mariadb/ndb/examples/ndbapi_scan_example/ndbapi_scan.cpp
2004-09-15 14:52:39 +02:00

816 lines
21 KiB
C++

/* Copyright (C) 2003 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*
* ndbapi_scan.cpp:
* Illustrates how to use the scan api in the NDBAPI.
* The example shows how to do scan, scan for update and scan for delete
* using NdbScanFilter and NdbScanOperation
*
* Classes and methods used in this example:
*
* Ndb
* init()
* waitUntilRead()
* getDictionary()
* startTransaction()
* closeTransaction()
* sendPreparedTransactions()
* pollNdb()
*
* NdbConnection
* getNdbOperation()
* executeAsynchPrepare()
* getNdbError()
* executeScan()
* nextScanResult()
*
* NdbDictionary::Dictionary
* getTable()
* dropTable()
* createTable()
*
* NdbDictionary::Column
* setName()
* setType()
* setLength()
* setPrimaryKey()
* setNullable()
*
* NdbDictionary::Table
* setName()
* addColumn()
*
* NdbOperation
* insertTuple()
* equal()
* setValue()
* openScanRead()
* openScanExclusive()
*
* NdbRecAttr
* aRef()
* u_32_value()
*
* NdbResultSet
* nextResult()
* deleteTuple()
* updateTuple()
*
* NdbScanOperation
* getValue()
* readTuplesExclusive()
*
* NdbScanFilter
* begin()
* eq()
* end()
*
*
*/
#include <ndb_global.h>
#include <NdbApi.hpp>
#include <NdbScanFilter.hpp>
// Used for cout
#include <iostream>
/**
* Helper sleep function
*/
int
milliSleep(int milliseconds){
int result = 0;
struct timespec sleeptime;
sleeptime.tv_sec = milliseconds / 1000;
sleeptime.tv_nsec = (milliseconds - (sleeptime.tv_sec * 1000)) * 1000000;
result = nanosleep(&sleeptime, NULL);
return result;
}
/**
* Helper sleep function
*/
#define APIERROR(error) \
{ std::cout << "Error in " << __FILE__ << ", line:" << __LINE__ << ", code:" \
<< error.code << ", msg: " << error.message << "." << std::endl; \
exit(-1); }
/*
* callback : This is called when the transaction is polled
*
* (This function must have three arguments:
* - The result of the transaction,
* - The NdbConnection object, and
* - A pointer to an arbitrary object.)
*/
static void
callback(int result, NdbConnection* myTrans, void* aObject)
{
if (result == -1) {
std::cout << "In callback: " << std::endl;
/**
* Put error checking code here (see ndb_async_example)
*/
APIERROR(myTrans->getNdbError());
} else {
/**
* Ok!
*/
return;
}
}
/**
* Function to create table
*/
int create_table(Ndb * myNdb)
{
NdbDictionary::Table myTable;
NdbDictionary::Column myColumn;
NdbDictionary::Dictionary* myDict = myNdb->getDictionary();
/*********************************************************
* Create a table named GARAGE if it does not exist *
*********************************************************/
if (myDict->getTable("GARAGE") != NULL) {
std::cout << "NDB already has example table: GARAGE. "
<< "Dropping it..." << std::endl;
if(myDict->dropTable("GARAGE") == -1)
{
std::cout << "Failed to drop: GARAGE." << std::endl;
exit(1);
}
}
myTable.setName("GARAGE");
myColumn.setName("REG_NO");
myColumn.setType(NdbDictionary::Column::Unsigned);
myColumn.setLength(1);
myColumn.setPrimaryKey(true);
myColumn.setNullable(false);
myTable.addColumn(myColumn);
myColumn.setName("BRAND");
myColumn.setType(NdbDictionary::Column::Char);
myColumn.setLength(20);
myColumn.setPrimaryKey(false);
myColumn.setNullable(false);
myTable.addColumn(myColumn);
myColumn.setName("COLOR");
myColumn.setType(NdbDictionary::Column::Char);
myColumn.setLength(20);
myColumn.setPrimaryKey(false);
myColumn.setNullable(false);
myTable.addColumn(myColumn);
if (myDict->createTable(myTable) == -1) {
APIERROR(myDict->getNdbError());
return -1;
}
return 1;
}
int populate(Ndb * myNdb)
{
NdbConnection* myNdbConnection[15]; // For transactions
NdbOperation* myNdbOperation; // For operations
/******************************************************
* Insert (we do 15 insert transactions in parallel) *
******************************************************/
/**
* Five blue mercedes
*/
for (int i = 0; i < 5; i++)
{
myNdbConnection[i] = myNdb->startTransaction();
if (myNdbConnection[i] == NULL)
APIERROR(myNdb->getNdbError());
myNdbOperation = myNdbConnection[i]->getNdbOperation("GARAGE");
// Error check. If error, then maybe table GARAGE is not in database
if (myNdbOperation == NULL)
APIERROR(myNdbConnection[i]->getNdbError());
myNdbOperation->insertTuple();
myNdbOperation->equal("REG_NO", i);
myNdbOperation->setValue("BRAND", "Mercedes");
myNdbOperation->setValue("COLOR", "Blue");
// Prepare transaction (the transaction is NOT yet sent to NDB)
myNdbConnection[i]->executeAsynchPrepare(Commit, &callback, NULL);
}
/**
* Five black bmw
*/
for (int i = 5; i < 10; i++)
{
myNdbConnection[i] = myNdb->startTransaction();
if (myNdbConnection[i] == NULL)
APIERROR(myNdb->getNdbError());
myNdbOperation = myNdbConnection[i]->getNdbOperation("GARAGE");
// Error check. If error, then maybe table MYTABLENAME is not in database
if (myNdbOperation == NULL)
APIERROR(myNdbConnection[i]->getNdbError());
myNdbOperation->insertTuple();
myNdbOperation->equal("REG_NO", i);
myNdbOperation->setValue("BRAND", "BMW");
myNdbOperation->setValue("COLOR", "Black");
// Prepare transaction (the transaction is NOT yet sent to NDB)
myNdbConnection[i]->executeAsynchPrepare(Commit, &callback, NULL);
}
/**
* Five pink toyotas
*/
for (int i = 10; i < 15; i++) {
myNdbConnection[i] = myNdb->startTransaction();
if (myNdbConnection[i] == NULL) APIERROR(myNdb->getNdbError());
myNdbOperation = myNdbConnection[i]->getNdbOperation("GARAGE");
// Error check. If error, then maybe table MYTABLENAME is not in database
if (myNdbOperation == NULL) APIERROR(myNdbConnection[i]->getNdbError());
myNdbOperation->insertTuple();
myNdbOperation->equal("REG_NO", i);
myNdbOperation->setValue("BRAND", "Toyota");
myNdbOperation->setValue("COLOR", "Pink");
// Prepare transaction (the transaction is NOT yet sent to NDB)
myNdbConnection[i]->executeAsynchPrepare(Commit, &callback, NULL);
}
// Send all transactions to NDB
myNdb->sendPreparedTransactions(0);
// Poll all transactions
myNdb->pollNdb(3000, 0);
// it is also possible to use sendPollNdb instead of
// myNdb->sendPreparedTransactions(0); and myNdb->pollNdb(3000, 15); above.
// myNdb->sendPollNdb(3000,0);
// Note! Neither sendPollNdb or pollNdb returs until all 15 callbacks have
// executed.
// Close all transactions. It is also possible to close transactions
// in the callback.
for (int i = 0; i < 15; i++)
myNdb->closeTransaction(myNdbConnection[i]);
return 1;
}
int scan_delete(Ndb* myNdb,
int parallelism,
int column,
int column_len,
const char * color)
{
// Scan all records exclusive and delete
// them one by one
int retryAttempt = 0;
const int retryMax = 10;
int deletedRows = 0;
int check;
NdbError err;
NdbConnection *myTrans;
NdbScanOperation *myScanOp;
/**
* Loop as long as :
* retryMax not reached
* failed operations due to TEMPORARY erros
*
* Exit loop;
* retyrMax reached
* Permanent error (return -1)
*/
while (true)
{
if (retryAttempt >= retryMax)
{
std::cout << "ERROR: has retried this operation " << retryAttempt
<< " times, failing!" << std::endl;
return -1;
}
myTrans = myNdb->startTransaction();
if (myTrans == NULL)
{
const NdbError err = myNdb->getNdbError();
if (err.status == NdbError::TemporaryError)
{
milliSleep(50);
retryAttempt++;
continue;
}
std::cout << err.message << std::endl;
return -1;
}
/**
* Get a scan operation.
*/
myScanOp = myTrans->getNdbScanOperation("GARAGE");
if (myScanOp == NULL)
{
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Define a result set for the scan.
*/
NdbResultSet * rs = myScanOp->readTuplesExclusive(parallelism);
if( rs == 0 ) {
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Use NdbScanFilter to define a search critera
*/
NdbScanFilter filter(myScanOp) ;
if(filter.begin(NdbScanFilter::AND) < 0 ||
filter.eq(column, color, column_len, false) <0||
filter.end() <0)
{
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Start scan (NoCommit since we are only reading at this stage);
*/
if(myTrans->execute(NoCommit) != 0){
err = myTrans->getNdbError();
if(err.status == NdbError::TemporaryError){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
milliSleep(50);
continue;
}
std::cout << err.code << std::endl;
std::cout << myTrans->getNdbError().code << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* start of loop: nextResult(true) means that "parallelism" number of
* rows are fetched from NDB and cached in NDBAPI
*/
while((check = rs->nextResult(true)) == 0){
do {
if (rs->deleteTuple() != 0){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
deletedRows++;
/**
* nextResult(false) means that the records
* cached in the NDBAPI are modified before
* fetching more rows from NDB.
*/
} while((check = rs->nextResult(false)) == 0);
/**
* Commit when all cached tuple have been marked for deletion
*/
if(check != -1){
check = myTrans->execute(Commit);
myTrans->releaseCompletedOperations();
}
/**
* Check for errors
*/
err = myTrans->getNdbError();
if(check == -1){
if(err.status == NdbError::TemporaryError){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
milliSleep(50);
continue;
}
}
/**
* End of loop
*/
}
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return 0;
}
if(myTrans!=0) {
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
}
return -1;
}
int scan_update(Ndb* myNdb,
int parallelism,
int column_len,
int update_column,
const char * column_name,
const char * before_color,
const char * after_color)
{
// Scan all records exclusive and update
// them one by one
int retryAttempt = 0;
const int retryMax = 10;
int updatedRows = 0;
int check;
NdbError err;
NdbConnection *myTrans;
NdbScanOperation *myScanOp;
/**
* Loop as long as :
* retryMax not reached
* failed operations due to TEMPORARY erros
*
* Exit loop;
* retyrMax reached
* Permanent error (return -1)
*/
while (true)
{
if (retryAttempt >= retryMax)
{
std::cout << "ERROR: has retried this operation " << retryAttempt
<< " times, failing!" << std::endl;
return -1;
}
myTrans = myNdb->startTransaction();
if (myTrans == NULL)
{
const NdbError err = myNdb->getNdbError();
if (err.status == NdbError::TemporaryError)
{
milliSleep(50);
retryAttempt++;
continue;
}
std::cout << err.message << std::endl;
return -1;
}
/**
* Get a scan operation.
*/
myScanOp = myTrans->getNdbScanOperation("GARAGE");
if (myScanOp == NULL)
{
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Define a result set for the scan.
*/
NdbResultSet * rs = myScanOp->readTuplesExclusive(parallelism);
if( rs == 0 ) {
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Use NdbScanFilter to define a search critera
*/
NdbScanFilter filter(myScanOp) ;
if(filter.begin(NdbScanFilter::AND) < 0 ||
filter.eq(update_column, before_color, column_len, false) <0||
filter.end() <0)
{
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Start scan (NoCommit since we are only reading at this stage);
*/
if(myTrans->execute(NoCommit) != 0){
err = myTrans->getNdbError();
if(err.status == NdbError::TemporaryError){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
milliSleep(50);
continue;
}
std::cout << myTrans->getNdbError().code << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Define an update operation
*/
NdbOperation * myUpdateOp;
/**
* start of loop: nextResult(true) means that "parallelism" number of
* rows are fetched from NDB and cached in NDBAPI
*/
while((check = rs->nextResult(true)) == 0){
do {
/**
* Get update operation
*/
myUpdateOp = rs->updateTuple();
if (myUpdateOp == 0){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
updatedRows++;
/**
* do the update
*/
myUpdateOp->setValue(update_column,after_color);
/**
* nextResult(false) means that the records
* cached in the NDBAPI are modified before
* fetching more rows from NDB.
*/
} while((check = rs->nextResult(false)) == 0);
/**
* Commit when all cached tuple have been updated
*/
if(check != -1){
check = myTrans->execute(Commit);
myTrans->releaseCompletedOperations();
}
/**
* Check for errors
*/
err = myTrans->getNdbError();
if(check == -1){
if(err.status == NdbError::TemporaryError){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
milliSleep(50);
continue;
}
}
/**
* End of loop
*/
}
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return 0;
}
if(myTrans!=0) {
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
}
return -1;
}
int scan_print(Ndb * myNdb, int parallelism,
int column_len_brand,
int column_len_color)
{
// Scan all records exclusive and update
// them one by one
int retryAttempt = 0;
const int retryMax = 10;
int fetchedRows = 0;
int check;
NdbError err;
NdbConnection *myTrans;
NdbScanOperation *myScanOp;
/* Result of reading attribute value, three columns:
REG_NO, BRAND, and COLOR
*/
NdbRecAttr * myRecAttr[3];
/**
* Loop as long as :
* retryMax not reached
* failed operations due to TEMPORARY erros
*
* Exit loop;
* retyrMax reached
* Permanent error (return -1)
*/
while (true)
{
if (retryAttempt >= retryMax)
{
std::cout << "ERROR: has retried this operation " << retryAttempt
<< " times, failing!" << std::endl;
return -1;
}
myTrans = myNdb->startTransaction();
if (myTrans == NULL)
{
const NdbError err = myNdb->getNdbError();
if (err.status == NdbError::TemporaryError)
{
milliSleep(50);
retryAttempt++;
continue;
}
std::cout << err.message << std::endl;
return -1;
}
/*
* Define a scan operation.
* NDBAPI.
*/
myScanOp = myTrans->getNdbScanOperation("GARAGE");
if (myScanOp == NULL)
{
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Define a result set for the scan.
*/
NdbResultSet * rs = myScanOp->readTuplesExclusive(parallelism);
if( rs == 0 ) {
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Define storage for fetched attributes.
* E.g., the resulting attributes of executing
* myOp->getValue("REG_NO") is placed in myRecAttr[0].
* No data exists in myRecAttr until transaction has commited!
*/
myRecAttr[0] = myScanOp->getValue("REG_NO");
myRecAttr[1] = myScanOp->getValue("BRAND");
myRecAttr[2] = myScanOp->getValue("COLOR");
if(myRecAttr[0] ==NULL || myRecAttr[1] == NULL || myRecAttr[2]==NULL)
{
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* Start scan (NoCommit since we are only reading at this stage);
*/
if(myTrans->execute(NoCommit) != 0){
err = myTrans->getNdbError();
if(err.status == NdbError::TemporaryError){
std::cout << myTrans->getNdbError().message << std::endl;
myNdb->closeTransaction(myTrans);
milliSleep(50);
continue;
}
std::cout << err.code << std::endl;
std::cout << myTrans->getNdbError().code << std::endl;
myNdb->closeTransaction(myTrans);
return -1;
}
/**
* start of loop: nextResult(true) means that "parallelism" number of
* rows are fetched from NDB and cached in NDBAPI
*/
while((check = rs->nextResult(true)) == 0){
do {
fetchedRows++;
/**
* print REG_NO unsigned int
*/
std::cout << myRecAttr[0]->u_32_value() << "\t";
char * buf_brand = new char[column_len_brand+1];
char * buf_color = new char[column_len_color+1];
/**
* print BRAND character string
*/
memcpy(buf_brand, myRecAttr[1]->aRef(), column_len_brand);
buf_brand[column_len_brand] = 0;
std::cout << buf_brand << "\t";
delete [] buf_brand;
/**
* print COLOR character string
*/
memcpy(buf_color, myRecAttr[2]->aRef(), column_len_color);
buf_brand[column_len_color] = 0;
std::cout << buf_color << std::endl;
delete [] buf_color;
/**
* nextResult(false) means that the records
* cached in the NDBAPI are modified before
* fetching more rows from NDB.
*/
} while((check = rs->nextResult(false)) == 0);
}
myNdb->closeTransaction(myTrans);
return 1;
}
return -1;
}
int main()
{
ndb_init();
Ndb* myNdb = new Ndb( "TEST_DB" ); // Object representing the database
/*******************************************
* Initialize NDB and wait until its ready *
*******************************************/
if (myNdb->init(1024) == -1) { // Set max 1024 parallel transactions
APIERROR(myNdb->getNdbError());
exit(-1);
}
if (myNdb->waitUntilReady(30) != 0) {
std::cout << "NDB was not ready within 30 secs." << std::endl;
exit(-1);
}
create_table(myNdb);
NdbDictionary::Dictionary* myDict = myNdb->getDictionary();
int column_color = myDict->getTable("GARAGE")->getColumn("COLOR")->getColumnNo();
int column_len_color =
myDict->getTable("GARAGE")->getColumn("COLOR")->getLength();
int column_len_brand =
myDict->getTable("GARAGE")->getColumn("BRAND")->getLength();
int parallelism = 16;
if(populate(myNdb) > 0)
std::cout << "populate: Success!" << std::endl;
if(scan_print(myNdb, parallelism, column_len_brand, column_len_color) > 0)
std::cout << "scan_print: Success!" << std::endl << std::endl;
std::cout << "Going to delete all pink cars!" << std::endl;
if(scan_delete(myNdb, parallelism, column_color,
column_len_color, "Pink") > 0)
std::cout << "scan_delete: Success!" << std::endl << std::endl;
if(scan_print(myNdb, parallelism, column_len_brand, column_len_color) > 0)
std::cout << "scan_print: Success!" << std::endl << std::endl;
std::cout << "Going to update all blue cars to black cars!" << std::endl;
if(scan_update(myNdb, parallelism, column_len_color, column_color,
"COLOR", "Blue", "Black") > 0)
{
std::cout << "scan_update: Success!" << std::endl << std::endl;
}
if(scan_print(myNdb, parallelism, column_len_brand, column_len_color) > 0)
std::cout << "scan_print: Success!" << std::endl << std::endl;
delete myNdb;
}