hash algorithm demo for font mapping.

diff --git a/src/texsourc/test-file/test-hash.c b/src/texsourc/test-file/test-hash.c
new file mode 100644 (file)
index 0000000..192254e
--- /dev/null
+++ b/src/texsourc/test-file/test-hash.c
@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <time.h>
+
+typedef struct _mapping_table mapping_table;
+typedef struct _mapping_entry mapping_entry;
+
+#define mapping_size 31627
+
+struct _mapping_table
+{
+  mapping_entry * entries[mapping_size];
+};
+
+struct _mapping_entry
+{
+  mapping_entry * next;
+  char * key;
+  int  * val;
+};
+
+unsigned int font_name_hash(const char * s)
+{
+  const char * p;
+  unsigned int h = 0, g;
+
+  for (p = s; *p != '\0'; p++)
+  {
+    h = (h << 4) + *p;
+
+    if ((g = h & 0xf0000000))
+    {
+      h = h ^ (g >> 24);
+      h = h ^ g;
+    }
+  }
+
+  return h;
+}
+
+mapping_table * font_name_hash_init (void)
+{
+  mapping_table * temp_table;
+  int i;
+
+  temp_table = (mapping_table *) malloc(sizeof(mapping_table));
+
+  for (i = 0; i < mapping_size; i++)
+    temp_table->entries[i] = NULL;
+
+  return temp_table;
+}
+
+void font_name_hash_free (mapping_table * tbl)
+{
+  int i;
+  mapping_entry *e, *next;
+
+  for (i = 0; i < mapping_size; i++)
+    for (e = tbl->entries[i]; e; e = next)
+    {
+      next = e->next;
+      free(e->key);
+      free(e);
+    }
+
+  free(tbl);
+}
+
+void font_name_hash_insert (mapping_table * tbl, const char *key, int val)
+{
+  int i;
+  mapping_entry * e;
+
+  i = font_name_hash(key) % mapping_size;
+  e = (mapping_entry *) malloc(sizeof(mapping_entry));
+  e->next = tbl->entries[i];
+  e->key  = (char *) strdup(key);
+  e->val  = val;
+  tbl->entries[i] = e;
+}
+
+int font_name_hash_lookup (mapping_table * tbl, const char *key)
+{
+  int i;
+  mapping_entry *e;
+
+  i = font_name_hash(key) % mapping_size;
+
+  for (e = tbl->entries[i]; e; e = e-> next)
+    if (!strcmp(key, e->key))
+      return e->val;
+
+  return -1;
+}
+
+mapping_table * gentbl;
+
+int main (void)
+{
+  gentbl = font_name_hash_init();
+  font_name_hash_insert(gentbl, "cmr10", 1022);
+  font_name_hash_insert(gentbl, "cmr17", 100);
+  font_name_hash_insert(gentbl, "cmmi10", 99);
+  printf("cmmi10: %d.\n", font_name_hash_lookup(gentbl, "cmmi10"));
+  printf("cmr10: %d.\n", font_name_hash_lookup(gentbl, "cmr10"));
+  printf("cmr17: %d.\n", font_name_hash_lookup(gentbl, "cmr17"));
+  font_name_hash_free(gentbl);
+  return 0;
+}