summaryrefslogtreecommitdiff
path: root/db2/common/db_shash.c
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>2000-01-02 06:01:06 +0000
committerUlrich Drepper <drepper@redhat.com>2000-01-02 06:01:06 +0000
commit8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3 (patch)
tree099a250d7366aef2ab028fdb24f0d692cd784b4a /db2/common/db_shash.c
parent9a6450d578556c11e7c173d2f28362345b8f1258 (diff)
Update.
* Makeconfig (all-subdirs): Remove db and db2. * db/*: Removed. * db2/*: Removed.
Diffstat (limited to 'db2/common/db_shash.c')
-rw-r--r--db2/common/db_shash.c126
1 files changed, 0 insertions, 126 deletions
diff --git a/db2/common/db_shash.c b/db2/common/db_shash.c
deleted file mode 100644
index 3f48a55907..0000000000
--- a/db2/common/db_shash.c
+++ /dev/null
@@ -1,126 +0,0 @@
-/*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1996, 1997, 1998
- * Sleepycat Software. All rights reserved.
- */
-
-#include "config.h"
-
-#ifndef lint
-static const char sccsid[] = "@(#)db_shash.c 10.9 (Sleepycat) 4/10/98";
-#endif /* not lint */
-
-#ifndef NO_SYSTEM_INCLUDES
-#include <sys/types.h>
-#endif
-
-#include "db_int.h"
-#include "shqueue.h"
-#include "common_ext.h"
-
-/*
- * Table of good hash values. Up to ~250,000 buckets, we use powers of 2.
- * After that, we slow the rate of increase by half. For each choice, we
- * then use a nearby prime number as the hash value.
- *
- * If a terabyte is the maximum cache we'll see, and we assume there are
- * 10 1K buckets on each hash chain, then 107374182 is the maximum number
- * of buckets we'll ever need.
- */
-static const struct {
- u_int32_t power;
- u_int32_t prime;
-} list[] = {
- { 64, 67}, /* 2^6 */
- { 128, 131}, /* 2^7 */
- { 256, 257}, /* 2^8 */
- { 512, 521}, /* 2^9 */
- { 1024, 1031}, /* 2^10 */
- { 2048, 2053}, /* 2^11 */
- { 4096, 4099}, /* 2^12 */
- { 8192, 8191}, /* 2^13 */
- { 16384, 16381}, /* 2^14 */
- { 32768, 32771}, /* 2^15 */
- { 65536, 65537}, /* 2^16 */
- { 131072, 131071}, /* 2^17 */
- { 262144, 262147}, /* 2^18 */
- { 393216, 393209}, /* 2^18 + 2^18/2 */
- { 524288, 524287}, /* 2^19 */
- { 786432, 786431}, /* 2^19 + 2^19/2 */
- { 1048576, 1048573}, /* 2^20 */
- { 1572864, 1572869}, /* 2^20 + 2^20/2 */
- { 2097152, 2097169}, /* 2^21 */
- { 3145728, 3145721}, /* 2^21 + 2^21/2 */
- { 4194304, 4194301}, /* 2^22 */
- { 6291456, 6291449}, /* 2^22 + 2^22/2 */
- { 8388608, 8388617}, /* 2^23 */
- { 12582912, 12582917}, /* 2^23 + 2^23/2 */
- { 16777216, 16777213}, /* 2^24 */
- { 25165824, 25165813}, /* 2^24 + 2^24/2 */
- { 33554432, 33554393}, /* 2^25 */
- { 50331648, 50331653}, /* 2^25 + 2^25/2 */
- { 67108864, 67108859}, /* 2^26 */
- { 100663296, 100663291}, /* 2^26 + 2^26/2 */
- { 134217728, 134217757}, /* 2^27 */
- { 201326592, 201326611}, /* 2^27 + 2^27/2 */
- { 268435456, 268435459}, /* 2^28 */
- { 402653184, 402653189}, /* 2^28 + 2^28/2 */
- { 536870912, 536870909}, /* 2^29 */
- { 805306368, 805306357}, /* 2^29 + 2^29/2 */
- {1073741824, 1073741827}, /* 2^30 */
- {0, 0}
-};
-
-/*
- * __db_tablesize --
- * Choose a size for the hash table.
- *
- * PUBLIC: int __db_tablesize __P((u_int32_t));
- */
-int
-__db_tablesize(n_buckets)
- u_int32_t n_buckets;
-{
- int i;
-
- /*
- * We try to be clever about how big we make the hash tables. Use a
- * prime number close to the "suggested" number of elements that will
- * be in the hash table. Use 64 as the minimum hash table size.
- *
- * Ref: Sedgewick, Algorithms in C, "Hash Functions"
- */
- if (n_buckets < 64)
- n_buckets = 64;
-
- for (i = 0;; ++i) {
- if (list[i].power == 0) {
- --i;
- break;
- }
- if (list[i].power >= n_buckets)
- break;
- }
- return (list[i].prime);
-}
-
-/*
- * __db_hashinit --
- * Initialize a hash table that resides in shared memory.
- *
- * PUBLIC: void __db_hashinit __P((void *, u_int32_t));
- */
-void
-__db_hashinit(begin, nelements)
- void *begin;
- u_int32_t nelements;
-{
- u_int32_t i;
- SH_TAILQ_HEAD(hash_head) *headp;
-
- headp = (struct hash_head *)begin;
-
- for (i = 0; i < nelements; i++, headp++)
- SH_TAILQ_INIT(headp);
-}