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//---------------------------------------------------------------------
// <copyright file="MultipartIdentifier.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//
// @owner Microsoft
// @backupOwner Microsoft
//---------------------------------------------------------------------
using System.Diagnostics;
using System.Text;
using System.Collections.Generic;
namespace System.Data.Common.Internal
{
/// <summary>
/// Copied from System.Data.dll
/// </summary>
internal static class MultipartIdentifier
{
private const int MaxParts = 4;
internal const int ServerIndex = 0;
internal const int CatalogIndex = 1;
internal const int SchemaIndex = 2;
internal const int TableIndex = 3;
private enum MPIState
{
MPI_Value,
MPI_ParseNonQuote,
MPI_LookForSeparator,
MPI_LookForNextCharOrSeparator,
MPI_ParseQuote,
MPI_RightQuote,
}
private static void IncrementStringCount(List<string> ary, ref int position)
{
++position;
ary.Add(string.Empty);
}
private static bool IsWhitespace(char ch)
{
return Char.IsWhiteSpace(ch);
}
/// <summary>
/// Core function for parsing the multipart identifer string.
/// Note: Left quote strings need to correspond 1 to 1 with the right quote strings
/// example: "ab" "cd", passed in for the left and the right quote
/// would set a or b as a starting quote character.
/// If a is the starting quote char then c would be the ending quote char
/// otherwise if b is the starting quote char then d would be the ending quote character.
/// </summary>
/// <param name="name">string to parse</param>
/// <param name="leftQuote">set of characters which are valid quoteing characters to initiate a quote</param>
/// <param name="rightQuote">set of characters which are valid to stop a quote, array index's correspond to the the leftquote array.</param>
/// <param name="separator">separator to use</param>
/// <returns></returns>
internal static List<string> ParseMultipartIdentifier(string name, string leftQuote, string rightQuote, char separator)
{
Debug.Assert(-1 == leftQuote.IndexOf(separator) && -1 == rightQuote.IndexOf(separator) && leftQuote.Length == rightQuote.Length, "Incorrect usage of quotes");
List<string> parsedNames = new List<string>();
parsedNames.Add(null);
int stringCount = 0; // index of current string in the list
MPIState state = MPIState.MPI_Value; // Initalize the starting state
StringBuilder sb = new StringBuilder(name.Length); // String buffer to hold the string being currently built, init the string builder so it will never be resized
StringBuilder whitespaceSB = null; // String buffer to hold white space used when parsing nonquoted strings 'a b . c d' = 'a b' and 'c d'
char rightQuoteChar = ' '; // Right quote character to use given the left quote character found.
for (int index = 0; index < name.Length; ++index)
{
char testchar = name[index];
switch (state)
{
case MPIState.MPI_Value:
{
int quoteIndex;
if (IsWhitespace(testchar))
{ // Is White Space then skip the whitespace
continue;
}
else
if (testchar == separator)
{ // If we found a separator, no string was found, initalize the string we are parsing to Empty and the next one to Empty.
// This is NOT a redundent setting of string.Empty it solves the case where we are parsing ".foo" and we should be returning null, null, empty, foo
parsedNames[stringCount] = string.Empty;
IncrementStringCount(parsedNames, ref stringCount);
}
else
if (-1 != (quoteIndex = leftQuote.IndexOf(testchar)))
{ // If we are a left quote
rightQuoteChar = rightQuote[quoteIndex]; // record the corresponding right quote for the left quote
sb.Length = 0;
state = MPIState.MPI_ParseQuote;
}
else
if (-1 != rightQuote.IndexOf(testchar))
{ // If we shouldn't see a right quote
throw EntityUtil.ADP_InvalidMultipartNameDelimiterUsage();
}
else
{
sb.Length = 0;
sb.Append(testchar);
state = MPIState.MPI_ParseNonQuote;
}
break;
}
case MPIState.MPI_ParseNonQuote:
{
if (testchar == separator)
{
parsedNames[stringCount] = sb.ToString(); // set the currently parsed string
IncrementStringCount(parsedNames, ref stringCount);
state = MPIState.MPI_Value;
}
else // Quotes are not valid inside a non-quoted name
if (-1 != rightQuote.IndexOf(testchar))
{
throw EntityUtil.ADP_InvalidMultipartNameDelimiterUsage();
}
else
if (-1 != leftQuote.IndexOf(testchar))
{
throw EntityUtil.ADP_InvalidMultipartNameDelimiterUsage();
}
else
if (IsWhitespace(testchar))
{ // If it is Whitespace
parsedNames[stringCount] = sb.ToString(); // Set the currently parsed string
if (null == whitespaceSB)
{
whitespaceSB = new StringBuilder();
}
whitespaceSB.Length = 0;
whitespaceSB.Append(testchar); // start to record the white space, if we are parsing a name like "name with space" we should return "name with space"
state = MPIState.MPI_LookForNextCharOrSeparator;
}
else
{
sb.Append(testchar);
}
break;
}
case MPIState.MPI_LookForNextCharOrSeparator:
{
if (!IsWhitespace(testchar))
{ // If it is not whitespace
if (testchar == separator)
{
IncrementStringCount(parsedNames, ref stringCount);
state = MPIState.MPI_Value;
}
else
{ // If its not a separator and not whitespace
sb.Append(whitespaceSB);
sb.Append(testchar);
parsedNames[stringCount] = sb.ToString(); // Need to set the name here in case the string ends here.
state = MPIState.MPI_ParseNonQuote;
}
}
else
{
whitespaceSB.Append(testchar);
}
break;
}
case MPIState.MPI_ParseQuote:
{
if (testchar == rightQuoteChar)
{ // if se are on a right quote see if we are escapeing the right quote or ending the quoted string
state = MPIState.MPI_RightQuote;
}
else
{
sb.Append(testchar); // Append what we are currently parsing
}
break;
}
case MPIState.MPI_RightQuote:
{
if (testchar == rightQuoteChar)
{ // If the next char is a another right quote then we were escapeing the right quote
sb.Append(testchar);
state = MPIState.MPI_ParseQuote;
}
else
if (testchar == separator)
{ // If its a separator then record what we've parsed
parsedNames[stringCount] = sb.ToString();
IncrementStringCount(parsedNames, ref stringCount);
state = MPIState.MPI_Value;
}
else
if (!IsWhitespace(testchar))
{ // If it is not white space we got problems
throw EntityUtil.ADP_InvalidMultipartNameDelimiterUsage();
}
else
{ // It is a whitespace character so the following char should be whitespace, separator, or end of string anything else is bad
parsedNames[stringCount] = sb.ToString();
state = MPIState.MPI_LookForSeparator;
}
break;
}
case MPIState.MPI_LookForSeparator:
{
if (!IsWhitespace(testchar))
{ // If it is not whitespace
if (testchar == separator)
{ // If it is a separator
IncrementStringCount(parsedNames, ref stringCount);
state = MPIState.MPI_Value;
}
else
{ // Othewise not a separator
throw EntityUtil.ADP_InvalidMultipartNameDelimiterUsage();
}
}
break;
}
}
}
// Resolve final states after parsing the string
switch (state)
{
case MPIState.MPI_Value: // These states require no extra action
case MPIState.MPI_LookForSeparator:
case MPIState.MPI_LookForNextCharOrSeparator:
break;
case MPIState.MPI_ParseNonQuote: // Dump what ever was parsed
case MPIState.MPI_RightQuote:
parsedNames[stringCount] = sb.ToString();
break;
case MPIState.MPI_ParseQuote: // Invalid Ending States
default:
throw EntityUtil.ADP_InvalidMultipartNameDelimiterUsage();
}
return parsedNames;
}
}
}
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