diff options
Diffstat (limited to 'include/rapidjson/internal/regex.h')
| -rw-r--r-- | include/rapidjson/internal/regex.h | 701 |
1 files changed, 0 insertions, 701 deletions
diff --git a/include/rapidjson/internal/regex.h b/include/rapidjson/internal/regex.h deleted file mode 100644 index 422a5240..00000000 --- a/include/rapidjson/internal/regex.h +++ /dev/null @@ -1,701 +0,0 @@ -// Tencent is pleased to support the open source community by making RapidJSON available. -// -// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved. -// -// Licensed under the MIT License (the "License"); you may not use this file except -// in compliance with the License. You may obtain a copy of the License at -// -// http://opensource.org/licenses/MIT -// -// Unless required by applicable law or agreed to in writing, software distributed -// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR -// CONDITIONS OF ANY KIND, either express or implied. See the License for the -// specific language governing permissions and limitations under the License. - -#ifndef RAPIDJSON_INTERNAL_REGEX_H_ -#define RAPIDJSON_INTERNAL_REGEX_H_ - -#include "../allocators.h" -#include "../stream.h" -#include "stack.h" - -#ifdef __clang__ -RAPIDJSON_DIAG_PUSH -RAPIDJSON_DIAG_OFF(padded) -RAPIDJSON_DIAG_OFF(switch-enum) -RAPIDJSON_DIAG_OFF(implicit-fallthrough) -#endif - -#ifdef __GNUC__ -RAPIDJSON_DIAG_PUSH -RAPIDJSON_DIAG_OFF(effc++) -#endif - -#ifdef _MSC_VER -RAPIDJSON_DIAG_PUSH -RAPIDJSON_DIAG_OFF(4512) // assignment operator could not be generated -#endif - -#ifndef RAPIDJSON_REGEX_VERBOSE -#define RAPIDJSON_REGEX_VERBOSE 0 -#endif - -RAPIDJSON_NAMESPACE_BEGIN -namespace internal { - -/////////////////////////////////////////////////////////////////////////////// -// GenericRegex - -static const SizeType kRegexInvalidState = ~SizeType(0); //!< Represents an invalid index in GenericRegex::State::out, out1 -static const SizeType kRegexInvalidRange = ~SizeType(0); - -//! Regular expression engine with subset of ECMAscript grammar. -/*! - Supported regular expression syntax: - - \c ab Concatenation - - \c a|b Alternation - - \c a? Zero or one - - \c a* Zero or more - - \c a+ One or more - - \c a{3} Exactly 3 times - - \c a{3,} At least 3 times - - \c a{3,5} 3 to 5 times - - \c (ab) Grouping - - \c ^a At the beginning - - \c a$ At the end - - \c . Any character - - \c [abc] Character classes - - \c [a-c] Character class range - - \c [a-z0-9_] Character class combination - - \c [^abc] Negated character classes - - \c [^a-c] Negated character class range - - \c [\b] Backspace (U+0008) - - \c \\| \\\\ ... Escape characters - - \c \\f Form feed (U+000C) - - \c \\n Line feed (U+000A) - - \c \\r Carriage return (U+000D) - - \c \\t Tab (U+0009) - - \c \\v Vertical tab (U+000B) - - \note This is a Thompson NFA engine, implemented with reference to - Cox, Russ. "Regular Expression Matching Can Be Simple And Fast (but is slow in Java, Perl, PHP, Python, Ruby,...).", - https://swtch.com/~rsc/regexp/regexp1.html -*/ -template <typename Encoding, typename Allocator = CrtAllocator> -class GenericRegex { -public: - typedef typename Encoding::Ch Ch; - - GenericRegex(const Ch* source, Allocator* allocator = 0) : - states_(allocator, 256), ranges_(allocator, 256), root_(kRegexInvalidState), stateCount_(), rangeCount_(), - stateSet_(), state0_(allocator, 0), state1_(allocator, 0), anchorBegin_(), anchorEnd_() - { - GenericStringStream<Encoding> ss(source); - DecodedStream<GenericStringStream<Encoding> > ds(ss); - Parse(ds); - } - - ~GenericRegex() { - Allocator::Free(stateSet_); - } - - bool IsValid() const { - return root_ != kRegexInvalidState; - } - - template <typename InputStream> - bool Match(InputStream& is) const { - return SearchWithAnchoring(is, true, true); - } - - bool Match(const Ch* s) const { - GenericStringStream<Encoding> is(s); - return Match(is); - } - - template <typename InputStream> - bool Search(InputStream& is) const { - return SearchWithAnchoring(is, anchorBegin_, anchorEnd_); - } - - bool Search(const Ch* s) const { - GenericStringStream<Encoding> is(s); - return Search(is); - } - -private: - enum Operator { - kZeroOrOne, - kZeroOrMore, - kOneOrMore, - kConcatenation, - kAlternation, - kLeftParenthesis - }; - - static const unsigned kAnyCharacterClass = 0xFFFFFFFF; //!< For '.' - static const unsigned kRangeCharacterClass = 0xFFFFFFFE; - static const unsigned kRangeNegationFlag = 0x80000000; - - struct Range { - unsigned start; // - unsigned end; - SizeType next; - }; - - struct State { - SizeType out; //!< Equals to kInvalid for matching state - SizeType out1; //!< Equals to non-kInvalid for split - SizeType rangeStart; - unsigned codepoint; - }; - - struct Frag { - Frag(SizeType s, SizeType o, SizeType m) : start(s), out(o), minIndex(m) {} - SizeType start; - SizeType out; //!< link-list of all output states - SizeType minIndex; - }; - - template <typename SourceStream> - class DecodedStream { - public: - DecodedStream(SourceStream& ss) : ss_(ss), codepoint_() { Decode(); } - unsigned Peek() { return codepoint_; } - unsigned Take() { - unsigned c = codepoint_; - if (c) // No further decoding when '\0' - Decode(); - return c; - } - - private: - void Decode() { - if (!Encoding::Decode(ss_, &codepoint_)) - codepoint_ = 0; - } - - SourceStream& ss_; - unsigned codepoint_; - }; - - State& GetState(SizeType index) { - RAPIDJSON_ASSERT(index < stateCount_); - return states_.template Bottom<State>()[index]; - } - - const State& GetState(SizeType index) const { - RAPIDJSON_ASSERT(index < stateCount_); - return states_.template Bottom<State>()[index]; - } - - Range& GetRange(SizeType index) { - RAPIDJSON_ASSERT(index < rangeCount_); - return ranges_.template Bottom<Range>()[index]; - } - - const Range& GetRange(SizeType index) const { - RAPIDJSON_ASSERT(index < rangeCount_); - return ranges_.template Bottom<Range>()[index]; - } - - template <typename InputStream> - void Parse(DecodedStream<InputStream>& ds) { - Allocator allocator; - Stack<Allocator> operandStack(&allocator, 256); // Frag - Stack<Allocator> operatorStack(&allocator, 256); // Operator - Stack<Allocator> atomCountStack(&allocator, 256); // unsigned (Atom per parenthesis) - - *atomCountStack.template Push<unsigned>() = 0; - - unsigned codepoint; - while (ds.Peek() != 0) { - switch (codepoint = ds.Take()) { - case '^': - anchorBegin_ = true; - break; - - case '$': - anchorEnd_ = true; - break; - - case '|': - while (!operatorStack.Empty() && *operatorStack.template Top<Operator>() < kAlternation) - if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1))) - return; - *operatorStack.template Push<Operator>() = kAlternation; - *atomCountStack.template Top<unsigned>() = 0; - break; - - case '(': - *operatorStack.template Push<Operator>() = kLeftParenthesis; - *atomCountStack.template Push<unsigned>() = 0; - break; - - case ')': - while (!operatorStack.Empty() && *operatorStack.template Top<Operator>() != kLeftParenthesis) - if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1))) - return; - if (operatorStack.Empty()) - return; - operatorStack.template Pop<Operator>(1); - atomCountStack.template Pop<unsigned>(1); - ImplicitConcatenation(atomCountStack, operatorStack); - break; - - case '?': - if (!Eval(operandStack, kZeroOrOne)) - return; - break; - - case '*': - if (!Eval(operandStack, kZeroOrMore)) - return; - break; - - case '+': - if (!Eval(operandStack, kOneOrMore)) - return; - break; - - case '{': - { - unsigned n, m; - if (!ParseUnsigned(ds, &n)) - return; - - if (ds.Peek() == ',') { - ds.Take(); - if (ds.Peek() == '}') - m = kInfinityQuantifier; - else if (!ParseUnsigned(ds, &m) || m < n) - return; - } - else - m = n; - - if (!EvalQuantifier(operandStack, n, m) || ds.Peek() != '}') - return; - ds.Take(); - } - break; - - case '.': - PushOperand(operandStack, kAnyCharacterClass); - ImplicitConcatenation(atomCountStack, operatorStack); - break; - - case '[': - { - SizeType range; - if (!ParseRange(ds, &range)) - return; - SizeType s = NewState(kRegexInvalidState, kRegexInvalidState, kRangeCharacterClass); - GetState(s).rangeStart = range; - *operandStack.template Push<Frag>() = Frag(s, s, s); - } - ImplicitConcatenation(atomCountStack, operatorStack); - break; - - case '\\': // Escape character - if (!CharacterEscape(ds, &codepoint)) - return; // Unsupported escape character - // fall through to default - - default: // Pattern character - PushOperand(operandStack, codepoint); - ImplicitConcatenation(atomCountStack, operatorStack); - } - } - - while (!operatorStack.Empty()) - if (!Eval(operandStack, *operatorStack.template Pop<Operator>(1))) - return; - - // Link the operand to matching state. - if (operandStack.GetSize() == sizeof(Frag)) { - Frag* e = operandStack.template Pop<Frag>(1); - Patch(e->out, NewState(kRegexInvalidState, kRegexInvalidState, 0)); - root_ = e->start; - -#if RAPIDJSON_REGEX_VERBOSE - printf("root: %d\n", root_); - for (SizeType i = 0; i < stateCount_ ; i++) { - State& s = GetState(i); - printf("[%2d] out: %2d out1: %2d c: '%c'\n", i, s.out, s.out1, (char)s.codepoint); - } - printf("\n"); -#endif - } - - // Preallocate buffer for SearchWithAnchoring() - RAPIDJSON_ASSERT(stateSet_ == 0); - if (stateCount_ > 0) { - stateSet_ = static_cast<unsigned*>(states_.GetAllocator().Malloc(GetStateSetSize())); - state0_.template Reserve<SizeType>(stateCount_); - state1_.template Reserve<SizeType>(stateCount_); - } - } - - SizeType NewState(SizeType out, SizeType out1, unsigned codepoint) { - State* s = states_.template Push<State>(); - s->out = out; - s->out1 = out1; - s->codepoint = codepoint; - s->rangeStart = kRegexInvalidRange; - return stateCount_++; - } - - void PushOperand(Stack<Allocator>& operandStack, unsigned codepoint) { - SizeType s = NewState(kRegexInvalidState, kRegexInvalidState, codepoint); - *operandStack.template Push<Frag>() = Frag(s, s, s); - } - - void ImplicitConcatenation(Stack<Allocator>& atomCountStack, Stack<Allocator>& operatorStack) { - if (*atomCountStack.template Top<unsigned>()) - *operatorStack.template Push<Operator>() = kConcatenation; - (*atomCountStack.template Top<unsigned>())++; - } - - SizeType Append(SizeType l1, SizeType l2) { - SizeType old = l1; - while (GetState(l1).out != kRegexInvalidState) - l1 = GetState(l1).out; - GetState(l1).out = l2; - return old; - } - - void Patch(SizeType l, SizeType s) { - for (SizeType next; l != kRegexInvalidState; l = next) { - next = GetState(l).out; - GetState(l).out = s; - } - } - - bool Eval(Stack<Allocator>& operandStack, Operator op) { - switch (op) { - case kConcatenation: - RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag) * 2); - { - Frag e2 = *operandStack.template Pop<Frag>(1); - Frag e1 = *operandStack.template Pop<Frag>(1); - Patch(e1.out, e2.start); - *operandStack.template Push<Frag>() = Frag(e1.start, e2.out, Min(e1.minIndex, e2.minIndex)); - } - return true; - - case kAlternation: - if (operandStack.GetSize() >= sizeof(Frag) * 2) { - Frag e2 = *operandStack.template Pop<Frag>(1); - Frag e1 = *operandStack.template Pop<Frag>(1); - SizeType s = NewState(e1.start, e2.start, 0); - *operandStack.template Push<Frag>() = Frag(s, Append(e1.out, e2.out), Min(e1.minIndex, e2.minIndex)); - return true; - } - return false; - - case kZeroOrOne: - if (operandStack.GetSize() >= sizeof(Frag)) { - Frag e = *operandStack.template Pop<Frag>(1); - SizeType s = NewState(kRegexInvalidState, e.start, 0); - *operandStack.template Push<Frag>() = Frag(s, Append(e.out, s), e.minIndex); - return true; - } - return false; - - case kZeroOrMore: - if (operandStack.GetSize() >= sizeof(Frag)) { - Frag e = *operandStack.template Pop<Frag>(1); - SizeType s = NewState(kRegexInvalidState, e.start, 0); - Patch(e.out, s); - *operandStack.template Push<Frag>() = Frag(s, s, e.minIndex); - return true; - } - return false; - - default: - RAPIDJSON_ASSERT(op == kOneOrMore); - if (operandStack.GetSize() >= sizeof(Frag)) { - Frag e = *operandStack.template Pop<Frag>(1); - SizeType s = NewState(kRegexInvalidState, e.start, 0); - Patch(e.out, s); - *operandStack.template Push<Frag>() = Frag(e.start, s, e.minIndex); - return true; - } - return false; - } - } - - bool EvalQuantifier(Stack<Allocator>& operandStack, unsigned n, unsigned m) { - RAPIDJSON_ASSERT(n <= m); - RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag)); - - if (n == 0) { - if (m == 0) // a{0} not support - return false; - else if (m == kInfinityQuantifier) - Eval(operandStack, kZeroOrMore); // a{0,} -> a* - else { - Eval(operandStack, kZeroOrOne); // a{0,5} -> a? - for (unsigned i = 0; i < m - 1; i++) - CloneTopOperand(operandStack); // a{0,5} -> a? a? a? a? a? - for (unsigned i = 0; i < m - 1; i++) - Eval(operandStack, kConcatenation); // a{0,5} -> a?a?a?a?a? - } - return true; - } - - for (unsigned i = 0; i < n - 1; i++) // a{3} -> a a a - CloneTopOperand(operandStack); - - if (m == kInfinityQuantifier) - Eval(operandStack, kOneOrMore); // a{3,} -> a a a+ - else if (m > n) { - CloneTopOperand(operandStack); // a{3,5} -> a a a a - Eval(operandStack, kZeroOrOne); // a{3,5} -> a a a a? - for (unsigned i = n; i < m - 1; i++) - CloneTopOperand(operandStack); // a{3,5} -> a a a a? a? - for (unsigned i = n; i < m; i++) - Eval(operandStack, kConcatenation); // a{3,5} -> a a aa?a? - } - - for (unsigned i = 0; i < n - 1; i++) - Eval(operandStack, kConcatenation); // a{3} -> aaa, a{3,} -> aaa+, a{3.5} -> aaaa?a? - - return true; - } - - static SizeType Min(SizeType a, SizeType b) { return a < b ? a : b; } - - void CloneTopOperand(Stack<Allocator>& operandStack) { - const Frag src = *operandStack.template Top<Frag>(); // Copy constructor to prevent invalidation - SizeType count = stateCount_ - src.minIndex; // Assumes top operand contains states in [src->minIndex, stateCount_) - State* s = states_.template Push<State>(count); - memcpy(s, &GetState(src.minIndex), count * sizeof(State)); - for (SizeType j = 0; j < count; j++) { - if (s[j].out != kRegexInvalidState) - s[j].out += count; - if (s[j].out1 != kRegexInvalidState) - s[j].out1 += count; - } - *operandStack.template Push<Frag>() = Frag(src.start + count, src.out + count, src.minIndex + count); - stateCount_ += count; - } - - template <typename InputStream> - bool ParseUnsigned(DecodedStream<InputStream>& ds, unsigned* u) { - unsigned r = 0; - if (ds.Peek() < '0' || ds.Peek() > '9') - return false; - while (ds.Peek() >= '0' && ds.Peek() <= '9') { - if (r >= 429496729 && ds.Peek() > '5') // 2^32 - 1 = 4294967295 - return false; // overflow - r = r * 10 + (ds.Take() - '0'); - } - *u = r; - return true; - } - - template <typename InputStream> - bool ParseRange(DecodedStream<InputStream>& ds, SizeType* range) { - bool isBegin = true; - bool negate = false; - int step = 0; - SizeType start = kRegexInvalidRange; - SizeType current = kRegexInvalidRange; - unsigned codepoint; - while ((codepoint = ds.Take()) != 0) { - if (isBegin) { - isBegin = false; - if (codepoint == '^') { - negate = true; - continue; - } - } - - switch (codepoint) { - case ']': - if (start == kRegexInvalidRange) - return false; // Error: nothing inside [] - if (step == 2) { // Add trailing '-' - SizeType r = NewRange('-'); - RAPIDJSON_ASSERT(current != kRegexInvalidRange); - GetRange(current).next = r; - } - if (negate) - GetRange(start).start |= kRangeNegationFlag; - *range = start; - return true; - - case '\\': - if (ds.Peek() == 'b') { - ds.Take(); - codepoint = 0x0008; // Escape backspace character - } - else if (!CharacterEscape(ds, &codepoint)) - return false; - // fall through to default - - default: - switch (step) { - case 1: - if (codepoint == '-') { - step++; - break; - } - // fall through to step 0 for other characters - - case 0: - { - SizeType r = NewRange(codepoint); - if (current != kRegexInvalidRange) - GetRange(current).next = r; - if (start == kRegexInvalidRange) - start = r; - current = r; - } - step = 1; - break; - - default: - RAPIDJSON_ASSERT(step == 2); - GetRange(current).end = codepoint; - step = 0; - } - } - } - return false; - } - - SizeType NewRange(unsigned codepoint) { - Range* r = ranges_.template Push<Range>(); - r->start = r->end = codepoint; - r->next = kRegexInvalidRange; - return rangeCount_++; - } - - template <typename InputStream> - bool CharacterEscape(DecodedStream<InputStream>& ds, unsigned* escapedCodepoint) { - unsigned codepoint; - switch (codepoint = ds.Take()) { - case '^': - case '$': - case '|': - case '(': - case ')': - case '?': - case '*': - case '+': - case '.': - case '[': - case ']': - case '{': - case '}': - case '\\': - *escapedCodepoint = codepoint; return true; - case 'f': *escapedCodepoint = 0x000C; return true; - case 'n': *escapedCodepoint = 0x000A; return true; - case 'r': *escapedCodepoint = 0x000D; return true; - case 't': *escapedCodepoint = 0x0009; return true; - case 'v': *escapedCodepoint = 0x000B; return true; - default: - return false; // Unsupported escape character - } - } - - template <typename InputStream> - bool SearchWithAnchoring(InputStream& is, bool anchorBegin, bool anchorEnd) const { - RAPIDJSON_ASSERT(IsValid()); - DecodedStream<InputStream> ds(is); - - state0_.Clear(); - Stack<Allocator> *current = &state0_, *next = &state1_; - const size_t stateSetSize = GetStateSetSize(); - std::memset(stateSet_, 0, stateSetSize); - - bool matched = AddState(*current, root_); - unsigned codepoint; - while (!current->Empty() && (codepoint = ds.Take()) != 0) { - std::memset(stateSet_, 0, stateSetSize); - next->Clear(); - matched = false; - for (const SizeType* s = current->template Bottom<SizeType>(); s != current->template End<SizeType>(); ++s) { - const State& sr = GetState(*s); - if (sr.codepoint == codepoint || - sr.codepoint == kAnyCharacterClass || - (sr.codepoint == kRangeCharacterClass && MatchRange(sr.rangeStart, codepoint))) - { - matched = AddState(*next, sr.out) || matched; - if (!anchorEnd && matched) - return true; - } - if (!anchorBegin) - AddState(*next, root_); - } - internal::Swap(current, next); - } - - return matched; - } - - size_t GetStateSetSize() const { - return (stateCount_ + 31) / 32 * 4; - } - - // Return whether the added states is a match state - bool AddState(Stack<Allocator>& l, SizeType index) const { - RAPIDJSON_ASSERT(index != kRegexInvalidState); - - const State& s = GetState(index); - if (s.out1 != kRegexInvalidState) { // Split - bool matched = AddState(l, s.out); - return AddState(l, s.out1) || matched; - } - else if (!(stateSet_[index >> 5] & (1 << (index & 31)))) { - stateSet_[index >> 5] |= (1 << (index & 31)); - *l.template PushUnsafe<SizeType>() = index; - } - return s.out == kRegexInvalidState; // by using PushUnsafe() above, we can ensure s is not validated due to reallocation. - } - - bool MatchRange(SizeType rangeIndex, unsigned codepoint) const { - bool yes = (GetRange(rangeIndex).start & kRangeNegationFlag) == 0; - while (rangeIndex != kRegexInvalidRange) { - const Range& r = GetRange(rangeIndex); - if (codepoint >= (r.start & ~kRangeNegationFlag) && codepoint <= r.end) - return yes; - rangeIndex = r.next; - } - return !yes; - } - - Stack<Allocator> states_; - Stack<Allocator> ranges_; - SizeType root_; - SizeType stateCount_; - SizeType rangeCount_; - - static const unsigned kInfinityQuantifier = ~0u; - - // For SearchWithAnchoring() - uint32_t* stateSet_; // allocated by states_.GetAllocator() - mutable Stack<Allocator> state0_; - mutable Stack<Allocator> state1_; - bool anchorBegin_; - bool anchorEnd_; -}; - -typedef GenericRegex<UTF8<> > Regex; - -} // namespace internal -RAPIDJSON_NAMESPACE_END - -#ifdef __clang__ -RAPIDJSON_DIAG_POP -#endif - -#ifdef _MSC_VER -RAPIDJSON_DIAG_POP -#endif - -#endif // RAPIDJSON_INTERNAL_REGEX_H_ |