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[era_debug] Display bitset entries in run-length fashion

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This commit is contained in:
Ming-Hung Tsai 2021-02-18 18:20:01 +08:00
parent afbd913e22
commit c95e31bef6
1 changed files with 126 additions and 2 deletions
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128
era/era_debug.cc
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@ -266,6 +266,131 @@ namespace {
typename ShowTraits::ref_counter rc_;
};
// FIXME: duplication
class show_bitset_block : public dbg::command {
typedef array_block<uint64_traits, block_manager::read_ref> rblock;
public:
explicit show_bitset_block(block_manager::ptr bm)
: bm_(bm),
BITS_PER_ARRAY_ENTRY(64) {
}
virtual void exec(strings const& args, ostream &out) {
if (args.size() != 2)
throw runtime_error("incorrect number of arguments");
block_address block = boost::lexical_cast<block_address>(args[1]);
block_manager::read_ref rr = bm_->read_lock(block);
rblock b(rr, rc_);
show_bitset_entries(b, out);
}
private:
void show_bitset_entries(rblock const& b, ostream &out) {
formatter::ptr f = create_xml_formatter();
uint32_t nr_entries = b.nr_entries();
field(*f, "max_entries", b.max_entries());
field(*f, "nr_entries", nr_entries);
field(*f, "value_size", b.value_size());
uint32_t end_pos = b.nr_entries() * BITS_PER_ARRAY_ENTRY;
std::pair<uint32_t, uint32_t> range = next_set_bits(b, 0);
for (; range.first < end_pos; range = next_set_bits(b, range.second)) {
formatter::ptr f2 = create_xml_formatter();
field(*f2, "begin", range.first);
field(*f2, "end", range.second);
f->child("set_bits", f2);
}
f->output(out, 0);
}
// Returns the range of set bits, starts from the offset.
pair<uint32_t, uint32_t> next_set_bits(rblock const &b, uint32_t offset) {
uint32_t end_pos = b.nr_entries() * BITS_PER_ARRAY_ENTRY;
uint32_t begin = find_first_set(b, offset);
if (begin == end_pos) // not found
return make_pair(end_pos, end_pos);
uint32_t end = find_first_unset(b, begin + 1);
return make_pair(begin, end);
}
// Returns the position (zero-based) of the first bit set
// in the array block, starts from the offset.
// Returns the pass-the-end position if not found.
uint32_t find_first_set(rblock const &b, uint32_t offset) {
uint32_t entry = offset / BITS_PER_ARRAY_ENTRY;
uint32_t nr_entries = b.nr_entries();
if (entry >= nr_entries)
return entry * BITS_PER_ARRAY_ENTRY;
uint32_t idx = offset % BITS_PER_ARRAY_ENTRY;
uint64_t v = b.get(entry++) >> idx;
while (!v && entry < nr_entries) {
v = b.get(entry++);
idx = 0;
}
if (!v) // not found
return entry * BITS_PER_ARRAY_ENTRY;
return (entry - 1) * BITS_PER_ARRAY_ENTRY + idx + ffsll(static_cast<long long>(v)) - 1;
}
// Returns the position (zero-based) of the first zero bit
// in the array block, starts from the offset.
// Returns the pass-the-end position if not found.
// FIXME: improve efficiency
uint32_t find_first_unset(rblock const& b, uint32_t offset) {
uint32_t entry = offset / BITS_PER_ARRAY_ENTRY;
uint32_t nr_entries = b.nr_entries();
if (entry >= nr_entries)
return entry * BITS_PER_ARRAY_ENTRY;
uint32_t idx = offset % BITS_PER_ARRAY_ENTRY;
uint64_t v = b.get(entry++);
while (all_bits_set(v, idx) && entry < nr_entries) {
v = b.get(entry++);
idx = 0;
}
if (all_bits_set(v, idx)) // not found
return entry * BITS_PER_ARRAY_ENTRY;
return (entry - 1) * BITS_PER_ARRAY_ENTRY + idx + count_leading_bits(v, idx);
}
// Returns true if all the bits beyond the position are set.
bool all_bits_set(uint64_t v, uint32_t offset) {
return (v >> offset) == (numeric_limits<uint64_t>::max() >> offset);
}
// Counts the number of leading 1's in the given value, starts from the offset
// FIXME: improve efficiency
uint32_t count_leading_bits(uint64_t v, uint32_t offset) {
uint32_t count = 0;
v >>= offset;
while (v & 0x1) {
v >>= 1;
count++;
}
return count;
}
block_manager::ptr bm_;
uint64_traits::ref_counter rc_;
const uint32_t BITS_PER_ARRAY_ENTRY;
};
//--------------------------------
int debug(string const &path) {
@ -278,8 +403,7 @@ namespace {
interp->register_command("hello", command::ptr(new hello));
interp->register_command("superblock", command::ptr(new show_superblock(bm)));
interp->register_command("block_node", command::ptr(new show_btree_node<uint64_show_traits>(bm)));
interp->register_command("bitset_block", command::ptr(new show_array_block<uint64_show_traits>(bm,
uint64_show_traits::ref_counter())));
interp->register_command("bitset_block", command::ptr(new show_bitset_block(bm)));
interp->register_command("era_block", command::ptr(new show_array_block<uint32_show_traits>(bm,
uint32_show_traits::ref_counter())));
interp->register_command("writeset_node", command::ptr(new show_btree_node<writeset_show_traits>(bm)));