v10-0002-Use-fasthash-for-the-search-path-cache.patch
text/x-patch
Filename: v10-0002-Use-fasthash-for-the-search-path-cache.patch
Type: text/x-patch
Part: 1
Patch
Same data as JSON:
GET /api/v1/attachments/:id/patch
the parsed metadata as JSON — format, series position, per-file stats; never the diff bytes.
API reference →
Format: format-patch
Series: patch v10-0002
Subject: Use fasthash for the search path cache
| File | + | − |
|---|---|---|
| src/backend/catalog/namespace.c | 19 | 5 |
From c7bd727b24a8935343df6fb24d10948fa6d4d57c Mon Sep 17 00:00:00 2001
From: John Naylor <john.naylor@postgresql.org>
Date: Mon, 18 Dec 2023 11:10:28 +0700
Subject: [PATCH v10 2/3] Use fasthash for the search path cache
This serves to demonstrate the incremental API, allowing inlined
hash calculation without a strlen call. This brings the general case
performance closer to the optimization done in commit a86c61c9ee.
WIP: roleid should be mixed in normally, unless we have
reason to just use it as a seed.
Jeff Davis, with switch to chunked interface by me
Discussion: https://www.postgresql.org/message-id/b40292c99e623defe5eadedab1d438cf51a4107c.camel%40j-davis.com
---
src/backend/catalog/namespace.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 5027efc91d..7fe2fd1fd4 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,7 +41,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "commands/dbcommands.h"
-#include "common/hashfn.h"
+#include "common/hashfn_unstable.h"
#include "funcapi.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
@@ -247,11 +247,25 @@ static bool MatchNamedCall(HeapTuple proctup, int nargs, List *argnames,
static inline uint32
spcachekey_hash(SearchPathCacheKey key)
{
- const unsigned char *bytes = (const unsigned char *) key.searchPath;
- int blen = strlen(key.searchPath);
+ const char *const start = key.searchPath;
+ const char *buf = key.searchPath;
+ fasthash_state hs;
- return hash_combine(hash_bytes(bytes, blen),
- hash_uint32(key.roleid));
+ /* WIP: maybe roleid should be mixed in normally */
+ fasthash_init(&hs, FH_UNKNOWN_LENGTH, key.roleid);
+ while (*buf)
+ {
+ int chunk_len = 0;
+
+ while (chunk_len < FH_SIZEOF_ACCUM && buf[chunk_len] != '\0')
+ chunk_len++;
+
+ fasthash_accum(&hs, buf, chunk_len);
+ buf += chunk_len;
+ }
+
+ /* pass the length to tweak the final mix */
+ return fasthash_final32(&hs, buf - start);
}
static inline bool
--
2.43.0