<const Latin1Char> range(latin1Chars().begin(), len);
      return NewInlineString<CanGC>(cx, range);
    }
  } else {
    if (JSInlineString::lengthFits<char16_t>(len)) {
      mozilla::Range<const char16_t> range(twoByteChars().begin(), len);
      return NewInlineString<CanGC>(cx, range);
    }
  }

  return isLatin1() ? FinishStringFlat<Latin1Char>(cx, *this, latin1Chars())
                    : FinishStringFlat<char16_t>(cx, *this, twoByteChars());
}

JSAtom* StringBuffer::finishAtom() {
  size_t len = length();
  if (len == 0) {
    return cx->names().empty;
  }

  if (isLatin1()) {
    JSAtom* atom = AtomizeChars(cx, latin1Chars().begin(), len);
    latin1Chars().clear();
    return atom;
  }

  JSAtom* atom = AtomizeChars(cx, twoByteChars().begin(), len);
  twoByteChars().clear();
  return atom;
}

bool js::ValueToStringBufferSlow(JSContext* cx, const Value& arg,
                                 StringBuffer& sb) {
  RootedValue v(cx, arg);
  if (!ToPrimitive(cx, JSTYPE_STRING, &v)) {
    return false;
  }

  if (v.isString()) {
    return sb.append(v.toString());
  }
  if (v.isNumber()) {
    return NumberValueToStringBuffer(cx, v, sb);
  }
  if (v.isBoolean()) {
    return BooleanToStringBuffer(v.toBoolean(), sb);
  }
  if (v.isNull()) {
    return sb.append(cx->names().null);
  }
  if (v.isSymbol()) {
    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
                              JSMSG_SYMBOL_TO_STRING);
    return false;
  }
  if (v.isBigInt()) {
    RootedBigInt i(cx, v.toBigInt());
    JSLinearString* str = BigInt::toString<CanGC>(cx, i, 10);
    if (!str) {
      return false;
    }
    return sb.append(str);
  }
  MOZ_ASSERT(v.isUndefined());
  return sb.append(cx->names().undefined);
}