/*
 * Copyright (c) 2019 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* IOString.m created by rsulack on Wed 17-Sep-1997 */
/* IOString.cpp converted to C++ on Tue 1998-9-22 */

#define IOKIT_ENABLE_SHARED_PTR

#include <string.h>

#include <libkern/c++/OSString.h>
#include <libkern/c++/OSSerialize.h>
#include <libkern/c++/OSSharedPtr.h>
#include <libkern/c++/OSLib.h>
#include <libkern/c++/OSData.h>
#include <string.h>

#define super OSObject

OSDefineMetaClassAndStructorsWithZone(OSString, OSObject,
    (zone_create_flags_t) (ZC_CACHING | ZC_ZFREE_CLEARMEM))
OSMetaClassDefineReservedUnused(OSString, 0);
OSMetaClassDefineReservedUnused(OSString, 1);
OSMetaClassDefineReservedUnused(OSString, 2);
OSMetaClassDefineReservedUnused(OSString, 3);
OSMetaClassDefineReservedUnused(OSString, 4);
OSMetaClassDefineReservedUnused(OSString, 5);
OSMetaClassDefineReservedUnused(OSString, 6);
OSMetaClassDefineReservedUnused(OSString, 7);
OSMetaClassDefineReservedUnused(OSString, 8);
OSMetaClassDefineReservedUnused(OSString, 9);
OSMetaClassDefineReservedUnused(OSString, 10);
OSMetaClassDefineReservedUnused(OSString, 11);
OSMetaClassDefineReservedUnused(OSString, 12);
OSMetaClassDefineReservedUnused(OSString, 13);
OSMetaClassDefineReservedUnused(OSString, 14);
OSMetaClassDefineReservedUnused(OSString, 15);

bool
OSString::initWithString(const OSString *aString)
{
	return initWithCString(aString->string);
}

bool
OSString::initWithCString(const char *cString)
{
	unsigned int   newLength;
	char         * newString;

	if (!cString || !super::init()) {
		return false;
	}

	newLength = (unsigned int) strnlen(cString, kMaxStringLength);
	if (newLength >= kMaxStringLength) {
		return false;
	}

	newLength++;
	newString = (char *)kalloc_data(newLength,
	    Z_VM_TAG_BT(Z_WAITOK, VM_KERN_MEMORY_LIBKERN));
	if (!newString) {
		return false;
	}

	bcopy(cString, newString, newLength);

	if (!(flags & kOSStringNoCopy) && string) {
		kfree_data(string, length);
		OSCONTAINER_ACCUMSIZE(-((size_t)length));
	}
	string = newString;
	length = newLength;
	flags &= ~kOSStringNoCopy;

	OSCONTAINER_ACCUMSIZE(length);

	return true;
}

bool
OSString::initWithStringOfLength(const char *cString, size_t inlength)
{
	unsigned int   newLength;
	unsigned int   cStringLength;
	char         * newString;

	if (!cString || !super::init()) {
		return false;
	}

	if (inlength >= kMaxStringLength) {
		return false;
	}

	cStringLength = (unsigned int)strnlen(cString, inlength);

	if (cStringLength < inlength) {
		inlength = cStringLength;
	}

	newLength = (unsigned int) (inlength + 1);
	newString = (char *)kalloc_data(newLength,
	    Z_VM_TAG_BT(Z_WAITOK, VM_KERN_MEMORY_LIBKERN));
	if (!newString) {
		return false;
	}

	bcopy(cString, newString, inlength);
	newString[inlength] = 0;

	if (!(flags & kOSStringNoCopy) && string) {
		kfree_data(string, length);
		OSCONTAINER_ACCUMSIZE(-((size_t)length));
	}

	string = newString;
	length = newLength;
	flags &= ~kOSStringNoCopy;

	OSCONTAINER_ACCUMSIZE(length);

	return true;
}

bool
OSString::initWithCStringNoCopy(const char *cString)
{
	if (!cString || !super::init()) {
		return false;
	}

	length = (unsigned int) strnlen(cString, kMaxStringLength);
	if (length >= kMaxStringLength) {
		return false;
	}

	length++;
	flags |= kOSStringNoCopy;
	string = const_cast<char *>(cString);

	return true;
}

OSSharedPtr<OSString>
OSString::withString(const OSString *aString)
{
	OSSharedPtr<OSString> me = OSMakeShared<OSString>();

	if (me && !me->initWithString(aString)) {
		return nullptr;
	}

	return me;
}

OSSharedPtr<OSString>
OSString::withCString(const char *cString)
{
	OSSharedPtr<OSString> me = OSMakeShared<OSString>();

	if (me && !me->initWithCString(cString)) {
		return nullptr;
	}

	return me;
}

OSSharedPtr<OSString>
OSString::withCStringNoCopy(const char *cString)
{
	OSSharedPtr<OSString> me = OSMakeShared<OSString>();

	if (me && !me->initWithCStringNoCopy(cString)) {
		return nullptr;
	}

	return me;
}

OSSharedPtr<OSString>
OSString::withCString(const char *cString, size_t length)
{
	OSSharedPtr<OSString> me = OSMakeShared<OSString>();

	if (me && !me->initWithStringOfLength(cString, length)) {
		return nullptr;
	}

	return me;
}



/* @@@ gvdl */
#if 0
OSString *
OSString::stringWithFormat(const char *format, ...)
{
#ifndef KERNEL                  // mach3xxx
	OSString *me;
	va_list argList;

	if (!format) {
		return 0;
	}

	va_start(argList, format);
	me = stringWithCapacity(256);
	me->length = vsnprintf(me->string, 256, format, argList);
	me->length++;   // we include the null in the length
	if (me->Length > 256) {
		me->Length = 256;
	}
	va_end(argList);

	return me;
#else
	return 0;
#endif
}
#endif /* 0 */

void
OSString::free()
{
	if (!(flags & kOSStringNoCopy) && string) {
		kfree_data(string, length);
		OSCONTAINER_ACCUMSIZE(-((size_t)length));
	}

	super::free();
}

unsigned int
OSString::getLength()  const
{
	return length - 1;
}

const char *
OSString::getCStringNoCopy() const
{
	return string;
}

bool
OSString::setChar(char aChar, unsigned int index)
{
	if (!(flags & kOSStringNoCopy) && index < length - 1) {
		string[index] = aChar;

		return true;
	} else {
		return false;
	}
}

char
OSString::getChar(unsigned int index) const
{
	if (index < length) {
		return string[index];
	} else {
		return '\0';
	}
}


bool
OSString::isEqualTo(const OSString *aString) const
{
	if (length != aString->length) {
		return false;
	} else {
		return isEqualTo((const char *) aString->string);
	}
}

bool
OSString::isEqualTo(const char *aCString) const
{
	return strncmp(string, aCString, length) == 0;
}

bool
OSString::isEqualTo(const OSMetaClassBase *obj) const
{
	OSString *  str;
	OSData *    data;

	if ((str = OSDynamicCast(OSString, obj))) {
		return isEqualTo(str);
	} else if ((data = OSDynamicCast(OSData, obj))) {
		return isEqualTo(data);
	} else {
		return false;
	}
}

bool
OSString::isEqualTo(const OSData *obj) const
{
	if (NULL == obj) {
		return false;
	}

	unsigned int dataLen = obj->getLength();
	const char * dataPtr = (const char *) obj->getBytesNoCopy();

	if (dataLen != length) {
		// check for the fact that OSData may be a buffer that
		// that includes a termination byte and will thus have
		// a length of the actual string length PLUS 1. In this
		// case we verify that the additional byte is a terminator
		// and if so count the two lengths as being the same.

		if ((dataLen - length) == 1) {
			if (dataPtr[dataLen - 1] != 0) {
				return false;
			}
			dataLen--;
		} else {
			return false;
		}
	}

	for (unsigned int i = 0; i < dataLen; i++) {
		if (*dataPtr++ != string[i]) {
			return false;
		}
	}

	return true;
}

bool
OSString::serialize(OSSerialize *s) const
{
	char *c = string;

	if (s->previouslySerialized(this)) {
		return true;
	}

	if (!s->addXMLStartTag(this, "string")) {
		return false;
	}
	while (*c) {
		if (*c == '<') {
			if (!s->addString("&lt;")) {
				return false;
			}
		} else if (*c == '>') {
			if (!s->addString("&gt;")) {
				return false;
			}
		} else if (*c == '&') {
			if (!s->addString("&amp;")) {
				return false;
			}
		} else {
			if (!s->addChar(*c)) {
				return false;
			}
		}
		c++;
	}

	return s->addXMLEndTag("string");
}