add jsw data structure code

[zpackage] / lib / jsw / jsw_hlib.h

diff --git a/lib/jsw/jsw_hlib.h b/lib/jsw/jsw_hlib.h
new file mode 100644 (file)
index 0000000..78cbdd7
--- /dev/null
+++ b/lib/jsw/jsw_hlib.h
@@ -0,0 +1,124 @@
+#ifndef JSW_HLIB
+#define JSW_HLIB
+
+/*
+  Hash table library using separate chaining
+
+    > Created (Julienne Walker): August 7, 2005
+    > Modified (Julienne Walker): August 11, 2005
+
+  This code is in the public domain. Anyone may
+  use it or change it in any way that they see
+  fit. The author assumes no responsibility for 
+  damages incurred through use of the original
+  code or any variations thereof.
+
+  It is requested, but not required, that due
+  credit is given to the original author and
+  anyone who has modified the code through
+  a header comment, such as this one.
+*/
+#ifdef __cplusplus
+#include <cstddef>
+
+using std::size_t;
+
+extern "C" {
+#else
+#include <stddef.h>
+#endif
+
+typedef struct jsw_hash jsw_hash_t;
+
+/* Application specific hash function */
+typedef unsigned (*hash_f) ( const void *key );
+
+/* Application specific key comparison function */
+typedef int      (*cmp_f) ( const void *a, const void *b );
+
+/* Application specific key copying function */
+typedef void    *(*keydup_f) ( const void *key );
+
+/* Application specific data copying function */
+typedef void    *(*itemdup_f) ( const void *item );
+
+/* Application specific key deletion function */
+typedef void     (*keyrel_f) ( void *key );
+
+/* Application specific data deletion function */
+typedef void     (*itemrel_f) ( void *item );
+
+typedef struct jsw_hstat {
+  double load;            /* Table load factor: (M chains)/(table size) */
+  double achain;          /* Average chain length */
+  size_t lchain;          /* Longest chain */
+  size_t schain;          /* Shortest non-empty chain */
+} jsw_hstat_t;
+
+/*
+  Create a new hash table with a capacity of size, and
+  user defined functions for handling keys and items.
+
+  Returns: An empty hash table, or NULL on failure.
+*/
+jsw_hash_t  *jsw_hnew ( size_t size, hash_f hash, cmp_f cmp,
+                       keydup_f keydup, itemdup_f itemdup,
+                       keyrel_f keyrel, itemrel_f itemrel );
+
+/* Release all memory used by the hash table */
+void         jsw_hdelete ( jsw_hash_t *htab );
+
+/*
+  Find an item with the selected key
+
+  Returns: The item, or NULL if not found
+*/
+void        *jsw_hfind ( jsw_hash_t *htab, void *key );
+
+/*
+  Insert an item with the selected key
+
+  Returns: non-zero for success, zero for failure
+*/
+int          jsw_hinsert ( jsw_hash_t *htab, void *key, void *item );
+
+/*
+  Remove an item with the selected key
+
+  Returns: non-zero for success, zero for failure
+*/
+int          jsw_herase ( jsw_hash_t *htab, void *key );
+
+/*
+  Grow or shrink the table, this is a slow operation
+  
+  Returns: non-zero for success, zero for failure
+*/
+int          jsw_hresize ( jsw_hash_t *htab, size_t new_size );
+
+/* Reset the traversal markers to the beginning */
+void         jsw_hreset ( jsw_hash_t *htab );
+
+/* Traverse forward by one key */
+int          jsw_hnext ( jsw_hash_t *htab );
+
+/* Get the current key */
+const void  *jsw_hkey ( jsw_hash_t *htab );
+
+/* Get the current item */
+void        *jsw_hitem ( jsw_hash_t *htab );
+
+/* Current number of items in the table */
+size_t       jsw_hsize ( jsw_hash_t *htab );
+
+/* Total allowable number of items without resizing */
+size_t       jsw_hcapacity ( jsw_hash_t *htab );
+
+/* Get statistics for the hash table */
+jsw_hstat_t *jsw_hstat ( jsw_hash_t *htab );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif