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Regex: make m_current_threads and m_next_threads local variable of exec

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This commit is contained in:
Maxime Coste 2017-10-04 10:49:40 +08:00
parent 54da8098ae
commit 1399563e40
1 changed files with 30 additions and 31 deletions
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61
src/regex_impl.hh
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@ -90,6 +90,12 @@ struct ThreadedRegexVM
return m_saves.back().get(); return m_saves.back().get();
} }
void release_saves(Saves* saves)
{
if (saves and --saves->refcount == 0)
m_free_saves.push_back(saves);
};
struct Thread struct Thread
{ {
const char* inst; const char* inst;
@ -97,7 +103,7 @@ struct ThreadedRegexVM
}; };
enum class StepResult { Consumed, Matched, Failed }; enum class StepResult { Consumed, Matched, Failed };
StepResult step(Thread& thread) StepResult step(Thread& thread, Vector<Thread>& threads)
{ {
const auto prog_start = m_program.bytecode.data(); const auto prog_start = m_program.bytecode.data();
const auto prog_end = prog_start + m_program.bytecode.size(); const auto prog_end = prog_start + m_program.bytecode.size();
@ -127,7 +133,7 @@ struct ThreadedRegexVM
thread.inst = parent; thread.inst = parent;
if (thread.saves) if (thread.saves)
++thread.saves->refcount; ++thread.saves->refcount;
m_current_threads.push_back({child, thread.saves}); threads.push_back({child, thread.saves});
break; break;
} }
case CompiledRegex::Split_PrioritizeChild: case CompiledRegex::Split_PrioritizeChild:
@ -137,7 +143,7 @@ struct ThreadedRegexVM
thread.inst = child; thread.inst = child;
if (thread.saves) if (thread.saves)
++thread.saves->refcount; ++thread.saves->refcount;
m_current_threads.push_back({parent, thread.saves}); threads.push_back({parent, thread.saves});
break; break;
} }
case CompiledRegex::Save: case CompiledRegex::Save:
@ -224,8 +230,9 @@ struct ThreadedRegexVM
m_flags = flags; m_flags = flags;
bool found_match = false; bool found_match = false;
m_current_threads.clear();
m_next_threads.clear(); if (flags & RegexExecFlags::NotInitialNull and m_begin == m_end)
return false;
Saves* initial_saves = nullptr; Saves* initial_saves = nullptr;
if (not (m_flags & RegexExecFlags::NoSaves)) if (not (m_flags & RegexExecFlags::NoSaves))
@ -234,24 +241,18 @@ struct ThreadedRegexVM
initial_saves = m_saves.back().get(); initial_saves = m_saves.back().get();
} }
const auto start_offset = (flags & RegexExecFlags::Search) ? 0 : CompiledRegex::search_prefix_size; const bool search = (flags & RegexExecFlags::Search);
m_current_threads.push_back({m_program.bytecode.data() + start_offset, initial_saves});
if (flags & RegexExecFlags::NotInitialNull and m_begin == m_end)
return false;
auto release_saves = [this](Saves* saves) {
if (saves and --saves->refcount == 0)
m_free_saves.push_back(saves);
};
const auto start_offset = search ? 0 : CompiledRegex::search_prefix_size;
Vector<Thread> current_threads{Thread{m_program.bytecode.data() + start_offset, initial_saves}};
Vector<Thread> next_threads;
for (m_pos = Utf8It{m_begin, m_begin, m_end}; m_pos != m_end; ++m_pos) for (m_pos = Utf8It{m_begin, m_begin, m_end}; m_pos != m_end; ++m_pos)
{ {
while (not m_current_threads.empty()) while (not current_threads.empty())
{ {
auto thread = m_current_threads.back(); auto thread = current_threads.back();
m_current_threads.pop_back(); current_threads.pop_back();
switch (step(thread)) switch (step(thread, current_threads))
{ {
case StepResult::Matched: case StepResult::Matched:
if (not (flags & RegexExecFlags::Search) or // We are not at end, this is not a full match if (not (flags & RegexExecFlags::Search) or // We are not at end, this is not a full match
@ -268,34 +269,34 @@ struct ThreadedRegexVM
return true; return true;
found_match = true; found_match = true;
m_current_threads.clear(); // remove this and lower priority threads current_threads.clear(); // remove this and lower priority threads
break; break;
case StepResult::Failed: case StepResult::Failed:
release_saves(thread.saves); release_saves(thread.saves);
break; break;
case StepResult::Consumed: case StepResult::Consumed:
if (contains_that(m_next_threads, [&](auto& t) { return t.inst == thread.inst; })) if (contains_that(next_threads, [&](auto& t) { return t.inst == thread.inst; }))
release_saves(thread.saves); release_saves(thread.saves);
else else
m_next_threads.push_back(thread); next_threads.push_back(thread);
break; break;
} }
} }
if (m_next_threads.empty()) if (next_threads.empty())
return found_match; return found_match;
std::swap(m_current_threads, m_next_threads); std::swap(current_threads, next_threads);
std::reverse(m_current_threads.begin(), m_current_threads.end()); std::reverse(current_threads.begin(), current_threads.end());
} }
if (found_match) if (found_match)
return true; return true;
// Step remaining threads to see if they match without consuming anything else // Step remaining threads to see if they match without consuming anything else
while (not m_current_threads.empty()) while (not current_threads.empty())
{ {
auto thread = m_current_threads.back(); auto thread = current_threads.back();
m_current_threads.pop_back(); current_threads.pop_back();
if (step(thread) == StepResult::Matched) if (step(thread, current_threads) == StepResult::Matched)
{ {
if (thread.saves) if (thread.saves)
m_captures = std::move(thread.saves->pos); m_captures = std::move(thread.saves->pos);
@ -325,8 +326,6 @@ struct ThreadedRegexVM
} }
const CompiledRegex& m_program; const CompiledRegex& m_program;
Vector<Thread> m_current_threads;
Vector<Thread> m_next_threads;
using Utf8It = utf8::iterator<Iterator>; using Utf8It = utf8::iterator<Iterator>;