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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /xpcom/ds/IncrementalTokenizer.cpp | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/ds/IncrementalTokenizer.cpp')
-rw-r--r-- | xpcom/ds/IncrementalTokenizer.cpp | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/xpcom/ds/IncrementalTokenizer.cpp b/xpcom/ds/IncrementalTokenizer.cpp new file mode 100644 index 0000000000..db6fddb82b --- /dev/null +++ b/xpcom/ds/IncrementalTokenizer.cpp @@ -0,0 +1,190 @@ +/* -*- 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 "mozilla/IncrementalTokenizer.h" + +#include "mozilla/AutoRestore.h" + +#include "nsIInputStream.h" +#include "IncrementalTokenizer.h" +#include <algorithm> + +namespace mozilla { + +IncrementalTokenizer::IncrementalTokenizer(Consumer&& aConsumer, + const char* aWhitespaces, + const char* aAdditionalWordChars, + uint32_t aRawMinBuffered) + : TokenizerBase(aWhitespaces, aAdditionalWordChars) +#ifdef DEBUG + , + mConsuming(false) +#endif + , + mNeedMoreInput(false), + mRollback(false), + mInputCursor(0), + mConsumer(std::move(aConsumer)) { + mInputFinished = false; + mMinRawDelivery = aRawMinBuffered; +} + +nsresult IncrementalTokenizer::FeedInput(const nsACString& aInput) { + NS_ENSURE_TRUE(mConsumer, NS_ERROR_NOT_INITIALIZED); + MOZ_ASSERT(!mInputFinished); + + mInput.Cut(0, mInputCursor); + mInputCursor = 0; + + mInput.Append(aInput); + + return Process(); +} + +nsresult IncrementalTokenizer::FeedInput(nsIInputStream* aInput, + uint32_t aCount) { + NS_ENSURE_TRUE(mConsumer, NS_ERROR_NOT_INITIALIZED); + MOZ_ASSERT(!mInputFinished); + MOZ_ASSERT(!mConsuming); + + mInput.Cut(0, mInputCursor); + mInputCursor = 0; + + nsresult rv = NS_OK; + while (NS_SUCCEEDED(rv) && aCount) { + nsCString::index_type remainder = mInput.Length(); + nsCString::index_type load = + std::min<nsCString::index_type>(aCount, PR_UINT32_MAX - remainder); + + if (!load) { + // To keep the API simple, we fail if the input data buffer if filled. + // It's highly unlikely there will ever be such amout of data cumulated + // unless a logic fault in the consumer code. + NS_ERROR("IncrementalTokenizer consumer not reading data?"); + return NS_ERROR_OUT_OF_MEMORY; + } + + if (!mInput.SetLength(remainder + load, fallible)) { + return NS_ERROR_OUT_OF_MEMORY; + } + + auto buffer = mInput.BeginWriting() + remainder; + + uint32_t read; + rv = aInput->Read(buffer, load, &read); + if (NS_SUCCEEDED(rv)) { + // remainder + load fits the uint32_t size, so must remainder + read. + mInput.SetLength(remainder + read); + aCount -= read; + + rv = Process(); + } + } + + return rv; +} + +nsresult IncrementalTokenizer::FinishInput() { + NS_ENSURE_TRUE(mConsumer, NS_ERROR_NOT_INITIALIZED); + MOZ_ASSERT(!mInputFinished); + MOZ_ASSERT(!mConsuming); + + mInput.Cut(0, mInputCursor); + mInputCursor = 0; + + mInputFinished = true; + nsresult rv = Process(); + mConsumer = nullptr; + return rv; +} + +bool IncrementalTokenizer::Next(Token& aToken) { + // Assert we are called only from the consumer callback + MOZ_ASSERT(mConsuming); + + if (mPastEof) { + return false; + } + + nsACString::const_char_iterator next = Parse(aToken); + mPastEof = aToken.Type() == TOKEN_EOF; + if (next == mCursor && !mPastEof) { + // Not enough input to make a deterministic decision. + return false; + } + + AssignFragment(aToken, mCursor, next); + mCursor = next; + return true; +} + +void IncrementalTokenizer::NeedMoreInput() { + // Assert we are called only from the consumer callback + MOZ_ASSERT(mConsuming); + + // When the input has been finished, we can't set the flag to prevent + // indefinite wait for more input (that will never come) + mNeedMoreInput = !mInputFinished; +} + +void IncrementalTokenizer::Rollback() { + // Assert we are called only from the consumer callback + MOZ_ASSERT(mConsuming); + + mRollback = true; +} + +nsresult IncrementalTokenizer::Process() { +#ifdef DEBUG + // Assert we are not re-entered + MOZ_ASSERT(!mConsuming); + + AutoRestore<bool> consuming(mConsuming); + mConsuming = true; +#endif + + MOZ_ASSERT(!mPastEof); + + nsresult rv = NS_OK; + + mInput.BeginReading(mCursor); + mCursor += mInputCursor; + mInput.EndReading(mEnd); + + while (NS_SUCCEEDED(rv) && !mPastEof) { + Token token; + nsACString::const_char_iterator next = Parse(token); + mPastEof = token.Type() == TOKEN_EOF; + if (next == mCursor && !mPastEof) { + // Not enough input to make a deterministic decision. + break; + } + + AssignFragment(token, mCursor, next); + + nsACString::const_char_iterator rollback = mCursor; + mCursor = next; + + mNeedMoreInput = mRollback = false; + + rv = mConsumer(token, *this); + if (NS_FAILED(rv)) { + break; + } + if (mNeedMoreInput || mRollback) { + mCursor = rollback; + mPastEof = false; + if (mNeedMoreInput) { + break; + } + } + } + + mInputCursor = mCursor - mInput.BeginReading(); + return rv; +} + +} // namespace mozilla |