--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 Red Hat <contact@redhat.com>
+ *
+ * LGPL2.1 (see COPYING-LGPL2.1) or later
+ */
+
+#ifndef BIT_VECTOR_HPP
+#define BIT_VECTOR_HPP
+
+#include "common/Formatter.h"
+#include "include/assert.h"
+#include "include/encoding.h"
+#include <utility>
+
+namespace ceph {
+
+template <uint8_t _bit_count>
+class BitVector
+{
+private:
+ static const uint8_t BITS_PER_BYTE = 8;
+ static const uint32_t ELEMENTS_PER_BLOCK = BITS_PER_BYTE / _bit_count;
+ static const uint8_t MASK = static_cast<uint8_t>((1 << _bit_count) - 1);
+
+ // must be power of 2
+ BOOST_STATIC_ASSERT((_bit_count != 0) && !(_bit_count & (_bit_count - 1)));
+ BOOST_STATIC_ASSERT(_bit_count <= BITS_PER_BYTE);
+
+ template <typename DataIterator>
+ class ReferenceImpl {
+ protected:
+ DataIterator m_data_iterator;
+ uint64_t m_shift;
+
+ ReferenceImpl(const DataIterator& data_iterator, uint64_t shift)
+ : m_data_iterator(data_iterator), m_shift(shift) {
+ }
+ ReferenceImpl(DataIterator&& data_iterator, uint64_t shift)
+ : m_data_iterator(std::move(data_iterator)), m_shift(shift) {
+ }
+
+ public:
+ inline operator uint8_t() const {
+ return (*m_data_iterator >> m_shift) & MASK;
+ }
+ };
+
+public:
+
+ class ConstReference : public ReferenceImpl<bufferlist::const_iterator> {
+ private:
+ friend class BitVector;
+
+ ConstReference(const bufferlist::const_iterator& data_iterator,
+ uint64_t shift)
+ : ReferenceImpl<bufferlist::const_iterator>(data_iterator, shift) {
+ }
+ ConstReference(bufferlist::const_iterator&& data_iterator, uint64_t shift)
+ : ReferenceImpl<bufferlist::const_iterator>(std::move(data_iterator),
+ shift) {
+ }
+ };
+
+ class Reference : public ReferenceImpl<bufferlist::iterator> {
+ public:
+ Reference& operator=(uint8_t v);
+
+ private:
+ friend class BitVector;
+
+ Reference(const bufferlist::iterator& data_iterator, uint64_t shift)
+ : ReferenceImpl<bufferlist::iterator>(data_iterator, shift) {
+ }
+ Reference(bufferlist::iterator&& data_iterator, uint64_t shift)
+ : ReferenceImpl<bufferlist::iterator>(std::move(data_iterator), shift) {
+ }
+ };
+
+public:
+ template <typename BitVectorT, typename DataIterator>
+ class IteratorImpl {
+ private:
+ friend class BitVector;
+
+ uint64_t m_offset = 0;
+ BitVectorT *m_bit_vector;
+
+ // cached derived values
+ uint64_t m_index = 0;
+ uint64_t m_shift = 0;
+ DataIterator m_data_iterator;
+
+ IteratorImpl(BitVectorT *bit_vector, uint64_t offset)
+ : m_bit_vector(bit_vector),
+ m_data_iterator(bit_vector->m_data.begin()) {
+ *this += offset;
+ }
+
+ public:
+ inline IteratorImpl& operator++() {
+ ++m_offset;
+
+ uint64_t index;
+ compute_index(m_offset, &index, &m_shift);
+
+ assert(index == m_index || index == m_index + 1);
+ if (index > m_index) {
+ m_index = index;
+ ++m_data_iterator;
+ }
+ return *this;
+ }
+ inline IteratorImpl& operator+=(uint64_t offset) {
+ m_offset += offset;
+ compute_index(m_offset, &m_index, &m_shift);
+ if (m_offset < m_bit_vector->size()) {
+ m_data_iterator.seek(m_index);
+ } else {
+ m_data_iterator = m_bit_vector->m_data.end();
+ }
+ return *this;
+ }
+
+ inline IteratorImpl operator++(int) {
+ IteratorImpl iterator_impl(*this);
+ ++iterator_impl;
+ return iterator_impl;
+ }
+ inline IteratorImpl operator+(uint64_t offset) {
+ IteratorImpl iterator_impl(*this);
+ iterator_impl += offset;
+ return iterator_impl;
+ }
+
+ inline bool operator==(const IteratorImpl& rhs) const {
+ return (m_offset == rhs.m_offset && m_bit_vector == rhs.m_bit_vector);
+ }
+ inline bool operator!=(const IteratorImpl& rhs) const {
+ return (m_offset != rhs.m_offset || m_bit_vector != rhs.m_bit_vector);
+ }
+
+ inline ConstReference operator*() const {
+ return ConstReference(m_data_iterator, m_shift);
+ }
+ inline Reference operator*() {
+ return Reference(m_data_iterator, m_shift);
+ }
+ };
+
+ typedef IteratorImpl<const BitVector,
+ bufferlist::const_iterator> ConstIterator;
+ typedef IteratorImpl<BitVector, bufferlist::iterator> Iterator;
+
+ static const uint32_t BLOCK_SIZE;
+ static const uint8_t BIT_COUNT = _bit_count;
+
+ BitVector();
+
+ inline ConstIterator begin() const {
+ return ConstIterator(this, 0);
+ }
+ inline ConstIterator end() const {
+ return ConstIterator(this, m_size);
+ }
+ inline Iterator begin() {
+ return Iterator(this, 0);
+ }
+ inline Iterator end() {
+ return Iterator(this, m_size);
+ }
+
+ void set_crc_enabled(bool enabled) {
+ m_crc_enabled = enabled;
+ }
+ void clear();
+
+ void resize(uint64_t elements);
+ uint64_t size() const;
+
+ const bufferlist& get_data() const;
+
+ Reference operator[](uint64_t offset);
+ ConstReference operator[](uint64_t offset) const;
+
+ void encode_header(bufferlist& bl) const;
+ void decode_header(bufferlist::iterator& it);
+ uint64_t get_header_length() const;
+
+ void encode_data(bufferlist& bl, uint64_t byte_offset,
+ uint64_t byte_length) const;
+ void decode_data(bufferlist::iterator& it, uint64_t byte_offset);
+ void get_data_extents(uint64_t offset, uint64_t length,
+ uint64_t *byte_offset, uint64_t *byte_length) const;
+
+ void encode_footer(bufferlist& bl) const;
+ void decode_footer(bufferlist::iterator& it);
+ uint64_t get_footer_offset() const;
+
+ void encode(bufferlist& bl) const;
+ void decode(bufferlist::iterator& it);
+ void dump(Formatter *f) const;
+
+ bool operator==(const BitVector &b) const;
+
+ static void generate_test_instances(std::list<BitVector *> &o);
+private:
+
+ bufferlist m_data;
+ uint64_t m_size;
+ bool m_crc_enabled;
+
+ mutable __u32 m_header_crc;
+ mutable std::vector<__u32> m_data_crcs;
+
+ static void compute_index(uint64_t offset, uint64_t *index, uint64_t *shift);
+
+};
+
+template <uint8_t _b>
+const uint32_t BitVector<_b>::BLOCK_SIZE = 4096;
+
+template <uint8_t _b>
+BitVector<_b>::BitVector() : m_size(0), m_crc_enabled(true), m_header_crc(0)
+{
+}
+
+template <uint8_t _b>
+void BitVector<_b>::clear() {
+ m_data.clear();
+ m_data_crcs.clear();
+ m_size = 0;
+ m_header_crc = 0;
+}
+
+template <uint8_t _b>
+void BitVector<_b>::resize(uint64_t size) {
+ uint64_t buffer_size = (size + ELEMENTS_PER_BLOCK - 1) / ELEMENTS_PER_BLOCK;
+ if (buffer_size > m_data.length()) {
+ m_data.append_zero(buffer_size - m_data.length());
+ } else if (buffer_size < m_data.length()) {
+ bufferlist bl;
+ bl.substr_of(m_data, 0, buffer_size);
+ bl.swap(m_data);
+ }
+ m_size = size;
+
+ uint64_t block_count = (buffer_size + BLOCK_SIZE - 1) / BLOCK_SIZE;
+ m_data_crcs.resize(block_count);
+}
+
+template <uint8_t _b>
+uint64_t BitVector<_b>::size() const {
+ return m_size;
+}
+
+template <uint8_t _b>
+const bufferlist& BitVector<_b>::get_data() const {
+ return m_data;
+}
+
+template <uint8_t _b>
+void BitVector<_b>::compute_index(uint64_t offset, uint64_t *index, uint64_t *shift) {
+ *index = offset / ELEMENTS_PER_BLOCK;
+ *shift = ((ELEMENTS_PER_BLOCK - 1) - (offset % ELEMENTS_PER_BLOCK)) * _b;
+}
+
+template <uint8_t _b>
+void BitVector<_b>::encode_header(bufferlist& bl) const {
+ bufferlist header_bl;
+ ENCODE_START(1, 1, header_bl);
+ ::encode(m_size, header_bl);
+ ENCODE_FINISH(header_bl);
+ m_header_crc = header_bl.crc32c(0);
+
+ ::encode(header_bl, bl);
+}
+
+template <uint8_t _b>
+void BitVector<_b>::decode_header(bufferlist::iterator& it) {
+ bufferlist header_bl;
+ ::decode(header_bl, it);
+
+ bufferlist::iterator header_it = header_bl.begin();
+ uint64_t size;
+ DECODE_START(1, header_it);
+ ::decode(size, header_it);
+ DECODE_FINISH(header_it);
+
+ resize(size);
+ m_header_crc = header_bl.crc32c(0);
+}
+
+template <uint8_t _b>
+uint64_t BitVector<_b>::get_header_length() const {
+ // 4 byte bl length, 6 byte encoding header, 8 byte size
+ return 18;
+}
+
+template <uint8_t _b>
+void BitVector<_b>::encode_data(bufferlist& bl, uint64_t byte_offset,
+ uint64_t byte_length) const {
+ assert(byte_offset % BLOCK_SIZE == 0);
+ assert(byte_offset + byte_length == m_data.length() ||
+ byte_length % BLOCK_SIZE == 0);
+
+ uint64_t end_offset = byte_offset + byte_length;
+ while (byte_offset < end_offset) {
+ uint64_t len = MIN(BLOCK_SIZE, end_offset - byte_offset);
+
+ bufferlist bit;
+ bit.substr_of(m_data, byte_offset, len);
+ m_data_crcs[byte_offset / BLOCK_SIZE] = bit.crc32c(0);
+
+ bl.claim_append(bit);
+ byte_offset += BLOCK_SIZE;
+ }
+}
+
+template <uint8_t _b>
+void BitVector<_b>::decode_data(bufferlist::iterator& it, uint64_t byte_offset) {
+ assert(byte_offset % BLOCK_SIZE == 0);
+ if (it.end()) {
+ return;
+ }
+
+ uint64_t end_offset = byte_offset + it.get_remaining();
+ if (end_offset > m_data.length()) {
+ throw buffer::end_of_buffer();
+ }
+
+ bufferlist data;
+ if (byte_offset > 0) {
+ data.substr_of(m_data, 0, byte_offset);
+ }
+
+ while (byte_offset < end_offset) {
+ uint64_t len = MIN(BLOCK_SIZE, end_offset - byte_offset);
+
+ bufferptr ptr;
+ it.copy_deep(len, ptr);
+
+ bufferlist bit;
+ bit.append(ptr);
+ if (m_crc_enabled &&
+ m_data_crcs[byte_offset / BLOCK_SIZE] != bit.crc32c(0)) {
+ throw buffer::malformed_input("invalid data block CRC");
+ }
+ data.append(bit);
+ byte_offset += bit.length();
+ }
+
+ if (m_data.length() > end_offset) {
+ bufferlist tail;
+ tail.substr_of(m_data, end_offset, m_data.length() - end_offset);
+ data.append(tail);
+ }
+ assert(data.length() == m_data.length());
+ data.swap(m_data);
+}
+
+template <uint8_t _b>
+void BitVector<_b>::get_data_extents(uint64_t offset, uint64_t length,
+ uint64_t *byte_offset,
+ uint64_t *byte_length) const {
+ // read BLOCK_SIZE-aligned chunks
+ assert(length > 0 && offset + length <= m_size);
+ uint64_t shift;
+ compute_index(offset, byte_offset, &shift);
+ *byte_offset -= (*byte_offset % BLOCK_SIZE);
+
+ uint64_t end_offset;
+ compute_index(offset + length - 1, &end_offset, &shift);
+ end_offset += (BLOCK_SIZE - (end_offset % BLOCK_SIZE));
+ assert(*byte_offset <= end_offset);
+
+ *byte_length = end_offset - *byte_offset;
+ if (*byte_offset + *byte_length > m_data.length()) {
+ *byte_length = m_data.length() - *byte_offset;
+ }
+}
+
+template <uint8_t _b>
+void BitVector<_b>::encode_footer(bufferlist& bl) const {
+ bufferlist footer_bl;
+ if (m_crc_enabled) {
+ ::encode(m_header_crc, footer_bl);
+ ::encode(m_data_crcs, footer_bl);
+ }
+ ::encode(footer_bl, bl);
+}
+
+template <uint8_t _b>
+void BitVector<_b>::decode_footer(bufferlist::iterator& it) {
+ bufferlist footer_bl;
+ ::decode(footer_bl, it);
+
+ m_crc_enabled = (footer_bl.length() > 0);
+ if (m_crc_enabled) {
+ bufferlist::iterator footer_it = footer_bl.begin();
+
+ __u32 header_crc;
+ ::decode(header_crc, footer_it);
+ if (m_header_crc != header_crc) {
+ throw buffer::malformed_input("incorrect header CRC");
+ }
+
+ uint64_t block_count = (m_data.length() + BLOCK_SIZE - 1) / BLOCK_SIZE;
+ ::decode(m_data_crcs, footer_it);
+ if (m_data_crcs.size() != block_count) {
+ throw buffer::malformed_input("invalid data block CRCs");
+ }
+ }
+}
+
+template <uint8_t _b>
+uint64_t BitVector<_b>::get_footer_offset() const {
+ return get_header_length() + m_data.length();
+}
+
+template <uint8_t _b>
+void BitVector<_b>::encode(bufferlist& bl) const {
+ encode_header(bl);
+ encode_data(bl, 0, m_data.length());
+ encode_footer(bl);
+}
+
+template <uint8_t _b>
+void BitVector<_b>::decode(bufferlist::iterator& it) {
+ decode_header(it);
+
+ bufferlist data_bl;
+ if (m_data.length() > 0) {
+ it.copy(m_data.length(), data_bl);
+ }
+
+ decode_footer(it);
+
+ bufferlist::iterator data_it = data_bl.begin();
+ decode_data(data_it, 0);
+}
+
+template <uint8_t _b>
+void BitVector<_b>::dump(Formatter *f) const {
+ f->dump_unsigned("size", m_size);
+ f->open_array_section("bit_table");
+ for (unsigned i = 0; i < m_data.length(); ++i) {
+ f->dump_format("byte", "0x%02hhX", m_data[i]);
+ }
+ f->close_section();
+}
+
+template <uint8_t _b>
+bool BitVector<_b>::operator==(const BitVector &b) const {
+ return (this->m_size == b.m_size && this->m_data == b.m_data);
+}
+
+template <uint8_t _b>
+typename BitVector<_b>::Reference BitVector<_b>::operator[](uint64_t offset) {
+ uint64_t index;
+ uint64_t shift;
+ compute_index(offset, &index, &shift);
+
+ bufferlist::iterator data_iterator(m_data.begin());
+ data_iterator.seek(index);
+ return Reference(std::move(data_iterator), shift);
+}
+
+template <uint8_t _b>
+typename BitVector<_b>::ConstReference BitVector<_b>::operator[](uint64_t offset) const {
+ uint64_t index;
+ uint64_t shift;
+ compute_index(offset, &index, &shift);
+
+ bufferlist::const_iterator data_iterator(m_data.begin());
+ data_iterator.seek(index);
+ return ConstReference(std::move(data_iterator), shift);
+}
+
+template <uint8_t _b>
+typename BitVector<_b>::Reference& BitVector<_b>::Reference::operator=(uint8_t v) {
+ uint8_t mask = MASK << this->m_shift;
+ char packed_value = (*this->m_data_iterator & ~mask) |
+ ((v << this->m_shift) & mask);
+ bufferlist::iterator it(this->m_data_iterator);
+ it.copy_in(1, &packed_value, true);
+ return *this;
+}
+
+template <uint8_t _b>
+void BitVector<_b>::generate_test_instances(std::list<BitVector *> &o) {
+ o.push_back(new BitVector());
+
+ BitVector *b = new BitVector();
+ const uint64_t radix = 1 << b->BIT_COUNT;
+ const uint64_t size = 1024;
+
+ b->resize(size);
+ for (uint64_t i = 0; i < size; ++i) {
+ (*b)[i] = rand() % radix;
+ }
+ o.push_back(b);
+}
+
+}
+
+WRITE_CLASS_ENCODER(ceph::BitVector<2>)
+
+template <uint8_t _b>
+inline std::ostream& operator<<(std::ostream& out, const ceph::BitVector<_b> &b)
+{
+ out << "ceph::BitVector<" << _b << ">(size=" << b.size() << ", data="
+ << b.get_data() << ")";
+ return out;
+}
+
+#endif // BIT_VECTOR_HPP
Code Review / stor4nfv.git / blobdiff