gStore/Util/Util.cpp

1271 lines
27 KiB
C++

/*=============================================================================
# Filename: Util.cpp
# Author: Bookug Lobert
# Mail: 1181955272@qq.com
# Last Modified: 2015-10-16 10:43
# Description:
1. firstly written by liyouhuan, modified by zengli
2. achieve functions in Util.h
=============================================================================*/
#include "Util.h"
using namespace std;
//NOTICE:used in Database, Join and Strategy
int Util::triple_num = 0;
int Util::pre_num = 0;
int Util::entity_num = 0;
int Util::literal_num = 0;
//database home directory, which is an absolute path by config
//TODO:everywhere using database, the prefix should be it
string Util::db_home = ".";
//false:single true:distribute
bool Util::gStore_mode = false;
//string Util::tmp_path = "../.tmp/";
//string Util::debug_path = "../.debug/";
string Util::tmp_path = ".tmp/";
string Util::debug_path = ".debug/";
//string Util::profile = "../init.conf";
string Util::profile = "init.conf";
//QUERY: assign all in Util()?
//BETTER:assigned in KVstore, not one tree?
FILE* Util::debug_kvstore = NULL; //used by KVstore
FILE* Util::debug_database = NULL; //used by Database
FILE* Util::debug_vstree = NULL; //used by VSTree
//set hash table
HashFunction Util::hash[] = { Util::simpleHash, Util::APHash, Util::BKDRHash, Util::DJBHash, Util::ELFHash, \
Util::DEKHash, Util::BPHash, Util::FNVHash, Util::HFLPHash, Util::HFHash, Util::JSHash, \
Util::PJWHash, Util::RSHash, Util::SDBMHash, Util::StrHash, Util::TianlHash, NULL};
//hash[0] = Util::simpleHash;
//hash[1] = Util::APHash;
//hash[2] = Util::BKDRHash;
//hash[3] = Util::DJBHash;
//hash[4] = Util::ELFHash;
//hash[5] = Util::DEKHash;
//hash[6] = Util::BPHash;
//hash[7] = Util::FNVHash;
//hash[8] = Util::HFLPHash;
//hash[9] = Util::HFHash;
//hash[10] = Util::JSHash;
//hash[11] = Util::PJWHash;
//hash[12] = Util::RSHash;
//hash[13] = Util::SDBMHash;
//hash[14] = Util::StrHash;
//hash[15] = Util::TianlHash;
//remove spaces in the left
char*
Util::l_trim(char* szOutput, const char* szInput)
{
assert(szInput != NULL);
assert(szOutput != NULL);
assert(szOutput != szInput);
for (; *szInput != '\0' && isspace(*szInput); ++szInput);
return strcpy(szOutput, szInput);
}
//remove spaces in the right
char*
Util::r_trim(char *szOutput, const char* szInput)
{
char *p = NULL;
assert(szInput != NULL);
assert(szOutput != NULL);
assert(szOutput != szInput);
strcpy(szOutput, szInput);
for(p = szOutput + strlen(szOutput) - 1; p >= szOutput && isspace(*p); --p);
*(++p) = '\0';
return szOutput;
}
//remove spaces in the two sides
char*
Util::a_trim(char * szOutput, const char * szInput)
{
char *p = NULL;
assert(szInput != NULL);
assert(szOutput != NULL);
l_trim(szOutput, szInput);
for (p = szOutput + strlen(szOutput) - 1; p >= szOutput && isspace(*p); --p);
*(++p) = '\0';
return szOutput;
}
bool
Util::configure()
{
return Util::config_setting() && Util::config_debug() && Util::config_advanced();
}
bool
Util::config_debug()
{
const unsigned len1 = 100;
const unsigned len2 = 505;
char AppName[] = "setting";
char KeyName[] = "mode";
char appname[len1], keyname[len1];
char KeyVal[len1];
char *buf, *c;
char buf_i[len1], buf_o[len1];
FILE *fp = NULL;
int status = 0; // 1 AppName 2 KeyName
return true;
}
bool
Util::config_advanced()
{
const unsigned len1 = 100;
const unsigned len2 = 505;
char AppName[] = "setting";
char KeyName[] = "mode";
char appname[len1], keyname[len1];
char KeyVal[len1];
char *buf, *c;
char buf_i[len1], buf_o[len1];
FILE *fp = NULL;
int status = 0; // 1 AppName 2 KeyName
return true;
}
bool
Util::config_setting()
{
//TODO:deal with more cases, need to be classified
//
//BETTER:different functions and function pointer array
//
//WARN:currently, we can call this function with different parameters
//to acquire different config module
const unsigned len1 = 100;
const unsigned len2 = 505;
char AppName[] = "setting";
char KeyName[] = "mode";
char appname[len1], keyname[len1];
char KeyVal[len1];
char *buf, *c;
char buf_i[len2], buf_o[len2];
FILE *fp = NULL;
int status = 0; // 1 AppName 2 KeyName
#ifdef DEBUG
fprintf(stderr, "profile: %s\n", profile.c_str());
#endif
if((fp = fopen(profile.c_str(), "r")) == NULL) //NOTICE: this is not a binary file
{
#ifdef DEBUG
fprintf(stderr, "openfile [%s] error [%s]\n", profile.c_str(), strerror(errno));
#endif
return false;
}
fseek(fp, 0, SEEK_SET);
memset(appname, 0, sizeof(appname));
sprintf(appname,"[%s]", AppName);
#ifdef DEBUG
fprintf(stderr, "appname: %s\n", appname);
#endif
while(!feof(fp) && fgets(buf_i, len2, fp) != NULL)
{
//fprintf(stderr, "buffer: %s\n", buf_i);
Util::l_trim(buf_o, buf_i);
if(strlen(buf_o) <= 0)
continue;
buf = NULL;
buf = buf_o;
if(buf[0] == '#')
{
continue;
}
if(status == 0)
{
if(strncmp(buf, appname, strlen(appname)) == 0)
{
#ifdef DEBUG
fprintf(stderr, "app found!\n");
#endif
status = 1;
continue;
}
}
else if(status == 1)
{
if(buf[0] == '[')
{
//NOTICE: nested module is not allowed
break;
}
else
{
if((c = (char*)strchr(buf, '=')) == NULL)
continue;
memset(keyname, 0, sizeof(keyname));
sscanf(buf, "%[^=|^ |^\t]", keyname);
#ifdef DEBUG
fprintf(stderr, "keyname: %s\n", keyname);
#endif
if(strcmp(keyname, KeyName) == 0)
{
#ifdef DEBUG
fprintf(stderr, "key found!\n");
#endif
sscanf(++c, "%[^\n]", KeyVal);
char *KeyVal_o = (char *)calloc(strlen(KeyVal) + 1, sizeof(char));
if(KeyVal_o != NULL)
{
Util::a_trim(KeyVal_o, KeyVal);
#ifdef DEBUG
fprintf(stderr, "KeyVal: %s\n", KeyVal_o);
#endif
if(KeyVal_o && strlen(KeyVal_o) > 0)
strcpy(KeyVal, KeyVal_o);
xfree(KeyVal_o);
}
status = 2;
break;
}
}
}
}
fclose(fp);
//if(found == 2)
//return(0);
//else
//return(-1);
//fprintf(stderr, "%s\n", KeyVal);
if(strcmp(KeyVal, "distribute") == 0)
{
#ifdef DEBUG
fprintf(stderr, "the gStore will run in distributed mode!\n");
#endif
Util::gStore_mode = true;
}
return true; //config success
}
Util::Util()
{
Util::configure();
#ifdef DEBUG_KVSTORE
if(this->debug_kvstore == NULL)
{
string s = this->debug_path + "kv.log";
this->debug_kvstore = fopen(s.c_str(), "w+");
if(this->debug_kvstore == NULL)
{
printf("open error: kv.log\n");
this->debug_kvstore = stderr;
}
}
#endif
#ifdef DEBUG_DATABASE
if(this->debug_database == NULL)
{
string s = this->debug_path + "db.log";
this->debug_database = fopen(s.c_str(), "w+");
if(this->debug_database == NULL)
{
printf("open error: db.log\n");
this->debug_database = stderr;
}
}
#endif
#ifdef DEBUG_VSTREE
if(this->debug_vstree == NULL)
{
string s = this->debug_path + "vs.log";
this->debug_vstree = fopen(s.c_str(), "w+");
if(this->debug_vstree == NULL)
{
printf("open error: vs.log\n");
this->debug_vstree = stderr;
}
}
#endif
}
Util::~Util()
{
#ifdef DEBUG_KVSTORE
fclose(this->debug_kvstore); //NULL is ok, just like free(NULL)
this->debug_kvstore = NULL;
#endif
#ifdef DEBUG_DATABASE
fclose(this->debug_database); //NULL is ok, just like free(NULL)
this->debug_database = NULL;
#endif
}
int
Util::memUsedPercentage()
{
FILE* fp = fopen("/proc/meminfo", "r");
if(fp == NULL)
return -1;
char str[20], tail[3];
unsigned t, sum, used = 0; //WARN:unsigned,memory cant be too large!
fscanf(fp, "%s%u%s", str, &sum, tail); //MemTotal, KB
fscanf(fp, "%s%u%s", str, &used, tail); //MemFree
fscanf(fp, "%s%u%s", str, &t, tail);
if(strcmp(str, "MemAvailable") == 0)
{
//QUERY:what is the relation between MemFree and MemAvailable?
used = t;
//scanf("%s%u%s", str, &t, tail); //Buffers
//used += t;
//scanf("%s%u%s", str, &t, tail); //Cached
//used += t;
}
//else //Buffers
//{
// scanf("%s%u%s", str, &t, tail); //Cached
// used += t;
//}
used = sum - used;
fclose(fp);
return (int)(used * 100.0 / sum);
}
int
Util::memoryLeft()
{
FILE* fp = fopen("/proc/meminfo", "r");
if(fp == NULL)
return -1;
char str[20], tail[3];
unsigned t, sum, unuse = 0; //WARN:unsigned,memory cant be too large!
fscanf(fp, "%s%u%s", str, &sum, tail); //MemTotal, KB
fscanf(fp, "%s%u%s", str, &unuse, tail); //MemFree
fscanf(fp, "%s%u%s", str, &t, tail);
if(strcmp(str, "MemAvailable") == 0)
{
unuse = t;
}
fclose(fp);
return unuse / Util::MB;
}
bool
Util::is_literal_ele(int _id)
{
return _id >= Util::LITERAL_FIRST_ID;
}
//NOTICE: require that the list is ordered
int
Util::removeDuplicate(int* _list, int _len)
{
int valid = 0, limit = _len - 1;
for(int i = 0; i < limit; ++i)
{
if(_list[i] != _list[i+1])
{
_list[valid++] = _list[i];
}
}
_list[valid++] = _list[limit];
return valid;
}
int
Util::cmp_int(const void* _i1, const void* _i2)
{
return *(int*)_i1 - *(int*)_i2;
}
void
Util::sort(int*& _id_list, int _list_len)
{
qsort(_id_list, _list_len, sizeof(int), Util::cmp_int);
}
int
Util::bsearch_int_uporder(int _key, const int* _array,int _array_num)
{
if (_array_num == 0)
{
return -1;
}
if (_array == NULL)
{
return -1;
}
int _first = _array[0];
int _last = _array[_array_num - 1];
if (_last == _key)
{
return _array_num - 1;
}
if (_last < _key || _first > _key)
{
return -1;
}
int low = 0;
int high = _array_num - 1;
int mid;
while (low <= high)
{
mid = (high - low) / 2 + low;
if (_array[mid] == _key)
{
return mid;
}
if (_array[mid] > _key)
{
high = mid - 1;
}
else
{
low = mid + 1;
}
}
return -1;
}
bool
Util::bsearch_preid_uporder(int _preid, int* _pair_idlist, int _list_len)
{
if(_list_len == 0)
{
return false;
}
int pair_num = _list_len / 2;
int _first = _pair_idlist[2*0 + 0];
int _last = _pair_idlist[2*(pair_num-1) + 0];
if(_preid == _last)
{
return true;
}
bool not_find = (_last < _preid || _first > _preid);
if(not_find)
{
return false;
}
int low = 0;
int high = pair_num - 1;
int mid;
while(low <= high)
{
mid = (high - low) / 2 + low;
if(_pair_idlist[2*mid + 0] == _preid)
{
return true;
}
if(_pair_idlist[2*mid + 0] > _preid)
{
high = mid - 1;
}
else
{
low = mid + 1;
}
}
return false;
}
int
Util::bsearch_vec_uporder(int _key, const vector<int>* _vec)
{
int tmp_size = _vec->size();
if (tmp_size == 0)
{
return -1;
}
int _first = (*_vec)[0];
int _last = (*_vec)[tmp_size - 1];
if (_key == _last)
{
return tmp_size - 1;
}
bool not_find = (_last < _key || _first > _key);
if (not_find)
{
return -1;
}
int low = 0;
int high = tmp_size - 1;
int mid;
while (low <= high)
{
mid = (high - low) / 2 + low;
if ((*_vec)[mid] == _key)
{
return mid;
}
if ((*_vec)[mid] > _key)
{
high = mid - 1;
}
else
{
low = mid + 1;
}
}
return -1;
}
string
Util::result_id_str(vector<int*>& _v, int _var_num)
{
stringstream _ss;
for(unsigned i = 0; i < _v.size(); i ++)
{
int* _p_int = _v[i];
_ss << "[";
for(int j = 0; j < _var_num-1; j ++)
{
_ss << _p_int[j] << ",";
}
_ss << _p_int[_var_num-1] << "]\t";
}
return _ss.str();
}
bool
Util::dir_exist(const string _dir)
{
return (opendir(_dir.c_str()) != NULL);
}
bool
Util::create_dir(const string _dir)
{
if(! Util::dir_exist(_dir))
{
mkdir(_dir.c_str(), 0755);
return true;
}
return false;
}
long
Util::get_cur_time()
{
timeval tv;
gettimeofday(&tv, NULL);
return (tv.tv_sec*1000 + tv.tv_usec/1000);
}
bool
Util::save_to_file(const char* _dir, const string _content)
{
ofstream fout(_dir);
if (fout.is_open())
{
fout << _content;
fout.close();
}
return false;
}
int
Util::compare(const char* _str1, unsigned _len1, const char* _str2, unsigned _len2)
{
int ifswap = 1; //1 indicate: not swapped
if(_len1 > _len2)
{
const char* str = _str1;
_str1 = _str2;
_str2 = str;
unsigned len = _len1;
_len1 = _len2;
_len2 = len;
ifswap = -1;
}
unsigned i;
//DEBUG: if char can be negative, which cause problem when comparing(128+)
//
//NOTICE:little-endian-storage, when string buffer poniter is changed to
//unsigned long long*, the first char is the lowest byte!
/*
unsigned long long *p1 = (unsigned long long*)_str1, *p2 = (unsigned long long*)_str2;
unsigned limit = _len1/8;
for(i = 0; i < limit; ++i, ++p1, ++p2)
{
if((*p1 ^ *p2) == 0) continue;
else
{
if(*p1 < *p2) return -1 * ifswap;
else return 1 * ifswap;
}
}
for(i = 8 * limit; i < _len1; ++i)
{
if(_str1[i] < _str2[i]) return -1 * ifswap;
else if(_str1[i] > _str2[i]) return 1 * ifswap;
else continue;
}
if(i == _len2) return 0;
else return -1 * ifswap;
*/
for(i = 0; i < _len1; ++i)
{ //ASCII: 0~127 but c: 0~255(-1) all transfered to unsigned char when comparing
if((unsigned char)_str1[i] < (unsigned char)_str2[i])
return -1 * ifswap;
else if((unsigned char)_str1[i] > (unsigned char)_str2[i])
return 1 * ifswap;
else;
}
if(i == _len2)
return 0;
else
return -1 * ifswap;
}
int
Util::string2int(string s)
{
return atoi(s.c_str());
}
string
Util::int2string(long n)
{
string s;
stringstream ss;
ss<<n;
ss>>s;
return s;
}
string
Util::showtime()
{
// fputs("\n\n", logsfp);
time_t now;
time(&now);
// fputs(ctime(&now), logsfp);
return string("\n\n") + ctime(&now);
}
string
Util::getQueryFromFile(const char* _file_path)
{
#ifdef DEBUG_PRECISE
printf("file to open: %s\n", _file_path);
#endif
char buf[10000];
std::string query_file;
ifstream fin(_file_path);
if(!fin)
{
printf("can not open: %s\n", _file_path);
return "";
}
memset(buf, 0, sizeof(buf));
stringstream _ss;
while(!fin.eof())
{
fin.getline(buf, 9999);
_ss << buf << "\n";
}
fin.close();
return _ss.str();
}
string
Util::getItemsFromDir(string _path)
{
DIR* dp = NULL;
struct dirent* entry;
string ret = "";
if((dp = opendir(_path.c_str())) == NULL)
{
fprintf(stderr, "error opening directory!\n");
}
else
{
while((entry = readdir(dp)) != NULL)
{
#ifdef DEBUG_PRECISE
fprintf(stderr, "%s\n", entry->d_name);
#endif
string name= string(entry->d_name);
int len = name.length();
if(len <= 3)
{
continue;
}
if(name.substr(len-3, 3) == ".db")
{
if(ret == "")
ret = name;
else
ret = ret + " " + name;
}
}
closedir(dp);
}
#ifdef DEBUG_PRECISE
fprintf(stderr, "OUT getItemsFromDir\n");
#endif
return ret;
}
string
Util::getSystemOutput(string cmd)
{
string ans = "";
string file = Util::tmp_path;
file += "ans.txt";
cmd += " > ";
cmd += file;
cerr << cmd << endl;
int ret = system(cmd.c_str());
cmd = "rm -rf " + file;
if(ret < 0)
{
fprintf(stderr, "system call failed!\n");
system(cmd.c_str());
return NULL;
}
ifstream fin(file.c_str());
if(!fin)
{
cerr << "getSystemOutput: Fail to open : " << file << endl;
return NULL;
}
string temp;
getline(fin, temp);
while(!fin.eof())
{
//cout<<"system line"<<endl;
if(ans == "")
ans = temp;
else
ans = ans + "\n" + temp;
getline(fin, temp);
}
fin.close();
//FILE *fp = NULL;
//if((fp = fopen(file.c_str(), "r")) == NULL)
//{
//fprintf(stderr, "unbale to open file: %s\n", file.c_str());
//}
//else
//{
//char *ans = (char *)malloc(100);
//fgets(path, 100, fp);
//char *find = strchr(path, '\n');
//if(find != NULL)
//*find = '\0';
//fclose(fp);
//}
system(cmd.c_str());
cout<<"ans: "<<ans<<endl;
return ans;
}
// Get the exact file path from given string: ~, ., symbol links
string
Util::getExactPath(const char *str)
{
string cmd = "realpath ";
cmd += string(str);
return getSystemOutput(cmd);
}
void
Util::logging(string _str)
{
_str += "\n";
#ifdef DEBUG_DATABASE
fputs(_str.c_str(), Util::debug_database);
fflush(Util::debug_database);
#endif
#ifdef DEBUG_VSTREE
fputs(_str.c_str(), Util::debug_vstree);
fflush(Util::debug_vstree);
#endif
}
unsigned
Util::BKDRHash(const char *_str)
{
unsigned int seed = 131; // 31 131 1313 13131 131313 etc..
unsigned int key = 0;
//for(unsigned i = 0; i < _len; ++i)
while(*_str)
{
//key = key * seed + _str[i];
key = key * seed + *(_str++);
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::simpleHash(const char *_str)
{
unsigned int key;
unsigned char *p;
for(key = 0, p = (unsigned char *)_str; *p; p++)
key = 31 * key + *p;
return (key & 0x7FFFFFFF);
}
unsigned
Util::RSHash(const char *_str)
{
unsigned int b = 378551;
unsigned int a = 63689;
unsigned int key = 0;
while (*_str)
{
key = key * a + (*_str++);
a *= b;
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::JSHash(const char *_str)
{
unsigned int key = 1315423911;
while (*_str)
{
key ^= ((key << 5) + (*_str++) + (key >> 2));
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::PJWHash(const char *_str)
{
unsigned int bits_in_unsigned_int = (unsigned int)(sizeof(unsigned int) * 8);
unsigned int three_quarters = (unsigned int)((bits_in_unsigned_int * 3) / 4);
unsigned int one_eighth = (unsigned int)(bits_in_unsigned_int / 8);
unsigned int high_bits = (unsigned int)(0xFFFFFFFF) << (bits_in_unsigned_int - one_eighth);
unsigned int key = 0;
unsigned int test = 0;
while (*_str)
{
key = (key << one_eighth) + (*_str++);
if ((test = key & high_bits) != 0)
{
key = ((key ^ (test >> three_quarters)) & (~high_bits));
}
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::ELFHash(const char *_str)
{
unsigned int key = 0;
unsigned int x = 0;
while (*_str)
{
key = (key << 4) + (*_str++);
if ((x = key & 0xF0000000L) != 0)
{
key ^= (x >> 24);
key &= ~x;
}
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::SDBMHash(const char *_str)
{
unsigned int key = 0;
while (*_str)
{
key = (*_str++) + (key << 6) + (key << 16) - key;
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::DJBHash(const char *_str)
{
unsigned int key = 5381;
while (*_str) {
key += (key << 5) + (*_str++);
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::APHash(const char *_str)
{
unsigned int key = 0;
int i;
for (i=0; *_str; i++)
{
if ((i & 1) == 0)
{
key ^= ((key << 7) ^ (*_str++) ^ (key >> 3));
}
else
{
key ^= (~((key << 11) ^ (*_str++) ^ (key >> 5)));
}
}
return (key & 0x7FFFFFFF);
}
unsigned
Util::DEKHash(const char* _str)
{
unsigned int hash = strlen(_str);
for(; *_str; _str++)
{
hash = ((hash << 5) ^ (hash >> 27)) ^ (*_str);
}
return hash;
}
unsigned
Util::BPHash(const char* _str)
{
unsigned int hash = 0;
for(; *_str; _str++)
{
hash = hash << 7 ^ (*_str);
}
return hash;
}
unsigned
Util::FNVHash(const char* _str)
{
const unsigned int fnv_prime = 0x811C9DC5;
unsigned int hash = 0;
for(; *_str; _str++)
{
hash *= fnv_prime;
hash ^= (*_str);
}
return hash;
}
unsigned
Util::HFLPHash(const char* _str)
{
unsigned int n = 0;
char* b = (char*)&n;
unsigned int len = strlen(_str);
for(unsigned i = 0; i < len; ++i)
{
b[i%4] ^= _str[i];
}
return n%len;
}
unsigned
Util::HFHash(const char* _str)
{
int result=0;
const char* ptr = _str;
int c;
unsigned int len = strlen(_str);
for(int i=1; (c=*ptr++); i++)
result += c*3*i;
if (result<0)
result = -result;
return result%len;
}
unsigned
Util::StrHash(const char* _str)
{
register unsigned int h;
register unsigned char *p;
for(h = 0, p = (unsigned char *)_str; *p; p++)
{
h = 31 * h + *p;
}
return h;
}
unsigned
Util::TianlHash(const char* _str)
{
unsigned long urlHashValue=0;
int ilength=strlen(_str);
int i;
unsigned char ucChar;
if(!ilength) {
return 0;
}
if(ilength<=256) {
urlHashValue=16777216*(ilength-1);
} else {
urlHashValue = 42781900080;
}
if(ilength<=96) {
for(i=1; i<=ilength; i++) {
ucChar = _str[i-1];
if(ucChar<='Z'&&ucChar>='A') {
ucChar=ucChar+32;
}
urlHashValue+=(3*i*ucChar*ucChar+5*i*ucChar+7*i+11*ucChar)%1677216;
}
} else {
for(i=1; i<=96; i++)
{
ucChar = _str[i+ilength-96-1];
if(ucChar<='Z'&&ucChar>='A')
{
ucChar=ucChar+32;
}
urlHashValue+=(3*i*ucChar*ucChar+5*i*ucChar+7*i+11*ucChar)%1677216;
}
}
return urlHashValue;
}
//NOTICE: the time of log() and sqrt() in C can be seen as constant
//NOTICE:_b must >= 1
double
Util::logarithm(double _a, double _b)
{
//REFRENCE: http://blog.csdn.net/liyuanbhu/article/details/8997850
//a>0 != 1; b>0 (b>=2 using log/log10/change, 1<b<2 using log1p, b<=1?)
if(_a <= 1 || _b < 1)
return -1.0;
double under = log(_a);
if(_b == 1)
return 0.0;
else if(_b < 2)
return log1p(_b - 1) / under;
else //_b >= 2
return log(_b) / under;
return -1.0;
}
void
Util::intersect(int*& _id_list, int& _id_list_len, const int* _list1, int _len1, const int* _list2, int _len2)
{
vector<int> res;
//cout<<"intersect prevar: "<<_len1<<" "<<_len2<<endl;
if(_list1 == NULL || _len1 == 0 || _list2 == NULL || _len2 == 0)
{
_id_list = NULL;
_id_list_len = 0;
}
//when size is almost the same, intersect O(n)
//when one size is small ratio, search in the larger one O(mlogn)
//
//n>0 m=nk(0<k<1)
//compare n(k+1) and nklogn: k0 = log(n/2)2 requiring that n>2
//k<=k0 binary search; k>k0 intersect
int method = -1; //0: intersect 1: search in list1 2: search in list2
int n = _len1;
double k = 0;
if(n < _len2)
{
k = (double)n / (double)_len2;
n = _len2;
method = 2;
}
else
{
k = (double)_len2 / (double)n;
method = 1;
}
if(n <= 2)
method = 0;
else
{
double limit = Util::logarithm(n/2, 2);
if(k > limit)
method = 0;
}
switch(method)
{
case 0:
{ //this bracket is needed if vars are defined in case
int id_i = 0;
int num = _len1;
for(int i = 0; i < num; ++i)
{
int can_id = _list1[i];
while((id_i < _len2) && (_list2[id_i] < can_id))
{
id_i ++;
}
if(id_i == _len2)
{
break;
}
if(can_id == _list2[id_i])
{
res.push_back(can_id);
id_i ++;
}
}
break;
}
case 1:
{
for(int i = 0; i < _len2; ++i)
{
if(Util::bsearch_int_uporder(_list2[i], _list1, _len1) != -1)
res.push_back(_list2[i]);
}
break;
}
case 2:
{
int m = _len1, i;
for(i = 0; i < m; ++i)
{
int t = _list1[i];
if(Util::bsearch_int_uporder(t, _list2, _len2) != -1)
res.push_back(t);
}
break;
}
default:
cerr << "no such method in Util::intersect()" << endl;
break;
}
_id_list_len = res.size();
_id_list = new int[_id_list_len];
for(int i = 0; i < _id_list_len; ++i)
_id_list[i] = res[i];
delete[] _list1;
delete[] _list2;
}
int
Util::compIIpair(int _a1, int _b1, int _a2, int _b2)
{
if(_a1 == _a2 && _b1 == _b2)
return 0;
else if(_a1 < _a2 || (_a1 == _a2 && _b1 <= _b2))
return -1;
else
return 1;
}
bool
Util::isValidPort(string str)
{
//valid port number: 0 - 65535
if(str.length() < 1 || str.length() > 5)
{
return false;
}
unsigned i;
for(i = 0; i < str.length(); i++)
{
if(str[i] < '0' || str[i] > '9')
{
return false;
}
}
int port = Util::string2int(str);
if(port < 0 || port>65535)
{
return false;
}
return true;
}
bool
Util::isValidIP(string str)
{
if(str == "localhost")
{
return true;
}
return (Util::isValidIPV4(str) || Util::isValidIPV6(str));
}
bool
Util::isValidIPV4(string str)
{
regex_t reg;
char pattern[] = "^(([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\\.){3}([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])$";
regcomp(&reg, pattern, REG_EXTENDED | REG_NOSUB);
regmatch_t pm[1];
int status = regexec(&reg, str.c_str(), 1, pm, 0);
regfree(&reg);
if(status == REG_NOMATCH)
{
return false;
}
return true;
}
bool
Util::isValidIPV6(string str)
{
//TO BE IMPLEMENTED
return false;
}