list* SearchSignatureDatabase(signature_db* SignatureDatabase, trie_unit* Data, size_t DataSize)
{
size_t NumMatches;
if (!SignatureDatabase || !Data || !DataSize)
return NULL;
if (!SignatureDatabase->SearchMachine)
return NULL;
match* Matches = FindMatches(SignatureDatabase->SearchMachine, Data, DataSize, &NumMatches);
// Translate signature identifiers to signatures
list* MatchingSignatures = NULL;
for (size_t MatchIndex = 0; MatchIndex < NumMatches; ++MatchIndex)
{
list* MatchList = Matches[MatchIndex].List;
for (; MatchList; MatchList = MatchList->Next)
{
for (size_t SignatureDatabaseIndex = 0; SignatureDatabaseIndex < SignatureDatabase->SignatureCount; ++SignatureDatabaseIndex)
{
if (memcmp(SignatureDatabase->Signatures[SignatureDatabaseIndex]->Data,
MatchList->Value,
SignatureDatabase->Signatures[SignatureDatabaseIndex]->DataSize) == 0)
{
if (!MatchingSignatures)
AllocateAndInitializeListHead(&MatchingSignatures, SignatureDatabase->Signatures[SignatureDatabaseIndex]);
else
UniqAppendToList(MatchingSignatures, SignatureDatabase->Signatures[SignatureDatabaseIndex]);
}
}
}
}
return MatchingSignatures;
}
int InitializeSearchMachine(search_machine* SearchMachine, trie* Trie)
{
SearchMachine->Trie = Trie;
// For each keyword in the keyword tree, set out(Node-For-Keyword) = {Keyword}
size_t TerminalCount;
trie** Terminals = GatherTerminals(Trie, &TerminalCount);
// Each state has an out (set of patterns recognized upon entering it
// out :: Map StateID [String]
SearchMachine->Out = xcalloc(GetTrieCount(), sizeof(list*));
for (size_t TerminalIndex = 0; TerminalIndex < TerminalCount; ++TerminalIndex)
{
size_t DataLength;
size_t TerminalIdentifier = Terminals[TerminalIndex]->Identifier;
trie_unit* DataUpToNode = GetDataString(Terminals[TerminalIndex], &DataLength);
Assert(DataUpToNode != NULL, "ISM1");
AllocateAndInitializeListHead(&(SearchMachine->Out[TerminalIdentifier]), DataUpToNode);
}
SearchMachine->Fail = xcalloc(GetTrieCount(), sizeof(trie *));
// goto :: Map (StateID, Symbol) StatePtr
SearchMachine->Goto = xcalloc(sizeof(void *), GetTrieCount());
// Copy over trie links into goto
for (size_t TrieIndex = 0; TrieIndex < GetTrieCount(); TrieIndex++)
{
SearchMachine->Goto[TrieIndex] = xcalloc(sizeof(trie*), UNIT_CARDINALITY);
trie* TrieToCopy = FindInTrieByIdentifier(Trie, TrieIndex);
memcpy(SearchMachine->Goto[TrieIndex], TrieToCopy->Children, sizeof(trie*) * UNIT_CARDINALITY);
}
// g(ROOT, a) := ROOT forall a in SIGMA where a doesn't leave ROOT
for (size_t AlphabetIndex = 0; AlphabetIndex < UNIT_CARDINALITY; ++AlphabetIndex)
{
if (Trie->Children[AlphabetIndex] == NULL)
{
SearchMachine->Goto[ROOT_IDENTIFIER][AlphabetIndex] = Trie;
}
}
return 0;
}
