Package org.apache.manifoldcf.crawler.jobs

Class HopCount.DocumentNode

  • Enclosing class:
    HopCount
    protected static class HopCount.DocumentNode
extends java.lang.Object
    This class keeps track of the data associated with a node in the hash map. This basically includes the following: - the document identifier - the 'question' that was asked, which has the form (link type, maximum distance) - possibly the 'answer' to the question, which is either ">(maximum distance)", or a number. - references to the nodes which care about this answer, if they are still queued. - summary of the information we've gathered from children so far (if answer not known yet) - references to the children of this node that can affect the answer, including link details (if answer not known yet)

    • Field Detail

      • databaseAnswerValue

        protected int databaseAnswerValue
        This is the original answer (if any), which is the current value in the database

      • databaseRow

        protected java.lang.Long databaseRow
        The original database row, if any

      • startingAnswer

        protected HopCount.Answer startingAnswer
        The answer, as calculated up to the level of all the completed children, which will not include incomplete child references of this node. This is a starting point for every reassessment of this node's current answer. It is adjust only when additional children are noted as being complete.

      • trialAnswer

        protected HopCount.Answer trialAnswer
        The current best answer. This takes into account the current status of all the child nodes. If the node is not complete, then the answer must be viewed as being less than or equal to this value.

      • bestPossibleAnswer

        protected HopCount.Answer bestPossibleAnswer
        The best (lowest) possible answer value for this node. This value is calculated based on the known child link structure of a node, and can only increase. The value will start low (at 0) and will climb as more knowledge is gained, as the children's best possible answer value increases upon re-evaluation. When the trial answer (above) reaches a value equal to the best possible value, then the node will be immediately marked as "complete", and further processing will be considered unnecessary. As far as dependencies are concerned, the bestPossibleAnswer includes dependencies that have gone into its assessment. These dependencies represent what would need to be changed to invalidate the answer as it stands. (Invalidation means that a smaller best possible answer would be possible, so only add dependencies would need consideration.)

      • isComplete

        protected boolean isComplete
        Answer complete flag. Will be set to true only if the value of "trialAnswer" is deemed final.

      • writeNeeded

        protected boolean writeNeeded
        This flag is meaningful only if the complete flag is set.

      • parentsWhoCare

        protected java.util.Map parentsWhoCare
        Parent nodes who care (i.e. are still queued). This map contains DocumentNode objects.

      • childReferences

        protected java.util.Map childReferences
        Child node references. This is a reference to an actual document node object which has a parent reference back to this one. If the child node is modified, there is an obligation to cause the parent node to be re-evaluated. The re-evaluation process examines all child nodes and may adjust the status of the trial answer, and may indeed even remove the reference to the child. This map contains NodeReference objects.

    • Constructor Detail

      • DocumentNode

        public DocumentNode​(HopCount.Question question)
        Create a document node. This will happen only if there is no comparable one already in the hash.

    • Method Detail

      • reset

        public void reset()
        Reset back to an "unknown" state.

      • clearChildReferences

        public void clearChildReferences()
        Clear child references.

      • hasChildren

        public boolean hasChildren()
        Check if there are children.

      • getFinalAnswer

        public int getFinalAnswer()
        Get an answer that's final. Returns "unknown" if the current answer is incomplete.

      • isAnswerComplete

        public boolean isAnswerComplete()
        Check if the answer is complete. Returns true if the answer is complete.

      • isComplete

        public boolean isComplete()
        Check if the node is complete, given the question it represents.

      • isWriteNeeded

        public boolean isWriteNeeded()
        Check if a write of the answer is needed to the database

      • isAnswerNeeded

        public boolean isAnswerNeeded()
        Check if answer is still needed.

      • getBestPossibleAnswer

        public HopCount.Answer getBestPossibleAnswer()
        Get best possible answer

      • setBestPossibleAnswer

        public void setBestPossibleAnswer​(HopCount.Answer answer)
        Set best possible answer

      • getTrialAnswer

        public HopCount.Answer getTrialAnswer()
        Get the current best answer.

      • setTrialAnswer

        public void setTrialAnswer​(HopCount.Answer answer)
        Set the answer for this node.

      • getStartingAnswer

        public HopCount.Answer getStartingAnswer()
        Get the starting (base) answer.

      • setStartingAnswer

        public void setStartingAnswer​(HopCount.Answer answer)
        Set the starting (base) answer.

      • makeComplete

        public void makeComplete()
        Mark the node as being "complete", with a write needed.

      • makeCompleteNoWrite

        public void makeCompleteNoWrite()
        Mark the answer as being "complete", and not needing a write.

      • addParent

        public void addParent​(HopCount.DocumentNode parent)
        Add a parent who should be notified if this node's answer changes. The parent is responsible for figuring out when this reference should be removed.

      • clearWriteNeeded

        public void clearWriteNeeded()
        Clear the 'write needed' flag, to prevent another write.

      • addChild

        public void addChild​(HopCount.NodeReference childRef)
        Add a child reference.
        Parameters:
        childRef - is the child node reference to add.

      • removeChild

        public void removeChild​(HopCount.NodeReference childRef)
        Remove a child reference.
        Parameters:
        childRef - is the child node reference to remove.

      • removeParent

        public void removeParent​(HopCount.DocumentNode parent)
        Remove a parent. This method will get called when the parent's answer no longer can be affected by this child's answer (probably because the child's answer has become complete).

      • getCurrentParents

        public java.util.Iterator getCurrentParents()
        Iterate through all current parents. This is an iterator over DocumentNode objects.

      • getCurrentChildren

        public java.util.Iterator getCurrentChildren()
        Iterate through current children. This is an iterator over NodeReference objects.

      • setSource

        public void setSource​(java.lang.Long rowID,
                      int answerValue)
        Set the database row and answer value

      • getDatabaseRow

        public java.lang.Long getDatabaseRow()
        Get the database row

      • getDatabaseValue

        public int getDatabaseValue()
        Get the database answer value