diff options
Diffstat (limited to 'NorthstarDLL/include/rapidjson/internal/regex.h')
| -rw-r--r-- | NorthstarDLL/include/rapidjson/internal/regex.h | 1402 |
1 files changed, 701 insertions, 701 deletions
diff --git a/NorthstarDLL/include/rapidjson/internal/regex.h b/NorthstarDLL/include/rapidjson/internal/regex.h index 422a5240..814972d9 100644 --- a/NorthstarDLL/include/rapidjson/internal/regex.h +++ b/NorthstarDLL/include/rapidjson/internal/regex.h @@ -1,701 +1,701 @@ -// 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_ +// 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_
|