string_pool.c

   1 #include <string.h>
   2
   3 #include "trp.h"
   4 #include "obj_pool.h"
   5 #include "string_pool.h"
   6
   7 typedef struct node_s node_t;
   8 typedef trp(node_t) tree_t;
   9 static tree_t tree = { ~0 };
  10
  11 struct node_s {
  12     uint32_t offset;
  13     trp_node(node_t) children;
  14 };
  15
  16 /* Create two memory pools: one for node_t, and another for strings */
  17 obj_pool_gen(node, node_t, 4096);
  18 obj_pool_gen(string, char, 4096);
  19
  20 static char *node_value(node_t *node)
  21 {
  22     return node ? string_pointer(node->offset) : NULL;
  23 }
  24
  25 static int node_value_cmp(node_t *a, node_t *b)
  26 {
  27     return strcmp(node_value(a), node_value(b));
  28 }
  29
  30 static int node_indentity_cmp(node_t *a, node_t *b)
  31 {
  32     int r = node_value_cmp(a, b);
  33     return r ? r : (((uintptr_t) a) > ((uintptr_t) b))
  34         - (((uintptr_t) a) < ((uintptr_t) b));
  35 }
  36
  37 /* Build a Treap from the node_s structure (a trp_node w/ offset) */
  38 trp_gen(static, tree_, tree_t, node_t, children, node,
  39         node_indentity_cmp);
  40
  41 char *pool_fetch(uint32_t entry)
  42 {
  43     return node_value(node_pointer(entry));
  44 }
  45
  46 uint32_t pool_intern(char *key)
  47 {
  48     node_t *match = NULL;
  49     uint32_t key_len;
  50     if (key == NULL)
  51         return ~0;
  52     key_len = strlen(key) + 1;
  53     node_t *node = node_pointer(node_alloc(1));
  54     node->offset = string_alloc(key_len);
  55     strcpy(node_value(node), key);
  56     match = tree_psearch(&tree, node);
  57     if (!match || node_value_cmp(node, match)) {
  58         tree_insert(&tree, node);
  59     } else {
  60         node_free(1);
  61         string_free(key_len);
  62         node = match;
  63     }
  64     return node_offset(node);
  65 }
  66
  67 uint32_t pool_tok_r(char *str, const char *delim, char **saveptr)
  68 {
  69     char *token = strtok_r(str, delim, saveptr);
  70     return token ? pool_intern(token) : ~0;
  71 }
  72
  73 void pool_print_seq(uint32_t len, uint32_t *seq, char delim, FILE *stream)
  74 {
  75     uint32_t i;
  76     for (i = 0; i < len && ~seq[i]; i++) {
  77         fputs(pool_fetch(seq[i]), stream);
  78         if (i < len - 1 && ~seq[i + 1])
  79             fputc(delim, stream);
  80     }
  81 }
  82
  83 uint32_t pool_tok_seq(uint32_t max, uint32_t *seq, char *delim, char *str)
  84 {
  85     char *context = NULL;
  86     uint32_t length = 0, token = str ? pool_tok_r(str, delim, &context) : ~0;
  87     while (length < max) {
  88         seq[length++] = token;
  89         if (token == ~0)
  90             break;
  91         token = pool_tok_r(NULL, delim, &context);
  92     }
  93     seq[length ? length - 1 : 0] = ~0;
  94     return length;
  95 }
  96
  97 void pool_reset(void)
  98 {
  99     node_reset();
 100     string_reset();
 101 }