lib/command_graph.h

   1 #ifndef COMMAND_GRAPH_H
   2 #define COMMAND_GRAPH_H
   3
   4 #include "command.h"
   5
   6 enum graph_node_type
   7 {
   8   WORD_GN,
   9   IPV4_GN,
  10   IPV4_PREFIX_GN,
  11   IPV6_GN,
  12   IPV6_PREFIX_GN,
  13   VARIABLE_GN,
  14   RANGE_GN,
  15   NUMBER_GN,
  16   SELECTOR_GN,
  17   OPTION_GN,
  18   NUL_GN,
  19   END_GN
  20 };
  21
  22 struct graph_node
  23 {
  24   enum graph_node_type type;// data type this node matches or holds
  25   int is_start;             // whether this node is a start node
  26   vector children;          // this node's children
  27   struct graph_node * end;  // pointer to end for SELECTOR_GN & OPTION_GN
  28
  29   char* text;       // for WORD_GN and VARIABLE_GN
  30   long value;       // for NUMBER_GN
  31   long min, max;    // for RANGE_GN
  32
  33   /* cmd_element struct pointer, only valid for END_GN */
  34   struct cmd_element *element;
  35   /* used for passing arguments to command functions */
  36   char *arg;
  37 };
  38
  39 /*
  40  * Adds a child to a node.
  41  * If the node already has the exact same child, nothing is done. This is
  42  * decided with cmp_node.
  43  *
  44  * @param[in] parent node
  45  * @param[in] child node
  46  * @return the new child, or the existing child if the parent already has the
  47  *         new child
  48  */
  49 extern struct graph_node *
  50 add_node(struct graph_node *, struct graph_node *);
  51
  52 /*
  53  * Compares two nodes for parsing equivalence.
  54  * Equivalence in this case means that a single user input token
  55  * should be able to unambiguously match one of the two nodes.
  56  * For example, two nodes which have all fields equal except their
  57  * function pointers would be considered equal.
  58  *
  59  * @param[in] first node to compare
  60  * @param[in] second node to compare
  61  * @return 1 if equal, zero otherwise.
  62  */
  63 extern int
  64 cmp_node(struct graph_node *, struct graph_node *);
  65
  66 /*
  67  * Create a new node.
  68  * Initializes all fields to default values and sets the node type.
  69  *
  70  * @param[in] node type
  71  * @return pointer to the newly allocated node
  72  */
  73 extern struct graph_node *
  74 new_node(enum graph_node_type);
  75
  76 /**
  77  * Walks a command DFA, printing structure to stdout.
  78  * For debugging.
  79  *
  80  * @param[in] start node of graph to walk
  81  * @param[in] graph depth for recursion, caller passes 0
  82  */
  83 extern void
  84 walk_graph(struct graph_node *, int);
  85
  86 /**
  87  * Returns a string representation of the given node.
  88  * @param[in] the node to describe
  89  * @param[out] the buffer to write the description into
  90  * @return pointer to description string
  91  */
  92 extern char *
  93 describe_node(struct graph_node *, char *, unsigned int);
  94
  95 /**
  96  * Frees the data associated with a graph_node.
  97  * @param[out] pointer to graph_node to free
  98  */
  99 void
 100 free_node(struct graph_node *);
 101 #endif