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Merged
maxitg merged 4 commits into from
Mar 1, 2021
+101 −47
Merged

Searcher checkpoints #21

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c989038
Separate checkpoint tries into explicit and automatic.
maxitg Mar 1, 2021
bc6e420
Perform enumeration in PostTagHistory to eliminate recreation of the …
maxitg Mar 1, 2021
a61c855
Add test.
maxitg Mar 1, 2021
3dba8e5
Fix integer comparison.
maxitg Mar 1, 2021
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88 changes: 58 additions & 30 deletions libPostTagSystem/PostTagHistory.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -49,25 +49,41 @@ class PostTagHistory::Implementation {
const TagState& init,
const EvaluationLimits& limits,
const CheckpointSpec& checkpointSpec) {
return evaluate(rule, std::vector<TagState>({init}), limits, checkpointSpec).front();
}

std::vector<EvaluationResult> evaluate(const NamedRule& rule,
const std::vector<TagState>& inits,
const EvaluationLimits& limits,
const CheckpointSpec& checkpointSpec) {
const ChunkEvaluationTable chunkEvaluationTable = createChunkEvaluationTable(rule);
if (limits.maxEventCount % chunkEvaluationTable.eventsAtOnce != 0) {
return {ConclusionReason::InvalidInput, {{}, std::numeric_limits<uint8_t>::max()}, 0, 0};
return std::vector<EvaluationResult>(
inits.size(), {ConclusionReason::InvalidInput, {{}, std::numeric_limits<uint8_t>::max()}, 0, 0});
}
auto chunkedState = toChunkedState(init);
CheckpointsTrie checkpointsTrie;
CheckpointsTrie explicitCheckpointsTrie;
for (const auto& checkpoint : checkpointSpec.states) {
checkpointsTrie.insert(toChunkedState(checkpoint));
explicitCheckpointsTrie.insert(toChunkedState(checkpoint));
}
uint64_t maxIntermediateTapeLength = tapeLength(chunkedState);
ConclusionReason conclusionReason;
const auto eventCount = evaluate(chunkEvaluationTable,
&chunkedState,
&conclusionReason,
&maxIntermediateTapeLength,
limits,
&checkpointsTrie,
checkpointSpec.flags);
return {conclusionReason, fromChunkedStateDestructively(&chunkedState), eventCount, maxIntermediateTapeLength};

std::vector<EvaluationResult> results;
results.reserve(inits.size());
for (const auto& init : inits) {
auto chunkedState = toChunkedState(init);
uint64_t maxIntermediateTapeLength = tapeLength(chunkedState);
ConclusionReason conclusionReason;
const auto eventCount = evaluate(chunkEvaluationTable,
&chunkedState,
&conclusionReason,
&maxIntermediateTapeLength,
limits,
explicitCheckpointsTrie,
checkpointSpec.flags);
results.push_back(
{conclusionReason, fromChunkedStateDestructively(&chunkedState), eventCount, maxIntermediateTapeLength});
}

return results;
}

private:
Expand All @@ -79,7 +95,7 @@ class PostTagHistory::Implementation {
return foundTable->second;
}

ChunkEvaluationTable createChunkEvaluationTable(const ChunkedRule& rule) {
static ChunkEvaluationTable createChunkEvaluationTable(const ChunkedRule& rule) {
ChunkEvaluationTable table;
table.eventsAtOnce = 8 / rule.inputLength;
table.phaseCount = rule.phaseCount;
Expand All @@ -94,7 +110,7 @@ class PostTagHistory::Implementation {
return table;
}

ChunkOutput createChunkOutput(const ChunkedRule& rule, const uint8_t inputTape, const uint8_t inputPhase) const {
static ChunkOutput createChunkOutput(const ChunkedRule& rule, const uint8_t inputTape, const uint8_t inputPhase) {
uint16_t output = 0;
uint8_t outputSize = 0;
auto phase = inputPhase;
Expand All @@ -110,7 +126,7 @@ class PostTagHistory::Implementation {
return {output, outputSize, phase};
}

ChunkedState toChunkedState(const TagState& state) const {
static ChunkedState toChunkedState(const TagState& state) {
ChunkedState result;
for (size_t i = 0; i < state.tape.size(); ++i) {
if (i % 8 == 0) result.chunks.push_back(0);
Expand All @@ -123,7 +139,7 @@ class PostTagHistory::Implementation {
return result;
}

TagState fromChunkedStateDestructively(ChunkedState* chunkedState) const {
static TagState fromChunkedStateDestructively(ChunkedState* chunkedState) {
std::vector<bool> tape;
if (chunkedState->chunks.size()) {
tape.reserve(8 * (chunkedState->chunks.size() - 1) + chunkedState->lastChunkSize);
Expand All @@ -145,26 +161,31 @@ class PostTagHistory::Implementation {
}
}

uint64_t evaluate(const ChunkEvaluationTable& evaluationTable,
ChunkedState* state,
ConclusionReason* conclusionReason,
uint64_t* maxIntermediateTapeLength,
const EvaluationLimits& limits,
CheckpointsTrie* checkpoints,
const CheckpointSpecFlags& checkpointFlags) const {
static uint64_t evaluate(const ChunkEvaluationTable& evaluationTable,
ChunkedState* state,
ConclusionReason* conclusionReason,
uint64_t* maxIntermediateTapeLength,
const EvaluationLimits& limits,
const CheckpointsTrie& explicitCheckpoints,
const CheckpointSpecFlags& checkpointFlags) {
CheckpointsTrie automaticCheckpoints;
uint64_t eventCount;
for (eventCount = 0; eventCount < limits.maxEventCount && state->chunks.size() > 1;
eventCount += evaluationTable.eventsAtOnce) {
if (*maxIntermediateTapeLength > limits.maxTapeLength) {
*conclusionReason = ConclusionReason::MaxTapeLengthExceeded;
return eventCount;
}
if (checkpoints->contains(*state)) {
*conclusionReason = ConclusionReason::ReachedCheckpoint;
if (explicitCheckpoints.contains(*state)) {
*conclusionReason = ConclusionReason::ReachedExplicitCheckpoint;
return eventCount;
}
if (automaticCheckpoints.contains(*state)) {
*conclusionReason = ConclusionReason::ReachedAutomaticCheckpoint;
return eventCount;
}
if (checkpointFlags.powerOfTwoEventCounts && !isPowerOfTwo(eventCount)) {
checkpoints->insert(*state);
automaticCheckpoints.insert(*state);
}
evaluateOnce(evaluationTable, state);
*maxIntermediateTapeLength = std::max(*maxIntermediateTapeLength, tapeLength(*state));
Expand All @@ -179,11 +200,11 @@ class PostTagHistory::Implementation {

static inline bool isPowerOfTwo(const uint64_t number) { return number & (number - 1); }

uint64_t tapeLength(const ChunkedState& state) const {
static uint64_t tapeLength(const ChunkedState& state) {
return std::max(0, static_cast<int>(state.chunks.size()) - 1) * 8 + state.lastChunkSize;
}

void evaluateOnce(const ChunkEvaluationTable& evaluationTable, ChunkedState* state) const {
static void evaluateOnce(const ChunkEvaluationTable& evaluationTable, ChunkedState* state) {
const auto nextChunkIndex = evaluationTable.phaseCount * state->chunks.front() + state->phase;
const auto& chunkOutput = evaluationTable.outputs[nextChunkIndex];
state->chunks.pop_front();
Expand Down Expand Up @@ -217,4 +238,11 @@ PostTagHistory::EvaluationResult PostTagHistory::evaluate(const NamedRule& rule,
const CheckpointSpec& checkpoints) {
return implementation_->evaluate(rule, init, limits, checkpoints);
}

std::vector<PostTagHistory::EvaluationResult> PostTagHistory::evaluate(const NamedRule& rule,
const std::vector<TagState>& inits,
const EvaluationLimits& limits,
const CheckpointSpec& checkpoints) {
return implementation_->evaluate(rule, inits, limits, checkpoints);
}
} // namespace PostTagSystem
8 changes: 7 additions & 1 deletion libPostTagSystem/PostTagHistory.hpp
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Expand Up @@ -13,7 +13,8 @@ class PostTagHistory {
enum class ConclusionReason {
InvalidInput,
Terminated,
ReachedCheckpoint,
ReachedExplicitCheckpoint,
ReachedAutomaticCheckpoint,
MaxEventCountExceeded,
MaxTapeLengthExceeded
};
Expand Down Expand Up @@ -51,6 +52,11 @@ class PostTagHistory {
const EvaluationLimits& limits,
const CheckpointSpec& checkpointSpec = CheckpointSpec());

std::vector<EvaluationResult> evaluate(const NamedRule& rule,
const std::vector<TagState>& inits,
const EvaluationLimits& limits,
const CheckpointSpec& checkpointSpec = CheckpointSpec());

private:
class Implementation;
std::shared_ptr<Implementation> implementation_;
Expand Down
24 changes: 14 additions & 10 deletions libPostTagSystem/PostTagSearcher.cpp
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Expand Up @@ -37,31 +37,35 @@ class PostTagSearcher::Implementation {
std::vector<EvaluationResult> evaluateGroup(const std::vector<TagState>& states,
const EvaluationParameters& parameters) {
// TODO(maxitg): Implement groupTimeConstraintNs parameter
// TODO(maxitg): Implement checkpoints parameter

std::vector<EvaluationResult> results;
results.reserve(states.size());
PostTagHistory evaluator;
PostTagHistory::EvaluationLimits limits;
limits.maxEventCount = parameters.maxEventCount;
limits.maxTapeLength = parameters.maxTapeLength;
for (const auto& init : states) {
const auto singleInitResult = evaluator.evaluate(PostTagHistory::NamedRule::Post, init, limits, {{}, {true}});
const auto singleInitResults =
evaluator.evaluate(PostTagHistory::NamedRule::Post, states, limits, {parameters.checkpoints, {true}});
for (size_t initIndex = 0; initIndex < states.size(); ++initIndex) {
EvaluationResult result;
result.eventCount = singleInitResult.eventCount;
result.maxTapeLength = singleInitResult.maxIntermediateTapeLength;
result.finalTapeLength = singleInitResult.finalState.tape.size();
result.initialState = init;
result.finalState = singleInitResult.finalState;
switch (singleInitResult.conclusionReason) {
result.eventCount = singleInitResults[initIndex].eventCount;
result.maxTapeLength = singleInitResults[initIndex].maxIntermediateTapeLength;
result.finalTapeLength = singleInitResults[initIndex].finalState.tape.size();
result.initialState = states[initIndex];
result.finalState = singleInitResults[initIndex].finalState;
switch (singleInitResults[initIndex].conclusionReason) {
case PostTagHistory::ConclusionReason::Terminated:
result.conclusionReason = ConclusionReason::Terminated;
break;

case PostTagHistory::ConclusionReason::ReachedCheckpoint:
case PostTagHistory::ConclusionReason::ReachedAutomaticCheckpoint:
result.conclusionReason = ConclusionReason::ReachedCycle;
break;

case PostTagHistory::ConclusionReason::ReachedExplicitCheckpoint:
result.conclusionReason = ConclusionReason::ReachedKnownCheckpoint;
break;

case PostTagHistory::ConclusionReason::MaxEventCountExceeded:
result.conclusionReason = ConclusionReason::MaxEventCountExceeded;
break;
Expand Down
28 changes: 22 additions & 6 deletions libPostTagSystem/test/PostTagSearcher_test.cpp
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Expand Up @@ -27,17 +27,20 @@ TEST(PostTagSearcher, emptyCases) {

void compareResults(const TagState& init,
const PostTagSearcher::EvaluationResult& result,
uint64_t eventLimit = std::numeric_limits<uint64_t>::max() - 7) {
const PostTagHistory::EvaluationLimits& limits = PostTagHistory::EvaluationLimits(),
const std::vector<TagState>& checkpoints = {}) {
PostTagHistory singleHistoryEvaluator;
const auto singleResult = singleHistoryEvaluator.evaluate(
PostTagHistory::NamedRule::Post, init, PostTagHistory::EvaluationLimits(eventLimit), {{}, {true}});
const auto singleResult =
singleHistoryEvaluator.evaluate(PostTagHistory::NamedRule::Post, init, limits, {checkpoints, {true}});

if (singleResult.conclusionReason == PostTagHistory::ConclusionReason::InvalidInput) {
ASSERT_EQ(result.conclusionReason, PostTagSearcher::ConclusionReason::InvalidInput);
} else if (singleResult.conclusionReason == PostTagHistory::ConclusionReason::Terminated) {
ASSERT_EQ(result.conclusionReason, PostTagSearcher::ConclusionReason::Terminated);
} else if (singleResult.conclusionReason == PostTagHistory::ConclusionReason::ReachedCheckpoint) {
} else if (singleResult.conclusionReason == PostTagHistory::ConclusionReason::ReachedAutomaticCheckpoint) {
ASSERT_EQ(result.conclusionReason, PostTagSearcher::ConclusionReason::ReachedCycle);
} else if (singleResult.conclusionReason == PostTagHistory::ConclusionReason::ReachedExplicitCheckpoint) {
ASSERT_EQ(result.conclusionReason, PostTagSearcher::ConclusionReason::ReachedKnownCheckpoint);
} else if (singleResult.conclusionReason == PostTagHistory::ConclusionReason::MaxEventCountExceeded) {
ASSERT_EQ(result.conclusionReason, PostTagSearcher::ConclusionReason::MaxEventCountExceeded);
}
Expand Down Expand Up @@ -100,7 +103,20 @@ TEST(PostTagSearcher, eventLimit) {
{{0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, 0}, {{0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, 2}, parameters);
ASSERT_EQ(result.size(), 2);

compareResults(TagState({0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, 0), result[0], 104);
compareResults(TagState({0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, 1), result[1], 104);
compareResults(
TagState({0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, 0), result[0], PostTagHistory::EvaluationLimits(104));
compareResults(
TagState({0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1}, 1), result[1], PostTagHistory::EvaluationLimits(104));
}

TEST(PostTagSearcher, checkpoints) {
PostTagSearcher searcher;
PostTagSearcher::EvaluationParameters parameters;
parameters.checkpoints = {{{0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0}, 2}};
const auto result = searcher.evaluateRange(20, 123, 125, parameters);
ASSERT_EQ(result.size(), 6);

compareResults(TagState(20, 123, 0), result[0], PostTagHistory::EvaluationLimits(), parameters.checkpoints);
compareResults(TagState(20, 124, 0), result[3], PostTagHistory::EvaluationLimits(), parameters.checkpoints);
}
} // namespace PostTagSystem