I'm trying to insert into a table data using SQLFetchScroll. The problem is if I set ROWSET_SIZE to 2, for example, of 1000 lines from source I only insert 500 lines (half) into destination table. I think the problem is with the function SQLExecute but I can't figure out how to set it right. Does anyone know how to solve this, please?
const SQLUSMALLINT ROWSET_SIZE = 2;
SQLSetStmtAttr(srcHStmt, SQL_ATTR_ROW_ARRAY_SIZE, (SQLPOINTER)ROWSET_SIZE, 0);
SQLLEN FetchOffset = 0;
while (TRUE)
{
srcReturn = SQLFetchScroll(srcHStmt, SQL_FD_FETCH_NEXT, FetchOffset);
if (srcReturn == SQL_NO_DATA_FOUND || srcReturn == SQL_ERROR)
{
if (srcReturn == SQL_ERROR) showError(SQL_HANDLE_DBC, srcHDBC);
break;
}
dstReturn = SQLExecute(dstHStmt);
}
Compiler: VS2015 / 64 bit machine.
When using SQL_FETCH_RELATIVE I'm having the same results.
SQLExecDirect(...);
SQLLEN FetchOffset = 2;
while (TRUE)
{
srcReturn = SQLFetchScroll(srcHStmt, SQL_FETCH_RELATIVE, FetchOffset);
if (srcReturn == SQL_NO_DATA_FOUND || srcReturn == SQL_ERROR)
{
if (srcReturn == SQL_ERROR) showError(SQL_HANDLE_DBC, srcHDBC);
break;
}
dstReturn = SQLExecute(dstHStmt);
}
Related
I'm working on a wrapper for MariaDB Connector C. There is a typical situation when a developer doesn't know a length of a data stored in a field. As I figured out, one of the ways to obtain a real length of the field is to pass a buffer of lengths to mysql_stmt_bind_result and then to fetch each column by calling mysql_stmt_fetch_column. But I can't understand how the function mysql_stmt_fetch_column works because I'm getting a memory corruption and app abortion.
Here is how I'm trying to reach my goal
// preparations here
...
if (!mysql_stmt_execute(stmt))
{
int columnNum = mysql_stmt_field_count(stmt);
if (columnNum > 0)
{
MYSQL_RES* metadata = mysql_stmt_result_metadata(stmt);
MYSQL_FIELD* fields = mysql_fetch_fields(metadata);
MYSQL_BIND* result = new MYSQL_BIND[columnNum];
std::memset(result, 0, sizeof (MYSQL_BIND) * columnNum);
std::vector<unsigned long> lengths;
lengths.resize(columnNum);
for (int i = 0; i < columnNum; ++i)
result[i].length = &lengths[i];
if (!mysql_stmt_bind_result(stmt, result))
{
while (true)
{
int status = mysql_stmt_fetch(stmt);
if (status == 1)
{
m_lastError = mysql_stmt_error(stmt);
isOK = false;
break;
}
else if (status == MYSQL_NO_DATA)
{
isOK = true;
break;
}
for (int i = 0; i < columnNum; ++i)
{
my_bool isNull = true;
if (lengths.at(i) > 0)
{
result[i].buffer_type = fields[i].type;
result[i].is_null = &isNull;
result[i].buffer = malloc(lengths.at(i));
result[i].buffer_length = lengths.at(i);
mysql_stmt_fetch_column(stmt, result, i, 0);
if (!isNull)
{
// here I'm trying to read a result and I'm getting a valid result only from the first column
}
}
}
}
}
}
If I put an array to the mysql_stmt_fetch_column then I'm fetching the only first field valid, all other fields are garbage. If I put a single MYSQL_BIND structure to this function, then I'm getting an abortion of the app on approximately 74th field (funny thing that it's always this field). If I use another array of MYSQL_BIND then the situation is the same as the first case.
Please help me to understand how to use it correctly! Thanks
Minimal reproducible example
I am trying to implement a simple Gif-Reader in c++.
I currently stuck with decompressing the Imagedata.
If an image includes a Clear Code my decompression algorithm fails.
After the Clear Code I rebuild the CodeTable reset the CodeSize to MinimumLzwCodeSize + 1.
Then I read the next code and add it to the indexstream. The problem is that after clearing, the next codes include values greater than the size of the current codetable.
For example the sample file from wikipedia: rotating-earth.gif has a code value of 262 but the GlobalColorTable is only 256. How do I handle this?
I implemented the lzw decompression according to gif spec..
here is the main code part of decompressing:
int prevCode = GetCode(ptr, offset, codeSize);
codeStream.push_back(prevCode);
while (true)
{
auto code = GetCode(ptr, offset, codeSize);
//
//Clear code
//
if (code == IndexClearCode)
{
//reset codesize
codeSize = blockA.LZWMinimumCodeSize + 1;
currentNodeValue = pow(2, codeSize) - 1;
//reset codeTable
codeTable.resize(colorTable.size() + 2);
//read next code
prevCode = GetCode(ptr, offset, codeSize);
codeStream.push_back(prevCode);
continue;
}
else if (code == IndexEndOfInformationCode)
break;
//exists in dictionary
if (codeTable.size() > code)
{
if (prevCode >= codeTable.size())
{
prevCode = code;
continue;
}
for (auto c : codeTable[code])
codeStream.push_back(c);
newEntry = codeTable[prevCode];
newEntry.push_back(codeTable[code][0]);
codeTable.push_back(newEntry);
prevCode = code;
if (codeTable.size() - 1 == currentNodeValue)
{
codeSize++;
currentNodeValue = pow(2, codeSize) - 1;
}
}
else
{
if (prevCode >= codeTable.size())
{
prevCode = code;
continue;
}
newEntry = codeTable[prevCode];
newEntry.push_back(codeTable[prevCode][0]);
for (auto c : newEntry)
codeStream.push_back(c);
codeTable.push_back(newEntry);
prevCode = codeTable.size() - 1;
if (codeTable.size() - 1 == currentNodeValue)
{
codeSize++;
currentNodeValue = pow(2, codeSize) - 1;
}
}
}
Found the solution.
It is called Deferred clear code. So when I check if the codeSize needs to be incremented I also need to check if the codeSize is already max(12), as it is possible to to get codes that are of the maximum Code Size. See spec-gif89a.txt.
if (codeTable.size() - 1 == currentNodeValue && codeSize < 12)
{
codeSize++;
currentNodeValue = (1 << codeSize) - 1;
}
I have an application that tries to verify the mmc.exe (services) signature. (the context of the application I think is irrelevant) I am trying with winapi function which both fails with
WinVerifyTrust. I get TRUST_E_BAD_DIGEST when I am trying with verification from catalog, and
TRUST_E_NOSIGNATURE when trying from file info. it is very important to mention that my function succeeds on win7, XP but fails on win8.
this is the code snippet for the function
CATALOG_INFO InfoStruct = {0};
InfoStruct.cbStruct = sizeof(CATALOG_INFO);
WINTRUST_CATALOG_INFO WintrustCatalogStructure = {0};
WintrustCatalogStructure.cbStruct = sizeof(WINTRUST_CATALOG_INFO);
WINTRUST_FILE_INFO WintrustFileStructure = {0};
WintrustFileStructure.cbStruct = sizeof(WINTRUST_FILE_INFO);
GUID ActionGuid = WINTRUST_ACTION_GENERIC_VERIFY_V2;
//Get a context for signature verification.
HCATADMIN Context = NULL;
if(!::CryptCATAdminAcquireContext(&Context, NULL, 0) ){
return false;
}
//Open file.
cx_handle hFile(::CreateFileW(filename_.c_str(), GENERIC_READ, 7, NULL, OPEN_EXISTING, 0, NULL));
if( INVALID_HANDLE_VALUE == (HANDLE)hFile )
{
CryptCATAdminReleaseContext(Context, 0);
return false;
}
//Get the size we need for our hash.
DWORD HashSize = 0;
::CryptCATAdminCalcHashFromFileHandle(hFile, &HashSize, NULL, 0);
if( HashSize == 0 )
{
//0-sized has means error!
::CryptCATAdminReleaseContext(Context, 0);
return false;
}
//Allocate memory.
buffer hashbuf(HashSize);
//Actually calculate the hash
if( !CryptCATAdminCalcHashFromFileHandle(hFile, &HashSize, hashbuf.data, 0) )
{
CryptCATAdminReleaseContext(Context, 0);
return false;
}
//Convert the hash to a string.
buffer MemberTag(((HashSize * 2) + 1) * sizeof(wchar_t));
for( unsigned int i = 0; i < HashSize; i++ ){
swprintf(&((PWCHAR)MemberTag.data)[i * 2], L"%02X", hashbuf.data[i ]);
}
//Get catalog for our context.
HCATINFO CatalogContext = CryptCATAdminEnumCatalogFromHash(Context, hashbuf, HashSize, 0, NULL);
if ( CatalogContext )
{
//If we couldn't get information
if ( !CryptCATCatalogInfoFromContext(CatalogContext, &InfoStruct, 0) )
{
//Release the context and set the context to null so it gets picked up below.
CryptCATAdminReleaseCatalogContext(Context, CatalogContext, 0);
CatalogContext = NULL;
}
}
//If we have a valid context, we got our info.
//Otherwise, we attempt to verify the internal signature.
WINTRUST_DATA WintrustStructure = {0};
WintrustStructure.cbStruct = sizeof(WINTRUST_DATA);
if( !CatalogContext )
{
load_signature_verification_from_file_info(WintrustFileStructure, WintrustStructure);
}
else
{
load_signature_verification_from_catalog(WintrustStructure, WintrustCatalogStructure, InfoStruct, MemberTag);
}
//Call our verification function.
long verification_res = ::WinVerifyTrust(0, &ActionGuid, &WintrustStructure);
//Check return.
bool is_success = SUCCEEDED(verification_res) ? true : false;
// if failed with CatalogContext, try with FILE_INFO
if(!is_success && CatalogContext && verification_res != TRUST_E_NOSIGNATURE)
{
//warning2(L"Failed verification with Catalog Context: 0x%x %s ; Retrying with FILE_INFO.", verification_res, (const wchar_t*)format_last_error(verification_res));
load_signature_verification_from_file_info(WintrustFileStructure, WintrustStructure);
verification_res = ::WinVerifyTrust(0, &ActionGuid, &WintrustStructure);
is_success = SUCCEEDED(verification_res) ? true : false;
}
if(perr && !is_success && verification_res != TRUST_E_NOSIGNATURE)
{
perr->code = verification_res;
perr->description = format_last_error(verification_res);
}
//Free context.
if( CatalogContext ){
::CryptCATAdminReleaseCatalogContext(Context, CatalogContext, 0);
}
//If we successfully verified, we need to free.
if( is_success )
{
WintrustStructure.dwStateAction = WTD_STATEACTION_CLOSE;
::WinVerifyTrust(0, &ActionGuid, &WintrustStructure);
}
::CryptCATAdminReleaseContext(Context, 0);
return is_success;
I don't think any thing had changed in this function from win7 to win 8 so what could possibly go wrong?
UPDATE
I did notice that my function does work for task manager at win 8.
but again for the mmc it does not work.
It appears that your general approach is correct and the functions themselves haven't changed. However there are subtle changes; namely the data on which they operate has changed. The hashes stored for files on Windows 8, according to comments on CryptCATAdminCalcHashFromFileHandle, are calculated using SHA-256 hashes.
The SHA-256 hashing algorithm is not supported by CryptCATAdminCalcHashFromFileHandle, so you must update the code to use CryptCATAdminAcquireContext2 and CryptCATAdminCalcHashFromFileHandle2 on Windows 8; the former allows you to acquire a HCATADMIN with a specified hash algorithm, and the latter allows using that HCATADMIN.
(Interestingly, WINTRUST_CATALOG_INFO also points this direction with its HCATADMIN hCatAdmin member, documented as "Windows 8 and Windows Server 2012: Support for this member begins.")
I'm curious, if there's any way to find out the UTC date/time when the next Daylight Saving adjustment will take place?
Something akin to what Windows reports (see circled):
This information is provided in Windows by the EnumDynamicTimeZoneInformation function.
See http://msdn.microsoft.com/en-us/library/windows/desktop/hh706893%28v=vs.85%29.aspx
There is a database that has code and data: http://www.iana.org/time-zones
I don't think there's a specific API for this. I would just do a binary search, using localtime (and maybe time and mktime) from <ctime> (C++) or <time.h> (C).
A basic approach is to scan ahead three months at a time until the tm_isdst flag in the returned data structure is flipped. Then you can start binary searching between the last two two dates to figure out exactly when it flips.
See http://www.cplusplus.com/reference/ctime/tm/ for reference material.
I appreciate all your replies. And, yes, indeed I was asking about a WinAPI for Windows.
I did more research and came up with the following method that does what I wanted. It uses C++ and MFC's COleDateTime for easier date/time calculations. Other than that it's just C++ and WinAPIs. Please check if I understood the documentation for the DYNAMIC_TIME_ZONE_INFORMATION correctly. Here's the code:
int GetNextDaylightSavingAdjustmentTime(SYSTEMTIME* pOutDtNextDST_Local, int* pnOutAdjustmentMin)
{
//Get next time when DST adjustment will take place
//'pOutDtNextDST_Local' = if not NULL, receives the (local) time when next DST adjustment will take place
//'pnOutAdjustmentMin' = if not NULL, receives the amount of adjustment in minutes
//RETURN:
// = 1 if got the time, or
// = 0 if DST is not used
// = -1 if error (check GetLastError() for info)
int nOSError = NO_ERROR;
//Load API dynamically (in case of Windows XP)
BOOL (WINAPI *pfnGetDynamicTimeZoneInformation)(PDYNAMIC_TIME_ZONE_INFORMATION);
(FARPROC&)pfnGetDynamicTimeZoneInformation =
::GetProcAddress(::GetModuleHandle(L"Kernel32.dll"), "GetDynamicTimeZoneInformation");
DWORD tzID;
SYSTEMTIME StandardDate;
SYSTEMTIME DaylightDate;
int nBiasDaylight;
//Use newer API if possible
if(pfnGetDynamicTimeZoneInformation)
{
DYNAMIC_TIME_ZONE_INFORMATION dtzi = {0};
tzID = pfnGetDynamicTimeZoneInformation(&dtzi);
StandardDate = dtzi.StandardDate;
DaylightDate = dtzi.DaylightDate;
nBiasDaylight = dtzi.DaylightBias;
}
else
{
//Older API
TIME_ZONE_INFORMATION tzi = {0};
tzID = GetTimeZoneInformation(&tzi);
StandardDate = tzi.StandardDate;
DaylightDate = tzi.DaylightDate;
nBiasDaylight = tzi.DaylightBias;
}
int nRes = -1;
int nAdjMins = 0;
SYSTEMTIME stDstChange;
memset(&stDstChange, 0, sizeof(stDstChange));
SYSTEMTIME stDst;
if(tzID == TIME_ZONE_ID_STANDARD ||
tzID == TIME_ZONE_ID_DAYLIGHT)
{
stDst = tzID != TIME_ZONE_ID_DAYLIGHT ? DaylightDate : StandardDate;
if(stDst.wMonth >= 1 &&
stDst.wMonth <= 12 &&
stDst.wDay >= 1 &&
stDst.wDayOfWeek >= 0 &&
stDst.wDayOfWeek <= 6)
{
//Get adjustment bias
nAdjMins = tzID != TIME_ZONE_ID_DAYLIGHT ? -nBiasDaylight : nBiasDaylight;
if(stDst.wYear == 0)
{
//Relative date
SYSTEMTIME stLocal;
::GetLocalTime(&stLocal);
//Begin from the 1st day of the month &
//make sure that the date is in the future
COleDateTime dt;
for(int nYear = stLocal.wYear;; nYear++)
{
dt.SetDateTime(nYear, stDst.wMonth, 1, stDst.wHour, stDst.wMinute, stDst.wSecond);
if(dt > COleDateTime::GetCurrentTime())
break;
}
int nRequiredWeek = stDst.wDay >= 1 && stDst.wDay <= 5 ? stDst.wDay : 5;
for(int nCntDOW = 1;;)
{
//0=Sunday, 1=Monday; 2=Tuesday; 3=Wednesday; 4=Thursday; 5=Friday; 6=Saturday
int dow = dt.GetDayOfWeek() - 1;
ASSERT(dow >= 0 && dow <= 6);
if(dow == stDst.wDayOfWeek)
{
if(nCntDOW >= nRequiredWeek)
{
//Stop
break;
}
else
{
nCntDOW++;
}
}
//Go to next day
dt += COleDateTimeSpan(1, 0, 0, 0);
}
//Convert back to system time
if(dt.GetAsSystemTime(stDstChange))
{
//Success
nRes = 1;
}
else
{
//Failed
nOSError = ERROR_INVALID_FUNCTION;
ASSERT(NULL);
}
}
else
{
//Absolute date
stDstChange = stDst;
nRes = 1;
}
}
else
{
//Failed
nOSError = ERROR_INVALID_PARAMETER;
ASSERT(NULL);
}
}
else
{
//DST is not used
if(tzID == TIME_ZONE_ID_UNKNOWN)
{
nRes = 0;
}
else
{
//Error
nOSError = ERROR_INVALID_DATA;
ASSERT(NULL);
}
}
if(pOutDtNextDST_Local)
*pOutDtNextDST_Local = stDstChange;
if(pnOutAdjustmentMin)
*pnOutAdjustmentMin = nAdjMins;
::SetLastError(nOSError);
return nRes;
}
PS. And scratch my request for the UTC time. As I learned, it is easier to deal with local time in this situation.
I'm trying to upgrade the FFMpeg source used with one of our projects but get_buffer has gone away. I'm not 100% sure on which method to replace it with. Here are two contexts in which its used, any help is appreciated.
I look forward to hearing from you soon,
Thanks,
Kevin
cur_offset = avio_tell(pb);
if (!para->playctrl_info.read_end_flag && (0 == pkt->data_size)) {
rev_byte = get_buffer(pb, pbuf, para->max_raw_size);
if ((rev_byte > 0) && (cur_offset <= para->pFormatCtx->data_offset)) {
try_count = 0;
pkt->data_size = rev_byte;
para->read_size.total_bytes += rev_byte;
pkt->avpkt_newflag = 1;
pkt->avpkt_isvalid = 1;
do {
read_length = get_buffer(s->pb, data + 12, read_size);
if ((read_length <= 0) || (sync_flag == 1024)) {
if (read_length == AVERROR(EAGAIN)) {
continue;
} else {
FREE(data);
log_error("[%s]get data failed. ret=%d\n", __FUNCTION__, read_length);
return 0;
}
} else {
break;
}
} while (retry_get_data < am_p->playctrl_info.read_max_retry_cnt);
pkt = data;
Although you already found your answer I will provide an answer in case others have the same issue. durandal_1707 provided the answer to you (I assume) in #ffmpeg-devel IRC:
expresspotato: I'm having trouble integrating the latest version of
ffmpeg against an old one from about a year and a half ago. It appears
get_buffer defined in aviobuf.c has gone away. Do you know which
method I should replace it with?
durandal_1707: in e63a362857d9807b23e65872598d782fa53bb6af get_buffer
have been renamed to avio_read