// We come here from syntax like
// SELECT * FROM :hv PROTOTYPE 'cat.sch.tbl'; -- host variable, static SQL
// TABLE $ev; -- env var, static or dynam
// (Internally, both host vars and env vars are HostVar objects.)
//
// If there's an environment variable, get its value at time of compilation,
// and stick that into the internal prototype value. Generator will need
// to save these env var name/value pairs in the generated code;
// Executor needs to use the saved compile-time value of any name that is not
// defined at run-time.
//
// If there's a prototype value, parse it as an actual table name
// (1, 2, or 3-part name) and overwrite the bogus values in *this with the
// parsed prototype value. Our caller, applyDefaults, will overwrite any
// remaining blank name parts. Generator needs to save the host var names
// for actual input at run-time, and to save the prototype values for
// similarity check at run-time.
//
// We avoid re-parsing and re-overwriting this CorrName by checking/setting
// its bound state. Note that we do not rely on its prototype's bound state
// because that is a separate, pointed at object: some Binder subroutines
// make local copies of CorrNames, and any apply methods invoked on the locals
// would not be propagated to the caller's originals: relying on the then True
// value of the prototype's bound state would be fallacious.
//
// If no error in proto, node is bound and bindWA errStatus unchanged
// (note that not having a proto is not an error).
// If error in proto, node is left unbound and bindWA errStatus is set.
//
void CorrName::applyPrototype(BindWA *bindWA)
{
if (nodeIsBound()) return;
HostVar *proto = getPrototype();
if (!proto) {
markAsBound();
return;
}
// CMPASSERT(this == proto->getPrototypeTarget());
CMPASSERT(!proto->getName().isNull());
if (proto->isEnvVar()) {
char *value = getenv(proto->getName());
if (!value) {
// Environment variable has no defined value.
*CmpCommon::diags() << DgSqlCode(-4086) << DgString0(proto->getName());
bindWA->setErrStatus();
return;
}
// upcase value returned by getenv
#pragma nowarn(1506) // warning elimination
Int32 len = strlen(value);
#pragma warn(1506) // warning elimination
char * ucValue = new (bindWA->wHeap()) char[len+1];
str_cpy_convert(ucValue, value, len, -1/*upshift*/);
ucValue[len] = 0;
proto->getPrototypeValue() = ucValue;
// do not free "ucValue" here, it is still used in "proto"
// to prevent Coverity RESOURCE_LEAK error, add the following
// coverity[leaked_storage]
}
// defines can not be used on linux platform
if (proto->isDefine()) {
*CmpCommon::diags() << DgSqlCode(-4155) << DgString0(proto->getName());
bindWA->setErrStatus();
return;
}
CMPASSERT(!proto->getPrototypeValue().isNull());
// Some of the following code is cloned from the QualifiedName ctor above
Parser parser(bindWA->currentCmpContext());
NAString ns("TABLE " + proto->getPrototypeValue() + ";",
CmpCommon::statementHeap());
#pragma nowarn(1506) // warning elimination
// save the current parserflags setting
ULng32 savedParserFlags = Get_SqlParser_Flags (0xFFFFFFFF);
StmtQuery *stmt = (StmtQuery *)parser.parseDML(ns, ns.length(), GetAnsiNameCharSet());
// Restore parser flags settings
Set_SqlParser_Flags (savedParserFlags);
#pragma warn(1506) // warning elimination
if (stmt) {
CMPASSERT(stmt->getOperatorType() == STM_QUERY);
CorrName &protoCorrName =
stmt->getQueryExpression()->getScanNode()->getTableName();
// Unless the hostvar type was forced directly,
// copy the special table type to me, the prototype may be a
// resource fork
if (getSpecialType() == ExtendedQualName::NORMAL_TABLE)
setSpecialType(protoCorrName);
// This if-test prevents pathologies such as
// SELECT col FROM :hv1 PROTOTYPE ':hv2 PROTOTYPE ''tbl''';
// but allows
// SELECT col FROM :hv1 PROTOTYPE '$ev';
//
// (The assertion below ensures that only host var syntax allows prototypes,
// that you can't say ... FROM $ev PROTOTYPE '...'.)
//
HostVar *proto2 = protoCorrName.getPrototype();
CMPASSERT(!proto2 || !proto->isEnvVar());
if (!proto2 || proto2->isEnvVar()) {
if (proto2) {
// Here if proto2->isEnvVar.
// Recurse (once only; the assertion above ensures that)
// to get the value of the var, parse it and all.
protoCorrName.applyPrototype(bindWA);
if (bindWA->errStatus()) return;
}
#ifndef NDEBUG
if (getenv("HV_DEBUG"))
cout << "HostVar/Prototype: parsed ("
<< (Int32)proto->nodeIsBound() << ") "
<< proto->getName() << " "
<< protoCorrName.getExposedNameAsAnsiString() << endl;
#endif
// assert *before* overwriting with 0
// CMPASSERT(!getQualifiedNameObj().getNamePosition());
getQualifiedNameObj() = protoCorrName.getQualifiedNameObj();
proto->setPrototypeType(HostVar::QUALIFIEDNAME);
// mark that we, the trusted CorrName, are bound
markAsBound();
}
}
if (!nodeIsBound()) {
// Clear parser syntax error and emit "Prototype value not valid"
#ifndef NDEBUG
if (!getenv("HV_DEBUG"))
#endif
CmpCommon::diags()->clear();
*CmpCommon::diags() << DgSqlCode(-4087)
<< DgString0(proto->getPrototypeValue());
bindWA->setErrStatus();
}
delete stmt;
} // applyPrototype
RelExpr* Scan::normalizeForCache(CacheWA& cwa, BindWA& bindWA)
{
if (nodeIsNormalizedForCache()) {
return this;
}
if (CmpCommon::getDefault(QUERY_CACHE_TABLENAME) == DF_OFF) {
// replace descendants' literals into ConstantParameters
return RelExpr::normalizeForCache(cwa, bindWA);
}
// replace tablename with a prototyped tablename.
TableDesc * td = getTableDesc();
CorrName &origName = td->getCorrNameObj();
if (origName.getPrototype() == NULL)
{
Lng32 CACHED_MAX_ANSI_NAME_EXTERNAL_LEN = 128;
NAString hvName("dummy_name");
HostVar * hv =
new(bindWA.wHeap())
HostVar(hvName,
new(bindWA.wHeap()) SQLChar(CACHED_MAX_ANSI_NAME_EXTERNAL_LEN));
hv->setPrototypeValue(origName.getQualifiedNameAsString());
hv->synthTypeAndValueId();
hv->setIsCachedParam(TRUE);
CorrName cn("HostVar$",
bindWA.wHeap(),
hv->getName(), // debugging ease
"$bogus");
cn.setPrototype(hv);
NAString *tmpName =
new (bindWA.wHeap())
NAString(hv->getPrototypeValue(), bindWA.wHeap());
cn.setUgivenName(*tmpName);
cn.applyDefaults(&bindWA, bindWA.getDefaultSchema());
td->setCorrName(cn);
setTableName(cn);
char * strval =
new(bindWA.wHeap()) char[CACHED_MAX_ANSI_NAME_EXTERNAL_LEN];
strcpy(strval, origName.getQualifiedNameAsString().data());
CharType * typ =
new(bindWA.wHeap()) SQLChar(CACHED_MAX_ANSI_NAME_EXTERNAL_LEN, FALSE);
ConstValue * cv =
new(bindWA.wHeap()) ConstValue(typ, strval, CACHED_MAX_ANSI_NAME_EXTERNAL_LEN);
ConstantParameter* result = new(bindWA.wHeap()) ConstantParameter
(*cv, bindWA.wHeap(), cwa.getPhase() == CmpMain::PARSE);
result->synthTypeAndValueId();
cwa.addConstParam(result, bindWA);
hv->setPMOrdPosAndIndex(COM_UNKNOWN_DIRECTION,
-1,
(Int32)cwa.getConstParams().entries());
}
// replace descendants' literals into ConstantParameters
return RelExpr::normalizeForCache(cwa, bindWA);
}