libxml2 SAX + file input stream

libxmlFileInputStream.m

- (BOOL)parse
{
    NSArray *libraryDatabases = [[[NSUserDefaults standardUserDefaults] persistentDomainForName:@"com.apple.iApps"] objectForKey:@"iTunesRecentDatabases"];
    NSURL *libraryURL = (([libraryDatabases count])) ? [NSURL URLWithString:[libraryDatabases objectAtIndex:0]] : nil;
    assert(libraryURL);
    const char *libPath = [libraryURL.path UTF8String];
    const int min = 4;
    FILE *fp = fopen(libPath, "r");
    assert(fp);
    char buffer[min];
    int i, c;
    for (i = 0; (c = getc(fp)) != EOF && i < min; buffer[i++] = c);
    if (i != min) { 
        fclose(fp);
        return NO; 
    }
    xmlParserCtxtPtr ctx = xmlCreatePushParserCtxt(&_saxHandlerStruct, (__bridge void*)self, buffer, 4, NULL);
    int options = XML_PARSE_RECOVER | XML_PARSE_NOENT | XML_PARSE_DTDLOAD;
    xmlCtxtUseOptions(ctx, options);
    c = 0;
    while (c != EOF) {
        char chunk[PAGE_SIZE];
        for (i = 0; (c = getc(fp)) != EOF && i < PAGE_SIZE; chunk[i++] = c);
        xmlParseChunk(ctx, chunk, i, 0);
    }
    xmlParseChunk(ctx, NULL, 0, 1);
    xmlFreeParserCtxt(ctx);
    xmlCleanupParser();
    fclose(fp);
    return YES;
}