想象一个包含5000组数据的xml文件。解析时，我NSLog一个元素，它返回了我5000套数据，但我有一个循环，将数据插入sqlite3数据库。似乎在400+之后停止插入。我环顾四周，发现它吞噬了内存？在泄漏仪器中，负责的库是libsqlite3.dylib而责任框架是sqlite3MemMalloc所以我现在如何解决？下面是我的代码。该方法在NSXMLParser didEndElement方法中。
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{
//NSLog(@"ended element: %@", elementName);
MedicalBedAppDelegate *appDelegate = (MedicalBedAppDelegate *)[[UIApplication sharedApplication] delegate];
if ([elementName isEqualToString:@"Status"]) {
//setup some globals
databaseName = @"MedicalBedDatabase.sql";
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [documentPaths objectAtIndex:0];
databasePath = [documentsDir stringByAppendingPathComponent:databaseName];
//Method Stackoverflow
sqlite3 *database;
NSInteger i;
NSString *p = [[[NSString alloc]init] autorelease];
NSString *p2 = [[[NSString alloc]init] autorelease];
NSString *str = [NSString stringWithFormat:@"INSERT INTO UsageData(Date,Time,NoOfMovementRegistered,BreathingRate,TimeSinceLastMovement,Status,bID) VALUES ('%@','%@','%@','%@','%@','%@','%@')",currentDate,currentTime,currentNoMove,currentNoBreathe,currentTimeSinceLastMovement,currentStatus,currentBedNo];
const char *sqlStmt = [str UTF8String];
sqlite3_stmt *cmp_sqlStmt;
NSString *str1 = [NSString stringWithFormat:@"INSERT INTO XMLEntryID(EntryID,bID) VALUES ('%@','%@')",currentEntryID ,p];
const char *sqlStmt1 = [str1 UTF8String];
sqlite3_stmt *cmp_sqlStmt1;
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {
for (i = 0; i<([appDelegate.beds count]) ; i++) {
Bed *aBedInstance = (Bed *)[appDelegate.beds objectAtIndex:i];
EntryID *aEntryIDInstance = (EntryID *)[appDelegate.entryids objectAtIndex:i];
p = aBedInstance.bedno;
p2 = aEntryIDInstance.bedID;
if ([p intValue] == [currentBedNo intValue]) {
if ([aEntryIDInstance.bedID intValue] == [currentBedNo intValue])
{
if ([aEntryIDInstance.entryID intValue] > [currentEntryID intValue] && [aEntryIDInstance.bedID intValue] == [currentBedNo intValue]) {
//NSLog(@"xmlEntryID is lower then dBCount");
}
else if ([aEntryIDInstance.entryID intValue] == [currentEntryID intValue] && [aEntryIDInstance.bedID intValue] == [currentBedNo intValue])
{
//This if else if statement is needed because if the dbCount == currentEntryID , it would still consider it
// to be dbCount < currentEntryID
//NSLog(@" IT IS EQUAL ");
}
else if ([aEntryIDInstance.entryID intValue] < [currentEntryID intValue] && [aEntryIDInstance.bedID intValue] == [currentBedNo intValue] ) {
////NSLog(@"dBCount at selectionScreen = %d",[[appDelegate.dBCount objectAtIndex:0] intValue]);
//NSLog(@"currentEntryID at selectionScreen = %d",[currentEntryID intValue]);
//NSLog(@"xmlEntryID is higher then dBCount");
if(sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL) == SQLITE_OK)
{
int returnValue = sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL);
((returnValue ==SQLITE_OK)? NSLog(@"INSERT into USAGEDATA SUCCESS") : NSLog(@"INSERT into USAGEDATA Fail"));
sqlite3_step(cmp_sqlStmt);
}
sqlite3_finalize(cmp_sqlStmt);
sqlite3_close(database);
if(sqlite3_prepare_v2(database, sqlStmt1, -1, &cmp_sqlStmt1, NULL) == SQLITE_OK)
{
int returnValue = sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt1, NULL);
((returnValue ==SQLITE_OK) ? NSLog(@"INSERT into XMLEntryID SUCCESS") : NSLog(@"INSERT into XMLEntryID Fail"));
sqlite3_step(cmp_sqlStmt1);
}
sqlite3_finalize(cmp_sqlStmt1);
sqlite3_close(database);
}
}
}else if ([p intValue] != [currentBedNo intValue]) {
}
}
}
NSLog(@"adding currentEntryID: %@", currentEntryID);
sqlite3_close(database);
}
}
答案 0 :(得分：2)
你在浪费记忆
NSString *p = [[[NSString alloc]init] autorelease];
NSString *p2 = [[[NSString alloc]init] autorelease]
....
p = aBedInstance.bedno;
p2 = aEntryIDInstance.bedID;
当您所做的只是测试aBedInstance.bedno的值时，无需创建新实例。块{/ p>中的其他地方根本没有使用p2
删除前两行并在for循环
for (... ) {
NSString *p = [aBedInstance.bedno retain]; // thread safety
NSString *p2 = [aEntryIDInstance.bedID retain]; // FIXME: p2 is not used in the scope of this method
if (....) {
....
}
....
[p release];
[p2 release];
}
代码还有其他问题。
if(sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL) == SQLITE_OK) {
int returnValue = sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL);
((returnValue ==SQLITE_OK)? NSLog(@"INSERT into USAGEDATA SUCCESS") : NSLog(@"INSERT into USAGEDATA Fail"));
sqlite3_step(cmp_sqlStmt);
}
sqlite3_finalize(cmp_sqlStmt);
sqlite3_close(database);
if(sqlite3_prepare_v2(database, sqlStmt1, -1, &cmp_sqlStmt1, NULL) == SQLITE_OK) {
int returnValue = sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt1, NULL);
((returnValue ==SQLITE_OK) ? NSLog(@"INSERT into XMLEntryID SUCCESS") : NSLog(@"INSERT into XMLEntryID Fail"));
sqlite3_step(cmp_sqlStmt1);
}
sqlite3_finalize(cmp_sqlStmt1);
sqlite3_close(database);
您应该为每个语句调用一次prepare。对sqlStmt1的sqlite3函数调用将失败，因为您已经关闭了数据库。
if (SQLITE_OK != sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL)) {
NSLog(@"Prepare INSERT into USAGEDATA FAILED");
} else {
if (SQLITE_DONE != sqlite3_step(cmp_sqlStmt)) {
NSLog(@"INSERT into USAGEDATA FAILED");
} else {
NSLog(@"INSERT into USAGEDATA SUCCEEDED");
}
sqlite3_finalize(cmp_sqlStmt);
}
if (SQLITE_OK != sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt1, NULL)) {
NSLog(@"Prepare INSERT into XMLEntryID FAILED");
} else {
if (SQLITE_DONE != sqlite3_step(cmp_sqlStmt1)) {
NSLog(@"INSERT into XMLEntryID FAILED");
} else {
NSLog(@"INSERT into XMLEntryID SUCCEEDED");
}
sqlite3_finalize(cmp_sqlStmt1);
}
sqlite3_close(database);
请注意，通过使用使用参数的静态sql字符串，在for循环之外准备语句然后使用sqlite3_bind_*例程来设置for循环内的值，可以提高整体性能。
语句对象的生命周期如下：
答案 1 :(得分：1)
我解决了它，而不是使用prepare语句，而是使用了exec语句
if (sqlite3_exec(database, [str UTF8String], NULL, NULL, &errorMsg)!=SQLITE_OK) {
NSAssert1(0,@"Error updating tables: %s",errorMsg);
sqlite3_free(errorMsg);
}
sqlite3_close(database);