52 lines
1.7 KiB
C++
52 lines
1.7 KiB
C++
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#include <fstream>
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#include <iostream>
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#include <vector>
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#include <cstdint>
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#include <algorithm>
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#include <cstring>
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static constexpr uint32_t BLOCK_SIZE = 96 * 1024;
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static constexpr uint32_t NUM_BLOCKS = 4608;
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int main(int argc, char* argv[]) {
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if (argc != 4) {
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std::cerr << "Usage: " << argv[0] << " <cache_file> <output> <num_blocks>\n";
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return 1;
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}
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std::ifstream cache(argv[1], std::ios::binary);
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std::ofstream out(argv[2], std::ios::binary);
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int want_blocks = std::stoi(argv[3]);
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// Read all slots to find the last written block
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std::vector<std::pair<int, std::vector<uint8_t>>> slots;
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std::vector<uint8_t> slot(BLOCK_SIZE);
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for (int i = 0; i < NUM_BLOCKS; ++i) {
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cache.read(reinterpret_cast<char*>(slot.data()), BLOCK_SIZE);
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uint32_t size = *reinterpret_cast<uint32_t*>(slot.data());
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if (size > 0 && size < BLOCK_SIZE - 4) {
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std::vector<uint8_t> data(size);
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memcpy(data.data(), slot.data() + 4, size);
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slots.push_back({i, std::move(data)});
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}
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}
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std::cout << "Found " << slots.size() << " valid blocks in cache\n";
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// Take the last N blocks (most recent)
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int start = std::max(0, (int)slots.size() - want_blocks);
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int written = 0;
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for (int i = start; i < slots.size(); ++i) {
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uint32_t size = slots[i].second.size();
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out.write(reinterpret_cast<char*>(&size), 4);
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out.write(reinterpret_cast<char*>(slots[i].second.data()), size);
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written++;
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}
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std::cout << "Extracted " << written << " consecutive blocks (slots " << slots[start].first << " to " << slots.back().first << ")\n";
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return 0;
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}
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