Commit cbfaa9de authored by unknown's avatar unknown

Merge tulin@bk-internal.mysql.com:/home/bk/mysql-5.0-ndb

into poseidon.ndb.mysql.com:/home/tomas/mysql-5.0-ndb

parents 75b5d105 bd653371
......@@ -24,73 +24,78 @@ class NdbEventOperationImpl;
* @class NdbEventOperation
* @brief Class of operations for getting change events from database.
*
* An NdbEventOperation object is instantiated by
* Ndb::createEventOperation
*
* Prior to that an event must have been created in the Database through
* NdbDictionary::createEvent
*
* The instance is removed by Ndb::dropEventOperation
* Brief description on how to work with events:
*
* - An event i created in the Database through
* NdbDictionary::Dictionary::createEvent() (note that this can be done
* by any application or thread and not necessarily by the "listener")
* - To listen to events, an NdbEventOperation object is instantiated by
* Ndb::createEventOperation()
* - execute() starts the event flow. Use Ndb::pollEvents() to wait
* for an event to occur. Use next() to iterate
* through the events that have occured.
* - The instance is removed by Ndb::dropEventOperation()
*
* For more info see:
* @ref ndbapi_event.cpp
*
* Known limitations:
*
* Maximum number of active NdbEventOperations are now set at compile time.
* - Maximum number of active NdbEventOperations are now set at compile time.
* Today 100. This will become a configuration parameter later.
*
* Maximum number of NdbEventOperations tied to same event are maximum 16
* - Maximum number of NdbEventOperations tied to same event are maximum 16
* per process.
*
* Known issues:
*
* When several NdbEventOperation's are tied to the same event in the same
* - When several NdbEventOperation's are tied to the same event in the same
* process they will share the circular buffer. The BufferLength will then
* be the same for all and decided by the first NdbEventOperation
* instantiation. Just make sure to instantiate the "largest" one first.
*
* Today all events INSERT/DELETE/UPDATE and all changed attributes are
* - Today all events INSERT/DELETE/UPDATE and all changed attributes are
* sent to the API, even if only specific attributes have been specified.
* These are however hidden from the user and only relevant data is shown
* after next().
* However false exits from Ndb::pollEvents() may occur and thus
* - "False" exits from Ndb::pollEvents() may occur and thus
* the subsequent next() will return zero,
* since there was no available data. Just do Ndb::pollEvents() again.
*
* Event code does not check table schema version. Make sure to drop events
* - Event code does not check table schema version. Make sure to drop events
* after table is dropped. Will be fixed in later
* versions.
*
* If a node failure has occured not all events will be recieved
* - If a node failure has occured not all events will be recieved
* anymore. Drop NdbEventOperation and Create again after nodes are up
* again. Will be fixed in later versions.
*
* Test status:
* Tests have been run on 1-node and 2-node systems
*
* Known bugs:
*
* None, except if we can call some of the "issues" above bugs
* - Tests have been run on 1-node and 2-node systems
*
* Useful API programs:
*
* ndb_select_all -d sys 'NDB$EVENTS_0'
* Will show contents in the system table containing created events.
* - ndb_select_all -d sys 'NDB$EVENTS_0'
* shows contents in the system table containing created events.
*
* @note this is an inteface to viewing events that is subject to change
*/
class NdbEventOperation {
public:
/**
* State of the NdbEventOperation object
*/
enum State {
EO_CREATED, ///< Created but execute() not called
EO_EXECUTING, ///< execute() called
EO_ERROR ///< An error has occurred. Object unusable.
};
/**
* Retrieve current state of the NdbEventOperation object
*/
enum State {CREATED,EXECUTING,ERROR};
State getState();
/**
* Activates the NdbEventOperation to start receiving events. The
* changed attribute values may be retrieved after next() has returned
* a value greater than zero. The getValue() methods below must be called
* a value greater than zero. The getValue() methods must be called
* prior to execute().
*
* @return 0 if successful otherwise -1.
......@@ -112,21 +117,21 @@ public:
* aligned appropriately. The buffer is used directly
* (avoiding a copy penalty) only if it is aligned on a
* 4-byte boundary and the attribute size in bytes
* (i.e. NdbRecAttr::attrSize times NdbRecAttr::arraySize is
* (i.e. NdbRecAttr::attrSize() times NdbRecAttr::arraySize() is
* a multiple of 4).
*
* @note There are two versions, NdbOperation::getValue and
* NdbOperation::getPreValue for retrieving the current and
* @note There are two versions, getValue() and
* getPreValue() for retrieving the current and
* previous value repectively.
*
* @note This method does not fetch the attribute value from
* the database! The NdbRecAttr object returned by this method
* is <em>not</em> readable/printable before the
* NdbEventConnection::execute has been made and
* NdbEventConnection::next has returned a value greater than
* execute() has been made and
* next() has returned a value greater than
* zero. If a specific attribute has not changed the corresponding
* NdbRecAttr will be in state UNDEFINED. This is checked by
* NdbRecAttr::isNull which then returns -1.
* NdbRecAttr::isNull() which then returns -1.
*
* @param anAttrName Attribute name
* @param aValue If this is non-NULL, then the attribute value
......@@ -143,11 +148,11 @@ public:
/**
* Retrieves event resultset if available, inserted into the NdbRecAttrs
* specified in getValue() and getPreValue(). To avoid polling for
* a resultset, one can use Ndb::pollEvents
* a resultset, one can use Ndb::pollEvents()
* which will wait on a mutex until an event occurs or the specified
* timeout occurs.
*
* @return >=0 if successful otherwise -1. Return value inicates number
* @return >=0 if successful otherwise -1. Return value indicates number
* of available events. By sending pOverRun one may query for buffer
* overflow and *pOverRun will indicate the number of events that have
* overwritten.
......
......@@ -1177,7 +1177,14 @@ NdbEventOperation* Ndb::createEventOperation(const char* eventName,
tOp = new NdbEventOperation(this, eventName, bufferLength);
if (tOp->getState() != NdbEventOperation::CREATED) {
if (tOp == 0)
{
theError.code= 4000;
return NULL;
}
if (tOp->getState() != NdbEventOperation::EO_CREATED) {
theError.code= tOp->getNdbError().code;
delete tOp;
tOp = NULL;
}
......
......@@ -55,9 +55,8 @@ NdbEventOperationImpl::NdbEventOperationImpl(NdbEventOperation &N,
const char* eventName,
const int bufferLength)
: NdbEventOperation(*this), m_ndb(theNdb),
m_state(ERROR), m_bufferL(bufferLength)
m_state(EO_ERROR), m_bufferL(bufferLength)
{
m_eventId = 0;
theFirstRecAttrs[0] = NULL;
theCurrentRecAttrs[0] = NULL;
......@@ -71,16 +70,15 @@ NdbEventOperationImpl::NdbEventOperationImpl(NdbEventOperation &N,
// we should lookup id in Dictionary, TODO
// also make sure we only have one listener on each event
if (!m_ndb) { ndbout_c("m_ndb=NULL"); return; }
if (!m_ndb) abort();
NdbDictionary::Dictionary *myDict = m_ndb->getDictionary();
if (!myDict) { ndbout_c("getDictionary=NULL"); return; }
if (!myDict) { m_error.code= m_ndb->getNdbError().code; return; }
const NdbDictionary::Event *myEvnt = myDict->getEvent(eventName);
if (!myEvnt) { ndbout_c("getEvent()=NULL"); return; }
if (!myEvnt) { m_error.code= myDict->getNdbError().code; return; }
m_eventImpl = &myEvnt->m_impl;
if (!m_eventImpl) { ndbout_c("m_impl=NULL"); return; }
m_bufferHandle = m_ndb->getGlobalEventBufferHandle();
if (m_bufferHandle->m_bufferL > 0)
......@@ -88,7 +86,7 @@ NdbEventOperationImpl::NdbEventOperationImpl(NdbEventOperation &N,
else
m_bufferHandle->m_bufferL = m_bufferL;
m_state = CREATED;
m_state = EO_CREATED;
}
NdbEventOperationImpl::~NdbEventOperationImpl()
......@@ -106,7 +104,7 @@ NdbEventOperationImpl::~NdbEventOperationImpl()
p = p_next;
}
}
if (m_state == NdbEventOperation::EXECUTING) {
if (m_state == EO_EXECUTING) {
stop();
// m_bufferHandle->dropSubscribeEvent(m_bufferId);
; // We should send stop signal here
......@@ -122,7 +120,7 @@ NdbEventOperationImpl::getState()
NdbRecAttr*
NdbEventOperationImpl::getValue(const char *colName, char *aValue, int n)
{
if (m_state != NdbEventOperation::CREATED) {
if (m_state != EO_CREATED) {
ndbout_c("NdbEventOperationImpl::getValue may only be called between instantiation and execute()");
return NULL;
}
......@@ -211,8 +209,8 @@ NdbEventOperationImpl::execute()
{
NdbDictionary::Dictionary *myDict = m_ndb->getDictionary();
if (!myDict) {
ndbout_c("NdbEventOperation::execute(): getDictionary=NULL");
return 0;
m_error.code= m_ndb->getNdbError().code;
return -1;
}
if (theFirstRecAttrs[0] == NULL) { // defaults to get all
......@@ -245,14 +243,14 @@ NdbEventOperationImpl::execute()
if (r) {
//Error
m_bufferHandle->unprepareAddSubscribeEvent(m_bufferId);
m_state = NdbEventOperation::ERROR;
m_state = EO_ERROR;
} else {
m_bufferHandle->addSubscribeEvent(m_bufferId, this);
m_state = NdbEventOperation::EXECUTING;
m_state = EO_EXECUTING;
}
} else {
//Error
m_state = NdbEventOperation::ERROR;
m_state = EO_ERROR;
}
return r;
}
......@@ -261,14 +259,14 @@ int
NdbEventOperationImpl::stop()
{
DBUG_ENTER("NdbEventOperationImpl::stop");
if (m_state != NdbEventOperation::EXECUTING)
if (m_state != EO_EXECUTING)
DBUG_RETURN(-1);
// ndbout_c("NdbEventOperation::stopping()");
NdbDictionary::Dictionary *myDict = m_ndb->getDictionary();
if (!myDict) {
ndbout_c("NdbEventOperation::stop(): getDictionary=NULL");
m_error.code= m_ndb->getNdbError().code;
DBUG_RETURN(-1);
}
......@@ -299,13 +297,13 @@ NdbEventOperationImpl::stop()
//Error
m_bufferHandle->unprepareDropSubscribeEvent(m_bufferId);
m_error.code= myDictImpl.m_error.code;
m_state = NdbEventOperation::ERROR;
m_state = EO_ERROR;
} else {
#ifdef EVENT_DEBUG
ndbout_c("NdbEventOperation::dropping()");
#endif
m_bufferHandle->dropSubscribeEvent(m_bufferId);
m_state = NdbEventOperation::CREATED;
m_state = EO_CREATED;
}
DBUG_RETURN(r);
......
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