Question

我试图为this案例提供更好的错误报告（可能的错误）（关于judySArray给出不正确的结果，但我不知道哪个键给出了错误的结果）。来自此here的代码folder，请注意此blog。依赖关系：judySArray.h和cedar.h

// judy.cpp
#include "deps/judySArray.h"
#include <string>
#include <iostream>
#include <cstdlib>
#include <cstring>
using namespace std;
typedef judySArray<double> MSD;
const int MAX_DATA = 12000000;
const char i2ch[] = {'0','1','2','3','4','5','6','7','8','9','a','B','c','D','e','F'};
int get_first_digit(double d) {
    while(d > 10) d /= 10;
    return d;
}
string to_rhex(int v) {
    char hex[32];   
    int start = 0;
    while(v>0) {
        hex[start] = i2ch[v%16];
        v /= 16;
        ++start;
    }
    hex[start] = 0;
    return hex;
}
void add_or_inc(MSD &m, const string& key,double set, double inc, int& ctr) {
    const char* cstr = key.c_str();
    double it = m.find(cstr);
    if(!it) {
        m.insert(cstr,set);
        return;
    }
    m.insert(cstr,it+inc);
    ++ctr;
}
int main() {
    MSD m(64);  
    int dup1 = 0, dup2 = 0, dup3 = 0;
    for(int z=MAX_DATA;z>0;--z) {
        int val2 = MAX_DATA-z;
        int val3 = MAX_DATA*2-z;
        string key1 = to_string(z);
        string key2 = to_string(val2);
        string key3 = to_rhex(val3);
        add_or_inc(m,key1,z,val2,dup1);
        add_or_inc(m,key2,val2,val3,dup2);
        add_or_inc(m,key3,val3,z,dup3);
    }
    cout << dup1 << ' ' << dup2 << ' ' << dup3 << endl;
    int total = 0, verify = 0, count = 0;
    for(auto &it = m.begin();m.success(); m.next()) {
        total += get_first_digit(it.value); 
        verify += strlen((const char *) it.key);
        count += 1;
    }
    cout << total << ' ' << verify << ' ' << count << endl;
}

其他实现（map，unordered_map，hat-trie和cedar）给出正确的结果：

6009354 6009348 611297
36186112 159701682 23370001

但是朱迪没有：

6009354 6009348 611297
36186112 159701681 23370000

问题是，哪个键的结果不正确？

我尝试构建code，将这些密钥插入另一个数据结构（即cedar），但仍未检测到错误的密钥：

// judy.cpp
#include "deps/judySArray.h"
#include <string>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <vector>
using namespace std;
typedef judySArray<double> MSD;
const int MAX_DATA = 12000000;
const char i2ch[] = {'0','1','2','3','4','5','6','7','8','9','a','B','c','D','e','F'};
int get_first_digit(double d) {
    while(d > 10) d /= 10;
    return d;
}
string to_rhex(int v) {
    char hex[32];   
    int start = 0;
    while(v>0) {
        hex[start] = i2ch[v%16];
        v /= 16;
        ++start;
    }
    hex[start] = 0;
    return hex;
}
void add_or_inc(MSD &m, const string& key,double set, double inc, int& ctr) {
    const char* cstr = key.c_str();
    double it = m.find(cstr);
    if(!it) {
        m.insert(cstr,set);
        return;
    }
    m.insert(cstr,it+inc);
    ++ctr;
}
#include "deps/cedar.h"
class MSD2  {
public:
    vector<double> data;
    typedef cedar::da<int> CI;
    CI da;
    bool exists(const string& key,double &old) {
        int idx = -1;
        bool found = da.exactMatchExists(key.c_str(),key.size(),&idx);
        if(found) old = data[idx];
        return found;
    }
    void insert(const string& key,double val) {
        da.update(key.c_str(),key.size(),data.size());
        data.push_back(val);
    }
    void update(const string& key,double val) {
        int idx = -1;
        bool found = da.exactMatchExists(key.c_str(),key.size(),&idx);
        if(found) {
            data[idx] = val;
            return;
        }
        insert(key,val);
    }
};
void add_or_inc(MSD2 &m, const string& key,double set, double inc, int& ctr) {
    double old;
    if(!m.exists(key,old)) {
        m.insert(key,set);
        return;
    }
    m.update(key,old+inc);
    ++ctr;
}
int main() {
    MSD m(64);  
    MSD2 m2;
    int dup1 = 0, dup2 = 0, dup3 = 0;
    int vup1 = 0, vup2 = 0, vup3 = 0;
    for(int z=MAX_DATA;z>0;--z) {
        int val2 = MAX_DATA-z;
        int val3 = MAX_DATA*2-z;
        string key1 = to_string(z);
        string key2 = to_string(val2);
        string key3 = to_rhex(val3);
        add_or_inc(m,key1,z,val2,dup1);
        add_or_inc(m,key2,val2,val3,dup2);
        add_or_inc(m,key3,val3,z,dup3);
        add_or_inc(m2,key1,z,val2,vup1);
        add_or_inc(m2,key2,val2,val3,vup2);
        add_or_inc(m2,key3,val3,z,vup3);
    }
    cout << dup1 << ' ' << dup2 << ' ' << dup3 << endl;
    cout << vup1 << ' ' << vup2 << ' ' << vup3 << endl;
    int total = 0, verify = 0, count = 0;
    int xotal = 0, xerify = 0, xount = 0;
    union { int i; int x; } b;
    size_t from = 0, p = 0;
    char key[256] = {0};
    for (b.i = m2.da.begin(from, p); b.i != MSD2::CI::CEDAR_NO_PATH; b.i = m2.da.next(from, p)) {
        double it2 = m2.data[b.x]; // <-- find cedar's
        xotal += get_first_digit(it2); 
        m2.da.suffix(key,p,from);
        xerify += strlen(key);
        xount += 1;
        double it = m.find(key); // <-- find judy's
        if(it != it2) { // if value doesn't match, print:
            cout << "mismatch value for " << key << " : " << it2 << " vs " << it << endl;
        }
    }
    for(auto &it = m.begin();m.success(); m.next()) {
        total += get_first_digit(it.value); 
        verify += strlen((const char *) it.key);
        count += 1;
    }
    cout << total << ' ' << verify << ' ' << count << endl;
    cout << xotal << ' ' << xerify << ' ' << xount << endl;
}

编译：{{1}}（或clang++ -std=c++11 judy-findbug.cpp）

输出将是：

g++ -std=c++11

6009354 6009348 611297 6009354 6009348 611297 36186112 159701681 23370000 <-- judy's 36186112 159701682 23370001 <-- cedar's的价值比cedar多一个（这是正确的），但上面的代码没有检测到它。如何找到不正确的密钥？

Answer 1

代码上的错误是某人（我）取消注释assert(value != 0)。

错误是卡尔的Judy实现不应该存储空值（0值）。

解决方案：使用Doug Baskins＆＃39;朱迪的实施。

找到JudyArray的错误实现

1 个答案: