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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2024
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/common.h"
#include "td/utils/misc.h"
#include "td/utils/Slice.h"
#include "td/utils/Status.h"
#include "td/utils/tests.h"
#include "td/utils/utf8.h"
#include <algorithm>
namespace td {
class RangeSet {
template <class T>
static auto find(T &ranges, int64 begin) {
return std::lower_bound(ranges.begin(), ranges.end(), begin,
[](const Range &range, int64 begin) { return range.end < begin; });
}
auto find(int64 begin) const {
return find(ranges_, begin);
}
auto find(int64 begin) {
return find(ranges_, begin);
}
public:
struct Range {
int64 begin;
int64 end;
};
static constexpr int64 BIT_SIZE = 1024;
static RangeSet create_one_range(int64 end, int64 begin = 0) {
RangeSet res;
res.ranges_.push_back({begin, end});
return res;
}
static Result<RangeSet> decode(CSlice data) {
if (!check_utf8(data)) {
return Status::Error("Invalid encoding");
}
uint32 curr = 0;
bool is_empty = false;
RangeSet res;
for (auto begin = data.ubegin(); begin != data.uend();) {
uint32 size;
begin = next_utf8_unsafe(begin, &size);
if (!is_empty && size != 0) {
res.ranges_.push_back({curr * BIT_SIZE, (curr + size) * BIT_SIZE});
}
curr += size;
is_empty = !is_empty;
}
return res;
}
string encode(int64 prefix_size = -1) const {
vector<uint32> sizes;
uint32 all_end = 0;
if (prefix_size != -1) {
prefix_size = (prefix_size + BIT_SIZE - 1) / BIT_SIZE * BIT_SIZE;
}
for (auto it : ranges_) {
if (prefix_size != -1 && it.begin >= prefix_size) {
break;
}
if (prefix_size != -1 && it.end > prefix_size) {
it.end = prefix_size;
}
CHECK(it.begin % BIT_SIZE == 0);
CHECK(it.end % BIT_SIZE == 0);
auto begin = narrow_cast<uint32>(it.begin / BIT_SIZE);
auto end = narrow_cast<uint32>(it.end / BIT_SIZE);
if (sizes.empty()) {
if (begin != 0) {
sizes.push_back(0);
sizes.push_back(begin);
}
} else {
sizes.push_back(begin - all_end);
}
sizes.push_back(end - begin);
all_end = end;
}
string res;
for (auto c : sizes) {
append_utf8_character(res, c);
}
return res;
}
int64 get_ready_prefix_size(int64 offset, int64 file_size = -1) const {
auto it = find(offset);
if (it == ranges_.end()) {
return 0;
}
if (it->begin > offset) {
return 0;
}
CHECK(offset >= it->begin);
CHECK(offset <= it->end);
auto end = it->end;
if (file_size != -1 && end > file_size) {
end = file_size;
}
if (end < offset) {
return 0;
}
return end - offset;
}
int64 get_total_size(int64 file_size) const {
int64 res = 0;
for (auto it : ranges_) {
if (it.begin >= file_size) {
break;
}
if (it.end > file_size) {
it.end = file_size;
}
res += it.end - it.begin;
}
return res;
}
int64 get_ready_parts(int64 offset_part, int32 part_size) const {
auto offset = offset_part * part_size;
auto it = find(offset);
if (it == ranges_.end()) {
return 0;
}
if (it->begin > offset) {
return 0;
}
return (it->end - offset) / part_size;
}
bool is_ready(int64 begin, int64 end) const {
auto it = find(begin);
if (it == ranges_.end()) {
return false;
}
return it->begin <= begin && end <= it->end;
}
void set(int64 begin, int64 end) {
CHECK(begin % BIT_SIZE == 0);
CHECK(end % BIT_SIZE == 0);
// 1. skip all with r.end < begin
auto it_begin = find(begin);
// 2. combine with all r.begin <= end
auto it_end = it_begin;
for (; it_end != ranges_.end() && it_end->begin <= end; ++it_end) {
}
if (it_begin == it_end) {
ranges_.insert(it_begin, Range{begin, end});
} else {
begin = td::min(begin, it_begin->begin);
--it_end;
end = td::max(end, it_end->end);
*it_end = Range{begin, end};
ranges_.erase(it_begin, it_end);
}
}
vector<int32> as_vector(int32 part_size) const {
vector<int32> res;
for (const auto &it : ranges_) {
auto begin = narrow_cast<int32>((it.begin + part_size - 1) / part_size);
auto end = narrow_cast<int32>(it.end / part_size);
while (begin < end) {
res.push_back(begin++);
}
}
return res;
}
private:
vector<Range> ranges_;
};
TEST(Bitmask, simple) {
auto validate_encoding = [](auto &rs) {
auto str = rs.encode();
RangeSet rs2 = RangeSet::decode(str).move_as_ok();
auto str2 = rs2.encode();
rs = std::move(rs2);
CHECK(str2 == str);
};
{
RangeSet rs;
int32 S = 128 * 1024;
int32 O = S * 5000;
for (int i = 1; i < 30; i++) {
if (i % 2 == 0) {
rs.set(O + S * i, O + S * (i + 1));
}
}
validate_encoding(rs);
}
{
RangeSet rs;
int32 S = 1024;
auto get = [&](auto p) {
return rs.get_ready_prefix_size(p * S) / S;
};
auto set = [&](auto l, auto r) {
rs.set(l * S, r * S);
validate_encoding(rs);
ASSERT_TRUE(rs.is_ready(l * S, r * S));
ASSERT_TRUE(get(l) >= (r - l));
};
set(6, 7);
ASSERT_EQ(1, get(6));
ASSERT_EQ(0, get(5));
set(8, 9);
ASSERT_EQ(0, get(7));
set(7, 8);
ASSERT_EQ(2, get(7));
ASSERT_EQ(3, get(6));
set(3, 5);
ASSERT_EQ(1, get(4));
set(4, 6);
ASSERT_EQ(5, get(4));
set(10, 11);
set(9, 10);
ASSERT_EQ(8, get(3));
set(14, 16);
set(12, 13);
ASSERT_EQ(8, get(3));
ASSERT_EQ(10, rs.get_ready_prefix_size(S * 3, S * 3 + 10));
ASSERT_TRUE(!rs.is_ready(S * 11, S * 12));
ASSERT_EQ(3, rs.get_ready_parts(2, S * 2));
ASSERT_EQ(vector<int32>({2, 3, 4, 7}), rs.as_vector(S * 2));
}
}
} // namespace td
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