1 files changed, 630 insertions, 0 deletions
diff --git a/xpcom/string/nsReadableUtils.cpp b/xpcom/string/nsReadableUtils.cpp
new file mode 100644
index 0000000000..fa4c4bc69b
--- /dev/null
+++ b/xpcom/string/nsReadableUtils.cpp
@@ -0,0 +1,630 @@
+/* -*- 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 "nsReadableUtils.h"
+
+#include <algorithm>
+
+#include "mozilla/CheckedInt.h"
+#include "mozilla/Utf8.h"
+
+#include "nscore.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "nsUTF8Utils.h"
+
+using mozilla::Span;
+
+/**
+ * A helper function that allocates a buffer of the desired character type big
+ * enough to hold a copy of the supplied string (plus a zero terminator).
+ *
+ * @param aSource an string you will eventually be making a copy of
+ * @return a new buffer which you must free with |free|.
+ *
+ */
+template <class FromStringT, class CharT>
+inline CharT* AllocateStringCopy(const FromStringT& aSource, CharT*) {
+  return static_cast<CharT*>(
+      malloc((size_t(aSource.Length()) + 1) * sizeof(CharT)));
+}
+
+char* ToNewCString(const nsAString& aSource) {
+  char* str = ToNewCString(aSource, mozilla::fallible);
+  if (!str) {
+    MOZ_CRASH("Unable to allocate memory");
+  }
+  return str;
+}
+
+char* ToNewCString(const nsAString& aSource,
+                   const mozilla::fallible_t& aFallible) {
+  char* dest = AllocateStringCopy(aSource, (char*)nullptr);
+  if (!dest) {
+    return nullptr;
+  }
+
+  auto len = aSource.Length();
+  LossyConvertUtf16toLatin1(aSource, Span(dest, len));
+  dest[len] = 0;
+  return dest;
+}
+
+char* ToNewUTF8String(const nsAString& aSource, uint32_t* aUTF8Count,
+                      const mozilla::fallible_t& aFallible) {
+  auto len = aSource.Length();
+  // The uses of this function seem temporary enough that it's not
+  // worthwhile to be fancy about the allocation size. Let's just use
+  // the worst case.
+  // Times 3 plus 1, because ConvertUTF16toUTF8 requires times 3 and
+  // then we have the terminator.
+  // Using CheckedInt<uint32_t>, because aUTF8Count is uint32_t* for
+  // historical reasons.
+  mozilla::CheckedInt<uint32_t> destLen(len);
+  destLen *= 3;
+  destLen += 1;
+  if (!destLen.isValid()) {
+    return nullptr;
+  }
+  size_t destLenVal = destLen.value();
+  char* dest = static_cast<char*>(malloc(destLenVal));
+  if (!dest) {
+    return nullptr;
+  }
+
+  size_t written = ConvertUtf16toUtf8(aSource, Span(dest, destLenVal));
+  dest[written] = 0;
+
+  if (aUTF8Count) {
+    *aUTF8Count = written;
+  }
+
+  return dest;
+}
+
+char* ToNewUTF8String(const nsAString& aSource, uint32_t* aUTF8Count) {
+  char* str = ToNewUTF8String(aSource, aUTF8Count, mozilla::fallible);
+  if (!str) {
+    MOZ_CRASH("Unable to allocate memory");
+  }
+  return str;
+}
+
+char* ToNewCString(const nsACString& aSource) {
+  char* str = ToNewCString(aSource, mozilla::fallible);
+  if (!str) {
+    MOZ_CRASH("Unable to allocate memory");
+  }
+  return str;
+}
+
+char* ToNewCString(const nsACString& aSource,
+                   const mozilla::fallible_t& aFallible) {
+  // no conversion needed, just allocate a buffer of the correct length and copy
+  // into it
+
+  char* dest = AllocateStringCopy(aSource, (char*)nullptr);
+  if (!dest) {
+    return nullptr;
+  }
+
+  auto len = aSource.Length();
+  memcpy(dest, aSource.BeginReading(), len * sizeof(char));
+  dest[len] = 0;
+  return dest;
+}
+
+char16_t* ToNewUnicode(const nsAString& aSource) {
+  char16_t* str = ToNewUnicode(aSource, mozilla::fallible);
+  if (!str) {
+    MOZ_CRASH("Unable to allocate memory");
+  }
+  return str;
+}
+
+char16_t* ToNewUnicode(const nsAString& aSource,
+                       const mozilla::fallible_t& aFallible) {
+  // no conversion needed, just allocate a buffer of the correct length and copy
+  // into it
+
+  char16_t* dest = AllocateStringCopy(aSource, (char16_t*)nullptr);
+  if (!dest) {
+    return nullptr;
+  }
+
+  auto len = aSource.Length();
+  memcpy(dest, aSource.BeginReading(), len * sizeof(char16_t));
+  dest[len] = 0;
+  return dest;
+}
+
+char16_t* ToNewUnicode(const nsACString& aSource) {
+  char16_t* str = ToNewUnicode(aSource, mozilla::fallible);
+  if (!str) {
+    MOZ_CRASH("Unable to allocate memory");
+  }
+  return str;
+}
+
+char16_t* ToNewUnicode(const nsACString& aSource,
+                       const mozilla::fallible_t& aFallible) {
+  char16_t* dest = AllocateStringCopy(aSource, (char16_t*)nullptr);
+  if (!dest) {
+    return nullptr;
+  }
+
+  auto len = aSource.Length();
+  ConvertLatin1toUtf16(aSource, Span(dest, len));
+  dest[len] = 0;
+  return dest;
+}
+
+char16_t* UTF8ToNewUnicode(const nsACString& aSource, uint32_t* aUTF16Count,
+                           const mozilla::fallible_t& aFallible) {
+  // Compute length plus one as required by ConvertUTF8toUTF16
+  uint32_t lengthPlusOne = aSource.Length() + 1;  // Can't overflow
+
+  mozilla::CheckedInt<size_t> allocLength(lengthPlusOne);
+  // Add space for zero-termination
+  allocLength += 1;
+  // We need UTF-16 units
+  allocLength *= sizeof(char16_t);
+
+  if (!allocLength.isValid()) {
+    return nullptr;
+  }
+
+  char16_t* dest = (char16_t*)malloc(allocLength.value());
+  if (!dest) {
+    return nullptr;
+  }
+
+  size_t written = ConvertUtf8toUtf16(aSource, Span(dest, lengthPlusOne));
+  dest[written] = 0;
+
+  if (aUTF16Count) {
+    *aUTF16Count = written;
+  }
+
+  return dest;
+}
+
+char16_t* UTF8ToNewUnicode(const nsACString& aSource, uint32_t* aUTF16Count) {
+  char16_t* str = UTF8ToNewUnicode(aSource, aUTF16Count, mozilla::fallible);
+  if (!str) {
+    MOZ_CRASH("Unable to allocate memory");
+  }
+  return str;
+}
+
+char16_t* CopyUnicodeTo(const nsAString& aSource, uint32_t aSrcOffset,
+                        char16_t* aDest, uint32_t aLength) {
+  MOZ_ASSERT(aSrcOffset + aLength <= aSource.Length());
+  memcpy(aDest, aSource.BeginReading() + aSrcOffset,
+         size_t(aLength) * sizeof(char16_t));
+  return aDest;
+}
+
+void ToUpperCase(nsACString& aCString) {
+  char* cp = aCString.BeginWriting();
+  char* end = cp + aCString.Length();
+  while (cp != end) {
+    char ch = *cp;
+    if (ch >= 'a' && ch <= 'z') {
+      *cp = ch - ('a' - 'A');
+    }
+    ++cp;
+  }
+}
+
+void ToUpperCase(const nsACString& aSource, nsACString& aDest) {
+  aDest.SetLength(aSource.Length());
+  const char* src = aSource.BeginReading();
+  const char* end = src + aSource.Length();
+  char* dst = aDest.BeginWriting();
+  while (src != end) {
+    char ch = *src;
+    if (ch >= 'a' && ch <= 'z') {
+      *dst = ch - ('a' - 'A');
+    } else {
+      *dst = ch;
+    }
+    ++src;
+    ++dst;
+  }
+}
+
+void ToLowerCase(nsACString& aCString) {
+  char* cp = aCString.BeginWriting();
+  char* end = cp + aCString.Length();
+  while (cp != end) {
+    char ch = *cp;
+    if (ch >= 'A' && ch <= 'Z') {
+      *cp = ch + ('a' - 'A');
+    }
+    ++cp;
+  }
+}
+
+void ToLowerCase(const nsACString& aSource, nsACString& aDest) {
+  aDest.SetLength(aSource.Length());
+  const char* src = aSource.BeginReading();
+  const char* end = src + aSource.Length();
+  char* dst = aDest.BeginWriting();
+  while (src != end) {
+    char ch = *src;
+    if (ch >= 'A' && ch <= 'Z') {
+      *dst = ch + ('a' - 'A');
+    } else {
+      *dst = ch;
+    }
+    ++src;
+    ++dst;
+  }
+}
+
+void ParseString(const nsACString& aSource, char aDelimiter,
+                 nsTArray<nsCString>& aArray) {
+  nsACString::const_iterator start, end;
+  aSource.BeginReading(start);
+  aSource.EndReading(end);
+
+  for (;;) {
+    nsACString::const_iterator delimiter = start;
+    FindCharInReadable(aDelimiter, delimiter, end);
+
+    if (delimiter != start) {
+      aArray.AppendElement(Substring(start, delimiter));
+    }
+
+    if (delimiter == end) {
+      break;
+    }
+    start = ++delimiter;
+    if (start == end) {
+      break;
+    }
+  }
+}
+
+template <class StringT, class IteratorT>
+bool FindInReadable_Impl(
+    const StringT& aPattern, IteratorT& aSearchStart, IteratorT& aSearchEnd,
+    nsTStringComparator<typename StringT::char_type> aCompare) {
+  bool found_it = false;
+
+  // only bother searching at all if we're given a non-empty range to search
+  if (aSearchStart != aSearchEnd) {
+    IteratorT aPatternStart, aPatternEnd;
+    aPattern.BeginReading(aPatternStart);
+    aPattern.EndReading(aPatternEnd);
+
+    // outer loop keeps searching till we find it or run out of string to search
+    while (!found_it) {
+      // fast inner loop (that's what it's called, not what it is) looks for a
+      // potential match
+      while (aSearchStart != aSearchEnd &&
+             aCompare(aPatternStart.get(), aSearchStart.get(), 1, 1)) {
+        ++aSearchStart;
+      }
+
+      // if we broke out of the `fast' loop because we're out of string ...
+      // we're done: no match
+      if (aSearchStart == aSearchEnd) {
+        break;
+      }
+
+      // otherwise, we're at a potential match, let's see if we really hit one
+      IteratorT testPattern(aPatternStart);
+      IteratorT testSearch(aSearchStart);
+
+      // slow inner loop verifies the potential match (found by the `fast' loop)
+      // at the current position
+      for (;;) {
+        // we already compared the first character in the outer loop,
+        //  so we'll advance before the next comparison
+        ++testPattern;
+        ++testSearch;
+
+        // if we verified all the way to the end of the pattern, then we found
+        // it!
+        if (testPattern == aPatternEnd) {
+          found_it = true;
+          aSearchEnd = testSearch;  // return the exact found range through the
+                                    // parameters
+          break;
+        }
+
+        // if we got to end of the string we're searching before we hit the end
+        // of the
+        //  pattern, we'll never find what we're looking for
+        if (testSearch == aSearchEnd) {
+          aSearchStart = aSearchEnd;
+          break;
+        }
+
+        // else if we mismatched ... it's time to advance to the next search
+        // position
+        //  and get back into the `fast' loop
+        if (aCompare(testPattern.get(), testSearch.get(), 1, 1)) {
+          ++aSearchStart;
+          break;
+        }
+      }
+    }
+  }
+
+  return found_it;
+}
+
+/**
+ * This searches the entire string from right to left, and returns the first
+ * match found, if any.
+ */
+template <class StringT, class IteratorT>
+bool RFindInReadable_Impl(
+    const StringT& aPattern, IteratorT& aSearchStart, IteratorT& aSearchEnd,
+    nsTStringComparator<typename StringT::char_type> aCompare) {
+  IteratorT patternStart, patternEnd, searchEnd = aSearchEnd;
+  aPattern.BeginReading(patternStart);
+  aPattern.EndReading(patternEnd);
+
+  // Point to the last character in the pattern
+  --patternEnd;
+  // outer loop keeps searching till we run out of string to search
+  while (aSearchStart != searchEnd) {
+    // Point to the end position of the next possible match
+    --searchEnd;
+
+    // Check last character, if a match, explore further from here
+    if (aCompare(patternEnd.get(), searchEnd.get(), 1, 1) == 0) {
+      // We're at a potential match, let's see if we really hit one
+      IteratorT testPattern(patternEnd);
+      IteratorT testSearch(searchEnd);
+
+      // inner loop verifies the potential match at the current position
+      do {
+        // if we verified all the way to the end of the pattern, then we found
+        // it!
+        if (testPattern == patternStart) {
+          aSearchStart = testSearch;  // point to start of match
+          aSearchEnd = ++searchEnd;   // point to end of match
+          return true;
+        }
+
+        // if we got to end of the string we're searching before we hit the end
+        // of the
+        //  pattern, we'll never find what we're looking for
+        if (testSearch == aSearchStart) {
+          aSearchStart = aSearchEnd;
+          return false;
+        }
+
+        // test previous character for a match
+        --testPattern;
+        --testSearch;
+      } while (aCompare(testPattern.get(), testSearch.get(), 1, 1) == 0);
+    }
+  }
+
+  aSearchStart = aSearchEnd;
+  return false;
+}
+
+bool FindInReadable(const nsAString& aPattern,
+                    nsAString::const_iterator& aSearchStart,
+                    nsAString::const_iterator& aSearchEnd,
+                    nsStringComparator aComparator) {
+  return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
+}
+
+bool FindInReadable(const nsACString& aPattern,
+                    nsACString::const_iterator& aSearchStart,
+                    nsACString::const_iterator& aSearchEnd,
+                    nsCStringComparator aComparator) {
+  return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
+}
+
+bool CaseInsensitiveFindInReadable(const nsACString& aPattern,
+                                   nsACString::const_iterator& aSearchStart,
+                                   nsACString::const_iterator& aSearchEnd) {
+  return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd,
+                             nsCaseInsensitiveCStringComparator);
+}
+
+bool RFindInReadable(const nsAString& aPattern,
+                     nsAString::const_iterator& aSearchStart,
+                     nsAString::const_iterator& aSearchEnd,
+                     const nsStringComparator aComparator) {
+  return RFindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
+}
+
+bool RFindInReadable(const nsACString& aPattern,
+                     nsACString::const_iterator& aSearchStart,
+                     nsACString::const_iterator& aSearchEnd,
+                     const nsCStringComparator aComparator) {
+  return RFindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
+}
+
+bool FindCharInReadable(char16_t aChar, nsAString::const_iterator& aSearchStart,
+                        const nsAString::const_iterator& aSearchEnd) {
+  ptrdiff_t fragmentLength = aSearchEnd.get() - aSearchStart.get();
+
+  const char16_t* charFoundAt =
+      nsCharTraits<char16_t>::find(aSearchStart.get(), fragmentLength, aChar);
+  if (charFoundAt) {
+    aSearchStart.advance(charFoundAt - aSearchStart.get());
+    return true;
+  }
+
+  aSearchStart.advance(fragmentLength);
+  return false;
+}
+
+bool FindCharInReadable(char aChar, nsACString::const_iterator& aSearchStart,
+                        const nsACString::const_iterator& aSearchEnd) {
+  ptrdiff_t fragmentLength = aSearchEnd.get() - aSearchStart.get();
+
+  const char* charFoundAt =
+      nsCharTraits<char>::find(aSearchStart.get(), fragmentLength, aChar);
+  if (charFoundAt) {
+    aSearchStart.advance(charFoundAt - aSearchStart.get());
+    return true;
+  }
+
+  aSearchStart.advance(fragmentLength);
+  return false;
+}
+
+bool StringBeginsWith(const nsAString& aSource, const nsAString& aSubstring) {
+  nsAString::size_type src_len = aSource.Length(),
+                       sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, 0, sub_len).Equals(aSubstring);
+}
+
+bool StringBeginsWith(const nsAString& aSource, const nsAString& aSubstring,
+                      nsStringComparator aComparator) {
+  nsAString::size_type src_len = aSource.Length(),
+                       sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, 0, sub_len).Equals(aSubstring, aComparator);
+}
+
+bool StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring) {
+  nsACString::size_type src_len = aSource.Length(),
+                        sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, 0, sub_len).Equals(aSubstring);
+}
+
+bool StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring,
+                      nsCStringComparator aComparator) {
+  nsACString::size_type src_len = aSource.Length(),
+                        sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, 0, sub_len).Equals(aSubstring, aComparator);
+}
+
+bool StringEndsWith(const nsAString& aSource, const nsAString& aSubstring) {
+  nsAString::size_type src_len = aSource.Length(),
+                       sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring);
+}
+
+bool StringEndsWith(const nsAString& aSource, const nsAString& aSubstring,
+                    nsStringComparator aComparator) {
+  nsAString::size_type src_len = aSource.Length(),
+                       sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, src_len - sub_len, sub_len)
+      .Equals(aSubstring, aComparator);
+}
+
+bool StringEndsWith(const nsACString& aSource, const nsACString& aSubstring) {
+  nsACString::size_type src_len = aSource.Length(),
+                        sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring);
+}
+
+bool StringEndsWith(const nsACString& aSource, const nsACString& aSubstring,
+                    nsCStringComparator aComparator) {
+  nsACString::size_type src_len = aSource.Length(),
+                        sub_len = aSubstring.Length();
+  if (sub_len > src_len) {
+    return false;
+  }
+  return Substring(aSource, src_len - sub_len, sub_len)
+      .Equals(aSubstring, aComparator);
+}
+
+static const char16_t empty_buffer[1] = {'\0'};
+
+const nsString& EmptyString() {
+  static const nsDependentString sEmpty(empty_buffer);
+
+  return sEmpty;
+}
+
+const nsCString& EmptyCString() {
+  static const nsDependentCString sEmpty((const char*)empty_buffer);
+
+  return sEmpty;
+}
+
+const nsString& VoidString() {
+  static const nsString sNull(mozilla::detail::StringDataFlags::VOIDED);
+
+  return sNull;
+}
+
+const nsCString& VoidCString() {
+  static const nsCString sNull(mozilla::detail::StringDataFlags::VOIDED);
+
+  return sNull;
+}
+
+int32_t CompareUTF8toUTF16(const nsACString& aUTF8String,
+                           const nsAString& aUTF16String, bool* aErr) {
+  const char* u8;
+  const char* u8end;
+  aUTF8String.BeginReading(u8);
+  aUTF8String.EndReading(u8end);
+
+  const char16_t* u16;
+  const char16_t* u16end;
+  aUTF16String.BeginReading(u16);
+  aUTF16String.EndReading(u16end);
+
+  for (;;) {
+    if (u8 == u8end) {
+      if (u16 == u16end) {
+        return 0;
+      }
+      return -1;
+    }
+    if (u16 == u16end) {
+      return 1;
+    }
+    // No need for ASCII optimization, since both NextChar()
+    // calls get inlined.
+    uint32_t scalar8 = UTF8CharEnumerator::NextChar(&u8, u8end, aErr);
+    uint32_t scalar16 = UTF16CharEnumerator::NextChar(&u16, u16end, aErr);
+    if (scalar16 == scalar8) {
+      continue;
+    }
+    if (scalar8 < scalar16) {
+      return -1;
+    }
+    return 1;
+  }
+}
+
+void AppendUCS4ToUTF16(const uint32_t aSource, nsAString& aDest) {
+  NS_ASSERTION(IS_VALID_CHAR(aSource), "Invalid UCS4 char");
+  if (IS_IN_BMP(aSource)) {
+    aDest.Append(char16_t(aSource));
+  } else {
+    aDest.Append(H_SURROGATE(aSource));
+    aDest.Append(L_SURROGATE(aSource));
+  }
+}