v2-0001-Implement-UUID-v7-and-v8-as-per-IETF-draft.patch

From 9f4c97a81aae3087581a024374a06e49156f2689 Mon Sep 17 00:00:00 2001
From: Andrey Borodin <xformmm@amazon.com>
Date: Fri, 10 Feb 2023 15:38:40 -0800
Subject: [PATCH v2] Implement UUID v7 and v8 as per IETF draft

---
 doc/src/sgml/func.sgml                   | 18 ++++-
 src/backend/utils/adt/uuid.c             | 87 ++++++++++++++++++++++++
 src/include/catalog/pg_proc.dat          |  6 ++
 src/test/regress/expected/opr_sanity.out |  2 +
 src/test/regress/expected/uuid.out       | 20 ++++++
 src/test/regress/sql/uuid.sql            | 12 ++++
 6 files changed, 144 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..b8b5ee210a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -13947,13 +13947,29 @@ CREATE TYPE rainbow AS ENUM ('red', 'orange', 'yellow', 'green', 'blue', 'purple
    <primary>gen_random_uuid</primary>
   </indexterm>
 
+  <indexterm>
+   <primary>gen_uuid_v7</primary>
+  </indexterm>
+
+  <indexterm>
+   <primary>gen_uuid_v8</primary>
+  </indexterm>
+
   <para>
-   <productname>PostgreSQL</productname> includes one function to generate a UUID:
+   <productname>PostgreSQL</productname> includes three functions to generate a UUID:
 <synopsis>
 <function>gen_random_uuid</function> () <returnvalue>uuid</returnvalue>
 </synopsis>
    This function returns a version 4 (random) UUID.  This is the most commonly
    used type of UUID and is appropriate for most applications.
+<synopsis>
+<function>gen_uuid_v7</function> () <returnvalue>uuid</returnvalue>
+</synopsis>
+   This function returns a version 7 (time-ordered + random) UUID.
+<synopsis>
+<function>gen_uuid_v8</function> () <returnvalue>uuid</returnvalue>
+</synopsis>
+   This function returns a version 8 (time-ordered + random + node ID + rolling sequence number) UUID.
   </para>
 
   <para>
diff --git a/src/backend/utils/adt/uuid.c b/src/backend/utils/adt/uuid.c
index 4f7aa768fd..44deead6b1 100644
--- a/src/backend/utils/adt/uuid.c
+++ b/src/backend/utils/adt/uuid.c
@@ -13,6 +13,9 @@
 
 #include "postgres.h"
 
+#include <sys/time.h>
+
+#include "access/xlog.h"
 #include "common/hashfn.h"
 #include "lib/hyperloglog.h"
 #include "libpq/pqformat.h"
@@ -421,3 +424,87 @@ gen_random_uuid(PG_FUNCTION_ARGS)
 
 	PG_RETURN_UUID_P(uuid);
 }
+
+Datum
+gen_uuid_v7(PG_FUNCTION_ARGS)
+{
+	pg_uuid_t  *uuid = palloc(UUID_LEN);
+	struct timeval tp;
+	uint64_t tms;
+
+	gettimeofday(&tp, NULL);
+
+	tms = ((uint64_t)tp.tv_sec) * 1000;
+	tms += ((uint64_t)tp.tv_usec) / 1000;
+
+	tms = pg_hton64(tms<<16);
+
+	/* Fill in time part */
+	memcpy(&uuid->data[0], &tms, 6);
+
+	/* fill everything after the timestamp with random bytes */
+	if (!pg_strong_random(&uuid->data[6], UUID_LEN - 6))
+		ereport(ERROR,
+				(errcode(ERRCODE_INTERNAL_ERROR),
+				 errmsg("could not generate random values")));
+
+	/*
+	 * Set magic numbers for a "version 7" (pseudorandom) UUID, see
+	 * http://tools.ietf.org/html/rfc ???
+	 * https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format#name-creating-a-uuidv7-value
+	 */
+	/* set version field, top four bits are 0, 1, 1, 1 */
+	uuid->data[6] = (uuid->data[6] & 0x0f) | 0x70;
+	/* set variant field, top two bits are 1, 0 */
+	uuid->data[8] = (uuid->data[8] & 0x3f) | 0x80;
+
+	PG_RETURN_UUID_P(uuid);
+}
+
+static uint8_t sequence_counter;
+
+Datum
+gen_uuid_v8(PG_FUNCTION_ARGS)
+{
+	pg_uuid_t  *uuid = palloc(UUID_LEN);
+	struct timeval tp;
+	uint32_t t;
+	uint16_t ut;
+	uint8_t node_id = GetSystemIdentifier();
+	uint8_t sequence = sequence_counter++;
+
+	/*
+	TODO: Consider supplying node ID and rolling sequence number
+	if (PG_NARGS() >= 1)
+		node_id = PG_GETARG_CHAR(0);
+	if (PG_NARGS() >= 2)
+		node_id = PG_GETARG_CHAR(1);
+	*/
+
+	gettimeofday(&tp, NULL);
+	t = tp.tv_sec - 1577836800;
+	t = pg_hton32(t);
+	memcpy(&uuid->data[0], &t, 4);
+
+	/* 16 bit subsecond fraction (~15 microsecond resolution) */
+	ut = ((uint64_t)tp.tv_usec << 16) / 1000000;
+	memcpy(&uuid->data[4], &ut, 2);
+
+	/* fill everything after the timestamp with random bytes */
+	if (!pg_strong_random(&uuid->data[6], UUID_LEN - 6))
+		ereport(ERROR,
+				(errcode(ERRCODE_INTERNAL_ERROR),
+				 errmsg("could not generate random values")));
+
+	/*
+	 * Set magic numbers for a "version 8" UID, see
+	 * https://datatracker.ietf.org/doc/html/draft-ietf-uuidrev-rfc4122bis#name-creating-a-uuidv8-value
+	 */
+	uuid->data[6] = (uuid->data[6] & 0x0f) | 0x80;
+	uuid->data[8] = (uuid->data[8] & 0x3f) | 0x80;
+
+	uuid->data[14] = node_id;
+	uuid->data[15] = sequence;
+
+	PG_RETURN_UUID_P(uuid);
+}
\ No newline at end of file
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6996073989..0c82f9280f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -9119,6 +9119,12 @@
 { oid => '3432', descr => 'generate random UUID',
   proname => 'gen_random_uuid', proleakproof => 't', provolatile => 'v',
   prorettype => 'uuid', proargtypes => '', prosrc => 'gen_random_uuid' },
+{ oid => '3813', descr => 'generate UUID version 7',
+  proname => 'gen_uuid_v7', proleakproof => 't', provolatile => 'v',
+  prorettype => 'uuid', proargtypes => '', prosrc => 'gen_uuid_v7' },
+{ oid => '3814', descr => 'generate UUID version 8',
+  proname => 'gen_uuid_v8', proleakproof => 't', provolatile => 'v',
+  prorettype => 'uuid', proargtypes => '', prosrc => 'gen_uuid_v8' },
 
 # pg_lsn
 { oid => '3229', descr => 'I/O',
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index a1bdf2c0b5..1fb9c654d3 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -857,6 +857,8 @@ sha384(bytea)
 sha512(bytea)
 gen_random_uuid()
 starts_with(text,text)
+gen_uuid_v7()
+gen_uuid_v8()
 macaddr8_eq(macaddr8,macaddr8)
 macaddr8_lt(macaddr8,macaddr8)
 macaddr8_le(macaddr8,macaddr8)
diff --git a/src/test/regress/expected/uuid.out b/src/test/regress/expected/uuid.out
index 8e7f21910d..516d4998a7 100644
--- a/src/test/regress/expected/uuid.out
+++ b/src/test/regress/expected/uuid.out
@@ -168,5 +168,25 @@ SELECT count(DISTINCT guid_field) FROM guid1;
      2
 (1 row)
 
+-- generation test for v7
+TRUNCATE guid1;
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v7());
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v7());
+SELECT count(DISTINCT guid_field) FROM guid1;
+ count 
+-------
+     2
+(1 row)
+
+-- generation test for v8
+TRUNCATE guid1;
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v8());
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v8());
+SELECT count(DISTINCT guid_field) FROM guid1;
+ count 
+-------
+     2
+(1 row)
+
 -- clean up
 DROP TABLE guid1, guid2 CASCADE;
diff --git a/src/test/regress/sql/uuid.sql b/src/test/regress/sql/uuid.sql
index 9a8f437c7d..0d6784e70b 100644
--- a/src/test/regress/sql/uuid.sql
+++ b/src/test/regress/sql/uuid.sql
@@ -85,5 +85,17 @@ INSERT INTO guid1 (guid_field) VALUES (gen_random_uuid());
 INSERT INTO guid1 (guid_field) VALUES (gen_random_uuid());
 SELECT count(DISTINCT guid_field) FROM guid1;
 
+-- generation test for v7
+TRUNCATE guid1;
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v7());
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v7());
+SELECT count(DISTINCT guid_field) FROM guid1;
+
+-- generation test for v8
+TRUNCATE guid1;
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v8());
+INSERT INTO guid1 (guid_field) VALUES (gen_uuid_v8());
+SELECT count(DISTINCT guid_field) FROM guid1;
+
 -- clean up
 DROP TABLE guid1, guid2 CASCADE;
-- 
2.37.1 (Apple Git-137.1)