// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "util/coding.h"
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#include <filesystem>
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namespace leveldb {
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void PutFixed32(std::string* dst, uint32_t value) {
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char buf[sizeof(value)];
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EncodeFixed32(buf, value);
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dst->append(buf, sizeof(buf));
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}
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void PutFixed64(std::string* dst, uint64_t value) {
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char buf[sizeof(value)];
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EncodeFixed64(buf, value);
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dst->append(buf, sizeof(buf));
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}
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char* EncodeVarint32(char* dst, uint32_t v) {
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// Operate on characters as unsigneds
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uint8_t* ptr = reinterpret_cast<uint8_t*>(dst);
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static const int B = 128;
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if (v < (1 << 7)) {
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*(ptr++) = v;
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} else if (v < (1 << 14)) {
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*(ptr++) = v | B;
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*(ptr++) = v >> 7;
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} else if (v < (1 << 21)) {
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*(ptr++) = v | B;
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*(ptr++) = (v >> 7) | B;
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*(ptr++) = v >> 14;
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} else if (v < (1 << 28)) {
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*(ptr++) = v | B;
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*(ptr++) = (v >> 7) | B;
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*(ptr++) = (v >> 14) | B;
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*(ptr++) = v >> 21;
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} else {
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*(ptr++) = v | B;
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*(ptr++) = (v >> 7) | B;
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*(ptr++) = (v >> 14) | B;
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*(ptr++) = (v >> 21) | B;
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*(ptr++) = v >> 28;
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}
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return reinterpret_cast<char*>(ptr);
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}
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void PutVarint32(std::string* dst, uint32_t v) {
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char buf[5];
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char* ptr = EncodeVarint32(buf, v);
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dst->append(buf, ptr - buf);
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}
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char* EncodeVarint64(char* dst, uint64_t v) {
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static const int B = 128;
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uint8_t* ptr = reinterpret_cast<uint8_t*>(dst);
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while (v >= B) {
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*(ptr++) = v | B;
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v >>= 7;
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}
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*(ptr++) = static_cast<uint8_t>(v);
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return reinterpret_cast<char*>(ptr);
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}
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void PutVarint64(std::string* dst, uint64_t v) {
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char buf[10];
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char* ptr = EncodeVarint64(buf, v);
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dst->append(buf, ptr - buf);
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}
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void PutLengthPrefixedSlice(std::string* dst, const Slice& value) {
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PutVarint32(dst, value.size());
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dst->append(value.data(), value.size());
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}
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int VarintLength(uint64_t v) {
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int len = 1;
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while (v >= 128) {
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v >>= 7;
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len++;
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}
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return len;
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}
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const char* GetVarint32PtrFallback(const char* p, const char* limit,
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uint32_t* value) {
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uint32_t result = 0;
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for (uint32_t shift = 0; shift <= 28 && p < limit; shift += 7) {
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uint32_t byte = *(reinterpret_cast<const uint8_t*>(p));
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p++;
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if (byte & 128) {
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// More bytes are present
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result |= ((byte & 127) << shift);
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} else {
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result |= (byte << shift);
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*value = result;
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return reinterpret_cast<const char*>(p);
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}
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}
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return nullptr;
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}
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bool GetVarint32(Slice* input, uint32_t* value) {
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const char* p = input->data();
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const char* limit = p + input->size();
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const char* q = GetVarint32Ptr(p, limit, value);
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if (q == nullptr) {
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return false;
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} else {
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*input = Slice(q, limit - q);
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return true;
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}
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}
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const char* GetVarint64Ptr(const char* p, const char* limit, uint64_t* value) {
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uint64_t result = 0;
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for (uint32_t shift = 0; shift <= 63 && p < limit; shift += 7) {
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uint64_t byte = *(reinterpret_cast<const uint8_t*>(p));
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p++;
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if (byte & 128) {
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// More bytes are present
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result |= ((byte & 127) << shift);
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} else {
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result |= (byte << shift);
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*value = result;
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return reinterpret_cast<const char*>(p);
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}
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}
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return nullptr;
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}
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bool GetVarint64(Slice* input, uint64_t* value) {
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const char* p = input->data();
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const char* limit = p + input->size();
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const char* q = GetVarint64Ptr(p, limit, value);
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if (q == nullptr) {
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return false;
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} else {
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*input = Slice(q, limit - q);
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return true;
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}
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}
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bool GetLengthPrefixedSlice(Slice* input, Slice* result) {
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uint32_t len;
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if (GetVarint32(input, &len) && input->size() >= len) {
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*result = Slice(input->data(), len);
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input->remove_prefix(len);
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return true;
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} else {
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return false;
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}
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}
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// 判断文件是否为 valuelog 文件
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bool IsValueLogFile(const std::string& filename) {
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// 检查文件是否以 ".valuelog" 结尾
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const std::string suffix = ".valuelog";
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return filename.size() > suffix.size() &&
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filename.substr(filename.size() - suffix.size()) == suffix;
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}
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// 示例:解析 sstable 中的元信息
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void ParseStoredValue(const std::string& stored_value, uint64_t& valuelog_id,
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uint64_t& offset) {
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// 假设 stored_value 格式为:valuelog_id|offset
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Slice tmp(stored_value.data(), stored_value.size());
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GetVarint64(&tmp, &valuelog_id);
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GetVarint64(&tmp, &offset);
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}
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// 示例:获取 ValueLog 文件 ID
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uint64_t GetValueLogID(const std::string& valuelog_name) {
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// 使用 std::filesystem::path 解析文件名
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std::filesystem::path file_path(valuelog_name);
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std::string filename = file_path.filename().string(); // 获取文件名部分
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// 查找文件名中的 '.' 位置,提取数字部分
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auto pos = filename.find('.');
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if (pos == std::string::npos) {
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assert(0);
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}
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// 提取数字部分
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std::string id_str = filename.substr(0, pos);
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// 检查提取的部分是否为有效数字
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for (char c : id_str) {
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if (!isdigit(c)) {
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assert(0);
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}
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}
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return std::stoull(id_str); // 转换为 uint64_t
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}
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// Helper function to split the set of files into chunks
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void SplitIntoChunks(const std::set<std::string>& files, int num_workers,
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std::vector<std::vector<std::string>>* chunks) {
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chunks->resize(num_workers);
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int index = 0;
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for (const auto& file : files) {
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(*chunks)[index % num_workers].push_back(file);
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++index;
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}
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}
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} // namespace leveldb
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