// Numerical user_key format: "%s%ld%s",prefix,inc_number,suffix
// if no numbers found, treat it as string
int NumericalComparatorImpl::Compare(const leveldb::Slice& a, const leveldb::Slice& b) const
{
assert(a.size() > LDB_COMPARE_META_ALL_SIZE && b.size() > LDB_COMPARE_META_ALL_SIZE );
int64_t num_a = 0, num_b = 0;
int ret = 0;
const char *prefix_a, *prefix_b, *delimiter_a, *delimiter_b, *suffix_a, *suffix_b;
prefix_a = MetaSkip(a.data() + LDB_COMPARE_META_ALL_SIZE, a.size() - LDB_COMPARE_META_ALL_SIZE);
delimiter_a = FindNumber(prefix_a, a.size() - (prefix_a - a.data()));
prefix_b = MetaSkip(b.data() + LDB_COMPARE_META_ALL_SIZE, b.size() - LDB_COMPARE_META_ALL_SIZE);
delimiter_b = FindNumber(prefix_b, b.size() - (prefix_b - b.data()));
//compare bucket_num+area+meta+prefix
const size_t pre_len_a = delimiter_a - a.data() - LDB_COMPARE_SKIP_SIZE;
const size_t pre_len_b = delimiter_b - b.data() - LDB_COMPARE_SKIP_SIZE;
ret = StringCompare(a.data() + LDB_COMPARE_SKIP_SIZE, pre_len_a, b.data() + LDB_COMPARE_SKIP_SIZE, pre_len_b);
if (ret == 0)
{
//prefixs equal, compare number
num_a = Strntoul(delimiter_a, a.size() - (delimiter_a - a.data()), &suffix_a);
num_b = Strntoul(delimiter_b, b.size() - (delimiter_b - b.data()), &suffix_b);
if (num_a != num_b)
{
ret = (num_a - num_b) > 0 ? 1 : -1;
}
else
{
//numbers equal or no numbers found, compare suffix
const size_t suf_len_a = a.size() - (suffix_a - a.data());
const size_t suf_len_b = b.size() - (suffix_b - b.data());
ret = StringCompare(suffix_a, suf_len_a, suffix_b, suf_len_b);
}
}
return ret;
}
char *FindIPAddressInString (char *psz)
{
psz = FindNumber(psz);
while (psz && !IsIPAddress(psz))
{
while (psz && isdigit(*psz))
++psz;
psz = FindNumber(psz);
}
return psz;
}
int ProcessExpress(char *instring) /*对原表达式进行预处理*/
{
int len,pos;
inlength=-1;
parencount=0;
tokencount=LASTOPERAND;
len=strlen(instring);
instring[len]='\0';
for (pos=0;pos<len;)
{
if (instring[pos]==' ') /*忽略空格字符*/
pos++;
else if (isalpha(instring[pos])) /*处理字母*/
pos=FindWord(instring,pos);
else if (isdigit(instring[pos]) || instring[pos]=='.') /*处理数字*/
pos=FindNumber(instring,pos);
else /*处理符号*/
pos=FindSymbol(instring,pos);
if (pos==-1)
return 0;
}
if (parencount!=0)
printf("左右括号不匹配\n");
PutToken(0); /*在infix中添加ENDEXPR*/
return 1;
}
