bool DictionaryDatabase::stringCacheLookup(OperationContext &context,
DbXmlDbt &dbt, NameID &id) const
{
nameId_t *nid = 0;
Transaction *txn = getTxn(context);
if (txn) {
DictionaryStringCache *dsc =
txn->getStringCache(const_cast<DictionaryDatabase*>(this), false);
if (dsc) {
nid = dsc->lookup(&dbt);
if (nid) {
DbXmlDbt dbt((void *)nid, sizeof(nameId_t));
id.setThisFromDbtAsId(dbt);
return true;
}
}
}
nid = stringCache_.lookup(&dbt);
if (nid) {
DbXmlDbt tdbt((void *)nid, sizeof(nameId_t));
id.setThisFromDbtAsId(tdbt);
return true;
}
return false;
}
int DictionaryDatabase::lookupIDFromName(OperationContext &context,
const Name &name,
NameID &id, bool define)
{
int err = 0;
if (name == Name::dbxml_colon_name) {
id = nidName_;
} else if (name == Name::dbxml_colon_root) {
id = nidRoot_;
}
if (id == 0) {
MutexLock ml(mutex_);
u_int32_t flags = (getTxn(context) && !define) ? DB_READ_COMMITTED : 0;
name.setDbtFromThis_SecondaryKey(context.key());
if (stringCacheLookup(context, context.key(), id))
return 0;
err = secondary_->get(getTxn(context), &context.key(), &context.data(), flags);
if (err == 0) {
id.setThisFromDbt(context.data());
stringCache_.insert(&context.key(), id.raw());
} else if (err == DB_NOTFOUND && define) {
err = defineName(context, name, id); // define from name:uri
} else {
id.reset();
}
}
return err;
}
void DictionaryDatabase::display(OperationContext &context, ostream &out) const
{
{
Cursor myCursor(const_cast<PrimaryDatabase&>(*primary_.get()), getTxn(context), CURSOR_READ, 0);
if(myCursor.error() != 0) throw XmlException(myCursor.error());
int err = 0;
NameID id;
while((err = myCursor.get(context.key(), context.data(), DB_NEXT)) == 0) {
id.setThisFromDbtAsId(context.key());
Buffer val(context.data().data, context.data().size, true);
out << id << " -> " << val.asString(true) << endl;
}
}
{
Cursor myCursor(const_cast<SecondaryDatabase&>(*secondary_.get()), getTxn(context), CURSOR_READ, 0);
if(myCursor.error() != 0) throw XmlException(myCursor.error());
int err = 0;
NameID id;
while((err = myCursor.get(context.key(), context.data(), DB_NEXT)) == 0) {
Buffer val(context.key().data, context.key().size, true);
id.setThisFromDbt(context.data());
out << val.asString(true) << " -> " << id << endl;
}
}
}
static void unmarshalKey(const DbtOut &dbt, NameID &id1, NameID &id2)
{
const xmlbyte_t *ptr = (const xmlbyte_t*)dbt.data;
const xmlbyte_t *end = ptr + dbt.size;
++ptr; // Skip the prefix
if(ptr < end) ptr += id1.unmarshal(ptr);
if(ptr < end) ptr += id2.unmarshal(ptr);
}
static void marshalKey(const NameID &id1, const NameID &id2, DbtOut &dbt)
{
DBXML_ASSERT(id1 != 0 || id2 == 0);
int size = 1;
if(id1 != 0) size += id1.marshalSize();
if(id2 != 0) size += id2.marshalSize();
dbt.set(0, size);
xmlbyte_t *ptr = (xmlbyte_t*)dbt.data;
*ptr++ = KEY_PREFIX_BYTE;
if(id1 != 0) ptr += id1.marshal(ptr);
if(id2 != 0) ptr += id2.marshal(ptr);
}
int DictionaryDatabase::lookupNameFromID(OperationContext &context,
const NameID &id, Name &name) const
{
int err = 0;
nameId_t raw = id.raw() - 1; // id space is 1-based, not 0
if (id == nidName_) {
name = Name::dbxml_colon_name;
return 0;
} else if (id == nidRoot_) {
name = Name::dbxml_colon_root;
return 0;
}
if ((raw < DICTIONARY_RESERVE_SIZE) && usePreloads_) {
name = preloadNames[raw];
} else {
err = lookupFromID(context, context.data(), id);
if (err == 0) {
name.setThisFromDbt(context.data());
} else {
name.reset();
}
}
return err;
}
// Basic lookup, returning a pointer that will be valid
// until this object is deleted. Lookup does not require locking
// because entries are never removed, and they are only added
// at the beginning of the hash chain with a simple pointer update.
// A race condition could theoretically happen if a compiler reorders
// some of the code in insert
bool
DictionaryCache::lookup(OperationContext &context, const NameID &id,
DbtOut &dbt, bool useDictionary)
{
while (true) { // will only ever loop once
nameId_t nid = id.raw();
int bucket = hash(nid);
DictionaryCacheEntry *current = htable_[bucket];
while (current && (current->getNid() != nid))
current = current->getNext();
if (current) {
dbt.set(current->getValue(), current->getLen());
return true;
}
if (!useDictionary)
return false;
// read through the dictionary
int ret = ddb_->lookupStringNameFromID(context, id, dbt);
if (ret == 0) {
DBXML_ASSERT(dbt.size);
insert(nid, dbt);
} else {
// this should never happen, but if it does,
// be silent (for now)
return false;
}
}
}
int PrimaryDatabase::appendPrimary(OperationContext &context, NameID &id,
const DbXmlDbt &data, u_int32_t flags)
{
int err = put(context.txn(), &context.key(), &(const_cast<DbXmlDbt&>(data)),
flags | DB_APPEND);
if (err == 0)
id.setThisFromDbtAsId(context.key());
return err;
}
// puts result in dbt, which may be context.data(), or may be user-provided
int DictionaryDatabase::lookupFromID(
OperationContext &context, DbtOut &dbt,
const NameID &id) const
{
int err = 0;
if (cache_.lookup(context, id, dbt, false))
return 0;
u_int32_t flags = (getTxn(context)) ? DB_READ_COMMITTED : 0;
// primary key is the integer value of the id (database is
// recno)
id.setDbtFromThisAsId(context.key());
MutexLock ml(mutex_);
err = primary_->get(getTxn(context), &context.key(),
&dbt, flags);
if (err == 0)
cache_.insert(id.raw(), dbt);
return err;
}
// mutex is locked if present and necessary
int DictionaryDatabase::defineStringName(OperationContext &context,
const char *name, size_t namelen,
NameID &id)
{
// Primary { id -> name\0 }
// Secondary { name -> id }
int err = 0;
id.reset();
DbtIn primaryData((void*)name, namelen + 1); // add null
DbtIn secondaryKey((void*)name, namelen); // don't add null
err = primary_->appendPrimary(context, id,
primaryData, /*no flags*/0);
if (err == 0) {
/* Cache after insert. This prevents the cache from returning bad answers
* on a transaction abort, and speeds up access to newly inserted element
* and attribute names that are needed for indexing after an insert.
*/
cache_.insert(id.raw(), primaryData);
id.setDbtFromThis(context.key());
Transaction *txn = getTxn(context);
err = secondary_->put(txn, &secondaryKey,
&context.key(),
/*no flags*/0);
if (err == 0) {
/* Add to the transaction's string cache, that way if an abort occurs
* the values can be removed from the cache.
*/
if (txn) {
DictionaryStringCache *dsc = txn->getStringCache(this, true);
dsc->insert(&secondaryKey, id.raw());
}
if (Log::isLogEnabled(Log::C_DICTIONARY, Log::L_INFO)) {
ostringstream oss;
oss << "Define new name " << id << " -> " << name;
Log::log(environment_, Log::C_DICTIONARY, Log::L_INFO,
name_.c_str(),
oss.str().c_str());
}
}
}
return err;
}
int DictionaryDatabase::lookupIDFromStringNameInternal(
OperationContext &context,
DbXmlDbt &dbt,
NameID &id,
bool define) const
{
if (!dbt.size) {
id.reset();
return 0;
}
u_int32_t flags = (getTxn(context) && !define) ? DB_READ_COMMITTED : 0;
if (stringCacheLookup(context, dbt, id))
return 0;
int err = secondary_->get(getTxn(context), &dbt,
&context.data(), flags);
if (err == 0) {
id.setThisFromDbt(context.data());
stringCache_.insert(&dbt, id.raw());
} else
id.reset();
return err;
}
int DictionaryDatabase::lookupStringNameFromID(
OperationContext &context,
const NameID &id, DbtOut &dbt) const
{
int err = 0;
nameId_t raw = id.raw() - 1; // id space is 1-based, not 0
if ((raw < DICTIONARY_RESERVE_SIZE) && usePreloads_) {
const char *name = preloadNames[raw];
dbt.set((const void *)name, ::strlen(name) + 1);
} else
err = lookupFromID(context, dbt, id);
return err;
}
int DictionaryDatabase::lookupStringNameFromID(
OperationContext &context,
const NameID &id, const char **name) const
{
int err = 0;
nameId_t raw = id.raw() - 1; // id space is 1-based, not 0
if ((raw < DICTIONARY_RESERVE_SIZE) && usePreloads_) {
*name = preloadNames[raw];
} else {
err = lookupFromID(context, context.data(), id);
if (err == 0)
*name = (const char *)context.data().data;
}
return err;
}
// use DB prefix iterator to remove all index entries for the specified index.
// do both index and statistics databases.
// The prefix is <indexKeyPrefix>[<nameId>]
int SyntaxDatabase::removeIndex(OperationContext &context, const Index &index,
const NameID &id)
{
// key is <indexType><name ID>, which is one byte plus a marshaled integer.
unsigned char keybuf[10];
keybuf[0] = index.getKeyPrefix();
u_int32_t sz = 1;
if (id != 0) {
// not a default index
sz += id.marshal(keybuf+1);
}
int err = removeIndexEntries(context, *index_.get(), keybuf, sz);
if (err == 0)
err = removeIndexEntries(context, *statistics_.get(), keybuf, sz);
return err;
}
int PrimaryDatabase::getPrimary(OperationContext &context, const NameID &id,
DbtOut *data, u_int32_t flags) const
{
id.setDbtFromThis(context.key());
return get(context.txn(), &context.key(), data, flags);
}
int PrimaryDatabase::deletePrimary(OperationContext &context,
const NameID &id, u_int32_t flags)
{
id.setDbtFromThis(context.key());
return del(context.txn(), &context.key(), flags);
}
int PrimaryDatabase::putPrimary(OperationContext &context, const NameID &id,
const DbXmlDbt &data, u_int32_t flags)
{
id.setDbtFromThis(context.key());
return put(context.txn(), &context.key(), &(const_cast<DbXmlDbt&>(data)), flags);
}