COMMON: Add simple UTF-32 string class U32String.

3 files changed, 485 insertions, 0 deletions

diff --git a/common/module.mk b/common/module.mk
index 1b34d151d0..67c498df00 100644
--- a/common/module.mk
+++ b/common/module.mk
@@ -35,6 +35,7 @@ MODULE_OBJS := \
 	translation.o \
 	unarj.o \
 	unzip.o \
+	ustr.o \
 	util.o \
 	winexe.o \
 	winexe_ne.o \
diff --git a/common/ustr.cpp b/common/ustr.cpp
new file mode 100644
index 0000000000..fbc831cb56
--- /dev/null
+++ b/common/ustr.cpp
@@ -0,0 +1,329 @@
+/* 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.
+ */
+
+#include "common/ustr.h"
+#include "common/memorypool.h"
+#include "common/util.h"
+
+namespace Common {
+
+extern MemoryPool *g_refCountPool;
+
+static uint32 computeCapacity(uint32 len) {
+	// By default, for the capacity we use the next multiple of 32
+	return ((len + 32 - 1) & ~0x1F);
+}
+
+U32String::U32String(const value_type *str) : _size(0), _str(_storage) {
+	if (str == 0) {
+		_storage[0] = 0;
+		_size = 0;
+	} else {
+		uint32 len = 0;
+		const value_type *s = str;
+		while (*s++) {
+			++len;
+		}
+		initWithCStr(str, len);
+	}
+}
+
+U32String::U32String(const value_type *str, uint32 len) : _size(0), _str(_storage) {
+	initWithCStr(str, len);
+}
+
+U32String::U32String(const value_type *beginP, const value_type *endP) : _size(0), _str(_storage) {
+	assert(endP >= beginP);
+	initWithCStr(beginP, endP - beginP);
+}
+
+U32String::U32String(const U32String &str)
+    : _size(str._size) {
+	if (str.isStorageIntern()) {
+		// String in internal storage: just copy it
+		memcpy(_storage, str._storage, _builtinCapacity * sizeof(value_type));
+		_str = _storage;
+	} else {
+		// String in external storage: use refcount mechanism
+		str.incRefCount();
+		_extern._refCount = str._extern._refCount;
+		_extern._capacity = str._extern._capacity;
+		_str = str._str;
+	}
+	assert(_str != 0);
+}
+
+U32String::~U32String() {
+	decRefCount(_extern._refCount);
+}
+
+U32String &U32String::operator=(const U32String &str) {
+	if (&str == this)
+		return *this;
+
+	if (str.isStorageIntern()) {
+		decRefCount(_extern._refCount);
+		_size = str._size;
+		_str = _storage;
+		memcpy(_str, str._str, (_size + 1) * sizeof(value_type));
+	} else {
+		str.incRefCount();
+		decRefCount(_extern._refCount);
+
+		_extern._refCount = str._extern._refCount;
+		_extern._capacity = str._extern._capacity;
+		_size = str._size;
+		_str = str._str;
+	}
+
+	return *this;
+}
+
+U32String &U32String::operator+=(const U32String &str) {
+	if (&str == this) {
+		return operator+=(U32String(str));
+	}
+
+	int len = str._size;
+	if (len > 0) {
+		ensureCapacity(_size + len, true);
+
+		memcpy(_str + _size, str._str, (len + 1) * sizeof(value_type));
+		_size += len;
+	}
+	return *this;
+}
+
+U32String &U32String::operator+=(value_type c) {
+	ensureCapacity(_size + 1, true);
+
+	_str[_size++] = c;
+	_str[_size] = 0;
+
+	return *this;
+}
+
+bool U32String::equals(const U32String &x) const {
+	if (this == &x || _str == x._str) {
+		return true;
+	}
+
+	if (x.size() != _size) {
+		return false;
+	}
+
+	return !memcmp(_str, x._str, _size * sizeof(value_type));
+}
+
+bool U32String::contains(value_type x) const {
+	for (uint32 i = 0; i < _size; ++i) {
+		if (_str[i] == x) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+void U32String::deleteChar(uint32 p) {
+	assert(p < _size);
+
+	makeUnique();
+	while (p++ < _size)
+		_str[p - 1] = _str[p];
+	_size--;
+}
+
+void U32String::clear() {
+	decRefCount(_extern._refCount);
+
+	_size = 0;
+	_str = _storage;
+	_storage[0] = 0;
+}
+
+void U32String::toLowercase() {
+	makeUnique();
+	for (uint32 i = 0; i < _size; ++i) {
+		if (_str[i] < 128) {
+			_str[i] = tolower(_str[i]);
+		}
+	}
+}
+
+void U32String::toUppercase() {
+	makeUnique();
+	for (uint32 i = 0; i < _size; ++i) {
+		if (_str[i] < 128) {
+			_str[i] = toupper(_str[i]);
+		}
+	}
+}
+
+uint32 U32String::find(const U32String &str, uint32 pos) const {
+	if (pos >= _size) {
+		return npos;
+	}
+
+	const value_type *strP = str.c_str();
+
+	for (const_iterator cur = begin() + pos; *cur; ++cur) {
+		uint i = 0;
+		while (true) {
+			if (!strP[i]) {
+				return cur - begin();
+			}
+
+			if (cur[i] != strP[i]) {
+				break;
+			}
+
+			++i;
+		}
+	}
+
+	return npos;
+}
+
+void U32String::makeUnique() {
+	ensureCapacity(_size, true);
+}
+
+void U32String::ensureCapacity(uint32 new_size, bool keep_old) {
+	bool isShared;
+	uint32 curCapacity, newCapacity;
+	value_type *newStorage;
+	int *oldRefCount = _extern._refCount;
+
+	if (isStorageIntern()) {
+		isShared = false;
+		curCapacity = _builtinCapacity;
+	} 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_size < curCapacity)
+		return;
+
+	if (isShared && new_size < _builtinCapacity) {
+		// We share the storage, but there is enough internal storage: Use that.
+		newStorage = _storage;
+		newCapacity = _builtinCapacity;
+	} else {
+		// We need to allocate storage on the heap!
+
+		// Compute a suitable new capacity limit
+		// If the current capacity is sufficient we use the same capacity
+		if (new_size < curCapacity)
+			newCapacity = curCapacity;
+		else
+			newCapacity = MAX(curCapacity * 2, computeCapacity(new_size+1));
+
+		// Allocate new storage
+		newStorage = new value_type[newCapacity];
+		assert(newStorage);
+	}
+
+	// Copy old data if needed, elsewise reset the new storage.
+	if (keep_old) {
+		assert(_size < newCapacity);
+		memcpy(newStorage, _str, (_size + 1) * sizeof(value_type));
+	} else {
+		_size = 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;
+	}
+}
+
+void U32String::incRefCount() const {
+	assert(!isStorageIntern());
+	if (_extern._refCount == 0) {
+		if (g_refCountPool == 0) {
+			g_refCountPool = new MemoryPool(sizeof(int));
+			assert(g_refCountPool);
+		}
+
+		_extern._refCount = (int *)g_refCountPool->allocChunk();
+		*_extern._refCount = 2;
+	} else {
+		++(*_extern._refCount);
+	}
+}
+
+void U32String::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.
+		if (oldRefCount) {
+			assert(g_refCountPool);
+			g_refCountPool->freeChunk(oldRefCount);
+		}
+		delete[] _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.
+	}
+}
+
+void U32String::initWithCStr(const value_type *str, uint32 len) {
+	assert(str);
+
+	_storage[0] = 0;
+
+	_size = len;
+
+	if (len >= _builtinCapacity) {
+		// Not enough internal storage, so allocate more
+		_extern._capacity = computeCapacity(len+1);
+		_extern._refCount = 0;
+		_str = new value_type[_extern._capacity];
+		assert(_str != 0);
+	}
+
+	// Copy the string into the storage area
+	memmove(_str, str, len * sizeof(value_type));
+	_str[len] = 0;
+}
+
+} // End of namespace Common
diff --git a/common/ustr.h b/common/ustr.h
new file mode 100644
index 0000000000..e549c5f9c4
--- /dev/null
+++ b/common/ustr.h
@@ -0,0 +1,155 @@
+/* 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.
+ */
+
+#ifndef COMMON_USTR_H
+#define COMMON_USTR_H
+
+#include "common/scummsys.h"
+
+namespace Common {
+
+class U32String {
+public:
+	static const uint32 npos = 0xFFFFFFFF;
+
+	typedef uint32 value_type;
+	typedef uint32 unsigned_type;
+private:
+	/**
+	 * The size of the internal storage. Increasing this means less heap
+	 * allocations are needed, at the cost of more stack memory usage,
+	 * and of course lots of wasted memory.
+	 */
+	static const uint32 _builtinCapacity = 32;
+
+	/**
+	 * Length of the string.
+	 */
+	uint32 _size;
+
+	/**
+	 * Pointer to the actual string storage. Either points to _storage,
+	 * or to a block allocated on the heap via malloc.
+	 */
+	value_type  *_str;
+
+
+	union {
+		/**
+		 * Internal string storage.
+		 */
+		value_type _storage[_builtinCapacity];
+		/**
+		 * External string storage data -- the refcounter, and the
+		 * capacity of the string _str points to.
+		 */
+		struct {
+			mutable int *_refCount;
+			uint32       _capacity;
+		} _extern;
+	};
+
+	inline bool isStorageIntern() const {
+		return _str == _storage;
+	}
+
+public:
+	U32String() : _size(0), _str(_storage) { _storage[0] = 0; }
+
+	explicit U32String(const value_type *str);
+
+	U32String(const value_type *str, uint32 len);
+
+	U32String(const value_type *beginP, const value_type *endP);
+
+	U32String(const U32String &str);
+
+	~U32String();
+
+	U32String &operator=(const U32String &str);
+	U32String &operator+=(const U32String &str);
+	U32String &operator+=(value_type c);
+
+	bool operator==(const U32String &x) const { return equals(x); }
+
+	bool equals(const U32String &x) const;
+
+	bool contains(value_type x) const;
+
+	inline const value_type *c_str() const { return _str; }
+	inline uint32 size() const             { return _size; }
+
+	inline bool empty() const { return (_size == 0); }
+
+	value_type operator[](int idx) const {
+		assert(_str && idx >= 0 && idx < (int)_size);
+		return _str[idx];
+	}
+
+	/** Remove the character at position p from the string. */
+	void deleteChar(uint32 p);
+
+	/** Clears the string, making it empty. */
+	void clear();
+
+	/** Convert all characters in the string to lowercase. */
+	void toLowercase();
+
+	/** Convert all characters in the string to uppercase. */
+	void toUppercase();
+
+	uint32 find(const U32String &str, uint32 pos = 0) const;
+
+	typedef value_type *        iterator;
+	typedef const value_type *  const_iterator;
+
+	iterator begin() {
+		// Since the user could potentially
+		// change the string via the returned
+		// iterator we have to assure we are
+		// pointing to a unique storage.
+		makeUnique();
+
+		return _str;
+	}
+
+	iterator end() {
+		return begin() + size();
+	}
+
+	const_iterator begin() const {
+		return _str;
+	}
+
+	const_iterator end() const {
+		return begin() + size();
+	}
+private:
+	void makeUnique();
+	void ensureCapacity(uint32 new_size, bool keep_old);
+	void incRefCount() const;
+	void decRefCount(int *oldRefCount);
+	void initWithCStr(const value_type *str, uint32 len);
+};
+
+} // End of namespace Common
+
+#endif