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   IPV4_GN,
   9   IPV4_PREFIX_GN,
  10   IPV6_GN,
  11   IPV6_PREFIX_GN,
  12   WORD_GN,
  13   RANGE_GN,
  14   NUMBER_GN,
  15   VARIABLE_GN,
  16   SELECTOR_GN,
  17   OPTION_GN,
  18   NUL_GN,
  19   START_GN,
  20   END_GN
  21 };
  22
  23 struct graph_node
  24 {
  25   enum graph_node_type type;// data type this node matches or holds
  26   int is_start;             // whether this node is a start node
  27   vector children;          // this node's children
  28   struct graph_node * end;  // pointer to end for SELECTOR_GN & OPTION_GN
  29
  30   char* text;               // for WORD_GN and VARIABLE_GN
  31   long value;               // for NUMBER_GN
  32   long min, max;            // for RANGE_GN
  33
  34   /* cmd_element struct pointer, only valid for END_GN */
  35   struct cmd_element *element;
  36   /* used for passing arguments to command functions */
  37   char *arg;
  38
  39   /* refcount for node parents */
  40   int refs;
  41 };
  42
  43 /*
  44  * Adds a node as a child of another node.
  45  * If the new parent has a child that is equal to the prospective child, as
  46  * determined by cmp_node, then a pointer to the existing node is returned and
  47  * the prospective child is not added. Otherwise the child node is returned.
  48  *
  49  * @param[in] parent node
  50  * @param[in] child node
  51  * @return pointer to child if it is added, pointer to existing child otherwise
  52  */
  53 struct graph_node *
  54 add_node(struct graph_node *, struct graph_node *);
  55
  56 /*
  57  * Compares two nodes for parsing equivalence.
  58  * Equivalence in this case means that a single user input token
  59  * should be able to unambiguously match one of the two nodes.
  60  * For example, two nodes which have all fields equal except their
  61  * function pointers would be considered equal.
  62  *
  63  * @param[in] first node to compare
  64  * @param[in] second node to compare
  65  * @return 1 if equal, zero otherwise.
  66  */
  67 int
  68 cmp_node(struct graph_node *, struct graph_node *);
  69
  70 /*
  71  * Create a new node.
  72  * Initializes all fields to default values and sets the node type.
  73  *
  74  * @param[in] node type
  75  * @return pointer to the newly allocated node
  76  */
  77 struct graph_node *
  78 new_node(enum graph_node_type);
  79
  80 /**
  81  * Frees the data associated with a graph_node.
  82  * @param[out] pointer to graph_node to free
  83  */
  84 void
  85 free_node(struct graph_node *);
  86
  87 /**
  88  * Recursively calls free_node on a graph node
  89  * and all its children.
  90  * @param[out] graph to free
  91  */
  92 void
  93 free_graph(struct graph_node *);
  94
  95 /**
  96  * Walks a command DFA, printing structure to stdout.
  97  * For debugging.
  98  *
  99  * @param[in] start node of graph to walk
 100  * @param[in] graph depth for recursion, caller passes 0
 101  */
 102 void
 103 walk_graph(struct graph_node *, int);
 104
 105 /**
 106  * Returns a string representation of the given node.
 107  * @param[in] the node to describe
 108  * @param[out] the buffer to write the description into
 109  * @return pointer to description string
 110  */
 111 char *
 112 describe_node(struct graph_node *, char *, unsigned int);
 113
 114 void
 115 dump_node (struct graph_node *);
 116 #endif