--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/sqlite/src/hash.h	Thu Feb 25 14:29:19 2010 +0000
@@ -0,0 +1,110 @@
+/*
+** 2001 September 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This is the header file for the generic hash-table implemenation
+** used in SQLite.
+**
+** $Id: hash.h 1282 2008-11-13 09:31:33Z LarsPson $
+*/
+#ifndef _SQLITE_HASH_H_
+#define _SQLITE_HASH_H_
+
+/* Forward declarations of structures. */
+typedef struct Hash Hash;
+typedef struct HashElem HashElem;
+
+/* A complete hash table is an instance of the following structure.
+** The internals of this structure are intended to be opaque -- client
+** code should not attempt to access or modify the fields of this structure
+** directly.  Change this structure only by using the routines below.
+** However, many of the "procedures" and "functions" for modifying and
+** accessing this structure are really macros, so we can't really make
+** this structure opaque.
+*/
+struct Hash {
+  char keyClass;          /* SQLITE_HASH_INT, _POINTER, _STRING, _BINARY */
+  char copyKey;           /* True if copy of key made on insert */
+  int count;              /* Number of entries in this table */
+  int htsize;             /* Number of buckets in the hash table */
+  HashElem *first;        /* The first element of the array */
+  struct _ht {            /* the hash table */
+    int count;               /* Number of entries with this hash */
+    HashElem *chain;         /* Pointer to first entry with this hash */
+  } *ht;
+};
+
+/* Each element in the hash table is an instance of the following 
+** structure.  All elements are stored on a single doubly-linked list.
+**
+** Again, this structure is intended to be opaque, but it can't really
+** be opaque because it is used by macros.
+*/
+struct HashElem {
+  HashElem *next, *prev;   /* Next and previous elements in the table */
+  void *data;              /* Data associated with this element */
+  void *pKey; int nKey;    /* Key associated with this element */
+};
+
+/*
+** There are 4 different modes of operation for a hash table:
+**
+**   SQLITE_HASH_INT         nKey is used as the key and pKey is ignored.
+**
+**   SQLITE_HASH_POINTER     pKey is used as the key and nKey is ignored.
+**
+**   SQLITE_HASH_STRING      pKey points to a string that is nKey bytes long
+**                           (including the null-terminator, if any).  Case
+**                           is ignored in comparisons.
+**
+**   SQLITE_HASH_BINARY      pKey points to binary data nKey bytes long. 
+**                           memcmp() is used to compare keys.
+**
+** A copy of the key is made for SQLITE_HASH_STRING and SQLITE_HASH_BINARY
+** if the copyKey parameter to HashInit is 1.  
+*/
+/* #define SQLITE_HASH_INT       1 // NOT USED */
+/* #define SQLITE_HASH_POINTER   2 // NOT USED */
+#define SQLITE_HASH_STRING    3
+#define SQLITE_HASH_BINARY    4
+
+/*
+** Access routines.  To delete, insert a NULL pointer.
+*/
+void sqlite3HashInit(Hash*, int keytype, int copyKey);
+void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData);
+void *sqlite3HashFind(const Hash*, const void *pKey, int nKey);
+HashElem *sqlite3HashFindElem(const Hash*, const void *pKey, int nKey);
+void sqlite3HashClear(Hash*);
+
+/*
+** Macros for looping over all elements of a hash table.  The idiom is
+** like this:
+**
+**   Hash h;
+**   HashElem *p;
+**   ...
+**   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
+**     SomeStructure *pData = sqliteHashData(p);
+**     // do something with pData
+**   }
+*/
+#define sqliteHashFirst(H)  ((H)->first)
+#define sqliteHashNext(E)   ((E)->next)
+#define sqliteHashData(E)   ((E)->data)
+#define sqliteHashKey(E)    ((E)->pKey)
+#define sqliteHashKeysize(E) ((E)->nKey)
+
+/*
+** Number of entries in a hash table
+*/
+#define sqliteHashCount(H)  ((H)->count)
+
+#endif /* _SQLITE_HASH_H_ */