Darwin-Streaming-Server/PrefsSourceLib/XMLParser.cpp

/*
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * Copyright (c) 1999-2008 Apple Inc.  All Rights Reserved.
 *
 * 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. 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_LICENSE_HEADER_END@
 *
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#ifndef __Win32__
#include <unistd.h>
#endif

#include "XMLParser.h"
#include "OSMemory.h"

XMLParser::XMLParser( char* inPath, DTDVerifier* verifier)
    : fRootTag(NULL), fFilePath(NULL)
{
    StrPtrLen thePath(inPath);
    fFilePath = thePath.GetAsCString();
    fFile.Set(inPath);
    fVerifier = verifier;
}

XMLParser::~XMLParser()
{
    if (fRootTag)
        delete fRootTag;

    delete [] fFilePath;
}

Bool16 XMLParser::ParseFile(char* errorBuffer, int errorBufferSize)
{
    if (fRootTag != NULL)
    {
        delete fRootTag;    // flush old data
        fRootTag = NULL;
    }
    
    fFile.Set(fFilePath);

    if (errorBufferSize < 500) errorBuffer = NULL;  // Just a hack to avoid checking everywhere
    if ((fFile.GetLength() == 0) || fFile.IsDir())
    {
        if (errorBuffer != NULL)
            qtss_snprintf(errorBuffer, errorBufferSize,  "Couldn't read xml file");
        return false;   // we don't have a valid file;
    }
    
    char* fileData = NEW char[ (SInt32) (fFile.GetLength() + 1)];
    UInt32 theLengthRead = 0;
    fFile.Read(0, fileData, (UInt32) fFile.GetLength(), &theLengthRead); 

    StrPtrLen theDataPtr(fileData, theLengthRead);
    StringParser theParser(&theDataPtr);
    
    fRootTag = NEW XMLTag();
    Bool16 result = fRootTag->ParseTag(&theParser, fVerifier, errorBuffer, errorBufferSize);
    if (!result)
    {
        // got error parsing file
        delete fRootTag;
        fRootTag = NULL;
    }
    
    delete fileData;
    
    fFile.Close();

    return result;
}

Bool16  XMLParser::DoesFileExist()
{
    Bool16 itExists = false;
    fFile.Set(fFilePath);
    if ((fFile.GetLength() > 0) && (!fFile.IsDir()))
        itExists = true;
    fFile.Close();
    
    return itExists;
}

Bool16  XMLParser::DoesFileExistAsDirectory()
{
    Bool16 itExists = false;
    fFile.Set(fFilePath);
    if (fFile.IsDir())
        itExists = true;
    fFile.Close();
    
    return itExists;
}

Bool16  XMLParser::CanWriteFile()
{
    //
    // First check if it exists for reading
    FILE* theFile = ::fopen(fFilePath, "r");
    if (theFile == NULL)
        return true;
    
    ::fclose(theFile);
    
    //
    // File exists for reading, check if we can write it
    theFile = ::fopen(fFilePath, "a");
    if (theFile == NULL)
        return false;
        
    //
    // We can read and write
    ::fclose(theFile);
    return true;
}

void XMLParser::SetRootTag(XMLTag* tag)
{
    if (fRootTag != NULL)
        delete fRootTag;
    fRootTag = tag;
}
    
void XMLParser::WriteToFile(char** fileHeader)
{
    char theBuffer[8192];
    ResizeableStringFormatter formatter(theBuffer, 8192);
    
    //
    // Write the file header
    for (UInt32 a = 0; fileHeader[a] != NULL; a++)
    {
        formatter.Put(fileHeader[a]);
        formatter.Put(kEOLString);
    }
    
        if (fRootTag)
                fRootTag->FormatData(&formatter, 0);

    //
    // New libC code. This seems to work better on Win32
    formatter.PutTerminator();
    FILE* theFile = ::fopen(fFilePath, "w");
    if (theFile == NULL)
        return;
        
    qtss_fprintf(theFile, "%s", formatter.GetBufPtr());
    ::fclose(theFile);
    
#if __MacOSX__
    (void) ::chown(fFilePath,76,80);//owner qtss, group admin
#endif

#ifndef __Win32__
    ::chmod(fFilePath, S_IRUSR | S_IWUSR | S_IRGRP );
#endif
}

UInt8 XMLTag::sNonNameMask[] =
{
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //0-9 
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //10-19 
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //20-29
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //30-39 
    1, 1, 1, 1, 1, 0, 0, 1, 0, 0, //40-49 '.' and '-' are name chars
    0, 0, 0, 0, 0, 0, 0, 0, 0, 1, //50-59 ':' is a name char
    1, 1, 1, 1, 1, 0, 0, 0, 0, 0, //60-69 //stop on every character except a letter or number
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //70-79
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //80-89
    0, 1, 1, 1, 1, 0, 1, 0, 0, 0, //90-99 '_' is a name char
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //100-109
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //110-119
    0, 0, 0, 1, 1, 1, 1, 1, 1, 1, //120-129
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //130-139
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //140-149
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //150-159
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //160-169
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //170-179
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //180-189
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //190-199
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //200-209
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //210-219
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //220-229
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //230-239
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //240-249
    1, 1, 1, 1, 1, 1             //250-255
};

XMLTag::XMLTag() :
    fTag(NULL),
    fValue(NULL),
    fElem(NULL)
{ fElem = this;
}

XMLTag::XMLTag(char* tagName) :
    fTag(NULL),
    fValue(NULL),
    fElem(NULL)
{   fElem = this;
    StrPtrLen temp(tagName);
    fTag = temp.GetAsCString();
}

XMLTag::~XMLTag()
{
    if (fTag)
        delete fTag;
    if (fValue)
        delete fValue;      
        
    OSQueueElem* elem;
    while ((elem = fAttributes.DeQueue()) != NULL)
    {
        XMLAttribute* attr = (XMLAttribute*)elem->GetEnclosingObject();
        delete attr;
    }       

    while ((elem = fEmbeddedTags.DeQueue()) != NULL)
    {
        XMLTag* tag = (XMLTag*)elem->GetEnclosingObject();
        delete tag;
    }
    
    if (fElem.IsMemberOfAnyQueue())
        fElem.InQueue()->Remove(&fElem);    // remove from parent tag
}

void XMLTag::ConsumeIfComment(StringParser* parser)
{
    if ((parser->GetDataRemaining() > 2) && ((*parser)[1] == '-') && ((*parser)[2] == '-'))
    {
        // this is a comment, so skip to end of comment
        parser->ConsumeLength(NULL, 2); // skip '--'
        
        // look for -->
        while((parser->GetDataRemaining() > 2) && ((parser->PeekFast() != '-') ||
                ((*parser)[1] != '-') || ((*parser)[2] != '>')))
        {
            if (parser->PeekFast() == '-') parser->ConsumeLength(NULL, 1);
            parser->ConsumeUntil(NULL, '-');
        }
        
        if (parser->GetDataRemaining() > 2) parser->ConsumeLength(NULL, 3); // consume -->
    }
}

bool XMLTag::ParseTag(StringParser* parser, DTDVerifier* verifier, char* errorBuffer, int errorBufferSize)
{
    while (true)
    {
        if (!parser->GetThru(NULL, '<'))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer, errorBufferSize, "Couldn't find a valid tag");
            return false;   // couldn't find beginning of tag
        }
            
        char c = parser->PeekFast();
        if (c == '/')
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer, errorBufferSize, "End tag with no begin tag on line %d", parser->GetCurrentLineNumber());
            return false;   // we shouldn't be seeing a close tag here
        }
            
        if ((c != '!') && (c != '?'))
            break;  // this should be the beginning of a regular tag
            
        ConsumeIfComment(parser);
        // otherwise this is a processing instruction or a c-data, so look for the next tag
    }
    
    int tagStartLine = parser->GetCurrentLineNumber();
    
    StrPtrLen temp;
    parser->ConsumeUntil(&temp, sNonNameMask);
    if (temp.Len == 0)
    {
        if (errorBuffer != NULL)
        {
            if (parser->GetDataRemaining() == 0)
                qtss_snprintf(errorBuffer, errorBufferSize, "Unexpected end of file on line %d", parser->GetCurrentLineNumber());
            else
                qtss_snprintf(errorBuffer,  errorBufferSize,"Unexpected character (%c) on line %d", parser->PeekFast(), parser->GetCurrentLineNumber());
        }
        return false;   // bad file
    }
        
    fTag = temp.GetAsCString();
    
    parser->ConsumeWhitespace();
    while ((parser->PeekFast() != '>') && (parser->PeekFast() != '/'))
    {
        // we must have an attribute value for this tag
        XMLAttribute* attr = new XMLAttribute;
        fAttributes.EnQueue(&attr->fElem);
        parser->ConsumeUntil(&temp, sNonNameMask);
        if (temp.Len == 0)
        {
            if (errorBuffer != NULL)
            {
                if (parser->GetDataRemaining() == 0)
                    qtss_snprintf(errorBuffer,  errorBufferSize, "Unexpected end of file on line %d", parser->GetCurrentLineNumber());
                else
                    qtss_snprintf(errorBuffer,  errorBufferSize,"Unexpected character (%c) on line %d", parser->PeekFast(), parser->GetCurrentLineNumber());
            }
            return false;   // bad file
        }

        attr->fAttrName = temp.GetAsCString();

        if (!parser->Expect('='))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer,  errorBufferSize,"Missing '=' after attribute %s on line %d", attr->fAttrName, parser->GetCurrentLineNumber());
            return false;   // bad attribute specification
        }
        if (!parser->Expect('"'))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer,  errorBufferSize,"Attribute %s value not in quotes on line %d", attr->fAttrName, parser->GetCurrentLineNumber());
            return false;   // bad attribute specification
        }
            
        parser->ConsumeUntil(&temp, '"');
        attr->fAttrValue = temp.GetAsCString();
        if (!parser->Expect('"'))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer, errorBufferSize, "Attribute %s value not in quotes on line %d", attr->fAttrName, parser->GetCurrentLineNumber());
            return false;   // bad attribute specification
        }
        
        if (verifier && !verifier->IsValidAttributeName(fTag, attr->fAttrName))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer, errorBufferSize, "Attribute %s not allowed in tag %s on line %d", attr->fAttrName, fTag, parser->GetCurrentLineNumber());
            return false;   // bad attribute specification
        }

        if (verifier && !verifier->IsValidAttributeValue(fTag, attr->fAttrName, attr->fAttrValue))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer,  errorBufferSize,"Bad value for attribute %s on line %d", attr->fAttrName, parser->GetCurrentLineNumber());
            return false;   // bad attribute specification
        }

        parser->ConsumeWhitespace();
    }
    
    if (parser->PeekFast() == '/')
    {
        // this is an empty element tag, i.e. no contents or end tag (e.g <TAG attr="value" />
        parser->Expect('/');
        if (!parser->Expect('>'))
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer,  errorBufferSize,"'>' must follow '/' on line %d", parser->GetCurrentLineNumber());
            return false;   // bad attribute specification
        }
        
        return true;    // we're done with this tag
    }
    
    if (!parser->Expect('>'))
    {
        if (errorBuffer != NULL)
            qtss_snprintf(errorBuffer,  errorBufferSize,"Bad format for tag <%s> on line %d", fTag, parser->GetCurrentLineNumber());
        return false;   // bad attribute specification
    }
    
    while(true)
    {
        parser->ConsumeUntil(&temp, '<');   // this is either value or whitespace
        if (parser->GetDataRemaining() < 4)
        {
            if (errorBuffer != NULL)
                qtss_snprintf(errorBuffer, errorBufferSize, "Reached end of file without end for tag <%s> declared on line %d", fTag, tagStartLine);
            return false;
        }
        if ((*parser)[1] == '/')
        {
            // we'll only assign a value if there were no embedded tags
            if (fEmbeddedTags.GetLength() == 0 && (!verifier || verifier->CanHaveValue(fTag)))
                fValue = temp.GetAsCString();
            else
            {
                // otherwise this needs to have been just whitespace
                StringParser tempParser(&temp);
                tempParser.ConsumeWhitespace();
                if (tempParser.GetDataRemaining() > 0)
                {
                    if (errorBuffer)
                    {
                        if (fEmbeddedTags.GetLength() > 0)
                            qtss_snprintf(errorBuffer,  errorBufferSize,"Unexpected text outside of tag on line %d", tagStartLine);
                        else
                            qtss_snprintf(errorBuffer, errorBufferSize, "Tag <%s> on line %d not allowed to have data", fTag, tagStartLine);
                    }
                }
            }
            break;  // we're all done with this tag
        }
        
        if (((*parser)[1] != '!') && ((*parser)[1] != '?'))
        {
            // this must be the beginning of an embedded tag
            XMLTag* tag = NEW XMLTag();
            fEmbeddedTags.EnQueue(&tag->fElem);
            if (!tag->ParseTag(parser, verifier, errorBuffer, errorBufferSize))
                return false;
                
            if (verifier && !verifier->IsValidSubtag(fTag, tag->GetTagName()))
            {
                if (errorBuffer != NULL)
                    qtss_snprintf(errorBuffer, errorBufferSize, "Tag %s not allowed in tag %s on line %d", tag->GetTagName(), fTag, parser->GetCurrentLineNumber());
                return false;   // bad attribute specification
            }
        }
        else
        {
            parser->ConsumeLength(NULL, 1); // skip '<'
            ConsumeIfComment(parser);
        }
    }

    parser->ConsumeLength(NULL, 2); // skip '</'
    parser->ConsumeUntil(&temp, sNonNameMask);
    if (!temp.Equal(fTag))
    {
        char* newTag = temp.GetAsCString();
        if (errorBuffer != NULL)
            qtss_snprintf(errorBuffer,  errorBufferSize,"End tag </%s> on line %d doesn't match tag <%s> declared on line %d", newTag, parser->GetCurrentLineNumber(),fTag, tagStartLine);
        delete newTag;
        return false;   // bad attribute specification
    }
    
    if (!parser->GetThru(NULL, '>'))
    {
        if (errorBuffer != NULL)
            qtss_snprintf(errorBuffer,  errorBufferSize,"Couldn't find end of tag <%s> declared on line %d", fTag, tagStartLine);
        return false;   // bad attribute specification
    }
    
    return true;
}

char* XMLTag::GetAttributeValue(const char* attrName)
{
    for (OSQueueIter iter(&fAttributes); !iter.IsDone(); iter.Next())
    {
        XMLAttribute* attr = (XMLAttribute*)iter.GetCurrent()->GetEnclosingObject();
        if (!strcmp(attr->fAttrName, attrName))
            return attr->fAttrValue;
    }
    
    return NULL;
}

XMLTag* XMLTag::GetEmbeddedTag(const UInt32 index)
{
    if (fEmbeddedTags.GetLength() <= index)
        return NULL;
    
    OSQueueIter iter(&fEmbeddedTags);
    for (UInt32 i = 0; i < index; i++)
    {
        iter.Next();
    }
    OSQueueElem* result = iter.GetCurrent();
    
    return (XMLTag*)result->GetEnclosingObject();
}

XMLTag* XMLTag::GetEmbeddedTagByName(const char* tagName, const UInt32 index)
{
    if (fEmbeddedTags.GetLength() <= index)
        return NULL;
    
    XMLTag* result = NULL;
    UInt32 curIndex = 0;
    for (OSQueueIter iter(&fEmbeddedTags); !iter.IsDone(); iter.Next())
    {
        XMLTag* temp = (XMLTag*)iter.GetCurrent()->GetEnclosingObject();
        if (!strcmp(temp->GetTagName(), tagName))
        {
            if (curIndex == index)
            {
                result = temp;
                break;
            }
                
            curIndex++;
        }
    }
    
    return result;
}

XMLTag* XMLTag::GetEmbeddedTagByAttr(const char* attrName, const char* attrValue, const UInt32 index)
{
    if (fEmbeddedTags.GetLength() <= index)
        return NULL;
    
    XMLTag* result = NULL;
    UInt32 curIndex = 0;
    for (OSQueueIter iter(&fEmbeddedTags); !iter.IsDone(); iter.Next())
    {
        XMLTag* temp = (XMLTag*)iter.GetCurrent()->GetEnclosingObject();
        if ((temp->GetAttributeValue(attrName) != NULL) && (!strcmp(temp->GetAttributeValue(attrName), attrValue)))
        {
            if (curIndex == index)
            {
                result = temp;
                break;
            }
                
            curIndex++;
        }
    }
    
    return result;
}

XMLTag* XMLTag::GetEmbeddedTagByNameAndAttr(const char* tagName, const char* attrName, const char* attrValue, const UInt32 index)
{
    if (fEmbeddedTags.GetLength() <= index)
        return NULL;
    
    XMLTag* result = NULL;
    UInt32 curIndex = 0;
    for (OSQueueIter iter(&fEmbeddedTags); !iter.IsDone(); iter.Next())
    {
        XMLTag* temp = (XMLTag*)iter.GetCurrent()->GetEnclosingObject();
        if (!strcmp(temp->GetTagName(), tagName) && (temp->GetAttributeValue(attrName) != NULL) && 
            (!strcmp(temp->GetAttributeValue(attrName), attrValue)))
        {
            if (curIndex == index)
            {
                result = temp;
                break;
            }
                
            curIndex++;
        }
    }
    
    return result;
}

void XMLTag::AddAttribute( char* attrName, char* attrValue)
{
    XMLAttribute* attr = NEW XMLAttribute;
    StrPtrLen temp(attrName);
    attr->fAttrName = temp.GetAsCString();
    temp.Set(attrValue);
    attr->fAttrValue = temp.GetAsCString();
    
    fAttributes.EnQueue(&attr->fElem);
}

void XMLTag::RemoveAttribute(char* attrName)
{
    for (OSQueueIter iter(&fAttributes); !iter.IsDone(); iter.Next())
    {
        XMLAttribute* attr = (XMLAttribute*)iter.GetCurrent()->GetEnclosingObject();
        if (!strcmp(attr->fAttrName, attrName))
        {
            fAttributes.Remove(&attr->fElem);
            delete attr;
            return;
        }
    }
}

void XMLTag::AddEmbeddedTag(XMLTag* tag)
{
    fEmbeddedTags.EnQueue(&tag->fElem);
}

void XMLTag::RemoveEmbeddedTag(XMLTag* tag)
{
    fEmbeddedTags.Remove(&tag->fElem);
}

void XMLTag::SetTagName( char* name)
{
    Assert (name != NULL);  // can't have a tag without a name!
    
    if (fTag != NULL)
        delete fTag;
        
    StrPtrLen temp(name);
    fTag = temp.GetAsCString();
}
    
void XMLTag::SetValue( char* value)
{
    if (fEmbeddedTags.GetLength() > 0)
        return;     // can't have a value with embedded tags
        
    if (fValue != NULL)
        delete fValue;
        
    if (value == NULL)
        fValue = NULL;
    else
    {
        StrPtrLen temp(value);
        fValue = temp.GetAsCString();
    }
}
    
void XMLTag::FormatData(ResizeableStringFormatter* formatter, UInt32 indent)
{
    for (UInt32 i=0; i<indent; i++) formatter->PutChar('\t');

    formatter->PutChar('<');
    formatter->Put(fTag);
    if (fAttributes.GetLength() > 0)
    {
        formatter->PutChar(' ');
        for (OSQueueIter iter(&fAttributes); !iter.IsDone(); iter.Next())
        {
            XMLAttribute* attr = (XMLAttribute*)iter.GetCurrent()->GetEnclosingObject();
            formatter->Put(attr->fAttrName);
            formatter->Put("=\"");
            formatter->Put(attr->fAttrValue);
            formatter->Put("\" ");
        }
    }
    formatter->PutChar('>');
    
    if (fEmbeddedTags.GetLength() == 0)
    {
        if (fValue > 0)
            formatter->Put(fValue);
    }
    else
    {
        formatter->Put(kEOLString);
        for (OSQueueIter iter(&fEmbeddedTags); !iter.IsDone(); iter.Next())
        {
            XMLTag* current = (XMLTag*)iter.GetCurrent()->GetEnclosingObject();
            current->FormatData(formatter, indent + 1);
        }

        for (UInt32 i=0; i<indent; i++) formatter->PutChar('\t');
    }
    
    formatter->Put("</");
    formatter->Put(fTag);
    formatter->PutChar('>');
    formatter->Put(kEOLString);
}

XMLAttribute::XMLAttribute()
    : fAttrName(NULL),
    fAttrValue(NULL)
{   fElem = this;
}

XMLAttribute::~XMLAttribute()
{
    if (fAttrName)
        delete fAttrName;
    if (fAttrValue)
        delete fAttrValue;      
}