1 files changed, 141 insertions, 0 deletions
diff --git a/src/backend/utils/hsearch.h b/src/backend/utils/hsearch.h
new file mode 100644
index 00000000000..d12664e4683
--- /dev/null
+++ b/src/backend/utils/hsearch.h
@@ -0,0 +1,141 @@
+/*-------------------------------------------------------------------------
+ *
+ * hsearch.h--
+ *    for hashing in the new buffer manager
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: hsearch.h,v 1.1.1.1 1996/07/09 06:22:02 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef HSEARCH_H
+#define HSEARCH_H
+
+#include "postgres.h"
+
+/*
+ * Constants
+ */
+# define DEF_BUCKET_SIZE	256
+# define DEF_BUCKET_SHIFT	8	/* log2(BUCKET) */
+# define DEF_SEGSIZE		256
+# define DEF_SEGSIZE_SHIFT		8      /* log2(SEGSIZE)	 */
+# define DEF_DIRSIZE		256
+# define PRIME1			37
+# define PRIME2			1048583
+# define DEF_FFACTOR		1
+# define SPLTMAX		8
+
+
+/*
+ * Hash bucket is actually bigger than this.  Key field can have
+ * variable length and a variable length data field follows it.
+ */
+typedef struct element {
+    unsigned long next;		/* secret from user	 */
+    long key;
+} ELEMENT;
+
+typedef unsigned long BUCKET_INDEX;
+/* segment is an array of bucket pointers  */
+typedef BUCKET_INDEX *SEGMENT;
+typedef unsigned long SEG_OFFSET;
+
+typedef struct hashhdr {
+    long bsize;			/* Bucket/Page Size */
+    long bshift;		/* Bucket shift */
+    long dsize;			/* Directory Size */
+    long ssize;			/* Segment Size */
+    long sshift;		/* Segment shift */
+    long max_bucket;		/* ID of Maximum bucket in use */
+    long high_mask;		/* Mask to modulo into entire table */
+    long low_mask;		/* Mask to modulo into lower half of table */
+    long ffactor;		/* Fill factor */
+    long nkeys;			/* Number of keys in hash table */
+    long nsegs;			/* Number of allocated segments */
+    long keysize;		/* hash key length in bytes */
+    long datasize;		/* elem data length in bytes */
+    long max_dsize;		/* 'dsize' limit if directory is fixed size */ 
+    BUCKET_INDEX freeBucketIndex;
+    /* index of first free bucket */
+#ifdef HASH_STATISTICS
+    long accesses;
+    long collisions;
+#endif
+} HHDR;
+
+typedef struct htab {
+    HHDR	*hctl;		/* shared control information */
+    long 	(*hash)(); 	/* Hash Function */
+    char 	*segbase; 	/* segment base address for 
+				 * calculating pointer values 
+				 */
+    SEG_OFFSET	*dir;		/* 'directory' of segm starts */
+    long 	*(*alloc)(); 	/* memory allocator 
+				 * (long * for alignment reasons)
+				 */
+
+} HTAB;
+
+typedef struct hashctl {
+    long bsize;		/* Bucket Size */
+    long ssize;		/* Segment Size */
+    long dsize;		/* Dirsize Size */
+    long ffactor;	/* Fill factor */
+    long (*hash)();	/* Hash Function */
+    long keysize;	/* hash key length in bytes */
+    long datasize;	/* elem data length in bytes */
+    long max_size;	/* limit to dsize if directory size is limited */
+    long *segbase;	/* base for calculating bucket + seg ptrs */
+    long * (*alloc)();	/* memory allocation function */
+    long *dir;		/* directory if allocated already */
+    long *hctl;		/* location of header information in shd mem */
+} HASHCTL;
+
+/* Flags to indicate action for hctl */
+#define HASH_BUCKET	0x001	/* Setting bucket size */
+#define HASH_SEGMENT	0x002	/* Setting segment size */
+#define HASH_DIRSIZE	0x004	/* Setting directory size */
+#define HASH_FFACTOR	0x008	/* Setting fill factor */
+#define HASH_FUNCTION	0x010	/* Set user defined hash function */
+#define HASH_ELEM	0x020	/* Setting key/data size */
+#define HASH_SHARED_MEM 0x040   /* Setting shared mem const */
+#define HASH_ATTACH	0x080   /* Do not initialize hctl */
+#define HASH_ALLOC	0x100   /* Setting memory allocator */ 
+
+
+/* seg_alloc assumes that INVALID_INDEX is 0*/
+#define INVALID_INDEX 		(0)
+#define NO_MAX_DSIZE 		(-1)
+/* number of hash buckets allocated at once */
+#define BUCKET_ALLOC_INCR	(30)
+
+/* hash_search operations */
+typedef enum { 
+    HASH_FIND, 
+    HASH_ENTER, 
+    HASH_REMOVE, 
+    HASH_FIND_SAVE, 
+    HASH_REMOVE_SAVED 
+} HASHACTION;
+
+/* 
+ * prototypes from functions in dynahash.c
+ */
+extern HTAB *hash_create(int nelem, HASHCTL *info, int flags);
+extern void hash_destroy(HTAB *hashp);
+extern void hash_stats(char *where, HTAB *hashp);
+extern long *hash_search(HTAB *hashp, char *keyPtr, HASHACTION action,
+			 bool *foundPtr);
+extern long *hash_seq(HTAB *hashp);
+
+/* 
+ * prototypes from functions in hashfn.c
+ */
+extern long string_hash(char *key, int keysize);
+extern long tag_hash(int *key, int keysize);
+extern long disk_hash(char *key);
+
+#endif /* HSEARCH_H */