Package com.tailf.navu

Class NavuLeaf

Object
com.tailf.navu.NavuNode
com.tailf.navu.NavuLeaf
Direct Known Subclasses:
NavuLeafList
public class NavuLeaf extends NavuNode
The NavuLeaf class corresponds to the YANG leaf and leaf-list node types. A NavuLeaf is a node in the NAVU-Tree that that does not have any children and holds a value.

To retrieve a value the method value() should be called which on first invocation retrieves the value through the current context. Subsequent calls to the value method will return the "cached" value. It is important to understand that the first call to value method will cache the value in the instance which means that subsequent calls to the value will return the cached value. To clear the cache held by an instance of NavuLeaf, the method reset() should be called.

  • Method Details

    • isKey

      public boolean isKey()
      Returns true if this NavuLeaf is a key node.
      Returns:
      true whether this NavuLeaf is a key node false otherwise

    • delete

      public NavuLeaf delete() throws NavuException
      Deletes a leaf.
      Returns:
      a pointer to self.
      Throws:
      NavuException

    • encodeXML

      public List<ConfXMLParam> encodeXML() throws NavuException
      Description copied from class: NavuNode
      Encodes the sub-tree including the current NavuNode as the topmost NavuNode as a ConfXMLParam array.

      The returned ConfXMLParam array contains no values except for list keys. The leaf elements are encoded as ConfXMLParamLeaf. Therefore, the returning array can be used as a the input parameter to NavuNode.getValues(ConfXMLParam[]) on the current node's parent. 

       NavuNode node = ...;
 ConfXMLParam[] cxa = node.encodeXML().toArray(new ConfXMLParam[0]);
 // cxa contains a structure that does not contain values except for
 // keys in list elements

 NavuNode parent = node.getParent();
 ConfXMLParam[] cxb = parent.getValues(cxa);
 // cxb contains the same sub-tree with all the values
      Specified by:
      encodeXML in class NavuNode
      Returns:
      A list of ConfXMLParam objects corresponding to the sub-tree of this node, with no values except list keys.
      Throws:
      NavuException
      See Also:

    • encodeValues

      public List<ConfXMLParam> encodeValues() throws NavuException
      Description copied from class: NavuNode
      Encodes the sub-tree including the current NavuNode as the topmost NavuNode as a ConfXMLParam array.

      As opposed to NavuNode.encodeXML(), the returned ConfXMLParam array does contain values in the form of ConfXMLParamValue

      Specified by:
      encodeValues in class NavuNode
      Returns:
      A list of ConfXMLParam objects corresponding to the sub-tree of this node, including all values.
      Throws:
      NavuException
      See Also:

    • reset

      public void reset()
      When navigating through NAVU to a certain leaf and retrieving its value, this value will be cached. This method will reset the cache and indicate that the value should be re-read next time the value is retrieved.
      Specified by:
      reset in class NavuNode

    • select

      public Collection<NavuNode> select(List<String> path) throws NavuException
      Specified by:
      select in class NavuNode
      Parameters:
      path - a list of regular expression.
      Returns:
      a collection a nodes marching the query
      Throws:
      NavuException

    • select

      public Collection<NavuNode> select(String path) throws NavuException
      Specified by:
      select in class NavuNode
      Parameters:
      path - a "/" separated regular expression.
      Returns:
      a collection a nodes marching the query
      Throws:
      NavuException

    • getValues

      public ConfXMLParam[] getValues(String xml) throws NavuException
      Description copied from class: NavuNode
      Read an arbitrary set of sub-elements of a container or list entry.

      The xml string must be pre-populated with tags and parameterized values ("?") which indicate that the operation should read the values of the corresponding tags.

      NOTE: The specified xml string should not contain the version tag (<?xml version="1.0" encoding="UTF-8"?>) and do not wrap xml string with current node tag.

      Example - Get tree in a service model: 
       list buzz-service {
   key name;
   leaf name {
     type string;
   }
   uses ncs:service-data;
   ncs:servicepoint buzz-service-servicepoint;
   container buzz {
     container servers {
       list server {
         key "srv-name";
         max-elements "64";
         leaf srv-name {
           type string;
         }
         leaf ip {
           type inet:host;
           mandatory true;
         }
         leaf port {
           type inet:port-number;
           default "80";
         }
         container foo {
           leaf bar {
             type int64;
             default "42";
           }
           leaf baz {
             type int64;
             default "7";
           }
         }
         list interface {
           key "if-name";
           max-elements "8";
           leaf if-name {
             type string;
           }
           leaf mtu {
             type int64;
             default "1500";
           }
         }
       }
     }
   }
 }

 NavuContainer buzz =
     ncsRoot.container(buzzService.hash)
            .list(buzzService._buzz_service)
            .elem("service1")
            .container(buzzService._buzz);

 ConfXMLParam[] param =
     buzz.getValues("<buzz xmlns=\"http://com/example/buzzservice\">"
                    + "<servers><server><srv-name>www1</srv-name>"
                    + "<ip>?</ip></server><server>"
                    + "<srv-name>www2</srv-name><ip>?</ip>"
                    + "</server></servers></buzz>");
      Overrides:
      getValues in class NavuNode
      Parameters:
      xml - XML structure corresponding to the part of the configuration tree that is to be fetched.
      Throws:
      NavuException

    • sharedSet

      public void sharedSet(ConfValue val) throws NavuException
      Sets the value of a leaf node with FastMap support, creating backpointers and reference counter similar to sharedCreate() All FastMap code shall (in principle) allways use this method instead of set()
      Throws:
      NavuException

    • sharedSet

      public void sharedSet(String val) throws NavuException
      SharedSet using string representation of value. Sets the value of a leaf node with FastMap support, creating backpointers and reference counter similar to sharedCreate() All FastMap code shall (in principle) always use this method instead of set()
      Throws:
      NavuException

    • set

      public void set(ConfValue val) throws NavuException
      Sets the value of the leaf node.

      When setting a leaf node the cached value inside the instance is reflected. Subsequent calls to value retrieves the cached value.

      Setting a leaf value is only valid when writing to a transaction or when writing to operational data store.

      When writing to the operational data store the write is done with the CdbLockType.LOCK_REQUEST lock type set.

      Parameters:
      val - - the value to set
      Throws:
      NavuException - If an error occurred when setting the leaf value the underlying/caused exception is wrapped inside the NavuException and should be retrieved through getCause method of Throwable.

      An IllegalArgumentException is wrapped inside a NavuException if writes is done to running with NavuContext created with CdbSession or Cdb.

    • setValues

      public void setValues(String xml) throws NavuException
      This method is almost identical to set(String) with the exception that the value should be wrapped inside XML tag.

      For example to set the value "123" it needs to be wrapped with "<leaf-name>123 </leaf-name>.

      Overrides:
      setValues in class NavuNode
      Parameters:
      xml - A string value wrapped inside XML tag.
      Throws:
      NavuException
      See Also:

    • set

      public void set(String val) throws NavuException
      Sets the value and tries to perform an update. For this to succeed, it must be possible to convert this string value into a value consistent with the type of the NavuLeaf. For example "123" if the YANG model has a leaf of, for example "int32".
      Parameters:
      val - The string representation of a new value. For this to succeed, it must be possible to convert this string value into a value consistent with the type of the NavuLeaf. For example "123" if the YANG model has a leaf of, for example "int32".
      Throws:
      NavuException

    • exists

      public boolean exists() throws NavuException
      Tests for the existence of the leaf node.
      Specified by:
      exists in class NavuNode
      Returns:
      boolean
      Throws:
      NavuException - on failure

    • create

      public void create() throws NavuException
      Create an empty leaf node.
      Throws:
      NavuException - on failure to create

    • safeCreate

      public void safeCreate() throws NavuException
      Create an empty leaf node, silently succeeding if the leaf already exists
      Throws:
      NavuException - on failure to create

    • sharedCreate

      public void sharedCreate() throws NavuException
      Create an empty leaf node, silently succeeding if the leaf already exists and also maintain the FASTMAP reference counter on the leaf.
      Throws:
      NavuException - on failure to create

    • toKey

      public ConfKey toKey() throws NavuException
      Convert the leaf value to a ConfKey. This is convenient, but only works for lists that have singleton keys.
      Returns:
      the leaf value represented as a key.
      Throws:
      NavuException

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • value

      public ConfValue value() throws NavuException
      Returns the effective value on the first call, or cached value in the subsequent calls of this leaf.

      After this method has been called the first time it stores the value in this object which means that subsequent calls to this method will return the cached value.

      Returns:
      the effective value (first call) or cached value in subsequent calls of this leaf.
      Throws:
      NavuException

    • valueAsString

      public String valueAsString() throws NavuException
      Returns the Schema aware string representation of a leaf.

      An example of the difference between this method and toString() is for ConfEnumerations where the schema aware representation is the label while toString() returns a representation of the ordinal value.

      Returns:
      String representation of the leaf
      Throws:
      NavuException

    • valueUpdateInd

      public void valueUpdateInd(NavuNode child)

    • getChangeFlag

      public DiffIterateOperFlag getChangeFlag()
      Returns the latest change that this NavuNode has been a subject to by a transaction.
      Overrides:
      getChangeFlag in class NavuNode
      Returns:
      Flag for the latest change
      See Also:

    • getOldValue

      public ConfValue getOldValue()
      Returns:
      the old value. null if no old value exists.

    • setChange

      public NavuNode setChange(List<ConfObject> kp, DiffIterateOperFlag op, ConfValue oldValue, NavuContext delContext) throws NavuException
      Throws:
      NavuException

    • getParent

      public NavuNode getParent()
      Description copied from class: NavuNode
      Returns the parent of the node.
      Overrides:
      getParent in class NavuNode
      Returns:
      - this node parent or null if this NavuNode represents the root node.

    • select

      public Collection<NavuNode> select(ConfObject[] query)
      Specified by:
      select in class NavuNode
      Returns:
      a collection a nodes matching a Regular Expression query

    • getCdbSession

      @Deprecated public CdbSession getCdbSession(CdbDBType dbType)
      Deprecated.
      This method is deprecated. Use one of NavuContextBase.getReadConfSession(), NavuContextBase.getReadConfSession() or NavuContextBase.getWriteOperSession() instead.
      Overrides:
      getCdbSession in class NavuNode
      Returns:
      The current CdbSession or null if this node is attached to a Maapi context

    • getRootNS

      public ConfNamespace getRootNS()
      Description copied from class: NavuNode
      Returns the root namespace of the topmost ancestor.
      Overrides:
      getRootNS in class NavuNode
      Returns:
      topmost namespace.

    • deref

      public List<NavuNode> deref() throws NavuException
      Derefs a leafref and returns the referenced objects
      Returns:
      array of keypaths where each keypath is an array of ConfObject
      Throws:
      NavuException

    • idrefDerivedOrSelf

      public boolean idrefDerivedOrSelf(ConfIdentityRef base) throws NavuException
      Throws:
      NavuException

    • equals

      public boolean equals(Object o)
      Compares the specified object with this NavuLeaf for equality. Returns true if the given object is also a NavuLeaf and it has the same ConfPath as this NavuLeaf. Note that the actual values held by the leaves (if any) are ignored as they are not relevant to this comparison.
      Specified by:
      equals in class NavuNode
      Parameters:
      o - the object to be compared for equality with this NavuLeaf
      Returns:
      true if the specified object is equal to this NavuLeaf