scummvm/common/str.cpp

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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*/
#include "common/str.h"
#include "common/hash-str.h"
2006-06-02 13:34:41 +00:00
#include "common/util.h"
namespace Common {
#if !(defined(PALMOS_ARM) || defined(PALMOS_DEBUG) || defined(__GP32__))
const String String::emptyString;
#else
const char *String::emptyString = "";
#endif
static int computeCapacity(int len) {
// By default, for the capacity we use the nearest multiple of 32
// that leaves at least 16 chars of extra space (in case the string
// grows a bit).
// Finally, we subtract 1 to compensate for the trailing zero byte.
len += 16;
return ((len + 32 - 1) & ~0x1F) - 1;
}
String::String(const char *str) : _len(0), _str(_storage) {
if (str == 0) {
_storage[0] = 0;
_len = 0;
} else
initWithCStr(str, strlen(str));
}
String::String(const char *str, uint32 len) : _len(0), _str(_storage) {
initWithCStr(str, len);
}
String::String(const char *beginP, const char *endP) : _len(0), _str(_storage) {
assert(endP >= beginP);
initWithCStr(beginP, endP - beginP);
}
void String::initWithCStr(const char *str, uint32 len) {
assert(str);
// Init _storage member explicitly (ie. without calling its constructor)
// for GCC 2.95.x compatibility (see also tracker item #1602879).
_storage[0] = 0;
_len = len;
if (len >= _builtinCapacity) {
// Not enough internal storage, so allocate more
_extern._capacity = computeCapacity(len);
_extern._refCount = 0;
_str = (char *)malloc(_extern._capacity+1);
assert(_str != 0);
}
// Copy the string into the storage area
memmove(_str, str, len);
_str[len] = 0;
}
String::String(const String &str)
: _len(str._len), _str(str.isStorageIntern() ? _storage : str._str) {
if (str.isStorageIntern()) {
// String in internal storage: just copy it
memcpy(_storage, str._storage, _builtinCapacity);
} else {
// String in external storage: use refcount mechanism
str.incRefCount();
_extern._refCount = str._extern._refCount;
_extern._capacity = str._extern._capacity;
}
assert(_str != 0);
}
String::String(char c)
: _len(0), _str(_storage) {
_storage[0] = c;
_storage[1] = 0;
// TODO/FIXME: There is no reason for the following check -- we *do*
// allow strings to contain 0 bytes!
_len = (c == 0) ? 0 : 1;
}
String::~String() {
decRefCount(_extern._refCount);
}
void String::incRefCount() const {
assert(!isStorageIntern());
if (_extern._refCount == 0) {
_extern._refCount = new int(2);
} else {
++(*_extern._refCount);
}
}
void String::decRefCount(int *oldRefCount) {
if (isStorageIntern())
return;
if (oldRefCount) {
--(*oldRefCount);
}
if (!oldRefCount || *oldRefCount <= 0) {
// The ref count reached zero, so we free the string storage
// and the ref count storage.
delete oldRefCount;
free(_str);
// Even though _str points to a freed memory block now,
// we do not change its value, because any code that calls
// decRefCount will have to do this afterwards anyway.
}
}
String& String::operator =(const char *str) {
uint32 len = strlen(str);
ensureCapacity(len, false);
_len = len;
memmove(_str, str, len + 1);
return *this;
}
String &String::operator =(const String &str) {
if (&str == this)
return *this;
if (str.isStorageIntern()) {
decRefCount(_extern._refCount);
_len = str._len;
_str = _storage;
memcpy(_str, str._str, _len + 1);
} else {
str.incRefCount();
decRefCount(_extern._refCount);
_extern._refCount = str._extern._refCount;
_extern._capacity = str._extern._capacity;
_len = str._len;
_str = str._str;
}
return *this;
}
String& String::operator =(char c) {
ensureCapacity(1, false);
_len = 1;
_str[0] = c;
_str[1] = 0;
return *this;
}
String &String::operator +=(const char *str) {
int len = strlen(str);
if (len > 0) {
ensureCapacity(_len + len, true);
memcpy(_str + _len, str, len + 1);
_len += len;
}
return *this;
}
String &String::operator +=(const String &str) {
int len = str._len;
if (len > 0) {
ensureCapacity(_len + len, true);
memcpy(_str + _len, str._str, len + 1);
_len += len;
}
return *this;
}
String &String::operator +=(char c) {
ensureCapacity(_len + 1, true);
_str[_len++] = c;
_str[_len] = 0;
return *this;
}
bool String::hasPrefix(const char *x) const {
assert(x != 0);
// Compare x with the start of _str.
const char *y = c_str();
while (*x && *x == *y) {
++x;
++y;
}
// It's a prefix, if and only if all letters in x are 'used up' before
// _str ends.
return *x == 0;
}
bool String::hasSuffix(const char *x) const {
assert(x != 0);
// Compare x with the end of _str.
const uint32 x_len = strlen(x);
if (x_len > _len)
return false;
const char *y = c_str() + _len - x_len;
while (*x && *x == *y) {
++x;
++y;
}
// It's a suffix, if and only if all letters in x are 'used up' before
// _str ends.
return *x == 0;
}
bool String::contains(const char *x) const {
assert(x != 0);
return strstr(c_str(), x) != NULL;
}
bool String::contains(char x) const {
return strchr(c_str(), x) != NULL;
}
void String::deleteLastChar() {
deleteChar(_len - 1);
}
void String::deleteChar(uint32 p) {
assert(p < _len);
// Call ensureCapacity to make sure we actually *own* the storage
// to which _str points to -- we wouldn't want to modify a storage
// which other string objects are sharing, after all.
ensureCapacity(_len, true);
while (p++ < _len)
_str[p-1] = _str[p];
_len--;
}
void String::clear() {
decRefCount(_extern._refCount);
_len = 0;
_str = _storage;
_storage[0] = 0;
}
void String::setChar(char c, uint32 p) {
assert(p <= _len);
ensureCapacity(_len, true);
_str[p] = c;
}
void String::insertChar(char c, uint32 p) {
assert(p <= _len);
ensureCapacity(_len + 1, true);
_len++;
for (uint32 i = _len; i > p; --i)
_str[i] = _str[i-1];
_str[p] = c;
}
void String::toLowercase() {
ensureCapacity(_len, true);
for (uint32 i = 0; i < _len; ++i)
_str[i] = tolower(_str[i]);
}
void String::toUppercase() {
ensureCapacity(_len, true);
for (uint32 i = 0; i < _len; ++i)
_str[i] = toupper(_str[i]);
}
/**
* Ensure that enough storage is available to store at least new_len
* characters plus a null byte. In addition, if we currently share
* the storage with another string, unshare it, so that we can safely
* write to the storage.
*/
void String::ensureCapacity(uint32 new_len, bool keep_old) {
bool isShared;
uint32 curCapacity, newCapacity;
char *newStorage;
int *oldRefCount = _extern._refCount;
if (isStorageIntern()) {
isShared = false;
curCapacity = _builtinCapacity - 1;
} else {
isShared = (oldRefCount && *oldRefCount > 1);
curCapacity = _extern._capacity;
}
// Special case: If there is enough space, and we do not share
// the storage, then there is nothing to do.
if (!isShared && new_len <= curCapacity)
return;
if (isShared && new_len <= _builtinCapacity - 1) {
// We share the storage, but there is enough internal storage: Use that.
newStorage = _storage;
newCapacity = _builtinCapacity - 1;
} else {
// We need to allocate storage on the heap!
// Compute a suitable new capacity limit
newCapacity = computeCapacity(new_len);
// Allocate new storage
newStorage = (char *)malloc(newCapacity+1);
assert(newStorage);
}
// Copy old data if needed, elsewise reset the new storage.
if (keep_old) {
assert(_len <= newCapacity);
memcpy(newStorage, _str, _len + 1);
} else {
_len = 0;
newStorage[0] = 0;
}
// Release hold on the old storage ...
decRefCount(oldRefCount);
// ... in favor of the new storage
_str = newStorage;
if (!isStorageIntern()) {
// Set the ref count & capacity if we use an external storage.
// It is important to do this *after* copying any old content,
// else we would override data that has not yet been copied!
_extern._refCount = 0;
_extern._capacity = newCapacity;
}
}
uint String::hash() const {
return hashit(c_str());
}
#pragma mark -
bool String::operator ==(const String &x) const {
return equals(x);
}
bool String::operator ==(const char *x) const {
assert(x != 0);
return equals(x);
}
bool String::operator !=(const String &x) const {
return !equals(x);
}
bool String::operator !=(const char *x) const {
assert(x != 0);
return !equals(x);
}
bool String::operator < (const String &x) const {
return compareTo(x) < 0;
}
bool String::operator <= (const String &x) const {
return compareTo(x) <= 0;
}
bool String::operator > (const String &x) const {
return compareTo(x) > 0;
}
bool String::operator >= (const String &x) const {
return compareTo(x) >= 0;
}
#pragma mark -
bool operator == (const char* y, const String &x) {
return (x == y);
}
bool operator != (const char* y, const String &x) {
return x != y;
}
#pragma mark -
bool String::equals(const String &x) const {
return (0 == compareTo(x));
}
bool String::equals(const char *x) const {
assert(x != 0);
return (0 == compareTo(x));
}
bool String::equalsIgnoreCase(const String &x) const {
return (0 == compareToIgnoreCase(x));
}
bool String::equalsIgnoreCase(const char *x) const {
assert(x != 0);
return (0 == compareToIgnoreCase(x));
}
int String::compareTo(const String &x) const {
return compareTo(x.c_str());
}
int String::compareTo(const char *x) const {
assert(x != 0);
return strcmp(c_str(), x);
}
int String::compareToIgnoreCase(const String &x) const {
return compareToIgnoreCase(x.c_str());
}
int String::compareToIgnoreCase(const char *x) const {
assert(x != 0);
return scumm_stricmp(c_str(), x);
}
#pragma mark -
String operator +(const String &x, const String &y) {
String temp(x);
temp += y;
return temp;
}
String operator +(const char *x, const String &y) {
String temp(x);
temp += y;
return temp;
}
String operator +(const String &x, const char *y) {
String temp(x);
temp += y;
return temp;
}
String operator +(char x, const String &y) {
String temp(x);
temp += y;
return temp;
}
String operator +(const String &x, char y) {
String temp(x);
temp += y;
return temp;
}
char *ltrim(char *t) {
while (isspace(*t))
t++;
return t;
}
char *rtrim(char *t) {
int l = strlen(t) - 1;
while (l >= 0 && isspace(t[l]))
t[l--] = 0;
return t;
}
char *trim(char *t) {
return rtrim(ltrim(t));
}
} // End of namespace Common