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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /xpcom/string/nsTSubstring.cpp
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/string/nsTSubstring.cpp')
-rw-r--r--xpcom/string/nsTSubstring.cpp1706
1 files changed, 1706 insertions, 0 deletions
diff --git a/xpcom/string/nsTSubstring.cpp b/xpcom/string/nsTSubstring.cpp
new file mode 100644
index 0000000000..ae9fda73c8
--- /dev/null
+++ b/xpcom/string/nsTSubstring.cpp
@@ -0,0 +1,1706 @@
+/* -*- 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 "double-conversion/double-conversion.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Printf.h"
+#include "mozilla/ResultExtensions.h"
+
+#include "nsASCIIMask.h"
+#include "nsCharTraits.h"
+#include "nsISupports.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+#ifdef DEBUG
+# include "nsStringStats.h"
+#else
+# define STRING_STAT_INCREMENT(_s)
+#endif
+
+// It's not worthwhile to reallocate the buffer and memcpy the
+// contents over when the size difference isn't large. With
+// power-of-two allocation buckets and 64 as the typical inline
+// capacity, considering that above 1000 there performance aspects
+// of realloc and memcpy seem to be absorbed, relative to the old
+// code, by the performance benefits of the new code being exact,
+// we need to choose which transitions of 256 to 128, 512 to 256
+// and 1024 to 512 to allow. As a guess, let's pick the middle
+// one as the the largest potential transition that we forgo. So
+// we'll shrink from 1024 bucket to 512 bucket but not from 512
+// bucket to 256 bucket. We'll decide by comparing the difference
+// of capacities. As bucket differences, the differences are 256
+// and 512. Since the capacities have various overheads, we
+// can't compare with 256 or 512 exactly but it's easier to
+// compare to some number that's between the two, so it's
+// far away from either to ignore the overheads.
+const uint32_t kNsStringBufferShrinkingThreshold = 384;
+
+using double_conversion::DoubleToStringConverter;
+
+// ---------------------------------------------------------------------------
+
+static const char16_t gNullChar = 0;
+
+char* const nsCharTraits<char>::sEmptyBuffer =
+ (char*)const_cast<char16_t*>(&gNullChar);
+char16_t* const nsCharTraits<char16_t>::sEmptyBuffer =
+ const_cast<char16_t*>(&gNullChar);
+
+// ---------------------------------------------------------------------------
+
+static void ReleaseData(void* aData, nsAString::DataFlags aFlags) {
+ if (aFlags & nsAString::DataFlags::REFCOUNTED) {
+ nsStringBuffer::FromData(aData)->Release();
+ } else if (aFlags & nsAString::DataFlags::OWNED) {
+ // Treat this as destruction of a "StringAdopt" object for leak
+ // tracking purposes.
+ MOZ_LOG_DTOR(aData, "StringAdopt", 1);
+
+ free(aData);
+ STRING_STAT_INCREMENT(AdoptFree);
+ }
+ // otherwise, nothing to do.
+}
+
+// ---------------------------------------------------------------------------
+
+#ifdef XPCOM_STRING_CONSTRUCTOR_OUT_OF_LINE
+template <typename T>
+nsTSubstring<T>::nsTSubstring(char_type* aData, size_type aLength,
+ DataFlags aDataFlags, ClassFlags aClassFlags)
+ : ::mozilla::detail::nsTStringRepr<T>(aData, aLength, aDataFlags,
+ aClassFlags) {
+ AssertValid();
+
+ if (aDataFlags & DataFlags::OWNED) {
+ STRING_STAT_INCREMENT(Adopt);
+ MOZ_LOG_CTOR(this->mData, "StringAdopt", 1);
+ }
+}
+#endif /* XPCOM_STRING_CONSTRUCTOR_OUT_OF_LINE */
+
+/**
+ * helper function for down-casting a nsTSubstring to an nsTAutoString.
+ */
+template <typename T>
+inline const nsTAutoString<T>* AsAutoString(const nsTSubstring<T>* aStr) {
+ return static_cast<const nsTAutoString<T>*>(aStr);
+}
+
+template <typename T>
+mozilla::Result<mozilla::BulkWriteHandle<T>, nsresult>
+nsTSubstring<T>::BulkWrite(size_type aCapacity, size_type aPrefixToPreserve,
+ bool aAllowShrinking) {
+ auto r = StartBulkWriteImpl(aCapacity, aPrefixToPreserve, aAllowShrinking);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return r.propagateErr();
+ }
+ return mozilla::BulkWriteHandle<T>(this, r.unwrap());
+}
+
+template <typename T>
+auto nsTSubstring<T>::StartBulkWriteImpl(size_type aCapacity,
+ size_type aPrefixToPreserve,
+ bool aAllowShrinking,
+ size_type aSuffixLength,
+ size_type aOldSuffixStart,
+ size_type aNewSuffixStart)
+ -> mozilla::Result<size_type, nsresult> {
+ // Note! Capacity does not include room for the terminating null char.
+
+ MOZ_ASSERT(aPrefixToPreserve <= aCapacity,
+ "Requested preservation of an overlong prefix.");
+ MOZ_ASSERT(aNewSuffixStart + aSuffixLength <= aCapacity,
+ "Requesed move of suffix to out-of-bounds location.");
+ // Can't assert aOldSuffixStart, because mLength may not be valid anymore,
+ // since this method allows itself to be called more than once.
+
+ // If zero capacity is requested, set the string to the special empty
+ // string.
+ if (MOZ_UNLIKELY(!aCapacity)) {
+ ReleaseData(this->mData, this->mDataFlags);
+ SetToEmptyBuffer();
+ return 0;
+ }
+
+ // Note! Capacity() returns 0 when the string is immutable.
+ const size_type curCapacity = Capacity();
+
+ bool shrinking = false;
+
+ // We've established that aCapacity > 0.
+ // |curCapacity == 0| means that the buffer is immutable or 0-sized, so we
+ // need to allocate a new buffer. We cannot use the existing buffer even
+ // though it might be large enough.
+
+ if (aCapacity <= curCapacity) {
+ if (aAllowShrinking) {
+ shrinking = true;
+ } else {
+ char_traits::move(this->mData + aNewSuffixStart,
+ this->mData + aOldSuffixStart, aSuffixLength);
+ if (aSuffixLength) {
+ char_traits::uninitialize(this->mData + aPrefixToPreserve,
+ XPCOM_MIN(aNewSuffixStart - aPrefixToPreserve,
+ kNsStringBufferMaxPoison));
+ char_traits::uninitialize(
+ this->mData + aNewSuffixStart + aSuffixLength,
+ XPCOM_MIN(curCapacity + 1 - aNewSuffixStart - aSuffixLength,
+ kNsStringBufferMaxPoison));
+ } else {
+ char_traits::uninitialize(this->mData + aPrefixToPreserve,
+ XPCOM_MIN(curCapacity + 1 - aPrefixToPreserve,
+ kNsStringBufferMaxPoison));
+ }
+ return curCapacity;
+ }
+ }
+
+ char_type* oldData = this->mData;
+ DataFlags oldFlags = this->mDataFlags;
+
+ char_type* newData;
+ DataFlags newDataFlags;
+ size_type newCapacity;
+
+ // If this is an nsTAutoStringN, it's possible that we can use the inline
+ // buffer.
+ if ((this->mClassFlags & ClassFlags::INLINE) &&
+ (aCapacity <= AsAutoString(this)->mInlineCapacity)) {
+ newCapacity = AsAutoString(this)->mInlineCapacity;
+ newData = (char_type*)AsAutoString(this)->mStorage;
+ newDataFlags = DataFlags::TERMINATED | DataFlags::INLINE;
+ } else {
+ // If |aCapacity > kMaxCapacity|, then our doubling algorithm may not be
+ // able to allocate it. Just bail out in cases like that. We don't want
+ // to be allocating 2GB+ strings anyway.
+ static_assert((sizeof(nsStringBuffer) & 0x1) == 0,
+ "bad size for nsStringBuffer");
+ if (MOZ_UNLIKELY(!this->CheckCapacity(aCapacity))) {
+ return mozilla::Err(NS_ERROR_OUT_OF_MEMORY);
+ }
+
+ // We increase our capacity so that the allocated buffer grows
+ // exponentially, which gives us amortized O(1) appending. Below the
+ // threshold, we use powers-of-two. Above the threshold, we grow by at
+ // least 1.125, rounding up to the nearest MiB.
+ const size_type slowGrowthThreshold = 8 * 1024 * 1024;
+
+ // nsStringBuffer allocates sizeof(nsStringBuffer) + passed size, and
+ // storageSize below wants extra 1 * sizeof(char_type).
+ const size_type neededExtraSpace =
+ sizeof(nsStringBuffer) / sizeof(char_type) + 1;
+
+ size_type temp;
+ if (aCapacity >= slowGrowthThreshold) {
+ size_type minNewCapacity =
+ curCapacity + (curCapacity >> 3); // multiply by 1.125
+ temp = XPCOM_MAX(aCapacity, minNewCapacity) + neededExtraSpace;
+
+ // Round up to the next multiple of MiB, but ensure the expected
+ // capacity doesn't include the extra space required by nsStringBuffer
+ // and null-termination.
+ const size_t MiB = 1 << 20;
+ temp = (MiB * ((temp + MiB - 1) / MiB)) - neededExtraSpace;
+ } else {
+ // Round up to the next power of two.
+ temp =
+ mozilla::RoundUpPow2(aCapacity + neededExtraSpace) - neededExtraSpace;
+ }
+
+ newCapacity = XPCOM_MIN(temp, base_string_type::kMaxCapacity);
+ MOZ_ASSERT(newCapacity >= aCapacity,
+ "should have hit the early return at the top");
+ // Avoid shrinking if the new buffer size is close to the old. Note that
+ // unsigned underflow is defined behavior.
+ if ((curCapacity - newCapacity) <= kNsStringBufferShrinkingThreshold &&
+ (this->mDataFlags & DataFlags::REFCOUNTED)) {
+ MOZ_ASSERT(aAllowShrinking, "How come we didn't return earlier?");
+ // We're already close enough to the right size.
+ newData = oldData;
+ newCapacity = curCapacity;
+ } else {
+ size_type storageSize = (newCapacity + 1) * sizeof(char_type);
+ // Since we allocate only by powers of 2 we always fit into a full
+ // mozjemalloc bucket, it's not useful to use realloc, which may spend
+ // time uselessly copying too much.
+ nsStringBuffer* newHdr = nsStringBuffer::Alloc(storageSize).take();
+ if (newHdr) {
+ newData = (char_type*)newHdr->Data();
+ } else if (shrinking) {
+ // We're still in a consistent state.
+ //
+ // Since shrinking is just a memory footprint optimization, we
+ // don't propagate OOM if we tried to shrink in order to avoid
+ // OOM crashes from infallible callers. If we're lucky, soon enough
+ // a fallible caller reaches OOM and is able to deal or we end up
+ // disposing of this string before reaching OOM again.
+ newData = oldData;
+ newCapacity = curCapacity;
+ } else {
+ return mozilla::Err(NS_ERROR_OUT_OF_MEMORY);
+ }
+ }
+ newDataFlags = DataFlags::TERMINATED | DataFlags::REFCOUNTED;
+ }
+
+ this->mData = newData;
+ this->mDataFlags = newDataFlags;
+
+ if (oldData == newData) {
+ char_traits::move(newData + aNewSuffixStart, oldData + aOldSuffixStart,
+ aSuffixLength);
+ if (aSuffixLength) {
+ char_traits::uninitialize(this->mData + aPrefixToPreserve,
+ XPCOM_MIN(aNewSuffixStart - aPrefixToPreserve,
+ kNsStringBufferMaxPoison));
+ char_traits::uninitialize(
+ this->mData + aNewSuffixStart + aSuffixLength,
+ XPCOM_MIN(newCapacity + 1 - aNewSuffixStart - aSuffixLength,
+ kNsStringBufferMaxPoison));
+ } else {
+ char_traits::uninitialize(this->mData + aPrefixToPreserve,
+ XPCOM_MIN(newCapacity + 1 - aPrefixToPreserve,
+ kNsStringBufferMaxPoison));
+ }
+ } else {
+ char_traits::copy(newData, oldData, aPrefixToPreserve);
+ char_traits::copy(newData + aNewSuffixStart, oldData + aOldSuffixStart,
+ aSuffixLength);
+ ReleaseData(oldData, oldFlags);
+ }
+
+ return newCapacity;
+}
+
+template <typename T>
+void nsTSubstring<T>::FinishBulkWriteImpl(size_type aLength) {
+ if (aLength) {
+ FinishBulkWriteImplImpl(aLength);
+ } else {
+ ReleaseData(this->mData, this->mDataFlags);
+ SetToEmptyBuffer();
+ }
+ AssertValid();
+}
+
+template <typename T>
+void nsTSubstring<T>::Finalize() {
+ ReleaseData(this->mData, this->mDataFlags);
+ // this->mData, this->mLength, and this->mDataFlags are purposefully left
+ // dangling
+}
+
+template <typename T>
+bool nsTSubstring<T>::ReplacePrep(index_type aCutStart, size_type aCutLength,
+ size_type aNewLength) {
+ aCutLength = XPCOM_MIN(aCutLength, this->mLength - aCutStart);
+
+ mozilla::CheckedInt<size_type> newTotalLen = this->Length();
+ newTotalLen += aNewLength;
+ newTotalLen -= aCutLength;
+ if (!newTotalLen.isValid()) {
+ return false;
+ }
+
+ if (aCutStart == this->mLength && Capacity() > newTotalLen.value()) {
+ this->mDataFlags &= ~DataFlags::VOIDED;
+ this->mData[newTotalLen.value()] = char_type(0);
+ this->mLength = newTotalLen.value();
+ return true;
+ }
+
+ return ReplacePrepInternal(aCutStart, aCutLength, aNewLength,
+ newTotalLen.value());
+}
+
+template <typename T>
+bool nsTSubstring<T>::ReplacePrepInternal(index_type aCutStart,
+ size_type aCutLen, size_type aFragLen,
+ size_type aNewLen) {
+ size_type newSuffixStart = aCutStart + aFragLen;
+ size_type oldSuffixStart = aCutStart + aCutLen;
+ size_type suffixLength = this->mLength - oldSuffixStart;
+
+ mozilla::Result<size_type, nsresult> r = StartBulkWriteImpl(
+ aNewLen, aCutStart, false, suffixLength, oldSuffixStart, newSuffixStart);
+ if (r.isErr()) {
+ return false;
+ }
+ FinishBulkWriteImpl(aNewLen);
+ return true;
+}
+
+template <typename T>
+typename nsTSubstring<T>::size_type nsTSubstring<T>::Capacity() const {
+ // return 0 to indicate an immutable or 0-sized buffer
+
+ size_type capacity;
+ if (this->mDataFlags & DataFlags::REFCOUNTED) {
+ // if the string is readonly, then we pretend that it has no capacity.
+ nsStringBuffer* hdr = nsStringBuffer::FromData(this->mData);
+ if (hdr->IsReadonly()) {
+ capacity = 0;
+ } else {
+ capacity = (size_t(hdr->StorageSize()) / sizeof(char_type)) - 1;
+ }
+ } else if (this->mDataFlags & DataFlags::INLINE) {
+ MOZ_ASSERT(this->mClassFlags & ClassFlags::INLINE);
+ capacity = AsAutoString(this)->mInlineCapacity;
+ } else if (this->mDataFlags & DataFlags::OWNED) {
+ // we don't store the capacity of an adopted buffer because that would
+ // require an additional member field. the best we can do is base the
+ // capacity on our length. remains to be seen if this is the right
+ // trade-off.
+ capacity = this->mLength;
+ } else {
+ capacity = 0;
+ }
+
+ return capacity;
+}
+
+template <typename T>
+bool nsTSubstring<T>::EnsureMutable(size_type aNewLen) {
+ if (aNewLen == size_type(-1) || aNewLen == this->mLength) {
+ if (this->mDataFlags & (DataFlags::INLINE | DataFlags::OWNED)) {
+ return true;
+ }
+ if ((this->mDataFlags & DataFlags::REFCOUNTED) &&
+ !nsStringBuffer::FromData(this->mData)->IsReadonly()) {
+ return true;
+ }
+
+ aNewLen = this->mLength;
+ }
+ return SetLength(aNewLen, mozilla::fallible);
+}
+
+// ---------------------------------------------------------------------------
+
+// This version of Assign is optimized for single-character assignment.
+template <typename T>
+void nsTSubstring<T>::Assign(char_type aChar) {
+ if (MOZ_UNLIKELY(!Assign(aChar, mozilla::fallible))) {
+ AllocFailed(1);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Assign(char_type aChar, const fallible_t&) {
+ auto r = StartBulkWriteImpl(1, 0, true);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ *this->mData = aChar;
+ FinishBulkWriteImpl(1);
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Assign(const char_type* aData, size_type aLength) {
+ if (MOZ_UNLIKELY(!Assign(aData, aLength, mozilla::fallible))) {
+ AllocFailed(aLength == size_type(-1) ? char_traits::length(aData)
+ : aLength);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Assign(const char_type* aData,
+ const fallible_t& aFallible) {
+ return Assign(aData, size_type(-1), aFallible);
+}
+
+template <typename T>
+bool nsTSubstring<T>::Assign(const char_type* aData, size_type aLength,
+ const fallible_t& aFallible) {
+ if (!aData || aLength == 0) {
+ Truncate();
+ return true;
+ }
+
+ if (MOZ_UNLIKELY(aLength == size_type(-1))) {
+ aLength = char_traits::length(aData);
+ }
+
+ if (MOZ_UNLIKELY(this->IsDependentOn(aData, aData + aLength))) {
+ return Assign(string_type(aData, aLength), aFallible);
+ }
+
+ auto r = StartBulkWriteImpl(aLength, 0, true);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ char_traits::copy(this->mData, aData, aLength);
+ FinishBulkWriteImpl(aLength);
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::AssignASCII(const char* aData, size_type aLength) {
+ if (MOZ_UNLIKELY(!AssignASCII(aData, aLength, mozilla::fallible))) {
+ AllocFailed(aLength);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::AssignASCII(const char* aData, size_type aLength,
+ const fallible_t& aFallible) {
+ MOZ_ASSERT(aLength != size_type(-1));
+
+ // A Unicode string can't depend on an ASCII string buffer,
+ // so this dependence check only applies to CStrings.
+ if constexpr (std::is_same_v<T, char>) {
+ if (this->IsDependentOn(aData, aData + aLength)) {
+ return Assign(string_type(aData, aLength), aFallible);
+ }
+ }
+
+ auto r = StartBulkWriteImpl(aLength, 0, true);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ char_traits::copyASCII(this->mData, aData, aLength);
+ FinishBulkWriteImpl(aLength);
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::AssignLiteral(const char_type* aData, size_type aLength) {
+ ReleaseData(this->mData, this->mDataFlags);
+ SetData(const_cast<char_type*>(aData), aLength,
+ DataFlags::TERMINATED | DataFlags::LITERAL);
+}
+
+template <typename T>
+void nsTSubstring<T>::Assign(const self_type& aStr) {
+ if (!Assign(aStr, mozilla::fallible)) {
+ AllocFailed(aStr.Length());
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Assign(const self_type& aStr,
+ const fallible_t& aFallible) {
+ // |aStr| could be sharable. We need to check its flags to know how to
+ // deal with it.
+
+ if (&aStr == this) {
+ return true;
+ }
+
+ if (!aStr.mLength) {
+ Truncate();
+ this->mDataFlags |= aStr.mDataFlags & DataFlags::VOIDED;
+ return true;
+ }
+
+ if (aStr.mDataFlags & DataFlags::REFCOUNTED) {
+ // nice! we can avoid a string copy :-)
+
+ // |aStr| should be null-terminated
+ NS_ASSERTION(aStr.mDataFlags & DataFlags::TERMINATED,
+ "shared, but not terminated");
+
+ ReleaseData(this->mData, this->mDataFlags);
+
+ SetData(aStr.mData, aStr.mLength,
+ DataFlags::TERMINATED | DataFlags::REFCOUNTED);
+
+ // get an owning reference to the this->mData
+ nsStringBuffer::FromData(this->mData)->AddRef();
+ return true;
+ }
+ if (aStr.mDataFlags & DataFlags::LITERAL) {
+ MOZ_ASSERT(aStr.mDataFlags & DataFlags::TERMINATED, "Unterminated literal");
+
+ AssignLiteral(aStr.mData, aStr.mLength);
+ return true;
+ }
+
+ // else, treat this like an ordinary assignment.
+ return Assign(aStr.Data(), aStr.Length(), aFallible);
+}
+
+template <typename T>
+void nsTSubstring<T>::Assign(self_type&& aStr) {
+ if (!Assign(std::move(aStr), mozilla::fallible)) {
+ AllocFailed(aStr.Length());
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AssignOwned(self_type&& aStr) {
+ MOZ_ASSERT(aStr.mDataFlags & (DataFlags::REFCOUNTED | DataFlags::OWNED),
+ "neither shared nor owned");
+
+ // If they have a REFCOUNTED or OWNED buffer, we can avoid a copy - so steal
+ // their buffer and reset them to the empty string.
+
+ // |aStr| should be null-terminated
+ MOZ_ASSERT(aStr.mDataFlags & DataFlags::TERMINATED,
+ "shared or owned, but not terminated");
+
+ ReleaseData(this->mData, this->mDataFlags);
+
+ SetData(aStr.mData, aStr.mLength, aStr.mDataFlags);
+ aStr.SetToEmptyBuffer();
+}
+
+template <typename T>
+bool nsTSubstring<T>::Assign(self_type&& aStr, const fallible_t& aFallible) {
+ // We're moving |aStr| in this method, so we need to try to steal the data,
+ // and in the fallback perform a copy-assignment followed by a truncation of
+ // the original string.
+
+ if (&aStr == this) {
+ NS_WARNING("Move assigning a string to itself?");
+ return true;
+ }
+
+ if (aStr.mDataFlags & (DataFlags::REFCOUNTED | DataFlags::OWNED)) {
+ AssignOwned(std::move(aStr));
+ return true;
+ }
+
+ // Otherwise treat this as a normal assignment, and truncate the moved string.
+ // We don't truncate the source string if the allocation failed.
+ if (!Assign(aStr, aFallible)) {
+ return false;
+ }
+ aStr.Truncate();
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Assign(const substring_tuple_type& aTuple) {
+ if (!Assign(aTuple, mozilla::fallible)) {
+ AllocFailed(aTuple.Length());
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::AssignNonDependent(const substring_tuple_type& aTuple,
+ size_type aTupleLength,
+ const mozilla::fallible_t& aFallible) {
+ NS_ASSERTION(aTuple.Length() == aTupleLength, "wrong length passed");
+
+ auto r = StartBulkWriteImpl(aTupleLength);
+ if (r.isErr()) {
+ return false;
+ }
+
+ aTuple.WriteTo(this->mData, aTupleLength);
+
+ FinishBulkWriteImpl(aTupleLength);
+ return true;
+}
+
+template <typename T>
+bool nsTSubstring<T>::Assign(const substring_tuple_type& aTuple,
+ const fallible_t& aFallible) {
+ const auto [isDependentOnThis, tupleLength] =
+ aTuple.IsDependentOnWithLength(this->mData, this->mData + this->mLength);
+ if (isDependentOnThis) {
+ string_type temp;
+ self_type& tempSubstring = temp;
+ if (!tempSubstring.AssignNonDependent(aTuple, tupleLength, aFallible)) {
+ return false;
+ }
+ AssignOwned(std::move(temp));
+ return true;
+ }
+
+ return AssignNonDependent(aTuple, tupleLength, aFallible);
+}
+
+template <typename T>
+void nsTSubstring<T>::Adopt(char_type* aData, size_type aLength) {
+ if (aData) {
+ ReleaseData(this->mData, this->mDataFlags);
+
+ if (aLength == size_type(-1)) {
+ aLength = char_traits::length(aData);
+ }
+
+ SetData(aData, aLength, DataFlags::TERMINATED | DataFlags::OWNED);
+
+ STRING_STAT_INCREMENT(Adopt);
+ // Treat this as construction of a "StringAdopt" object for leak
+ // tracking purposes.
+ MOZ_LOG_CTOR(this->mData, "StringAdopt", 1);
+ } else {
+ SetIsVoid(true);
+ }
+}
+
+// This version of Replace is optimized for single-character replacement.
+template <typename T>
+void nsTSubstring<T>::Replace(index_type aCutStart, size_type aCutLength,
+ char_type aChar) {
+ aCutStart = XPCOM_MIN(aCutStart, this->Length());
+
+ if (ReplacePrep(aCutStart, aCutLength, 1)) {
+ this->mData[aCutStart] = aChar;
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Replace(index_type aCutStart, size_type aCutLength,
+ char_type aChar, const fallible_t&) {
+ aCutStart = XPCOM_MIN(aCutStart, this->Length());
+
+ if (!ReplacePrep(aCutStart, aCutLength, 1)) {
+ return false;
+ }
+
+ this->mData[aCutStart] = aChar;
+
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Replace(index_type aCutStart, size_type aCutLength,
+ const char_type* aData, size_type aLength) {
+ if (!Replace(aCutStart, aCutLength, aData, aLength, mozilla::fallible)) {
+ AllocFailed(this->Length() - aCutLength + 1);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Replace(index_type aCutStart, size_type aCutLength,
+ const char_type* aData, size_type aLength,
+ const fallible_t& aFallible) {
+ // unfortunately, some callers pass null :-(
+ if (!aData) {
+ aLength = 0;
+ } else {
+ if (aLength == size_type(-1)) {
+ aLength = char_traits::length(aData);
+ }
+
+ if (this->IsDependentOn(aData, aData + aLength)) {
+ nsTAutoString<T> temp(aData, aLength);
+ return Replace(aCutStart, aCutLength, temp, aFallible);
+ }
+ }
+
+ aCutStart = XPCOM_MIN(aCutStart, this->Length());
+
+ bool ok = ReplacePrep(aCutStart, aCutLength, aLength);
+ if (!ok) {
+ return false;
+ }
+
+ if (aLength > 0) {
+ char_traits::copy(this->mData + aCutStart, aData, aLength);
+ }
+
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Replace(index_type aCutStart, size_type aCutLength,
+ const substring_tuple_type& aTuple) {
+ const auto [isDependentOnThis, tupleLength] =
+ aTuple.IsDependentOnWithLength(this->mData, this->mData + this->mLength);
+
+ if (isDependentOnThis) {
+ nsTAutoString<T> temp;
+ if (!temp.AssignNonDependent(aTuple, tupleLength, mozilla::fallible)) {
+ AllocFailed(tupleLength);
+ }
+ Replace(aCutStart, aCutLength, temp);
+ return;
+ }
+
+ aCutStart = XPCOM_MIN(aCutStart, this->Length());
+
+ if (ReplacePrep(aCutStart, aCutLength, tupleLength) && tupleLength > 0) {
+ aTuple.WriteTo(this->mData + aCutStart, tupleLength);
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::ReplaceLiteral(index_type aCutStart, size_type aCutLength,
+ const char_type* aData,
+ size_type aLength) {
+ aCutStart = XPCOM_MIN(aCutStart, this->Length());
+
+ if (!aCutStart && aCutLength == this->Length() &&
+ !(this->mDataFlags & DataFlags::REFCOUNTED)) {
+ // Check for REFCOUNTED above to avoid undoing the effect of
+ // SetCapacity().
+ AssignLiteral(aData, aLength);
+ } else if (ReplacePrep(aCutStart, aCutLength, aLength) && aLength > 0) {
+ char_traits::copy(this->mData + aCutStart, aData, aLength);
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::Append(char_type aChar) {
+ if (MOZ_UNLIKELY(!Append(aChar, mozilla::fallible))) {
+ AllocFailed(this->mLength + 1);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Append(char_type aChar, const fallible_t& aFallible) {
+ size_type oldLen = this->mLength;
+ size_type newLen = oldLen + 1; // Can't overflow
+ auto r = StartBulkWriteImpl(newLen, oldLen, false);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ this->mData[oldLen] = aChar;
+ FinishBulkWriteImpl(newLen);
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Append(const char_type* aData, size_type aLength) {
+ if (MOZ_UNLIKELY(!Append(aData, aLength, mozilla::fallible))) {
+ AllocFailed(this->mLength + (aLength == size_type(-1)
+ ? char_traits::length(aData)
+ : aLength));
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Append(const char_type* aData, size_type aLength,
+ const fallible_t& aFallible) {
+ if (MOZ_UNLIKELY(aLength == size_type(-1))) {
+ aLength = char_traits::length(aData);
+ }
+
+ if (MOZ_UNLIKELY(!aLength)) {
+ // Avoid undoing the effect of SetCapacity() if both
+ // mLength and aLength are zero.
+ return true;
+ }
+
+ if (MOZ_UNLIKELY(this->IsDependentOn(aData, aData + aLength))) {
+ return Append(string_type(aData, aLength), mozilla::fallible);
+ }
+ size_type oldLen = this->mLength;
+ mozilla::CheckedInt<size_type> newLen(oldLen);
+ newLen += aLength;
+ if (MOZ_UNLIKELY(!newLen.isValid())) {
+ return false;
+ }
+ auto r = StartBulkWriteImpl(newLen.value(), oldLen, false);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ char_traits::copy(this->mData + oldLen, aData, aLength);
+ FinishBulkWriteImpl(newLen.value());
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendASCII(const char* aData, size_type aLength) {
+ if (MOZ_UNLIKELY(!AppendASCII(aData, aLength, mozilla::fallible))) {
+ AllocFailed(this->mLength +
+ (aLength == size_type(-1) ? strlen(aData) : aLength));
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::AppendASCII(const char* aData,
+ const fallible_t& aFallible) {
+ return AppendASCII(aData, size_type(-1), aFallible);
+}
+
+template <typename T>
+bool nsTSubstring<T>::AppendASCII(const char* aData, size_type aLength,
+ const fallible_t& aFallible) {
+ if (MOZ_UNLIKELY(aLength == size_type(-1))) {
+ aLength = strlen(aData);
+ }
+
+ if (MOZ_UNLIKELY(!aLength)) {
+ // Avoid undoing the effect of SetCapacity() if both
+ // mLength and aLength are zero.
+ return true;
+ }
+
+ if constexpr (std::is_same_v<T, char>) {
+ // 16-bit string can't depend on an 8-bit buffer
+ if (MOZ_UNLIKELY(this->IsDependentOn(aData, aData + aLength))) {
+ return Append(string_type(aData, aLength), mozilla::fallible);
+ }
+ }
+
+ size_type oldLen = this->mLength;
+ mozilla::CheckedInt<size_type> newLen(oldLen);
+ newLen += aLength;
+ if (MOZ_UNLIKELY(!newLen.isValid())) {
+ return false;
+ }
+ auto r = StartBulkWriteImpl(newLen.value(), oldLen, false);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ char_traits::copyASCII(this->mData + oldLen, aData, aLength);
+ FinishBulkWriteImpl(newLen.value());
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Append(const self_type& aStr) {
+ if (MOZ_UNLIKELY(!Append(aStr, mozilla::fallible))) {
+ AllocFailed(this->mLength + aStr.Length());
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Append(const self_type& aStr,
+ const fallible_t& aFallible) {
+ // Check refcounted to avoid undoing the effects of SetCapacity().
+ if (MOZ_UNLIKELY(!this->mLength &&
+ !(this->mDataFlags & DataFlags::REFCOUNTED))) {
+ return Assign(aStr, mozilla::fallible);
+ }
+ return Append(aStr.BeginReading(), aStr.Length(), mozilla::fallible);
+}
+
+template <typename T>
+void nsTSubstring<T>::Append(const substring_tuple_type& aTuple) {
+ if (MOZ_UNLIKELY(!Append(aTuple, mozilla::fallible))) {
+ AllocFailed(this->mLength + aTuple.Length());
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::Append(const substring_tuple_type& aTuple,
+ const fallible_t& aFallible) {
+ const auto [isDependentOnThis, tupleLength] =
+ aTuple.IsDependentOnWithLength(this->mData, this->mData + this->mLength);
+
+ if (MOZ_UNLIKELY(!tupleLength)) {
+ // Avoid undoing the effect of SetCapacity() if both
+ // mLength and tupleLength are zero.
+ return true;
+ }
+
+ if (MOZ_UNLIKELY(isDependentOnThis)) {
+ return Append(string_type(aTuple), aFallible);
+ }
+
+ size_type oldLen = this->mLength;
+ mozilla::CheckedInt<size_type> newLen(oldLen);
+ newLen += tupleLength;
+ if (MOZ_UNLIKELY(!newLen.isValid())) {
+ return false;
+ }
+ auto r = StartBulkWriteImpl(newLen.value(), oldLen, false);
+ if (MOZ_UNLIKELY(r.isErr())) {
+ return false;
+ }
+ aTuple.WriteTo(this->mData + oldLen, tupleLength);
+ FinishBulkWriteImpl(newLen.value());
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::SetCapacity(size_type aCapacity) {
+ if (!SetCapacity(aCapacity, mozilla::fallible)) {
+ AllocFailed(aCapacity);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::SetCapacity(size_type aCapacity, const fallible_t&) {
+ size_type length = this->mLength;
+ // This method can no longer be used to shorten the
+ // logical length.
+ size_type capacity = XPCOM_MAX(aCapacity, length);
+
+ auto r = StartBulkWriteImpl(capacity, length, true);
+ if (r.isErr()) {
+ return false;
+ }
+
+ if (MOZ_UNLIKELY(!capacity)) {
+ // Zero capacity was requested on a zero-length
+ // string. In this special case, we are pointing
+ // to the special empty buffer, which is already
+ // zero-terminated and not writable, so we must
+ // not attempt to zero-terminate it.
+ AssertValid();
+ return true;
+ }
+
+ // FinishBulkWriteImpl with argument zero releases
+ // the heap-allocated buffer. However, SetCapacity()
+ // is a special case that allows mLength to be zero
+ // while a heap-allocated buffer exists.
+ // By calling FinishBulkWriteImplImpl, we skip the
+ // zero case handling that's inappropriate in the
+ // SetCapacity() case.
+ FinishBulkWriteImplImpl(length);
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::SetLength(size_type aLength) {
+ if (!SetLength(aLength, mozilla::fallible)) {
+ AllocFailed(aLength);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::SetLength(size_type aLength,
+ const fallible_t& aFallible) {
+ size_type preserve = XPCOM_MIN(aLength, this->Length());
+ auto r = StartBulkWriteImpl(aLength, preserve, true);
+ if (r.isErr()) {
+ return false;
+ }
+
+ FinishBulkWriteImpl(aLength);
+
+ return true;
+}
+
+template <typename T>
+void nsTSubstring<T>::Truncate() {
+ ReleaseData(this->mData, this->mDataFlags);
+ SetToEmptyBuffer();
+ AssertValid();
+}
+
+template <typename T>
+void nsTSubstring<T>::SetIsVoid(bool aVal) {
+ if (aVal) {
+ Truncate();
+ this->mDataFlags |= DataFlags::VOIDED;
+ } else {
+ this->mDataFlags &= ~DataFlags::VOIDED;
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::StripChar(char_type aChar) {
+ if (this->mLength == 0) {
+ return;
+ }
+
+ if (!EnsureMutable()) { // XXX do this lazily?
+ AllocFailed(this->mLength);
+ }
+
+ // XXX(darin): this code should defer writing until necessary.
+
+ char_type* to = this->mData;
+ char_type* from = this->mData;
+ char_type* end = this->mData + this->mLength;
+
+ while (from < end) {
+ char_type theChar = *from++;
+ if (aChar != theChar) {
+ *to++ = theChar;
+ }
+ }
+ *to = char_type(0); // add the null
+ this->mLength = to - this->mData;
+}
+
+template <typename T>
+void nsTSubstring<T>::StripChars(const char_type* aChars) {
+ if (this->mLength == 0) {
+ return;
+ }
+
+ if (!EnsureMutable()) { // XXX do this lazily?
+ AllocFailed(this->mLength);
+ }
+
+ // XXX(darin): this code should defer writing until necessary.
+
+ char_type* to = this->mData;
+ char_type* from = this->mData;
+ char_type* end = this->mData + this->mLength;
+
+ while (from < end) {
+ char_type theChar = *from++;
+ const char_type* test = aChars;
+
+ for (; *test && *test != theChar; ++test)
+ ;
+
+ if (!*test) {
+ // Not stripped, copy this char.
+ *to++ = theChar;
+ }
+ }
+ *to = char_type(0); // add the null
+ this->mLength = to - this->mData;
+}
+
+template <typename T>
+void nsTSubstring<T>::StripTaggedASCII(const ASCIIMaskArray& aToStrip) {
+ if (this->mLength == 0) {
+ return;
+ }
+
+ size_t untaggedPrefixLength = 0;
+ for (; untaggedPrefixLength < this->mLength; ++untaggedPrefixLength) {
+ uint32_t theChar = (uint32_t)this->mData[untaggedPrefixLength];
+ if (mozilla::ASCIIMask::IsMasked(aToStrip, theChar)) {
+ break;
+ }
+ }
+
+ if (untaggedPrefixLength == this->mLength) {
+ return;
+ }
+
+ if (!EnsureMutable()) {
+ AllocFailed(this->mLength);
+ }
+
+ char_type* to = this->mData + untaggedPrefixLength;
+ char_type* from = to;
+ char_type* end = this->mData + this->mLength;
+
+ while (from < end) {
+ uint32_t theChar = (uint32_t)*from++;
+ // Replacing this with a call to ASCIIMask::IsMasked
+ // regresses performance somewhat, so leaving it inlined.
+ if (!mozilla::ASCIIMask::IsMasked(aToStrip, theChar)) {
+ // Not stripped, copy this char.
+ *to++ = (char_type)theChar;
+ }
+ }
+ *to = char_type(0); // add the null
+ this->mLength = to - this->mData;
+}
+
+template <typename T>
+void nsTSubstring<T>::StripCRLF() {
+ // Expanding this call to copy the code from StripTaggedASCII
+ // instead of just calling it does somewhat help with performance
+ // but it is not worth it given the duplicated code.
+ StripTaggedASCII(mozilla::ASCIIMask::MaskCRLF());
+}
+
+template <typename T>
+struct MOZ_STACK_CLASS PrintfAppend : public mozilla::PrintfTarget {
+ explicit PrintfAppend(nsTSubstring<T>* aString) : mString(aString) {}
+
+ bool append(const char* aStr, size_t aLen) override {
+ if (aLen == 0) {
+ return true;
+ }
+
+ mString->AppendASCII(aStr, aLen);
+ return true;
+ }
+
+ private:
+ nsTSubstring<T>* mString;
+};
+
+template <typename T>
+void nsTSubstring<T>::AppendPrintf(const char* aFormat, ...) {
+ PrintfAppend<T> appender(this);
+ va_list ap;
+ va_start(ap, aFormat);
+ bool r = appender.vprint(aFormat, ap);
+ if (!r) {
+ MOZ_CRASH("Allocation or other failure in PrintfTarget::print");
+ }
+ va_end(ap);
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendVprintf(const char* aFormat, va_list aAp) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.vprint(aFormat, aAp);
+ if (!r) {
+ MOZ_CRASH("Allocation or other failure in PrintfTarget::print");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntDec(int32_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntDec(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntDec(uint32_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntDec(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntOct(uint32_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntOct(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntHex(uint32_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntHex(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntDec(int64_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntDec(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntDec(uint64_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntDec(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntOct(uint64_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntOct(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendIntHex(uint64_t aInteger) {
+ PrintfAppend<T> appender(this);
+ bool r = appender.appendIntHex(aInteger);
+ if (MOZ_UNLIKELY(!r)) {
+ MOZ_CRASH("Allocation or other failure while appending integers");
+ }
+}
+
+// Returns the length of the formatted aDouble in aBuf.
+static int FormatWithoutTrailingZeros(char (&aBuf)[40], double aDouble,
+ int aPrecision) {
+ static const DoubleToStringConverter converter(
+ DoubleToStringConverter::UNIQUE_ZERO |
+ DoubleToStringConverter::NO_TRAILING_ZERO |
+ DoubleToStringConverter::EMIT_POSITIVE_EXPONENT_SIGN,
+ "Infinity", "NaN", 'e', -6, 21, 6, 1);
+ double_conversion::StringBuilder builder(aBuf, sizeof(aBuf));
+ converter.ToPrecision(aDouble, aPrecision, &builder);
+ int length = builder.position();
+ builder.Finalize();
+ return length;
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendFloat(float aFloat) {
+ char buf[40];
+ int length = FormatWithoutTrailingZeros(buf, aFloat, 6);
+ AppendASCII(buf, length);
+}
+
+template <typename T>
+void nsTSubstring<T>::AppendFloat(double aFloat) {
+ char buf[40];
+ int length = FormatWithoutTrailingZeros(buf, aFloat, 15);
+ AppendASCII(buf, length);
+}
+
+template <typename T>
+size_t nsTSubstring<T>::SizeOfExcludingThisIfUnshared(
+ mozilla::MallocSizeOf aMallocSizeOf) const {
+ if (this->mDataFlags & DataFlags::REFCOUNTED) {
+ return nsStringBuffer::FromData(this->mData)
+ ->SizeOfIncludingThisIfUnshared(aMallocSizeOf);
+ }
+ if (this->mDataFlags & DataFlags::OWNED) {
+ return aMallocSizeOf(this->mData);
+ }
+
+ // If we reach here, exactly one of the following must be true:
+ // - DataFlags::VOIDED is set, and this->mData points to sEmptyBuffer;
+ // - DataFlags::INLINE is set, and this->mData points to a buffer within a
+ // string object (e.g. nsAutoString);
+ // - None of DataFlags::REFCOUNTED, DataFlags::OWNED, DataFlags::INLINE is
+ // set, and this->mData points to a buffer owned by something else.
+ //
+ // In all three cases, we don't measure it.
+ return 0;
+}
+
+template <typename T>
+size_t nsTSubstring<T>::SizeOfExcludingThisEvenIfShared(
+ mozilla::MallocSizeOf aMallocSizeOf) const {
+ // This is identical to SizeOfExcludingThisIfUnshared except for the
+ // DataFlags::REFCOUNTED case.
+ if (this->mDataFlags & DataFlags::REFCOUNTED) {
+ return nsStringBuffer::FromData(this->mData)
+ ->SizeOfIncludingThisEvenIfShared(aMallocSizeOf);
+ }
+ if (this->mDataFlags & DataFlags::OWNED) {
+ return aMallocSizeOf(this->mData);
+ }
+ return 0;
+}
+
+template <typename T>
+size_t nsTSubstring<T>::SizeOfIncludingThisIfUnshared(
+ mozilla::MallocSizeOf aMallocSizeOf) const {
+ return aMallocSizeOf(this) + SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+}
+
+template <typename T>
+size_t nsTSubstring<T>::SizeOfIncludingThisEvenIfShared(
+ mozilla::MallocSizeOf aMallocSizeOf) const {
+ return aMallocSizeOf(this) + SizeOfExcludingThisEvenIfShared(aMallocSizeOf);
+}
+
+template <typename T>
+nsTSubstringSplitter<T> nsTSubstring<T>::Split(const char_type aChar) const {
+ return nsTSubstringSplitter<T>(
+ nsTCharSeparatedTokenizerTemplate<
+ NS_TokenizerIgnoreNothing, T,
+ nsTokenizerFlags::IncludeEmptyTokenAtEnd>(*this, aChar));
+}
+
+// Common logic for nsTSubstring<T>::ToInteger and nsTSubstring<T>::ToInteger64.
+template <typename T, typename int_type>
+int_type ToIntegerCommon(const nsTSubstring<T>& aSrc, nsresult* aErrorCode,
+ uint32_t aRadix) {
+ MOZ_ASSERT(aRadix == 10 || aRadix == 16);
+
+ // Initial value, override if we find an integer.
+ *aErrorCode = NS_ERROR_ILLEGAL_VALUE;
+
+ // Begin by skipping over leading chars that shouldn't be part of the number.
+ auto cp = aSrc.BeginReading();
+ auto endcp = aSrc.EndReading();
+ bool negate = false;
+ bool done = false;
+
+ // NB: For backwards compatibility I'm not going to change this logic but
+ // it seems really odd. Previously there was logic to auto-detect the
+ // radix if kAutoDetect was passed in. In practice this value was never
+ // used, so it pretended to auto detect and skipped some preceding
+ // letters (excluding valid hex digits) but never used the result.
+ //
+ // For example if you pass in "Get the number: 10", aRadix = 10 we'd
+ // skip the 'G', and then fail to parse "et the number: 10". If aRadix =
+ // 16 we'd skip the 'G', and parse just 'e' returning 14.
+ while ((cp < endcp) && (!done)) {
+ switch (*cp++) {
+ // clang-format off
+ case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
+ case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ done = true;
+ break;
+ // clang-format on
+ case '-':
+ negate = true;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (!done) {
+ // No base 16 or base 10 digits were found.
+ return 0;
+ }
+
+ // Step back.
+ cp--;
+
+ mozilla::CheckedInt<int_type> result;
+
+ // Now iterate the numeric chars and build our result.
+ while (cp < endcp) {
+ auto theChar = *cp++;
+ if (('0' <= theChar) && (theChar <= '9')) {
+ result = (aRadix * result) + (theChar - '0');
+ } else if ((theChar >= 'A') && (theChar <= 'F')) {
+ if (10 == aRadix) {
+ // Invalid base 10 digit, error out.
+ return 0;
+ }
+ result = (aRadix * result) + ((theChar - 'A') + 10);
+ } else if ((theChar >= 'a') && (theChar <= 'f')) {
+ if (10 == aRadix) {
+ // Invalid base 10 digit, error out.
+ return 0;
+ }
+ result = (aRadix * result) + ((theChar - 'a') + 10);
+ } else if ((('X' == theChar) || ('x' == theChar)) && result == 0) {
+ // For some reason we support a leading 'x' regardless of radix. For
+ // example: "000000x500", aRadix = 10 would be parsed as 500 rather
+ // than 0.
+ continue;
+ } else {
+ // We've encountered a char that's not a legal number or sign and we can
+ // terminate processing.
+ break;
+ }
+
+ if (!result.isValid()) {
+ // Overflow!
+ return 0;
+ }
+ }
+
+ // Integer found.
+ *aErrorCode = NS_OK;
+
+ if (negate) {
+ result = -result;
+ }
+
+ return result.value();
+}
+
+template <typename T>
+int32_t nsTSubstring<T>::ToInteger(nsresult* aErrorCode,
+ uint32_t aRadix) const {
+ return ToIntegerCommon<T, int32_t>(*this, aErrorCode, aRadix);
+}
+
+/**
+ * nsTSubstring::ToInteger64
+ */
+template <typename T>
+int64_t nsTSubstring<T>::ToInteger64(nsresult* aErrorCode,
+ uint32_t aRadix) const {
+ return ToIntegerCommon<T, int64_t>(*this, aErrorCode, aRadix);
+}
+
+/**
+ * nsTSubstring::Mid
+ */
+template <typename T>
+typename nsTSubstring<T>::size_type nsTSubstring<T>::Mid(
+ self_type& aResult, index_type aStartPos, size_type aLengthToCopy) const {
+ if (aStartPos == 0 && aLengthToCopy >= this->mLength) {
+ aResult = *this;
+ } else {
+ aResult = Substring(*this, aStartPos, aLengthToCopy);
+ }
+
+ return aResult.mLength;
+}
+
+/**
+ * nsTSubstring::StripWhitespace
+ */
+
+template <typename T>
+void nsTSubstring<T>::StripWhitespace() {
+ if (!StripWhitespace(mozilla::fallible)) {
+ this->AllocFailed(this->mLength);
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::StripWhitespace(const fallible_t&) {
+ if (!this->EnsureMutable()) {
+ return false;
+ }
+
+ this->StripTaggedASCII(mozilla::ASCIIMask::MaskWhitespace());
+ return true;
+}
+
+/**
+ * nsTSubstring::ReplaceChar,ReplaceSubstring
+ */
+
+template <typename T>
+void nsTSubstring<T>::ReplaceChar(char_type aOldChar, char_type aNewChar) {
+ int32_t i = this->FindChar(aOldChar);
+ if (i == kNotFound) {
+ return;
+ }
+
+ if (!this->EnsureMutable()) {
+ this->AllocFailed(this->mLength);
+ }
+ for (; i != kNotFound; i = this->FindChar(aOldChar, i + 1)) {
+ this->mData[i] = aNewChar;
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::ReplaceChar(const string_view& aSet, char_type aNewChar) {
+ int32_t i = this->FindCharInSet(aSet);
+ if (i == kNotFound) {
+ return;
+ }
+
+ if (!this->EnsureMutable()) {
+ this->AllocFailed(this->mLength);
+ }
+ for (; i != kNotFound; i = this->FindCharInSet(aSet, i + 1)) {
+ this->mData[i] = aNewChar;
+ }
+}
+
+template <typename T>
+void nsTSubstring<T>::ReplaceSubstring(const char_type* aTarget,
+ const char_type* aNewValue) {
+ ReplaceSubstring(nsTDependentString<T>(aTarget),
+ nsTDependentString<T>(aNewValue));
+}
+
+template <typename T>
+bool nsTSubstring<T>::ReplaceSubstring(const char_type* aTarget,
+ const char_type* aNewValue,
+ const fallible_t& aFallible) {
+ return ReplaceSubstring(nsTDependentString<T>(aTarget),
+ nsTDependentString<T>(aNewValue), aFallible);
+}
+
+template <typename T>
+void nsTSubstring<T>::ReplaceSubstring(const self_type& aTarget,
+ const self_type& aNewValue) {
+ if (!ReplaceSubstring(aTarget, aNewValue, mozilla::fallible)) {
+ // Note that this may wildly underestimate the allocation that failed, as
+ // we could have been replacing multiple copies of aTarget.
+ this->AllocFailed(this->mLength + (aNewValue.Length() - aTarget.Length()));
+ }
+}
+
+template <typename T>
+bool nsTSubstring<T>::ReplaceSubstring(const self_type& aTarget,
+ const self_type& aNewValue,
+ const fallible_t&) {
+ struct Segment {
+ uint32_t mBegin, mLength;
+ Segment(uint32_t aBegin, uint32_t aLength)
+ : mBegin(aBegin), mLength(aLength) {}
+ };
+
+ if (aTarget.Length() == 0) {
+ return true;
+ }
+
+ // Remember all of the non-matching parts.
+ AutoTArray<Segment, 16> nonMatching;
+ uint32_t i = 0;
+ mozilla::CheckedUint32 newLength;
+ while (true) {
+ int32_t r = this->Find(aTarget, i);
+ int32_t until = (r == kNotFound) ? this->Length() - i : r - i;
+ nonMatching.AppendElement(Segment(i, until));
+ newLength += until;
+ if (r == kNotFound) {
+ break;
+ }
+
+ newLength += aNewValue.Length();
+ i = r + aTarget.Length();
+ if (i >= this->Length()) {
+ // Add an auxiliary entry at the end of the list to help as an edge case
+ // for the algorithms below.
+ nonMatching.AppendElement(Segment(this->Length(), 0));
+ break;
+ }
+ }
+
+ if (!newLength.isValid()) {
+ return false;
+ }
+
+ // If there's only one non-matching segment, then the target string was not
+ // found, and there's nothing to do.
+ if (nonMatching.Length() == 1) {
+ MOZ_ASSERT(
+ nonMatching[0].mBegin == 0 && nonMatching[0].mLength == this->Length(),
+ "We should have the correct non-matching segment.");
+ return true;
+ }
+
+ // Make sure that we can mutate our buffer.
+ // Note that we always allocate at least an this->mLength sized buffer,
+ // because the rest of the algorithm relies on having access to all of the
+ // original string. In other words, we over-allocate in the shrinking case.
+ uint32_t oldLen = this->Length();
+ auto r =
+ this->StartBulkWriteImpl(XPCOM_MAX(oldLen, newLength.value()), oldLen);
+ if (r.isErr()) {
+ return false;
+ }
+
+ if (aTarget.Length() >= aNewValue.Length()) {
+ // In the shrinking case, start filling the buffer from the beginning.
+ const uint32_t delta = (aTarget.Length() - aNewValue.Length());
+ for (i = 1; i < nonMatching.Length(); ++i) {
+ // When we move the i'th non-matching segment into position, we need to
+ // account for the characters deleted by the previous |i| replacements by
+ // subtracting |i * delta|.
+ const char_type* sourceSegmentPtr = this->mData + nonMatching[i].mBegin;
+ char_type* destinationSegmentPtr =
+ this->mData + nonMatching[i].mBegin - i * delta;
+ // Write the i'th replacement immediately before the new i'th non-matching
+ // segment.
+ char_traits::copy(destinationSegmentPtr - aNewValue.Length(),
+ aNewValue.Data(), aNewValue.Length());
+ char_traits::move(destinationSegmentPtr, sourceSegmentPtr,
+ nonMatching[i].mLength);
+ }
+ } else {
+ // In the growing case, start filling the buffer from the end.
+ const uint32_t delta = (aNewValue.Length() - aTarget.Length());
+ for (i = nonMatching.Length() - 1; i > 0; --i) {
+ // When we move the i'th non-matching segment into position, we need to
+ // account for the characters added by the previous |i| replacements by
+ // adding |i * delta|.
+ const char_type* sourceSegmentPtr = this->mData + nonMatching[i].mBegin;
+ char_type* destinationSegmentPtr =
+ this->mData + nonMatching[i].mBegin + i * delta;
+ char_traits::move(destinationSegmentPtr, sourceSegmentPtr,
+ nonMatching[i].mLength);
+ // Write the i'th replacement immediately before the new i'th non-matching
+ // segment.
+ char_traits::copy(destinationSegmentPtr - aNewValue.Length(),
+ aNewValue.Data(), aNewValue.Length());
+ }
+ }
+
+ // Adjust the length and make sure the string is null terminated.
+ this->FinishBulkWriteImpl(newLength.value());
+
+ return true;
+}
+
+/**
+ * nsTSubstring::Trim
+ */
+
+template <typename T>
+void nsTSubstring<T>::Trim(const std::string_view& aSet, bool aTrimLeading,
+ bool aTrimTrailing, bool aIgnoreQuotes) {
+ char_type* start = this->mData;
+ char_type* end = this->mData + this->mLength;
+
+ // skip over quotes if requested
+ if (aIgnoreQuotes && this->mLength > 2 &&
+ this->mData[0] == this->mData[this->mLength - 1] &&
+ (this->mData[0] == '\'' || this->mData[0] == '"')) {
+ ++start;
+ --end;
+ }
+
+ if (aTrimLeading) {
+ uint32_t cutStart = start - this->mData;
+ uint32_t cutLength = 0;
+
+ // walk forward from start to end
+ for (; start != end; ++start, ++cutLength) {
+ if ((*start & ~0x7F) || // non-ascii
+ aSet.find(char(*start)) == std::string_view::npos) {
+ break;
+ }
+ }
+
+ if (cutLength) {
+ this->Cut(cutStart, cutLength);
+
+ // reset iterators
+ start = this->mData + cutStart;
+ end = this->mData + this->mLength - cutStart;
+ }
+ }
+
+ if (aTrimTrailing) {
+ uint32_t cutEnd = end - this->mData;
+ uint32_t cutLength = 0;
+
+ // walk backward from end to start
+ --end;
+ for (; end >= start; --end, ++cutLength) {
+ if ((*end & ~0x7F) || // non-ascii
+ aSet.find(char(*end)) == std::string_view::npos) {
+ break;
+ }
+ }
+
+ if (cutLength) {
+ this->Cut(cutEnd - cutLength, cutLength);
+ }
+ }
+}
+
+/**
+ * nsTSubstring::CompressWhitespace.
+ */
+
+template <typename T>
+void nsTSubstring<T>::CompressWhitespace(bool aTrimLeading,
+ bool aTrimTrailing) {
+ // Quick exit
+ if (this->mLength == 0) {
+ return;
+ }
+
+ if (!this->EnsureMutable()) {
+ this->AllocFailed(this->mLength);
+ }
+
+ const ASCIIMaskArray& mask = mozilla::ASCIIMask::MaskWhitespace();
+
+ char_type* to = this->mData;
+ char_type* from = this->mData;
+ char_type* end = this->mData + this->mLength;
+
+ // Compresses runs of whitespace down to a normal space ' ' and convert
+ // any whitespace to a normal space. This assumes that whitespace is
+ // all standard 7-bit ASCII.
+ bool skipWS = aTrimLeading;
+ while (from < end) {
+ uint32_t theChar = *from++;
+ if (mozilla::ASCIIMask::IsMasked(mask, theChar)) {
+ if (!skipWS) {
+ *to++ = ' ';
+ skipWS = true;
+ }
+ } else {
+ *to++ = theChar;
+ skipWS = false;
+ }
+ }
+
+ // If we need to trim the trailing whitespace, back up one character.
+ if (aTrimTrailing && skipWS && to > this->mData) {
+ to--;
+ }
+
+ *to = char_type(0); // add the null
+ this->mLength = to - this->mData;
+}
+
+template class nsTSubstring<char>;
+template class nsTSubstring<char16_t>;