rocksdb/util/string_util.cc

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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
#include "util/string_util.h"
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
Refactor trimming logic for immutable memtables (#5022) Summary: MyRocks currently sets `max_write_buffer_number_to_maintain` in order to maintain enough history for transaction conflict checking. The effectiveness of this approach depends on the size of memtables. When memtables are small, it may not keep enough history; when memtables are large, this may consume too much memory. We are proposing a new way to configure memtable list history: by limiting the memory usage of immutable memtables. The new option is `max_write_buffer_size_to_maintain` and it will take precedence over the old `max_write_buffer_number_to_maintain` if they are both set to non-zero values. The new option accounts for the total memory usage of flushed immutable memtables and mutable memtable. When the total usage exceeds the limit, RocksDB may start dropping immutable memtables (which is also called trimming history), starting from the oldest one. The semantics of the old option actually works both as an upper bound and lower bound. History trimming will start if number of immutable memtables exceeds the limit, but it will never go below (limit-1) due to history trimming. In order the mimic the behavior with the new option, history trimming will stop if dropping the next immutable memtable causes the total memory usage go below the size limit. For example, assuming the size limit is set to 64MB, and there are 3 immutable memtables with sizes of 20, 30, 30. Although the total memory usage is 80MB > 64MB, dropping the oldest memtable will reduce the memory usage to 60MB < 64MB, so in this case no memtable will be dropped. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5022 Differential Revision: D14394062 Pulled By: miasantreble fbshipit-source-id: 60457a509c6af89d0993f988c9b5c2aa9e45f5c5
2019-08-23 22:54:09 +02:00
#include <cinttypes>
#include <cmath>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
#include "port/port.h"
#include "port/sys_time.h"
#include "rocksdb/slice.h"
namespace ROCKSDB_NAMESPACE {
const std::string kNullptrString = "nullptr";
std::vector<std::string> StringSplit(const std::string& arg, char delim) {
std::vector<std::string> splits;
std::stringstream ss(arg);
std::string item;
while (std::getline(ss, item, delim)) {
splits.push_back(item);
}
return splits;
}
// for micros < 10ms, print "XX us".
// for micros < 10sec, print "XX ms".
// for micros >= 10 sec, print "XX sec".
// for micros <= 1 hour, print Y:X M:S".
// for micros > 1 hour, print Z:Y:X H:M:S".
int AppendHumanMicros(uint64_t micros, char* output, int len,
bool fixed_format) {
if (micros < 10000 && !fixed_format) {
return snprintf(output, len, "%" PRIu64 " us", micros);
} else if (micros < 10000000 && !fixed_format) {
return snprintf(output, len, "%.3lf ms",
static_cast<double>(micros) / 1000);
} else if (micros < 1000000l * 60 && !fixed_format) {
return snprintf(output, len, "%.3lf sec",
static_cast<double>(micros) / 1000000);
} else if (micros < 1000000ll * 60 * 60 && !fixed_format) {
return snprintf(output, len, "%02" PRIu64 ":%05.3f M:S",
micros / 1000000 / 60,
static_cast<double>(micros % 60000000) / 1000000);
} else {
return snprintf(output, len, "%02" PRIu64 ":%02" PRIu64 ":%05.3f H:M:S",
micros / 1000000 / 3600, (micros / 1000000 / 60) % 60,
static_cast<double>(micros % 60000000) / 1000000);
}
}
// for sizes >=10TB, print "XXTB"
// for sizes >=10GB, print "XXGB"
// etc.
// append file size summary to output and return the len
int AppendHumanBytes(uint64_t bytes, char* output, int len) {
const uint64_t ull10 = 10;
if (bytes >= ull10 << 40) {
return snprintf(output, len, "%" PRIu64 "TB", bytes >> 40);
} else if (bytes >= ull10 << 30) {
return snprintf(output, len, "%" PRIu64 "GB", bytes >> 30);
} else if (bytes >= ull10 << 20) {
return snprintf(output, len, "%" PRIu64 "MB", bytes >> 20);
} else if (bytes >= ull10 << 10) {
return snprintf(output, len, "%" PRIu64 "KB", bytes >> 10);
} else {
return snprintf(output, len, "%" PRIu64 "B", bytes);
}
}
void AppendNumberTo(std::string* str, uint64_t num) {
char buf[30];
snprintf(buf, sizeof(buf), "%" PRIu64, num);
str->append(buf);
}
void AppendEscapedStringTo(std::string* str, const Slice& value) {
for (size_t i = 0; i < value.size(); i++) {
char c = value[i];
if (c >= ' ' && c <= '~') {
str->push_back(c);
} else {
char buf[10];
snprintf(buf, sizeof(buf), "\\x%02x",
static_cast<unsigned int>(c) & 0xff);
str->append(buf);
}
}
}
std::string NumberToString(uint64_t num) {
std::string r;
AppendNumberTo(&r, num);
return r;
}
std::string NumberToHumanString(int64_t num) {
char buf[19];
int64_t absnum = num < 0 ? -num : num;
if (absnum < 10000) {
snprintf(buf, sizeof(buf), "%" PRIi64, num);
} else if (absnum < 10000000) {
snprintf(buf, sizeof(buf), "%" PRIi64 "K", num / 1000);
} else if (absnum < 10000000000LL) {
snprintf(buf, sizeof(buf), "%" PRIi64 "M", num / 1000000);
} else {
snprintf(buf, sizeof(buf), "%" PRIi64 "G", num / 1000000000);
}
return std::string(buf);
}
std::string BytesToHumanString(uint64_t bytes) {
const char* size_name[] = {"KB", "MB", "GB", "TB"};
double final_size = static_cast<double>(bytes);
size_t size_idx;
// always start with KB
final_size /= 1024;
size_idx = 0;
while (size_idx < 3 && final_size >= 1024) {
final_size /= 1024;
size_idx++;
}
char buf[20];
snprintf(buf, sizeof(buf), "%.2f %s", final_size, size_name[size_idx]);
return std::string(buf);
}
std::string TimeToHumanString(int unixtime) {
char time_buffer[80];
time_t rawtime = unixtime;
struct tm tInfo;
struct tm* timeinfo = localtime_r(&rawtime, &tInfo);
assert(timeinfo == &tInfo);
strftime(time_buffer, 80, "%c", timeinfo);
return std::string(time_buffer);
}
std::string EscapeString(const Slice& value) {
std::string r;
AppendEscapedStringTo(&r, value);
return r;
}
bool ConsumeDecimalNumber(Slice* in, uint64_t* val) {
uint64_t v = 0;
int digits = 0;
while (!in->empty()) {
char c = (*in)[0];
if (c >= '0' && c <= '9') {
++digits;
const unsigned int delta = (c - '0');
static const uint64_t kMaxUint64 = ~static_cast<uint64_t>(0);
if (v > kMaxUint64 / 10 ||
(v == kMaxUint64 / 10 && delta > kMaxUint64 % 10)) {
// Overflow
return false;
}
v = (v * 10) + delta;
in->remove_prefix(1);
} else {
break;
}
}
*val = v;
return (digits > 0);
}
bool isSpecialChar(const char c) {
if (c == '\\' || c == '#' || c == ':' || c == '\r' || c == '\n') {
return true;
}
return false;
}
namespace {
using CharMap = std::pair<char, char>;
}
char UnescapeChar(const char c) {
static const CharMap convert_map[] = {{'r', '\r'}, {'n', '\n'}};
auto iter = std::find_if(std::begin(convert_map), std::end(convert_map),
[c](const CharMap& p) { return p.first == c; });
if (iter == std::end(convert_map)) {
return c;
}
return iter->second;
}
char EscapeChar(const char c) {
static const CharMap convert_map[] = {{'\n', 'n'}, {'\r', 'r'}};
auto iter = std::find_if(std::begin(convert_map), std::end(convert_map),
[c](const CharMap& p) { return p.first == c; });
if (iter == std::end(convert_map)) {
return c;
}
return iter->second;
}
std::string EscapeOptionString(const std::string& raw_string) {
std::string output;
for (auto c : raw_string) {
if (isSpecialChar(c)) {
output += '\\';
output += EscapeChar(c);
} else {
output += c;
}
}
return output;
}
std::string UnescapeOptionString(const std::string& escaped_string) {
bool escaped = false;
std::string output;
for (auto c : escaped_string) {
if (escaped) {
output += UnescapeChar(c);
escaped = false;
} else {
if (c == '\\') {
escaped = true;
continue;
}
output += c;
}
}
return output;
}
std::string trim(const std::string& str) {
if (str.empty()) return std::string();
size_t start = 0;
size_t end = str.size() - 1;
while (isspace(str[start]) != 0 && start < end) {
++start;
}
while (isspace(str[end]) != 0 && start < end) {
--end;
}
if (start <= end) {
return str.substr(start, end - start + 1);
}
return std::string();
}
#ifndef ROCKSDB_LITE
bool ParseBoolean(const std::string& type, const std::string& value) {
if (value == "true" || value == "1") {
return true;
} else if (value == "false" || value == "0") {
return false;
}
throw std::invalid_argument(type);
}
uint32_t ParseUint32(const std::string& value) {
uint64_t num = ParseUint64(value);
if ((num >> 32LL) == 0) {
return static_cast<uint32_t>(num);
} else {
throw std::out_of_range(value);
}
}
int32_t ParseInt32(const std::string& value) {
int64_t num = ParseInt64(value);
if (num <= port::kMaxInt32 && num >= port::kMinInt32) {
return static_cast<int32_t>(num);
} else {
throw std::out_of_range(value);
}
}
#endif
uint64_t ParseUint64(const std::string& value) {
size_t endchar;
#ifndef CYGWIN
uint64_t num = std::stoull(value.c_str(), &endchar);
#else
char* endptr;
uint64_t num = std::strtoul(value.c_str(), &endptr, 0);
endchar = endptr - value.c_str();
#endif
if (endchar < value.length()) {
char c = value[endchar];
if (c == 'k' || c == 'K')
num <<= 10LL;
else if (c == 'm' || c == 'M')
num <<= 20LL;
else if (c == 'g' || c == 'G')
num <<= 30LL;
else if (c == 't' || c == 'T')
num <<= 40LL;
}
return num;
}
int64_t ParseInt64(const std::string& value) {
size_t endchar;
#ifndef CYGWIN
int64_t num = std::stoll(value.c_str(), &endchar);
#else
char* endptr;
int64_t num = std::strtoll(value.c_str(), &endptr, 0);
endchar = endptr - value.c_str();
#endif
if (endchar < value.length()) {
char c = value[endchar];
if (c == 'k' || c == 'K')
num <<= 10LL;
else if (c == 'm' || c == 'M')
num <<= 20LL;
else if (c == 'g' || c == 'G')
num <<= 30LL;
else if (c == 't' || c == 'T')
num <<= 40LL;
}
return num;
}
int ParseInt(const std::string& value) {
size_t endchar;
#ifndef CYGWIN
int num = std::stoi(value.c_str(), &endchar);
#else
char* endptr;
int num = std::strtoul(value.c_str(), &endptr, 0);
endchar = endptr - value.c_str();
#endif
if (endchar < value.length()) {
char c = value[endchar];
if (c == 'k' || c == 'K')
num <<= 10;
else if (c == 'm' || c == 'M')
num <<= 20;
else if (c == 'g' || c == 'G')
num <<= 30;
}
return num;
}
double ParseDouble(const std::string& value) {
#ifndef CYGWIN
return std::stod(value);
#else
return std::strtod(value.c_str(), 0);
#endif
}
size_t ParseSizeT(const std::string& value) {
return static_cast<size_t>(ParseUint64(value));
}
std::vector<int> ParseVectorInt(const std::string& value) {
std::vector<int> result;
size_t start = 0;
while (start < value.size()) {
size_t end = value.find(':', start);
if (end == std::string::npos) {
result.push_back(ParseInt(value.substr(start)));
break;
} else {
result.push_back(ParseInt(value.substr(start, end - start)));
start = end + 1;
}
}
return result;
}
bool SerializeIntVector(const std::vector<int>& vec, std::string* value) {
*value = "";
for (size_t i = 0; i < vec.size(); ++i) {
if (i > 0) {
*value += ":";
}
*value += ToString(vec[i]);
}
return true;
}
} // namespace ROCKSDB_NAMESPACE