public void Parse(string statement)
{
Context.TraceEvent(100, 0, "DMV: Begin Parse");
// break the statement into tokens
List <Tokenizer.Token> tList = new List <ASStoredProcs.DMVParser.Tokenizer.Token>();
Tokenizer.Tokenizer t = new ASStoredProcs.DMVParser.Tokenizer.Tokenizer(statement);
tList = t.Tokens;
int ipos = 1;
List <string> cols = new List <string>();
// do not proceed if the first token is not the work "SELECT"
if (tList[0].Text.ToUpper() == "SELECT")
{
// check for a DISTINCT query
if (tList.Count >= 2 && tList[1].Text.ToUpper() == "DISTINCT")
{
mDistinct = true;
ipos++;
}
// collect columns
while (tList[ipos].Text.ToUpper() != "FROM")
{
if (tList[ipos].Type != ASStoredProcs.DMVParser.Tokenizer.TokenType.Comma &&
tList[ipos].Text != "[" &&
tList[ipos].Text != "]")
{
cols.Add(tList[ipos].Text);
}
ipos++;
}
mCols = cols.ToArray();
ipos++;
// Get the token for the schema that we are querying
mFrom = tList[ipos].Text;
ipos += 1;
// look for the WHERE clause (if it exists)
if (ipos < tList.Count && tList[ipos].Text.ToUpper() == "WHERE")
{
ipos++;
}
List <Tokenizer.Token> whereTokens = new List <ASStoredProcs.DMVParser.Tokenizer.Token>();
// where clause
while (ipos < tList.Count &&
!(tList[ipos].Text.ToUpper() == "ORDER" &&
tList[ipos < tList.Count - 2?ipos + 1:ipos].Text.ToUpper() == "BY"))
{
if (tList[ipos].Type == ASStoredProcs.DMVParser.Tokenizer.TokenType.String)
{
mWhere += "'" + tList[ipos].Text + "' ";
}
else if (tList[ipos].Text != "[" && tList[ipos].Text != "]")
{
mWhere += tList[ipos].Text + " ";
}
whereTokens.Add(tList[ipos]);
ipos++;
}
// build a list of where predicates to see if we can match them to the
// restrictions for the rowset.
int iwherePos = 0;
while (iwherePos <= (whereTokens.Count - 3))
{
WherePredicate w = new WherePredicate();
w.Operand1 = whereTokens[iwherePos];
w.Operator = whereTokens[iwherePos + 1];
w.Operand2 = whereTokens[iwherePos + 2];
// restriction matching can only be done with the "=" operator
if (w.Operand1.Type == ASStoredProcs.DMVParser.Tokenizer.TokenType.Bracket ||
w.Operand2.Type == ASStoredProcs.DMVParser.Tokenizer.TokenType.Bracket ||
w.Operator.Text != "=")
{
canMatchRestrictions = false;
whereList.Clear();
break;
}
whereList.Add(w);
iwherePos += 3;
if (iwherePos < whereTokens.Count)
{
// multiple predicates must be joined with a logical "AND"
// currently nested operations with brackets are not supported
if (whereTokens[iwherePos].Text.ToUpper() == "AND")
{
iwherePos++;
}
else
{
canMatchRestrictions = false;
whereList.Clear();
break;
}
}
}
// if we have left over tokens, something has gone wrong
if (iwherePos != whereTokens.Count)
{
whereList.Clear();
canMatchRestrictions = false;
}
if (canMatchRestrictions)
{
string xmlaRestr = DiscoverRestrictions(Context.CurrentServerID, this.FromClause);
List <string> restr = extractRestrictions(xmlaRestr);
mRestrictions = MatchRestrictions(restr);
}
ipos += 2;
// Order By clause
while (ipos < tList.Count)
{
mOrder += tList[ipos].Text + " ";
ipos++;
}
Context.TraceEvent(100, 0, "DMV: End Parse");
}
}
public void Parse(string statement)
{
Context.TraceEvent(100, 0, "DMV: Begin Parse");
// break the statement into tokens
List<Tokenizer.Token> tList = new List<ASStoredProcs.DMVParser.Tokenizer.Token>();
Tokenizer.Tokenizer t = new ASStoredProcs.DMVParser.Tokenizer.Tokenizer(statement);
tList = t.Tokens;
int ipos = 1;
List<string> cols = new List<string>();
// do not proceed if the first token is not the work "SELECT"
if (tList[0].Text.ToUpper() == "SELECT")
{
// check for a DISTINCT query
if (tList.Count >= 2 && tList[1].Text.ToUpper() == "DISTINCT")
{
mDistinct = true;
ipos++;
}
// collect columns
while (tList[ipos].Text.ToUpper() != "FROM")
{
if (tList[ipos].Type != ASStoredProcs.DMVParser.Tokenizer.TokenType.Comma
&& tList[ipos].Text != "["
&& tList[ipos].Text != "]")
{
cols.Add(tList[ipos].Text);
}
ipos++;
}
mCols = cols.ToArray();
ipos++;
// Get the token for the schema that we are querying
mFrom = tList[ipos].Text;
ipos += 1;
// look for the WHERE clause (if it exists)
if (ipos < tList.Count && tList[ipos].Text.ToUpper() == "WHERE")
{
ipos++;
}
List<Tokenizer.Token> whereTokens = new List<ASStoredProcs.DMVParser.Tokenizer.Token>();
// where clause
while (ipos < tList.Count
&& !(tList[ipos].Text.ToUpper() == "ORDER"
&& tList[ipos<tList.Count-2?ipos+1:ipos].Text.ToUpper() == "BY" ))
{
if (tList[ipos].Type == ASStoredProcs.DMVParser.Tokenizer.TokenType.String)
{
mWhere += "'" + tList[ipos].Text + "' ";
}
else if (tList[ipos].Text != "[" && tList[ipos].Text != "]")
{
mWhere += tList[ipos].Text + " ";
}
whereTokens.Add(tList[ipos]);
ipos++;
}
// build a list of where predicates to see if we can match them to the
// restrictions for the rowset.
int iwherePos = 0;
while (iwherePos <= (whereTokens.Count - 3))
{
WherePredicate w = new WherePredicate();
w.Operand1 = whereTokens[iwherePos];
w.Operator = whereTokens[iwherePos+1];
w.Operand2 = whereTokens[iwherePos+2];
// restriction matching can only be done with the "=" operator
if ( w.Operand1.Type == ASStoredProcs.DMVParser.Tokenizer.TokenType.Bracket
|| w.Operand2.Type == ASStoredProcs.DMVParser.Tokenizer.TokenType.Bracket
|| w.Operator.Text != "=")
{
canMatchRestrictions = false;
whereList.Clear();
break;
}
whereList.Add(w);
iwherePos += 3;
if (iwherePos < whereTokens.Count)
{
// multiple predicates must be joined with a logical "AND"
// currently nested operations with brackets are not supported
if (whereTokens[iwherePos].Text.ToUpper() == "AND")
{
iwherePos++;
}
else
{
canMatchRestrictions = false;
whereList.Clear();
break;
}
}
}
// if we have left over tokens, something has gone wrong
if (iwherePos != whereTokens.Count)
{
whereList.Clear();
canMatchRestrictions = false;
}
if (canMatchRestrictions)
{
string xmlaRestr = DiscoverRestrictions(Context.CurrentServerID, this.FromClause);
List<string> restr = extractRestrictions(xmlaRestr);
mRestrictions = MatchRestrictions(restr);
}
ipos += 2;
// Order By clause
while (ipos < tList.Count)
{
mOrder += tList[ipos].Text + " ";
ipos++;
}
Context.TraceEvent(100, 0, "DMV: End Parse");
}
}
