Files
scummvm-cursorfix/engines/ags/shared/util/string.h
2026-02-02 04:50:13 +01:00

471 lines
19 KiB
C++

/* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
//=============================================================================
//
// String class with simple memory management and copy-on-write behavior.
//
// String objects do reference counting and share data buffer on assignment.
// The reallocation and copying is done only when the string is modified.
//
// The copying of memory inside buffer is reduced to minimum. If the string is
// truncated, it is not aligned to buffer head each time, instead the c-str
// pointer is advanced, or null-terminator is put on the new place. Similarly,
// when string is enlarged and new characters are prepended or appended, only
// c-str pointer and null-terminator's position are changed, if there's enough
// space before and after meaningful string data.
//
// The class provides means to reserve large amount of buffer space before
// making modifications, as well as compacting buffer to minimal size.
//
// For all methods that expect C-string as parameter - if the null pointer is
// passed in place of C-string it is treated in all aspects as a valid empty
// string.
//
//=============================================================================
#ifndef AGS_SHARED_UTIL_STRING_H
#define AGS_SHARED_UTIL_STRING_H
//include <stdarg.h>
#include "common/str.h"
#include "common/std/vector.h"
#include "ags/shared/core/platform.h"
#include "ags/shared/core/types.h"
namespace AGS3 {
namespace AGS {
namespace Shared {
class Stream;
class String {
public:
static const size_t NoIndex = (size_t)-1;
// Standard constructor: intialize empty string
String();
// Copy constructor
String(const String &);
// Move constructor
String(String &&);
// Initialize with C-string
String(const char *cstr);
// Initialize by copying up to N chars from C-string
String(const char *cstr, size_t length);
// Initialize by filling N chars with certain value
String(char c, size_t count);
// Initialize from a ScummVM string
String(const Common::String &s);
~String();
// Get underlying C-string for reading; this method guarantees valid C-string
inline const char *GetCStr() const {
return _cstr;
}
// Get character count
inline size_t GetLength() const {
return _len;
}
// Know if the string is empty (has no meaningful characters)
inline bool IsEmpty() const {
return _len == 0;
}
// Tells if the string is either empty or has only whitespace characters
bool IsNullOrSpace() const;
// Those getters are for tests only, hence if AGS_PLATFORM_TEST
#if defined(AGS_PLATFORM_TEST) && AGS_PLATFORM_TEST
inline const char *GetBuffer() const {
return _buf;
}
inline size_t GetCapacity() const {
return _bufHead ? _bufHead->Capacity : 0;
}
inline size_t GetRefCount() const {
return _bufHead ? _bufHead->RefCount : 0;
}
#endif
// Read() method implies that string length is initially unknown.
// max_chars parameter determine the buffer size limit.
// If stop_at_limit flag is set, it will read only up to the max_chars.
// Otherwise (by default) hitting the limit won't stop stream reading;
// the data will be read until null-terminator or EOS is met, and buffer
// will contain only leftmost part of the longer string that fits in.
// This method is better fit for reading from binary streams.
void Read(Stream *in, size_t max_chars = 5 * 1024 * 1024, bool stop_at_limit = false);
// ReadCount() reads up to N characters from stream, ignoring null-
// terminator. This method is better fit for reading from text
// streams, or when the length of string is known beforehand.
void ReadCount(Stream *in, size_t count);
// Write() puts the null-terminated string into the stream.
void Write(Stream *out) const;
// WriteCount() writes N characters to stream, filling the remaining
// space with null-terminators when needed.
void WriteCount(Stream *out, size_t count) const;
//-------------------------------------------------------------------------
// String analysis methods
//-------------------------------------------------------------------------
// Compares with given string
int Compare(const String &str) const {
return Compare(str._cstr);
}
int Compare(const char *cstr) const;
int CompareNoCase(const String &str) const {
return CompareNoCase(str._cstr);
}
int CompareNoCase(const char *cstr) const;
// Compares the leftmost part of this string with given string
int CompareLeft(const String &str, size_t count = -1) const {
return CompareLeft(str._cstr, count != NoIndex ? count : str._len);
}
int CompareLeft(const char *cstr, size_t count = -1) const;
int CompareLeftNoCase(const String &str, size_t count = -1) const {
return CompareLeftNoCase(str._cstr, count != NoIndex ? count : str._len);
}
int CompareLeftNoCase(const char *cstr, size_t count = -1) const;
// Compares any part of this string with given string
int CompareMid(const String &str, size_t from, size_t count = -1) const {
return CompareMid(str._cstr, from, count != NoIndex ? count : str._len);
}
int CompareMid(const char *cstr, size_t from, size_t count = -1) const;
int CompareMidNoCase(const String &str, size_t from, size_t count = -1) const {
return CompareMidNoCase(str._cstr, from, count != NoIndex ? count : str._len);
}
int CompareMidNoCase(const char *cstr, size_t from, size_t count = -1) const;
// Compares the rightmost part of this string with given C-string
int CompareRight(const String &str, size_t count = -1) const {
return CompareRight(str._cstr, count != NoIndex ? count : str._len);
}
int CompareRight(const char *cstr, size_t count = -1) const;
int CompareRightNoCase(const String &str, size_t count = -1) const {
return CompareRightNoCase(str._cstr, count != NoIndex ? count : str._len);
}
int CompareRightNoCase(const char *cstr, size_t count = -1) const;
// Convenience aliases for Compare functions
inline bool Equals(const String &str) const {
return Compare(str) == 0;
}
inline bool Equals(const char *cstr) const {
return Compare(cstr) == 0;
}
inline bool StartsWith(const String &str) const {
return CompareLeft(str) == 0;
}
inline bool StartsWith(const char *cstr) const {
return CompareLeft(cstr) == 0;
}
inline bool EndsWidth(const String &str) const {
return CompareRight(str) == 0;
}
inline bool EndsWidth(const char *cstr) const {
return CompareRight(cstr) == 0;
}
// These functions search for character or substring inside this string
// and return the index of the (first) character, or -1 if nothing found.
size_t FindChar(char c, size_t from = 0) const;
size_t FindCharReverse(char c, size_t from = -1) const;
size_t FindString(const String &str, size_t from = 0) const {
return FindString(str._cstr, from);
}
size_t FindString(const char *cstr, size_t from = 0) const;
// Section methods treat string as a sequence of 'fields', separated by
// special character. They search for a substring consisting of all such
// 'fields' from the 'first' to the 'last', inclusive; the bounding
// separators are optionally included too.
// Section indexes are zero-based. The first (0th) section is always
// located before the first separator and the last section is always
// located after the last separator, meaning that if the outermost
// character in string is separator char, there's still an empty trailing
// field beyond that.
// This also means that there's always at least one section in any string,
// even if there are no separating chars.
bool FindSection(char separator, size_t first, size_t last, bool exclude_first_sep, bool exclude_last_sep,
size_t &from, size_t &to) const;
// Get Nth character with bounds check (as opposed to subscript operator)
inline char GetAt(size_t index) const {
return (index < _len) ? _cstr[index] : 0;
}
inline char GetLast() const {
return (_len > 0) ? _cstr[_len - 1] : 0;
}
//-------------------------------------------------------------------------
// Value cast methods
//-------------------------------------------------------------------------
int ToInt() const;
//-------------------------------------------------------------------------
// Factory methods
//-------------------------------------------------------------------------
// Wraps the given string buffer without owning it, won't count references,
// won't delete it at destruction. Can be used with string literals.
static String Wrapper(const char *cstr);
// TODO: investigate C++11 solution for variadic templates (would that be more convenient here?)
static String FromFormat(const char *fcstr, ...);
static String FromFormatV(const char *fcstr, va_list argptr);
// Reads stream until null-terminator or EOS
static String FromStream(Stream *in, size_t max_chars = 5 * 1024 * 1024, bool stop_at_limit = false);
// Reads up to N chars from stream
static String FromStreamCount(Stream *in, size_t count);
// Creates a lowercased copy of the string
String Lower() const;
// Creates an uppercased copy of the string
String Upper() const;
// Extract N leftmost characters as a new string
String Left(size_t count) const;
// Extract up to N characters starting from given index
String Mid(size_t from, size_t count = -1) const;
// Extract N rightmost characters
String Right(size_t count) const;
// Extract leftmost part, separated by the given char; if no separator was
// found returns the whole string
String LeftSection(char separator, bool exclude_separator = true) const;
// Extract rightmost part, separated by the given char; if no separator was
// found returns the whole string
String RightSection(char separator, bool exclude_separator = true) const;
// Extract the range of Xth to Yth fields, separated by the given character
String Section(char separator, size_t first, size_t last,
bool exclude_first_sep = true, bool exclude_last_sep = true) const;
// Splits the string into segments divided by the instances of a given character,
// including empty segments e.g. if separators follow each other;
// returns at least one segment (equal to full string if no separator was found)
std::vector<String> Split(char separator) const;
//-------------------------------------------------------------------------
// String modification methods
//-------------------------------------------------------------------------
// Ensure string has at least space to store N chars;
// this does not change string contents, nor length
void Reserve(size_t max_length);
// Ensure string has at least space to store N additional chars
void ReserveMore(size_t more_length);
// Make string's buffer as small as possible to hold current data
void Compact();
// Append* methods add content at the string's end, increasing its length
// Appends another string to this string
void Append(const String &str);
void Append(const char *cstr) {
String str = String::Wrapper(cstr);
Append(str);
}
void Append(const char *cstr, size_t len);
// Appends a single character
void AppendChar(char c);
// Appends a formatted string
void AppendFmt(MSVC_PRINTF const char *fcstr, ...) GCC_PRINTF(2, 3);
void AppendFmtv(const char *fcstr, va_list argptr);
// Clip* methods decrease the string, removing defined part
// Cuts off leftmost N characters
void ClipLeft(size_t count);
// Cuts out N characters starting from given index
void ClipMid(size_t from, size_t count = -1);
// Cuts off rightmost N characters
void ClipRight(size_t count);
// Cuts off leftmost part, separated by the given char; if no separator was
// found cuts whole string, leaving empty string
void ClipLeftSection(char separator, bool include_separator = true);
// Cuts off rightmost part, separated by the given char; if no separator
// was found cuts whole string, leaving empty string
void ClipRightSection(char separator, bool include_separator = true);
// Cuts out the range of Xth to Yth fields separated by the given character
void ClipSection(char separator, size_t first, size_t last,
bool include_first_sep = true, bool include_last_sep = true);
// Sets string length to zero
void Empty();
// Makes a new string by filling N chars with certain value
void FillString(char c, size_t count);
// Makes a new string by putting in parameters according to format string
void Format(const char *fcstr, ...);
void FormatV(const char *fcstr, va_list argptr);
// Decrement ref counter and deallocate data if must.
// Free() should be called only when buffer is not needed anymore;
// if string must be truncated to zero length, but retain the allocated
// memory, call Empty() instead.
void Free();
// Convert string to lowercase equivalent
void MakeLower();
// Convert string to uppercase equivalent
void MakeUpper();
// Merges sequences of same characters into one
void MergeSequences(char c = 0);
// Prepend* methods add content before the string's head, increasing its length
// Prepends another string to this string
void Prepend(const String &str);
void Prepend(const char *cstr) {
String str = String::Wrapper(cstr); Prepend(str);
}
// Prepends a single character
void PrependChar(char c);
// Replaces all occurrences of one character with another character
void Replace(char what, char with);
// Replaces all occurrences of one substring with another substring
void Replace(const String &what, const String &with);
void Replace(const char *what, const char *with) {
String whats = String::Wrapper(what), withs = String::Wrapper(with); Replace(whats, withs);
}
// Replaces particular substring with another substring; new substring
// may have different length
void ReplaceMid(size_t from, size_t count, const String &str);
void ReplaceMid(size_t from, size_t count, const char *cstr) {
String str = String::Wrapper(cstr); ReplaceMid(from, count, str);
}
// Reverses the string
void Reverse();
// Reverse the multibyte unicode string
// FIXME: name? invent some consistent naming for necessary multibyte funcs,
// proper utf8 support where necessary
void ReverseUTF8();
// Overwrite the Nth character of the string; does not change string's length
void SetAt(size_t index, char c);
// Makes a new string by copying up to N chars from C-string
void SetString(const char *cstr, size_t length = -1);
// For all Trim functions, if given character value is 0, all whitespace
// characters (space, tabs, CRLF) are removed.
// Remove heading and trailing characters from the string
void Trim(char c = 0);
// Remove heading characters from the string;
void TrimLeft(char c = 0);
// Remove trailing characters from the string
void TrimRight(char c = 0);
// Truncate* methods decrease the string to the part of itself
// Truncate the string to the leftmost N characters
void TruncateToLeft(size_t count);
// Truncate the string to the middle N characters
void TruncateToMid(size_t from, size_t count = -1);
// Truncate the string to the rightmost N characters
void TruncateToRight(size_t count);
// Truncate the string to the leftmost part, separated by the given char;
// if no separator was found leaves string unchanged
void TruncateToLeftSection(char separator, bool exclude_separator = true);
// Truncate the string to the rightmost part, separated by the given char;
// if no separator was found leaves string unchanged
void TruncateToRightSection(char separator, bool exclude_separator = true);
// Truncate the string to range of Xth to Yth fields separated by the
// given character
void TruncateToSection(char separator, size_t first, size_t last,
bool exclude_first_sep = true, bool exclude_last_sep = true);
// Wraps the given string buffer without owning it, won't count references,
// won't delete it at destruction. Can be used with string literals.
void Wrap(const char *cstr);
//-------------------------------------------------------------------------
// Operators
//-------------------------------------------------------------------------
// Assign String by sharing data reference
String &operator=(const String &str);
// Move operator
String &operator=(String &&str);
// Assign C-string by copying contents
String &operator=(const char *cstr);
inline char operator[](size_t index) const {
assert(index < _len);
return _cstr[index];
}
inline bool operator ==(const String &str) const {
return Compare(str) == 0;
}
inline bool operator ==(const char *cstr) const {
return Compare(cstr) == 0;
}
inline bool operator !=(const String &str) const {
return Compare(str) != 0;
}
inline bool operator !=(const char *cstr) const {
return Compare(cstr) != 0;
}
inline bool operator <(const String &str) const {
return Compare(str) < 0;
}
inline bool operator <(const char *cstr) const {
return Compare(cstr) < 0;
}
// Converts an AGS string to a ScummVM one
operator Common::String() const {
return Common::String(_cstr);
}
// Fixes compilation error in script_set
operator bool() const {
return !IsEmpty();
}
operator const char *() const {
return GetCStr();
}
private:
// Creates new empty string with buffer enough to fit given length
void Create(size_t buffer_length);
// Release string and copy data to the new buffer
void Copy(size_t buffer_length, size_t offset = 0);
// Aligns data at given offset
void Align(size_t offset);
// Tells if this object shares its string buffer with others
bool IsShared() const;
// Ensure this string is a writeable independent copy, with ref counter = 1
void BecomeUnique();
// Ensure this string is independent, and there's enough space before
// or after the current string data
void ReserveAndShift(bool left, size_t more_length);
// Internal String data
char *_cstr; // pointer to actual string data; always valid, never null
size_t _len; // valid string length, in characters, excluding null-term
// Header of a reference-counted buffer
struct BufHeader {
size_t RefCount = 0; // reference count
size_t Capacity = 0; // available space, in characters
};
// Union that groups mutually exclusive data (currently only ref counted buffer)
union {
char *_buf; // reference-counted data (raw ptr)
BufHeader *_bufHead; // the header of a reference-counted data
};
};
} // namespace Shared
} // namespace AGS
} // namespace AGS3
#endif