Examples of org.apache.derby.iapi.sql.conn.SQLSessionContext

org.apache.derby.iapi.sql.conn.SQLSessionContext
An implementation of this interface encapsulates some of the SQL session context's state variables, cf. SQL 2003, section 4.37.3, notably those which we need to save and restore when entering a stored procedure or function (which can contain SQL and thus a nested connection), cf. 4.37.3, 4.27.3 and 4.34.1.1.
Presently this set contains the following properties:
- current role
- current schema
The standard specifies that the authorization stack be copied onto the new SQL session context before it is pushed (and possibly modifed) with a new cell for the authorization ids (user, role). In our implementation we merge these two stacks for now. Also, the authorization id of current user is not represented yet, since it can not be modified in a session; Derby can not run routines with definer's rights yet.
SQL session context is implemented as follows: Statements at root connection level use the instance held by the the lcc, nested connections maintain instances of SQLSessionContext, held by the activation of the calling statement. This forms a logical stack as required by the standard. The statement context also holds a reference to the current SQLSessionContext.
When a dynamic result set references e.g. current role, the value retrieved will always be that of the current role when the statement is logically executed (inside procedure/function), not the current value when the result set is accessed outside the stored procedure/function. This works since the nested SQL session context is kept by the caller activation, so even though the statement context of the call has been popped, we can get at the final state of the nested SQL session context since the caller's activation is alive as long as dynamic result sets need it).
If more than one nested connection is used inside a shared procedure, they will share the same nested SQL session context. Since the same dynamic call context is involved, this seems correct. @see org.apache.derby.iapi.sql.conn.LanguageConnectionContext#setupNestedSessionContext

        Activation parent = activation.getParentActivation();
        SchemaDescriptor defaultSchema = getInitialDefaultSchemaDescriptor();


        // walk SQL session context chain
        while (parent != null) {
            SQLSessionContext ssc = parent.getSQLSessionContextForChildren();
            SchemaDescriptor s = ssc.getDefaultSchema();


            if (SanityManager.DEBUG) {
                SanityManager.ASSERT(s != null, "s should not be empty here");
            }


            if (schemaName.equals(s.getSchemaName())) {
                ssc.setDefaultSchema(defaultSchema);
            }
            parent = parent.getParentActivation();
        }


        // finally top level
        SQLSessionContext top = getTopLevelSQLSessionContext();
        SchemaDescriptor sd = top.getDefaultSchema();


        if (SanityManager.DEBUG) {
            SanityManager.ASSERT(sd != null, "sd should not be empty here");
        }


        if (schemaName.equals(sd.getSchemaName())) {
            top.setDefaultSchema(defaultSchema);
        }
    }

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     * Return the current SQL session context of the activation
     *
     * @param activation the activation
     */
    private SQLSessionContext getCurrentSQLSessionContext(Activation activation) {
        SQLSessionContext curr;


        Activation parent = activation.getParentActivation();


        if (parent == null ) {
            // top level

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    /**
     * Return the current SQL session context based on statement context
     */
    private SQLSessionContext getCurrentSQLSessionContext() {
        StatementContext ctx = getStatementContext();
        SQLSessionContext curr;


        if (ctx == null || !ctx.inUse()) {
            curr = getTopLevelSQLSessionContext();
        } else {
            // We are inside a nested connection in a procedure of

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            if (definersRights) {
                SanityManager.ASSERT(push);
            }
        }


        SQLSessionContext sc = a.setupSQLSessionContextForChildren(push);


        if (definersRights) {
            sc.setUser(definer);
        } else {
            // A priori: invoker's rights: Current user
            sc.setUser(getCurrentUserId(a));
        }




        if (definersRights) {
            // No role a priori. Cf. SQL 2008, section 10.4 <routine
            // invocation>, GR 5 j) i) 1) B) "If the external security
            // characteristic of R is DEFINER, then the top cell of the
            // authorization stack of RSC is set to contain only the routine
            // authorization identifier of R.


            sc.setRole(null);
        } else {
            // Semantics for roles dictate (SQL 4.34.1.1 and 4.27.3.) that the
            // role is initially inherited from the current session context
            // when we run with INVOKER security characteristic.
            sc.setRole(getCurrentRoleId(a));
        }




        if (definersRights) {
            SchemaDescriptor sd = getDataDictionary().getSchemaDescriptor(
                definer,
                getTransactionExecute(),
                false);


            if (sd == null) {
                sd = new SchemaDescriptor(
                    getDataDictionary(), definer, definer, (UUID) null, false);
            }


            sc.setDefaultSchema(sd);
        } else {
            // Inherit current default schema. The initial value of the
            // default schema is implementation defined. In Derby we
            // inherit it when we invoke stored procedures and functions.
            sc.setDefaultSchema(getDefaultSchema(a));
        }


        StatementContext stmctx = getStatementContext();


        // Since the statement is an invocation (iff push=true), it will now be

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    Activation parent = activation.getParentActivation();
    SchemaDescriptor defaultSchema = getInitialDefaultSchemaDescriptor();


    // walk SQL session context chain
    while (parent != null) {
      SQLSessionContext ssc = parent.getSQLSessionContextForChildren();
      SchemaDescriptor s = ssc.getDefaultSchema();


      if (SanityManager.DEBUG) {
        SanityManager.ASSERT(s != null, "s should not be empty here");
      }


      if (schemaName.equals(s.getSchemaName())) {
        ssc.setDefaultSchema(defaultSchema);
      }
      parent = parent.getParentActivation();
    }


    // finally top level
    SQLSessionContext top = getTopLevelSQLSessionContext();
    SchemaDescriptor sd = top.getDefaultSchema();


    if (SanityManager.DEBUG) {
      SanityManager.ASSERT(sd != null, "sd should not be empty here");
    }


    if (schemaName.equals(sd.getSchemaName())) {
      top.setDefaultSchema(defaultSchema);
    }
  }

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   * Return the current SQL session context of the activation
   *
   * @param activation the activation
   */
  private SQLSessionContext getCurrentSQLSessionContext(Activation activation) {
    SQLSessionContext curr;


    Activation parent = activation.getParentActivation();


    if (parent == null ) {
      // top level

View Full Code Here

  /**
   * Return the current SQL session context based on statement context
   */
  private SQLSessionContext getCurrentSQLSessionContext() {
    StatementContext ctx = getStatementContext();
    SQLSessionContext curr;


    if (ctx == null || !ctx.inUse()) {
      curr = getTopLevelSQLSessionContext();
    } else {
      // We are inside a nested connection in a procedure of

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    setupSessionContextMinion(a, true);
  }


  private void setupSessionContextMinion(Activation a,
                         boolean push) {
    SQLSessionContext sc = a.setupSQLSessionContextForChildren(push);


    // Semantics for roles dictate (SQL 4.34.1.1 and 4.27.3.) that the
    // role is initially inherited from the current session
    // context. (Since we always run with INVOKER security
    // characteristic. Derby can't yet run with DEFINER's rights).
    //
    sc.setRole(getCurrentRoleId(a));


    // Inherit current default schema. The initial value of the
    // default schema is implementation defined. In Derby we
    // inherit it when we invoke stored procedures and functions.
    sc.setDefaultSchema(getDefaultSchema(a));


    StatementContext stmctx = getStatementContext();


    // Since the statement is an invocation (iff push=true), it will now be
    // associated with the pushed SQLSessionContext (and no longer just

View Full Code Here

    Activation parent = activation.getParentActivation();
    SchemaDescriptor defaultSchema = getInitialDefaultSchemaDescriptor();


    // walk SQL session context chain
    while (parent != null) {
      SQLSessionContext ssc = parent.getSQLSessionContextForChildren();
      SchemaDescriptor s = ssc.getDefaultSchema();


      if (SanityManager.DEBUG) {
        SanityManager.ASSERT(s != null, "s should not be empty here");
      }


      if (schemaName.equals(s.getSchemaName())) {
        ssc.setDefaultSchema(defaultSchema);
      }
      parent = parent.getParentActivation();
    }


    // finally top level
    SQLSessionContext top = getTopLevelSQLSessionContext();
    SchemaDescriptor sd = top.getDefaultSchema();


    if (SanityManager.DEBUG) {
      SanityManager.ASSERT(sd != null, "sd should not be empty here");
    }


    if (schemaName.equals(sd.getSchemaName())) {
      top.setDefaultSchema(defaultSchema);
    }
  }

View Full Code Here

   * Return the current SQL session context of the activation
   *
   * @param activation the activation
   */
  private SQLSessionContext getCurrentSQLSessionContext(Activation activation) {
    SQLSessionContext curr;


    Activation parent = activation.getParentActivation();


    if (parent == null ) {
      // top level

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Related Classes of org.apache.derby.iapi.sql.conn.SQLSessionContext

org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext

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