void putDocWithMyCompression(XmlManager& mgr,
const string& containerName,
XmlDocument& xdoc,
XmlUpdateContext& uc,
XmlCompression& myCompression)
{
// Define an unique name to use for registering the compression
string compressionName = "myCompression";
// Register custom class
mgr.registerCompression(compressionName.c_str(), myCompression);
// Set the container type as WholedocContainer
// and use the custom compression
XmlContainerConfig contConf;
contConf.setAllowCreate(true);
contConf.setContainerType(XmlContainer::WholedocContainer);
contConf.setCompressionName(compressionName.c_str());
// Create container
XmlContainer cont = mgr.createContainer(containerName, contConf);
// Put Document
cont.putDocument(xdoc, uc);
}
void RepNode::openContainer()
{
// reopening a container is forbidden.
if (!cont_.isNull())
throwException("Attempt to re-open a container.");
XmlContainerConfig conf;
// wait for being elected as a Master or start up done(as a client).
while (!(isMaster() || appData_.isStartupDone()))
yield();
if (isMaster())
conf.setAllowCreate(true);
XmlTransaction txn;
while (true) {
try {
txn = mgr_->createTransaction();
cont_ = mgr_->openContainer(txn, containerName_, conf);
txn.commit();
return;
/*
* One thing to watch out for is a case where the databases
* you are trying to open do not yet exist. This can happen
* for replicas where the databases are being opened
* read-only. If this happens, ENOENT is returned by the
* open() call.
*/
} catch (XmlException &xe) {
ostringstream o;
XmlException::ExceptionCode ec = xe.getExceptionCode();
if (ec == XmlException::DATABASE_ERROR) {
int dbErr = xe.getDbErrno();
if (dbErr != ENOENT && dbErr != DB_REP_LOCKOUT) {
o << envHome_ << ":" << xe.what() << endl
<< "DB_ERRNO:" << dbErr << endl;
throwException(o.str());
}
} else if (ec != XmlException::CONTAINER_NOT_FOUND) {
o << envHome_ << ":" << xe.what() << endl
<< "ExceptionCode :" << ec << endl;
throwException(o.str());
}
yield();
}
}
}
void putDocWithoutDefaultCompression(XmlManager& mgr,
const string& containerName,
XmlDocument& xdoc,
XmlUpdateContext& uc)
{
// Set the container type as WholedocContainer and turn off
// the default compression
XmlContainerConfig contConf;
contConf.setAllowCreate(true);
contConf.setContainerType(XmlContainer::WholedocContainer);
contConf.setCompressionName(XmlContainerConfig::NO_COMPRESSION);
// Create container
XmlContainer cont = mgr.createContainer(containerName, contConf);
// Put Document
cont.putDocument(xdoc, uc);
}
void putDocWithDefaultCompression(XmlManager& mgr,
const string& containerName,
XmlDocument& xdoc,
XmlUpdateContext& uc)
{
// Set the container type as WholedocContainer and
// use the default compression
XmlContainerConfig contConf;
contConf.setAllowCreate(true);
contConf.setContainerType(XmlContainer::WholedocContainer);
// The following line is unnecessary because default compression
// would take effect if user do not turn off it explicitly.
contConf.setCompressionName(XmlContainerConfig::DEFAULT_COMPRESSION);
// Create container
XmlContainer cont = mgr.createContainer(containerName, contConf);
// Put Document
cont.putDocument(xdoc, uc);
}
int main(int argc, char **argv)
{
std::string path2DbEnv;
std::string theContainer = "namespaceExampleData.dbxml";
for ( int i=1; i<argc; i++ )
{
if ( argv[i][0] == '-' )
{
switch(argv[i][1])
{
case 'h':
path2DbEnv = argv[++i];
break;
default:
usage();
}
}
}
if (! path2DbEnv.length() )
usage();
// Berkeley DB environment flags
u_int32_t envFlags = DB_RECOVER|DB_CREATE|DB_INIT_MPOOL|
DB_INIT_LOCK|DB_INIT_TXN|DB_INIT_LOG;
// Berkeley DB cache size (64 MB). The default is quite small
u_int32_t envCacheSize = 64*1024*1024;
// Create and open a Berkeley DB Transactional Environment.
int dberr;
DB_ENV *dbEnv = 0;
dberr = db_env_create(&dbEnv, 0);
if (dberr == 0) {
dbEnv->set_cachesize(dbEnv, 0, envCacheSize, 1);
dberr = dbEnv->open(dbEnv, path2DbEnv.c_str(), envFlags, 0);
}
if (dberr) {
std::cout << "Unable to create environment handle due to the following error: " <<
db_strerror(dberr) << std::endl;
if (dbEnv) dbEnv->close(dbEnv, 0);
return -1;
}
//Have the XmlManager adopt the db environment
XmlManager mgr(dbEnv, DBXML_ADOPT_DBENV);
//Configure the container to use transactions
XmlContainerConfig config;
config.setTransactional(true);
//Open a container in the db environment
XmlContainer container = mgr.openContainer(theContainer, config);
//create a transaction
XmlTransaction txn = mgr.createTransaction();
//create a context and declare the namespaces
XmlQueryContext context = mgr.createQueryContext();
context.setNamespace( "fruits", "http://groceryItem.dbxml/fruits");
context.setNamespace( "vegetables", "http://groceryItem.dbxml/vegetables");
context.setNamespace( "desserts", "http://groceryItem.dbxml/desserts");
//Query for documents by their document names.
doContextQuery( txn, mgr, container.getName(),
"/*[dbxml:metadata('dbxml:name')='ZuluNut.xml']", context );
doContextQuery( txn, mgr, container.getName(),
"/*[dbxml:metadata('dbxml:name')='TrifleOrange.xml']", context );
doContextQuery( txn, mgr, container.getName(),
"/*[dbxml:metadata('dbxml:name')='TriCountyProduce.xml']", context );
//Get the document from the container using the document name
doGetDocument(txn, container, "ZuluNut.xml");
doGetDocument(txn, container, "TrifleOrange.xml");
doGetDocument(txn, container, "TriCountyProduce.xml");
//commit the transaction
txn.commit();
return 0;
}
int
main(int argc, char **argv)
{
// This program uses a named container, which will apear
// on disk
std::string containerName = "people.dbxml";
std::string content = "<people><person><name>joe</name></person><person><name>mary</name></person></people>";
std::string docName = "people";
// Note that the query uses a variable, which must be set
// in the query context
std::string queryString =
"collection('people.dbxml')/people/person[name=$name]";
std::string environmentDir = ".";
// Berkeley DB environment flags
u_int32_t envFlags = DB_RECOVER|DB_CREATE|DB_INIT_MPOOL|
DB_INIT_LOCK|DB_INIT_TXN|DB_INIT_LOG;
// Berkeley DB cache size (25 MB). The default is quite small
u_int32_t envCacheSize = 25*1024*1024;
// argument parsing should really use getopt(), but
// avoid it for platform-independence
if (argc == 3) {
if (std::string(argv[1]) != std::string("-h"))
usage(argv[0]);
environmentDir = argv[2];
} else if (argc != 1)
usage(argv[0]);
// Create and open a Berkeley DB Transactional Environment.
int dberr;
DB_ENV *dbEnv = 0;
dberr = db_env_create(&dbEnv, 0);
if (dberr == 0) {
dbEnv->set_cachesize(dbEnv, 0, envCacheSize, 1);
dbEnv->set_errcall(dbEnv, errcall); // set error callback
dbEnv->set_lk_detect(dbEnv, DB_LOCK_DEFAULT); // handle deadlocks
dberr = dbEnv->open(dbEnv, environmentDir.c_str(), envFlags, 0);
}
if (dberr) {
std::cout << "Unable to create environment handle due to the following error: " <<
db_strerror(dberr) << std::endl;
if (dbEnv) dbEnv->close(dbEnv, 0);
return -1;
}
try {
// All BDB XML programs require an XmlManager instance.
// Create it from the DbEnv
XmlManager mgr(dbEnv, DBXML_ADOPT_DBENV);
// Because the container will exist on disk, remove it
// first if it exists
if (mgr.existsContainer(containerName))
mgr.removeContainer(containerName);
/* Create a container that is transactional. The container
* type is NodeContainer, which is the default container type,
* and the index is on nodes, which is the default for a
* NodeContainer container. XmlContainerConfig can be used
* to set the container type and index type.
*/
XmlContainerConfig config;
config.setTransactional(true);
XmlContainer cont = mgr.createContainer(
containerName,
config);
// All Container modification operations need XmlUpdateContext
XmlUpdateContext uc = mgr.createUpdateContext();
// The following putDocument call will auto-transact
// and will abort/cleanup if the operation deadlocks or
// otherwise fails
cont.putDocument(docName, content, uc);
// Querying requires an XmlQueryContext
XmlQueryContext qc = mgr.createQueryContext();
// Add a variable to the query context, used by the query
qc.setVariableValue("name", "mary");
// Use try/catch and while to handle deadlock/retry
int retry = 0;
while (retry < 5) { // hard-code 5 retries
// Create a new transaction for the query
XmlTransaction txn = mgr.createTransaction();
try {
// o Note the passing of txn to both methods
// o Often the XmlQueryExpression object will be created and
// saved for reuse in order to amortize the cost of parsing a query
XmlQueryExpression expr = mgr.prepare(txn, queryString, qc);
XmlResults res = expr.execute(txn, qc);
// Note use of XmlQueryExpression::getQuery() and
// XmlResults::size()
std::cout << "The query, '" << expr.getQuery() << "' returned " <<
(unsigned int)res.size() << " result(s)" << std::endl;
// Process results -- just print them
XmlValue value;
std::cout << "Result: " << std::endl;
while (res.next(value)) {
std::cout << "\t" << value.asString() << std::endl;
}
// done with the transaction
txn.commit();
break;
} catch (XmlException &x) {
txn.abort(); // unconditional
if ((x.getExceptionCode() == XmlException::DATABASE_ERROR) &&
(x.getDbErrno() == DB_LOCK_DEADLOCK)) {
++retry;
continue; // try again
}
throw; // re-throw -- not deadlock
}
}
// In C++, resources are released as objects go out
// of scope.
} catch (XmlException &xe) {
std::cout << "XmlException: " << xe.what() << std::endl;
}
return 0;
}
int main(int argc, char **argv)
{
std::string path2DbEnv;
std::string theContainer = "simpleExampleData.dbxml";
for ( int i=1; i<argc; i++ )
{
if ( argv[i][0] == '-' )
{
switch(argv[i][1])
{
case 'h':
path2DbEnv = argv[++i];
break;
default:
usage();
}
}
}
if (! path2DbEnv.length() )
usage();
// Berkeley DB environment flags
u_int32_t envFlags = DB_RECOVER|DB_CREATE|DB_INIT_MPOOL|
DB_INIT_LOCK|DB_INIT_TXN|DB_INIT_LOG;
// Berkeley DB cache size (64 MB). The default is quite small
u_int32_t envCacheSize = 64*1024*1024;
// Create and open a Berkeley DB Transactional Environment.
int dberr;
DB_ENV *dbEnv = 0;
dberr = db_env_create(&dbEnv, 0);
if (dberr == 0) {
dbEnv->set_cachesize(dbEnv, 0, envCacheSize, 1);
dberr = dbEnv->open(dbEnv, path2DbEnv.c_str(), envFlags, 0);
}
if (dberr) {
std::cout << "Unable to create environment handle due to the following error: " <<
db_strerror(dberr) << std::endl;
if (dbEnv) dbEnv->close(dbEnv, 0);
return -1;
}
//Have the XmlManager adopt the db environment
XmlManager db(dbEnv, DBXML_ADOPT_DBENV);
//Configure the container to use transactions
XmlContainerConfig config;
config.setTransactional(true);
//Open a container in the db environment
XmlContainer container = db.openContainer(theContainer, config);
// Get an XmlUpdateContext. Useful from a performance perspective.
XmlUpdateContext updateContext = db.createUpdateContext();
//Get a transaction
XmlTransaction txn = db.createTransaction();
std::string document1 = "<aDoc><title>doc1</title><color>green</color></aDoc>";
std::string document2 = "<aDoc><title>doc2</title><color>yellow</color></aDoc>";
//Add the documents
XmlDocument myXMLDoc = db.createDocument();
/* Set the XmlDocument to the relevant string and then put it into the container.
* Using the flag DBXML_GEN_NAME means that a generated name will be assigned
* to the document if it does not have one. An exception will be thrown if
* a document is inserted without a name or the DBXML_GEN_NAME flag.
*/
myXMLDoc.setContent( document1 );
container.putDocument(txn, myXMLDoc, updateContext, DBXML_GEN_NAME);
//do it again for the second document
myXMLDoc.setContent( document2 );
container.putDocument(txn, myXMLDoc, updateContext, DBXML_GEN_NAME);
//Normally we would use a try/catch block to trap any exceptions.
// In the catch, we should call txn->abort() to avoid leaving the
// database in an indeterminate state in the event of an error.
// However, this simple example avoids error handling so as to
// highlite basic concepts, so that step if omitted here as well.
//Commit the writes. This causes the container write operations
// to be saved to the container.
txn.commit();
return 0;
}
int main(int argc, char **argv)
{
std::string path2DbEnv;
std::string theContainer = "namespaceExampleData.dbxml";
for ( int i=1; i<argc; i++ ) {
if ( argv[i][0] == '-' ) {
switch(argv[i][1])
{
case 'h':
path2DbEnv = argv[++i];
break;
default:
usage();
}
}
}
if (! path2DbEnv.length() )
usage();
// Berkeley DB environment flags
u_int32_t envFlags = DB_RECOVER|DB_CREATE|DB_INIT_MPOOL|
DB_INIT_LOCK|DB_INIT_TXN|DB_INIT_LOG;
// Berkeley DB cache size (64 MB). The default is quite small
u_int32_t envCacheSize = 64*1024*1024;
// Create and open a Berkeley DB Transactional Environment.
int dberr;
DB_ENV *dbEnv = 0;
dberr = db_env_create(&dbEnv, 0);
if (dberr == 0) {
dbEnv->set_cachesize(dbEnv, 0, envCacheSize, 1);
dberr = dbEnv->open(dbEnv, path2DbEnv.c_str(), envFlags, 0);
}
if (dberr) {
std::cout << "Unable to create environment handle due to the following error: " <<
db_strerror(dberr) << std::endl;
if (dbEnv) dbEnv->close(dbEnv, 0);
return -1;
}
//Have the XmlManager adopt the db environment
XmlManager db(dbEnv, DBXML_ADOPT_DBENV);
//Configure the container to use transactions
XmlContainerConfig config;
config.setTransactional(true);
XmlContainer container = db.openContainer(theContainer, config);
//Get a transaction
XmlTransaction txn = db.createTransaction();
XmlUpdateContext uc = db.createUpdateContext();
//Add an string equality index for the "product" element node.
addIndex( container, "", "product", "node-element-equality-string", txn, uc );
//Add an edge presence index for the product node
addIndex( container, "", "product", "edge-element-presence", txn, uc );
//commit the index adds
txn.commit();
return 0;
}
int main(int argc, char **argv)
{
std::string path2DbEnv;
std::string theContainer = "simpleExampleData.dbxml";
for ( int i=1; i<argc; i++ )
{
if ( argv[i][0] == '-' )
{
switch(argv[i][1])
{
case 'h':
path2DbEnv = argv[++i];
break;
default:
usage();
}
}
}
if (! path2DbEnv.length() )
usage();
// Berkeley DB environment flags
u_int32_t envFlags = DB_RECOVER|DB_CREATE|DB_INIT_MPOOL|
DB_INIT_LOCK|DB_INIT_TXN|DB_INIT_LOG;
// Berkeley DB cache size (64 MB). The default is quite small
u_int32_t envCacheSize = 64*1024*1024;
// Create and open a Berkeley DB Transactional Environment.
int dberr;
DB_ENV *dbEnv = 0;
dberr = db_env_create(&dbEnv, 0);
if (dberr == 0) {
dbEnv->set_cachesize(dbEnv, 0, envCacheSize, 1);
dberr = dbEnv->open(dbEnv, path2DbEnv.c_str(), envFlags, 0);
}
if (dberr) {
std::cout << "Unable to create environment handle due to the following error: " <<
db_strerror(dberr) << std::endl;
if (dbEnv) dbEnv->close(dbEnv, 0);
return -1;
}
//Have the XmlManager adopt the db environment
XmlManager db(dbEnv, DBXML_ADOPT_DBENV);
//Configure the container to use transactions
XmlContainerConfig config;
config.setTransactional(true);
//Open a container in the db environment
XmlContainer container = db.openContainer(theContainer, config);
//Create a transaction
XmlTransaction txn = db.createTransaction();
//perform the queries
//find all the Vendor documents in the database
doQuery( txn, db, container, "/vendor" );
//find all the vendors that are wholesale shops
doQuery( txn, db, container, "/vendor[@type=\"wholesale\"]");
//find the product document for "Lemon Grass"
doQuery( txn, db, container, "/product/item[.=\"Lemon Grass\"]");
//find all the products where the price is less than or equal to 0.11
doQuery( txn, db, container, "/product/inventory[price<=0.11]");
//find all the vegetables where the price is less than or equal to 0.11
doQuery( txn, db, container, "/product[inventory/price<=0.11 and category=\"vegetables\"]");
//commit the transaction
txn.commit();
return 0;
}
