--- /dev/null
+/*
+ * Copyright 2013 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+/**
+ * @author Philip Pronin (philipp@fb.com)
+ *
+ * Based on the paper by Sebastiano Vigna,
+ * "Quasi-succinct indices" (arxiv:1206.4300).
+ */
+
+#ifndef FOLLY_EXPERIMENTAL_ELIAS_FANO_CODING_H
+#define FOLLY_EXPERIMENTAL_ELIAS_FANO_CODING_H
+
+#ifndef __GNUC__
+#error EliasFanoCoding.h requires GCC
+#endif
+
+#if !defined(__x86_64__)
+#error EliasFanoCoding.h requires x86_64
+#endif
+
+#include <cstdlib>
+#include <endian.h>
+#include <algorithm>
+#include <limits>
+#include <type_traits>
+#include <boost/noncopyable.hpp>
+#include <glog/logging.h>
+#include "folly/Bits.h"
+#include "folly/CpuId.h"
+#include "folly/Likely.h"
+#include "folly/Range.h"
+
+#if __BYTE_ORDER != __LITTLE_ENDIAN
+#error EliasFanoCoding.h requires little endianness
+#endif
+
+namespace folly { namespace compression {
+
+template <class Value,
+ class SkipValue = size_t,
+ size_t kSkipQuantum = 0, // 0 = disabled
+ size_t kForwardQuantum = 0> // 0 = disabled
+struct EliasFanoCompressedList {
+ static_assert(std::is_integral<Value>::value &&
+ std::is_unsigned<Value>::value,
+ "Value should be unsigned integral");
+
+ typedef Value ValueType;
+ typedef SkipValue SkipValueType;
+
+ EliasFanoCompressedList()
+ : size(0), numLowerBits(0) { }
+
+ static constexpr size_t skipQuantum = kSkipQuantum;
+ static constexpr size_t forwardQuantum = kForwardQuantum;
+
+ size_t size;
+ uint8_t numLowerBits;
+
+ // WARNING: EliasFanoCompressedList has no ownership of
+ // lower, upper, skipPointers and forwardPointers.
+ // The 7 bytes following the last byte of lower and upper
+ // sequences should be readable.
+ folly::ByteRange lower;
+ folly::ByteRange upper;
+
+ folly::ByteRange skipPointers;
+ folly::ByteRange forwardPointers;
+
+ void free() {
+ ::free(const_cast<unsigned char*>(lower.data()));
+ ::free(const_cast<unsigned char*>(upper.data()));
+ ::free(const_cast<unsigned char*>(skipPointers.data()));
+ ::free(const_cast<unsigned char*>(forwardPointers.data()));
+ }
+
+ static uint8_t defaultNumLowerBits(size_t upperBound, size_t size) {
+ if (size == 0 || upperBound < size) {
+ return 0;
+ }
+ // floor(log(upperBound / size));
+ return folly::findLastSet(upperBound / size) - 1;
+ }
+
+ // WARNING: encode() mallocates lower, upper, skipPointers
+ // and forwardPointers. As EliasFanoCompressedList has
+ // no ownership of them, you need to call free() explicitly.
+ static void encode(const ValueType* list, size_t size,
+ EliasFanoCompressedList& result) {
+ encode(list, list + size, result);
+ }
+
+ template <class RandomAccessIterator>
+ static void encode(RandomAccessIterator begin,
+ RandomAccessIterator end,
+ EliasFanoCompressedList& result) {
+ auto list = begin;
+ const size_t size = end - begin;
+
+ if (size == 0) {
+ result = EliasFanoCompressedList();
+ return;
+ }
+
+ DCHECK(std::is_sorted(list, list + size));
+
+ const ValueType upperBound = list[size - 1];
+ uint8_t numLowerBits = defaultNumLowerBits(upperBound, size);
+
+ // This is detail::writeBits56 limitation.
+ numLowerBits = std::min<uint8_t>(numLowerBits, 56);
+ CHECK_LT(numLowerBits, 8 * sizeof(Value)); // As we shift by numLowerBits.
+
+ // WARNING: Current read/write logic assumes that the 7 bytes
+ // following the last byte of lower and upper sequences are
+ // readable (stored value doesn't matter and won't be changed),
+ // so we allocate additional 7B, but do not include them in size
+ // of returned value.
+
+ // *** Lower bits.
+ const size_t lowerSize = (numLowerBits * size + 7) / 8;
+ unsigned char* const lower =
+ static_cast<unsigned char*>(calloc(lowerSize + 7, 1));
+ const ValueType lowerMask = (ValueType(1) << numLowerBits) - 1;
+ for (size_t i = 0; i < size; ++i) {
+ const ValueType lowerBits = list[i] & lowerMask;
+ writeBits56(lower, i * numLowerBits, numLowerBits, lowerBits);
+ }
+
+ // *** Upper bits.
+ // Upper bits are stored using unary delta encoding.
+ // For example, (3 5 5 9) will be encoded as 1000011001000_2.
+ const size_t upperSizeBits =
+ (upperBound >> numLowerBits) + // Number of 0-bits to be stored.
+ size; // 1-bits.
+ const size_t upperSize = (upperSizeBits + 7) / 8;
+ unsigned char* const upper =
+ static_cast<unsigned char*>(calloc(upperSize + 7, 1));
+ for (size_t i = 0; i < size; ++i) {
+ const ValueType upperBits = list[i] >> numLowerBits;
+ const size_t pos = upperBits + i; // upperBits 0-bits and (i + 1) 1-bits.
+ upper[pos / 8] |= 1U << (pos % 8);
+ }
+
+ // *** Skip pointers.
+ // Store (1-indexed) position of every skipQuantum-th
+ // 0-bit in upper bits sequence.
+ SkipValueType* skipPointers = nullptr;
+ size_t numSkipPointers = 0;
+ /* static */ if (skipQuantum != 0) {
+ // Workaround to avoid 'division by zero' compile-time error.
+ constexpr size_t q = skipQuantum ?: 1;
+ CHECK_LT(upperSizeBits, std::numeric_limits<SkipValueType>::max());
+ // 8 * upperSize is used here instead of upperSizeBits, as that is
+ // more serialization-friendly way.
+ numSkipPointers = (8 * upperSize - size) / q;
+ skipPointers = static_cast<SkipValueType*>(
+ numSkipPointers == 0
+ ? nullptr
+ : calloc(numSkipPointers, sizeof(SkipValueType)));
+
+ for (size_t i = 0, pos = 0; i < size; ++i) {
+ const ValueType upperBits = list[i] >> numLowerBits;
+ for (; (pos + 1) * q <= upperBits; ++pos) {
+ skipPointers[pos] = i + (pos + 1) * q;
+ }
+ }
+ }
+
+ // *** Forward pointers.
+ // Store (1-indexed) position of every forwardQuantum-th
+ // 1-bit in upper bits sequence.
+ SkipValueType* forwardPointers = nullptr;
+ size_t numForwardPointers = 0;
+ /* static */ if (forwardQuantum != 0) {
+ // Workaround to avoid 'division by zero' compile-time error.
+ constexpr size_t q = forwardQuantum ?: 1;
+ CHECK_LT(upperSizeBits, std::numeric_limits<SkipValueType>::max());
+
+ numForwardPointers = size / q;
+ forwardPointers = static_cast<SkipValueType*>(
+ numForwardPointers == 0
+ ? nullptr
+ : malloc(numForwardPointers * sizeof(SkipValueType)));
+
+ for (size_t i = q - 1, pos = 0; i < size; i += q, ++pos) {
+ const ValueType upperBits = list[i] >> numLowerBits;
+ forwardPointers[pos] = upperBits + i + 1;
+ }
+ }
+
+ // *** Result.
+ result.size = size;
+ result.numLowerBits = numLowerBits;
+ result.lower.reset(lower, lowerSize);
+ result.upper.reset(upper, upperSize);
+ result.skipPointers.reset(
+ reinterpret_cast<unsigned char*>(skipPointers),
+ numSkipPointers * sizeof(SkipValueType));
+ result.forwardPointers.reset(
+ reinterpret_cast<unsigned char*>(forwardPointers),
+ numForwardPointers * sizeof(SkipValueType));
+ }
+
+ private:
+ // Writes value (with len up to 56 bits) to data starting at pos-th bit.
+ static void writeBits56(unsigned char* data, size_t pos,
+ uint8_t len, uint64_t value) {
+ DCHECK_LE(uint32_t(len), 56);
+ DCHECK_EQ(0, value & ~((uint64_t(1) << len) - 1));
+ unsigned char* const ptr = data + (pos / 8);
+ uint64_t ptrv = folly::loadUnaligned<uint64_t>(ptr);
+ ptrv |= value << (pos % 8);
+ folly::storeUnaligned<uint64_t>(ptr, ptrv);
+ }
+};
+
+// NOTE: It's recommended to compile EF coding with -msse4.2, starting
+// with Nehalem, Intel CPUs support POPCNT instruction and gcc will emit
+// it for __builtin_popcountll intrinsic.
+// But we provide an alternative way for the client code: it can switch to
+// the appropriate version of EliasFanoReader<> in realtime (client should
+// implement this switching logic itself) by specifying instruction set to
+// use explicitly.
+namespace instructions {
+
+struct Default {
+ static bool supported() {
+ return true;
+ }
+ static inline uint64_t popcount(uint64_t value) {
+ return __builtin_popcountll(value);
+ }
+ static inline int ctz(uint64_t value) {
+ DCHECK_GT(value, 0);
+ return __builtin_ctzll(value);
+ }
+};
+
+struct Fast : public Default {
+ static bool supported() {
+ folly::CpuId cpuId;
+ return cpuId.popcnt();
+ }
+ static inline uint64_t popcount(uint64_t value) {
+ uint64_t result;
+ asm ("popcntq %1, %0" : "=r" (result) : "r" (value));
+ return result;
+ }
+};
+
+} // namespace instructions
+
+namespace detail {
+
+template <class CompressedList, class Instructions>
+class UpperBitsReader {
+ typedef typename CompressedList::SkipValueType SkipValueType;
+ public:
+ typedef typename CompressedList::ValueType ValueType;
+
+ explicit UpperBitsReader(const CompressedList& list)
+ : forwardPointers_(list.forwardPointers.data()),
+ skipPointers_(list.skipPointers.data()),
+ start_(list.upper.data()),
+ block_(start_ != nullptr ? folly::loadUnaligned<block_t>(start_) : 0),
+ outer_(0), // outer offset: number of consumed bytes in upper.
+ inner_(-1), // inner offset: (bit) position in current block.
+ position_(-1), // index of current value (= #reads - 1).
+ value_(0) { }
+
+ size_t position() const { return position_; }
+ ValueType value() const { return value_; }
+
+ ValueType next() {
+ // Skip to the first non-zero block.
+ while (block_ == 0) {
+ outer_ += sizeof(block_t);
+ block_ = folly::loadUnaligned<block_t>(start_ + outer_);
+ }
+
+ ++position_;
+ inner_ = Instructions::ctz(block_);
+ block_ &= block_ - 1;
+
+ return setValue();
+ }
+
+ ValueType skip(size_t n) {
+ DCHECK_GT(n, 0);
+
+ position_ += n; // n 1-bits will be read.
+
+ // Use forward pointer.
+ if (CompressedList::forwardQuantum > 0 &&
+ n > CompressedList::forwardQuantum) {
+ // Workaround to avoid 'division by zero' compile-time error.
+ constexpr size_t q = CompressedList::forwardQuantum ?: 1;
+
+ const size_t steps = position_ / q;
+ const size_t dest =
+ folly::loadUnaligned<SkipValueType>(
+ forwardPointers_ + (steps - 1) * sizeof(SkipValueType));
+
+ reposition(dest);
+ n = position_ + 1 - steps * q; // n is > 0.
+ // correct inner_ will be set at the end.
+ }
+
+ size_t cnt;
+ // Find necessary block.
+ while ((cnt = Instructions::popcount(block_)) < n) {
+ n -= cnt;
+ outer_ += sizeof(block_t);
+ block_ = folly::loadUnaligned<block_t>(start_ + outer_);
+ }
+
+ // NOTE: Trying to skip half-block here didn't show any
+ // performance improvements.
+
+ DCHECK_GT(n, 0);
+
+ // Kill n - 1 least significant 1-bits.
+ for (size_t i = 0; i < n - 1; ++i) {
+ block_ &= block_ - 1;
+ }
+
+ inner_ = Instructions::ctz(block_);
+ block_ &= block_ - 1;
+
+ return setValue();
+ }
+
+ // Skip to the first element that is >= v and located *after* the current
+ // one (so even if current value equals v, position will be increased by 1).
+ ValueType skipToNext(ValueType v) {
+ DCHECK_GE(v, value_);
+
+ // Use skip pointer.
+ if (CompressedList::skipQuantum > 0 &&
+ v >= value_ + CompressedList::skipQuantum) {
+ // Workaround to avoid 'division by zero' compile-time error.
+ constexpr size_t q = CompressedList::skipQuantum ?: 1;
+
+ const size_t steps = v / q;
+ const size_t dest =
+ folly::loadUnaligned<SkipValueType>(
+ skipPointers_ + (steps - 1) * sizeof(SkipValueType));
+
+ reposition(dest);
+ position_ = dest - q * steps - 1;
+ // Correct inner_ and value_ will be set during the next()
+ // call at the end.
+
+ // NOTE: Corresponding block of lower bits sequence may be
+ // prefetched here (via __builtin_prefetch), but experiments
+ // didn't show any significant improvements.
+ }
+
+ // Skip by blocks.
+ size_t cnt;
+ size_t skip = v - (8 * outer_ - position_ - 1);
+
+ constexpr size_t kBitsPerBlock = 8 * sizeof(block_t);
+ while ((cnt = Instructions::popcount(~block_)) < skip) {
+ skip -= cnt;
+ position_ += kBitsPerBlock - cnt;
+ outer_ += sizeof(block_t);
+ block_ = folly::loadUnaligned<block_t>(start_ + outer_);
+ }
+
+ // Try to skip half-block.
+ constexpr size_t kBitsPerHalfBlock = 4 * sizeof(block_t);
+ constexpr block_t halfBlockMask = (block_t(1) << kBitsPerHalfBlock) - 1;
+ if ((cnt = Instructions::popcount(~block_ & halfBlockMask)) < skip) {
+ position_ += kBitsPerHalfBlock - cnt;
+ block_ &= ~halfBlockMask;
+ }
+
+ // Just skip until we see expected value.
+ while (next() < v) { }
+ return value_;
+ }
+
+ private:
+ ValueType setValue() {
+ value_ = static_cast<ValueType>(8 * outer_ + inner_ - position_);
+ return value_;
+ }
+
+ void reposition(size_t dest) {
+ outer_ = dest / 8;
+ block_ = folly::loadUnaligned<block_t>(start_ + outer_);
+ block_ &= ~((block_t(1) << (dest % 8)) - 1);
+ }
+
+ typedef unsigned long long block_t;
+ const unsigned char* const forwardPointers_;
+ const unsigned char* const skipPointers_;
+ const unsigned char* const start_;
+ block_t block_;
+ size_t outer_;
+ size_t inner_;
+ size_t position_;
+ ValueType value_;
+};
+
+} // namespace detail
+
+template <class CompressedList,
+ class Instructions = instructions::Default>
+class EliasFanoReader : private boost::noncopyable {
+ public:
+ typedef typename CompressedList::ValueType ValueType;
+
+ explicit EliasFanoReader(const CompressedList& list)
+ : list_(list),
+ lowerMask_((ValueType(1) << list_.numLowerBits) - 1),
+ upper_(list),
+ progress_(0),
+ value_(0) {
+ DCHECK(Instructions::supported());
+ // To avoid extra branching during skipTo() while reading
+ // upper sequence we need to know the last element.
+ if (UNLIKELY(list_.size == 0)) {
+ lastValue_ = 0;
+ return;
+ }
+ ValueType lastUpperValue = 8 * list_.upper.size() - list_.size;
+ auto it = list_.upper.end() - 1;
+ DCHECK_NE(*it, 0);
+ lastUpperValue -= 8 - folly::findLastSet(*it);
+ lastValue_ = readLowerPart(list_.size - 1) |
+ (lastUpperValue << list_.numLowerBits);
+ }
+
+ size_t size() const { return list_.size; }
+
+ size_t position() const { return progress_ - 1; }
+ ValueType value() const { return value_; }
+
+ bool next() {
+ if (UNLIKELY(progress_ == list_.size)) {
+ value_ = std::numeric_limits<ValueType>::max();
+ return false;
+ }
+ value_ = readLowerPart(progress_) |
+ (upper_.next() << list_.numLowerBits);
+ ++progress_;
+ return true;
+ }
+
+ bool skip(size_t n) {
+ CHECK_GT(n, 0);
+
+ progress_ += n - 1;
+ if (LIKELY(progress_ < list_.size)) {
+ value_ = readLowerPart(progress_) |
+ (upper_.skip(n) << list_.numLowerBits);
+ ++progress_;
+ return true;
+ }
+
+ progress_ = list_.size;
+ value_ = std::numeric_limits<ValueType>::max();
+ return false;
+ }
+
+ bool skipTo(ValueType value) {
+ DCHECK_GE(value, value_);
+ if (value <= value_) {
+ return true;
+ }
+ if (value > lastValue_) {
+ progress_ = list_.size;
+ value_ = std::numeric_limits<ValueType>::max();
+ return false;
+ }
+
+ upper_.skipToNext(value >> list_.numLowerBits);
+ progress_ = upper_.position();
+ value_ = readLowerPart(progress_) |
+ (upper_.value() << list_.numLowerBits);
+ ++progress_;
+ while (value_ < value) {
+ value_ = readLowerPart(progress_) |
+ (upper_.next() << list_.numLowerBits);
+ ++progress_;
+ }
+
+ return true;
+ }
+
+ private:
+ ValueType readLowerPart(size_t i) const {
+ const size_t pos = i * list_.numLowerBits;
+ const unsigned char* ptr = list_.lower.data() + (pos / 8);
+ const uint64_t ptrv = folly::loadUnaligned<uint64_t>(ptr);
+ return lowerMask_ & (ptrv >> (pos % 8));
+ }
+
+ const CompressedList list_;
+ const ValueType lowerMask_;
+ detail::UpperBitsReader<CompressedList, Instructions> upper_;
+ size_t progress_;
+ ValueType value_;
+ ValueType lastValue_;
+};
+
+}} // namespaces
+
+#endif // FOLLY_EXPERIMENTAL_ELIAS_FANO_CODING_H
--- /dev/null
+/*
+ * Copyright 2013 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 FOLLY_EXPERIMENTAL_CODING_TEST_UTILS_H
+#define FOLLY_EXPERIMENTAL_CODING_TEST_UTILS_H
+
+#include <algorithm>
+#include <fstream>
+#include <limits>
+#include <random>
+#include <string>
+#include <vector>
+#include <unordered_set>
+#include <glog/logging.h>
+#include <gtest/gtest.h>
+
+namespace folly { namespace compression {
+
+std::vector<uint32_t> generateRandomList(size_t n, uint32_t maxId) {
+ CHECK_LT(n, 2 * maxId);
+ std::mt19937 gen;
+ std::uniform_int_distribution<> uid(1, maxId);
+ std::unordered_set<uint32_t> dataset;
+ while (dataset.size() < n) {
+ uint32_t value = uid(gen);
+ if (dataset.count(value) == 0) {
+ dataset.insert(value);
+ }
+ }
+
+ std::vector<uint32_t> ids(dataset.begin(), dataset.end());
+ std::sort(ids.begin(), ids.end());
+ return ids;
+}
+
+std::vector<uint32_t> generateSeqList(uint32_t minId, uint32_t maxId,
+ uint32_t step = 1) {
+ CHECK_LE(minId, maxId);
+ CHECK_GT(step, 0);
+ std::vector<uint32_t> ids;
+ ids.reserve((maxId - minId) / step + 1);
+ for (uint32_t i = minId; i <= maxId; i += step) {
+ ids.push_back(i);
+ }
+ return ids;
+}
+
+std::vector<uint32_t> loadList(const std::string& filename) {
+ std::ifstream fin(filename);
+ std::vector<uint32_t> result;
+ uint32_t id;
+ while (fin >> id) {
+ result.push_back(id);
+ }
+ return result;
+}
+
+template <class Reader, class List>
+void testEmpty() {
+ List list;
+ const typename List::ValueType* const data = nullptr;
+ List::encode(data, 0, list);
+ {
+ Reader reader(list);
+ EXPECT_FALSE(reader.next());
+ EXPECT_EQ(reader.size(), 0);
+ }
+ {
+ Reader reader(list);
+ EXPECT_FALSE(reader.skip(1));
+ EXPECT_FALSE(reader.skip(10));
+ }
+ {
+ Reader reader(list);
+ EXPECT_FALSE(reader.skipTo(1));
+ }
+}
+
+template <class Reader, class List>
+void testNext(const std::vector<uint32_t>& data, const List& list) {
+ Reader reader(list);
+ EXPECT_EQ(reader.value(), 0);
+ for (size_t i = 0; i < data.size(); ++i) {
+ EXPECT_TRUE(reader.next());
+ EXPECT_EQ(reader.value(), data[i]);
+ }
+ EXPECT_FALSE(reader.next());
+ EXPECT_EQ(reader.value(), std::numeric_limits<uint32_t>::max());
+}
+
+template <class Reader, class List>
+void testSkip(const std::vector<uint32_t>& data, const List& list,
+ size_t skipStep) {
+ CHECK_GT(skipStep, 0);
+ Reader reader(list);
+ EXPECT_EQ(reader.value(), 0);
+ for (size_t i = skipStep - 1; i < data.size(); i += skipStep) {
+ EXPECT_TRUE(reader.skip(skipStep));
+ EXPECT_EQ(reader.value(), data[i]);
+ }
+ EXPECT_FALSE(reader.skip(skipStep));
+ EXPECT_EQ(reader.value(), std::numeric_limits<uint32_t>::max());
+ EXPECT_FALSE(reader.next());
+}
+
+template <class Reader, class List>
+void testSkip(const std::vector<uint32_t>& data, const List& list) {
+ for (size_t skipStep = 1; skipStep < 25; ++skipStep) {
+ testSkip<Reader, List>(data, list, skipStep);
+ }
+ for (size_t skipStep = 25; skipStep <= 500; skipStep += 25) {
+ testSkip<Reader, List>(data, list, skipStep);
+ }
+}
+
+template <class Reader, class List>
+void testSkipTo(const std::vector<uint32_t>& data, const List& list,
+ size_t skipToStep) {
+ CHECK_GT(skipToStep, 0);
+
+ Reader reader(list);
+ EXPECT_EQ(reader.value(), 0);
+
+ const uint32_t delta = std::max<uint32_t>(1, data.back() / skipToStep);
+ uint32_t value = delta;
+ auto it = data.begin();
+ while (true) {
+ it = std::lower_bound(it, data.end(), value);
+ if (it == data.end()) {
+ EXPECT_FALSE(reader.skipTo(value));
+ break;
+ }
+ EXPECT_TRUE(reader.skipTo(value));
+ EXPECT_EQ(reader.value(), *it);
+ value = reader.value() + delta;
+ }
+
+ EXPECT_EQ(reader.value(), std::numeric_limits<uint32_t>::max());
+ EXPECT_FALSE(reader.next());
+}
+
+template <class Reader, class List>
+void testSkipTo(const std::vector<uint32_t>& data, const List& list) {
+ for (size_t steps = 10; steps < 100; steps += 10) {
+ testSkipTo<Reader, List>(data, list, steps);
+ }
+ for (size_t steps = 100; steps <= 1000; steps += 100) {
+ testSkipTo<Reader, List>(data, list, steps);
+ }
+ testSkipTo<Reader, List>(data, list, std::numeric_limits<size_t>::max());
+ {
+ Reader reader(list);
+ EXPECT_FALSE(reader.skipTo(data.back() + 1));
+ EXPECT_EQ(reader.value(), std::numeric_limits<uint32_t>::max());
+ EXPECT_FALSE(reader.next());
+ }
+}
+
+template <class Reader, class List>
+void testAll(const std::vector<uint32_t>& data) {
+ List list;
+ List::encode(data.begin(), data.end(), list);
+ testNext<Reader>(data, list);
+ testSkip<Reader>(data, list);
+ testSkipTo<Reader>(data, list);
+ list.free();
+}
+
+template <class Reader, class List>
+void bmNext(const List& list, const std::vector<uint32_t>& data,
+ size_t iters) {
+ if (data.empty()) {
+ return;
+ }
+ for (size_t i = 0, j; i < iters; ) {
+ Reader reader(list);
+ for (j = 0; reader.next(); ++j, ++i) {
+ const uint32_t value = reader.value();
+ CHECK_EQ(value, data[j]) << j;
+ }
+ }
+}
+
+template <class Reader, class List>
+void bmSkip(const List& list, const std::vector<uint32_t>& data,
+ size_t skip, size_t iters) {
+ if (skip >= data.size()) {
+ return;
+ }
+ for (size_t i = 0, j; i < iters; ) {
+ Reader reader(list);
+ for (j = skip - 1; j < data.size(); j += skip, ++i) {
+ reader.skip(skip);
+ const uint32_t value = reader.value();
+ CHECK_EQ(value, data[j]);
+ }
+ }
+}
+
+template <class Reader, class List>
+void bmSkipTo(const List& list, const std::vector<uint32_t>& data,
+ size_t skip, size_t iters) {
+ if (skip >= data.size()) {
+ return;
+ }
+ for (size_t i = 0, j; i < iters; ) {
+ Reader reader(list);
+ for (j = 0; j < data.size(); j += skip, ++i) {
+ reader.skipTo(data[j]);
+ const uint32_t value = reader.value();
+ CHECK_EQ(value, data[j]);
+ }
+ }
+}
+
+}} // namespaces
+
+#endif // FOLLY_EXPERIMENTAL_CODING_TEST_UTILS_H
--- /dev/null
+/*
+ * Copyright 2013 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+#include "folly/experimental/test/CodingTestUtils.h"
+#include "folly/experimental/EliasFanoCoding.h"
+#include "folly/Benchmark.h"
+
+using namespace folly::compression;
+
+template <class List>
+void testAll() {
+ typedef EliasFanoReader<List> Reader;
+ testAll<Reader, List>(generateRandomList(100 * 1000, 10 * 1000 * 1000));
+ testAll<Reader, List>(generateSeqList(1, 100000, 100));
+}
+
+TEST(EliasFanoCompressedList, Empty) {
+ typedef EliasFanoCompressedList<uint32_t> List;
+ typedef EliasFanoReader<List> Reader;
+ testEmpty<Reader, List>();
+}
+
+TEST(EliasFanoCompressedList, Simple) {
+ testAll<EliasFanoCompressedList<uint32_t> >();
+}
+
+TEST(EliasFanoCompressedList, SkipPointers) {
+ testAll<EliasFanoCompressedList<uint32_t, uint32_t, 128, 0> >();
+}
+
+TEST(EliasFanoCompressedList, ForwardPointers) {
+ testAll<EliasFanoCompressedList<uint32_t, uint32_t, 0, 128> >();
+}
+
+TEST(EliasFanoCompressedList, SkipForwardPointers) {
+ testAll<EliasFanoCompressedList<uint32_t, uint32_t, 128, 128> >();
+}
+
+namespace bm {
+
+constexpr size_t k1M = 1000000;
+typedef EliasFanoCompressedList<uint32_t, uint32_t, 128, 128> List;
+typedef EliasFanoReader<List> Reader;
+
+std::vector<uint32_t> data;
+List list;
+
+void init() {
+ data = generateRandomList(100 * 1000, 10 * 1000 * 1000);
+ //data = loadList("/home/philipp/pl_test_dump.txt");
+ List::encode(data.data(), data.size(), bm::list);
+}
+
+void free() {
+ list.free();
+}
+
+} // namespace bm
+
+BENCHMARK(Next_1M) {
+ bmNext<bm::Reader>(bm::list, bm::data, bm::k1M);
+}
+
+BENCHMARK(Skip1_ForwarQ128_1M) {
+ bmSkip<bm::Reader>(bm::list, bm::data, 1, bm::k1M);
+}
+
+BENCHMARK(Skip10_ForwarQ128_1M) {
+ bmSkip<bm::Reader>(bm::list, bm::data, 10, bm::k1M);
+}
+
+BENCHMARK(Skip100_ForwardQ128_1M) {
+ bmSkip<bm::Reader>(bm::list, bm::data, 100, bm::k1M);
+}
+
+BENCHMARK(Skip1000_ForwardQ128_1M) {
+ bmSkip<bm::Reader>(bm::list, bm::data, 1000, bm::k1M);
+}
+
+BENCHMARK(SkipTo1_SkipQ128_1M) {
+ bmSkipTo<bm::Reader>(bm::list, bm::data, 1, bm::k1M);
+}
+
+BENCHMARK(SkipTo10_SkipQ128_1M) {
+ bmSkipTo<bm::Reader>(bm::list, bm::data, 10, bm::k1M);
+}
+
+BENCHMARK(SkipTo100_SkipQ128_1M) {
+ bmSkipTo<bm::Reader>(bm::list, bm::data, 100, bm::k1M);
+}
+
+BENCHMARK(SkipTo1000_SkipQ128_1M) {
+ bmSkipTo<bm::Reader>(bm::list, bm::data, 1000, bm::k1M);
+}
+
+int main(int argc, char** argv) {
+ testing::InitGoogleTest(&argc, argv);
+ google::ParseCommandLineFlags(&argc, &argv, true);
+
+ auto ret = RUN_ALL_TESTS();
+ if (ret == 0 && FLAGS_benchmark) {
+ bm::init();
+ folly::runBenchmarks();
+ bm::free();
+ }
+
+ return ret;
+}
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