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Diffstat (limited to 'src/mongo/util/mongoutils/str.h')
-rw-r--r-- | src/mongo/util/mongoutils/str.h | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/mongo/util/mongoutils/str.h b/src/mongo/util/mongoutils/str.h new file mode 100644 index 00000000000..97b121b0068 --- /dev/null +++ b/src/mongo/util/mongoutils/str.h @@ -0,0 +1,216 @@ +// @file str.h + +/* Copyright 2010 10gen Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#pragma once + +/* Things in the mongoutils namespace + (1) are not database specific, rather, true utilities + (2) are cross platform + (3) may require boost headers, but not libs + (4) are clean and easy to use in any c++ project without pulling in lots of other stuff + + Note: within this module, we use int for all offsets -- there are no unsigned offsets + and no size_t's. If you need 3 gigabyte long strings, don't use this module. +*/ + +#include <string> +#include <sstream> + +// this violates the README rules for mongoutils: +#include "../../bson/util/builder.h" + +namespace mongoutils { + + namespace str { + + typedef std::string string; + + /** the idea here is to make one liners easy. e.g.: + + return str::stream() << 1 << ' ' << 2; + + since the following doesn't work: + + (stringstream() << 1).str(); + */ + class stream { + public: + mongo::StringBuilder ss; + template<class T> + stream& operator<<(const T& v) { + ss << v; + return *this; + } + operator std::string () const { return ss.str(); } + }; + + inline bool startsWith(const char *str, const char *prefix) { + const char *s = str; + const char *p = prefix; + while( *p ) { + if( *p != *s ) return false; + p++; s++; + } + return true; + } + inline bool startsWith(string s, string p) { return startsWith(s.c_str(), p.c_str()); } + + // while these are trivial today use in case we do different wide char things later + inline bool startsWith(const char *p, char ch) { return *p == ch; } + inline bool startsWith(string s, char ch) { return startsWith(s.c_str(), ch); } + + inline bool endsWith(string s, string p) { + int l = p.size(); + int x = s.size(); + if( x < l ) return false; + return strncmp(s.c_str()+x-l, p.c_str(), l) == 0; + } + inline bool endsWith(const char *s, char p) { + size_t len = strlen(s); + return len && s[len-1] == p; + } + + inline bool equals( const char * a , const char * b ) { return strcmp( a , b ) == 0; } + + /** find char x, and return rest of string thereafter, or "" if not found */ + inline const char * after(const char *s, char x) { + const char *p = strchr(s, x); + return (p != 0) ? p+1 : ""; + } + inline string after(const string& s, char x) { + const char *p = strchr(s.c_str(), x); + return (p != 0) ? string(p+1) : ""; + } + + /** find string x, and return rest of string thereafter, or "" if not found */ + inline const char * after(const char *s, const char *x) { + const char *p = strstr(s, x); + return (p != 0) ? p+strlen(x) : ""; + } + inline string after(string s, string x) { + const char *p = strstr(s.c_str(), x.c_str()); + return (p != 0) ? string(p+x.size()) : ""; + } + + /** @return true if s contains x */ + inline bool contains(string s, string x) { + return strstr(s.c_str(), x.c_str()) != 0; + } + inline bool contains(string s, char x) { + return strchr(s.c_str(), x) != 0; + } + + /** @return everything before the character x, else entire string */ + inline string before(const string& s, char x) { + const char *p = strchr(s.c_str(), x); + return (p != 0) ? s.substr(0, p-s.c_str()) : s; + } + + /** @return everything before the string x, else entire string */ + inline string before(const string& s, const string& x) { + const char *p = strstr(s.c_str(), x.c_str()); + return (p != 0) ? s.substr(0, p-s.c_str()) : s; + } + + /** check if if strings share a common starting prefix + @return offset of divergence (or length if equal). 0=nothing in common. */ + inline int shareCommonPrefix(const char *p, const char *q) { + int ofs = 0; + while( 1 ) { + if( *p == 0 || *q == 0 ) + break; + if( *p != *q ) + break; + p++; q++; ofs++; + } + return ofs; + } + inline int shareCommonPrefix(const string &a, const string &b) + { return shareCommonPrefix(a.c_str(), b.c_str()); } + + /** string to unsigned. zero if not a number. can end with non-num chars */ + inline unsigned toUnsigned(const string& a) { + unsigned x = 0; + const char *p = a.c_str(); + while( 1 ) { + if( !isdigit(*p) ) + break; + x = x * 10 + (*p - '0'); + p++; + } + return x; + } + + /** split a string on a specific char. We don't split N times, just once + on the first occurrence. If char not present entire string is in L + and R is empty. + @return true if char found + */ + inline bool splitOn(const string &s, char c, string& L, string& R) { + const char *start = s.c_str(); + const char *p = strchr(start, c); + if( p == 0 ) { + L = s; R.clear(); + return false; + } + L = string(start, p-start); + R = string(p+1); + return true; + } + /** split scanning reverse direction. Splits ONCE ONLY. */ + inline bool rSplitOn(const string &s, char c, string& L, string& R) { + const char *start = s.c_str(); + const char *p = strrchr(start, c); + if( p == 0 ) { + L = s; R.clear(); + return false; + } + L = string(start, p-start); + R = string(p+1); + return true; + } + + /** @return number of occurrences of c in s */ + inline unsigned count( const string& s , char c ) { + unsigned n=0; + for ( unsigned i=0; i<s.size(); i++ ) + if ( s[i] == c ) + n++; + return n; + } + + /** trim leading spaces. spaces only, not tabs etc. */ + inline string ltrim(const string& s) { + const char *p = s.c_str(); + while( *p == ' ' ) p++; + return p; + } + + /** remove trailing chars in place */ + inline void stripTrailing(string& s, const char *chars) { + string::iterator i = s.end(); + while( s.begin() != i ) { + i--; + if( contains(chars, *i) ) { + s.erase(i); + } + } + } + + } + +} |