MDEV-33710 Implement UUID_TIMESTAMP() function

include/my_sys.h

@@ -1107,7 +1107,7 @@ int my_msync(int, void *, size_t, int);
 void my_uuid_init(ulong seed1, ulong seed2);
 void my_uuid(uchar *guid);
 void my_uuid_end(void);
-
+int my_uuid_extract_ts(const char *uuid, my_time_t *seconds, ulong *usec);
 static inline void my_uuid2str(const uchar *guid, char *s, int with_separators)
 {
   int i;

mysys/my_uuid.c

@@ -39,6 +39,7 @@
                                                      identifier.
 */
 
+#include <stdbool.h>
 #include "mysys_priv.h"
 #include <my_rnd.h>
 #include <m_string.h>
@@ -224,3 +225,66 @@ void my_uuid_end()
     mysql_mutex_destroy(&LOCK_uuid_generator);
   }
 }
+
+
+/**
+  Extract Unix timestamp from a UUIDv1 or UUIDv7
+
+  @param[in]  uuid     UUID bytes (16 bytes, big-endian)
+  @param[out] seconds  Unix timestamp seconds
+  @param[out] usec     Microseconds part
+
+  @return
+    @retval 0  Success
+    @retval 1  UUID version doesn't contain timestamp or timestamp invalid
+
+  UUIDv1 format (RFC 9562 Section 5.1, big-endian):
+    Bytes 0-3:  time_low (32 bits, low part of timestamp)
+    Bytes 4-5:  time_mid (16 bits, middle part of timestamp)
+    Bytes 6-7:  version (4 bits) + time_hi (12 bits, high part of timestamp)
+    Timestamp is 100-nanosecond intervals since 1582-10-15
+
+  UUIDv7 format (RFC 9562 Section 5.7, big-endian):
+    Bytes 0-5:  Unix timestamp in milliseconds (48 bits)
+    Bytes 6-7:  version (4 bits) + sub-millisecond precision (12 bits)
+*/
+int my_uuid_extract_ts(const char *uuid, my_time_t *seconds, ulong *usec)
+{
+  char version= uuid[6] >> 4;
+  ulonglong ts;
+
+  switch (version)
+  {
+  case 7:
+    /* UUIDv7: bytes 0-5 are Unix timestamp in milliseconds (big-endian) */
+    ts= mi_uint6korr(uuid);
+    *seconds= ts / 1000;
+    *usec= (ts % 1000) * 1000;
+    return false;
+
+  case 1:
+    /*
+      UUIDv1: reconstruct 60-bit timestamp from three fields:
+        - time_low  (bytes 0-3): bits 0-31 of timestamp
+        - time_mid  (bytes 4-5): bits 32-47 of timestamp
+        - time_hi   (bytes 6-7): bits 48-59 of timestamp (masked, 4 bits are version)
+      Formula: (time_hi << 48) | (time_mid << 32) | time_low
+    */
+    ts= ((ulonglong)(mi_uint2korr(uuid + 6) & 0x0FFF) << 48) |
+        ((ulonglong) mi_uint2korr(uuid + 4) << 32) |
+         (ulonglong) mi_uint4korr(uuid);
+
+    /* Timestamp before Unix epoch (1970-01-01) */
+    if (ts < UUID_TIME_OFFSET)
+      return true;
+
+    ts= (ts - UUID_TIME_OFFSET) / 10;  /* Convert to microseconds */
+    *seconds= ts / 1000000;
+    *usec= ts % 1000000;
+    return false;
+
+  default:
+    /* Other versions (e.g., v4) don't contain timestamps */
+    return true;
+  }
+}

plugin/type_uuid/item_uuidfunc.cc

@@ -29,3 +29,32 @@ String *Item_func_sys_guid::val_str(String *str)
   my_uuid2str(buf, const_cast<char*>(str->ptr()), 0);
   return str;
 }
+
+
+bool Item_func_uuid_timestamp::fix_length_and_dec(THD *thd)
+{
+  Type_std_attributes::set(
+    Type_temporal_attributes_not_fixed_dec(MAX_DATETIME_WIDTH,
+                                           TIME_SECOND_PART_DIGITS, false),
+    DTCollation_numeric());
+  set_maybe_null();
+  return false;
+}
+
+
+bool Item_func_uuid_timestamp::get_timestamp(my_time_t *sec, ulong *usec)
+{
+  Type_handler_uuid_new::Fbt_null uuid(args[0]);
+  if (uuid.is_null())
+    return true;
+  return my_uuid_extract_ts(uuid.to_lex_cstring().str, sec, usec);
+}
+
+
+bool Item_func_uuid_timestamp::val_native(THD *thd, Native *to)
+{
+  my_time_t seconds;
+  ulong usec;
+  return (null_value= get_timestamp(&seconds, &usec)) ||
+         (null_value= Timestamp(seconds, usec).to_native(to, TIME_SECOND_PART_DIGITS));
+}

plugin/type_uuid/item_uuidfunc.h

@@ -18,6 +18,7 @@
 
 
 #include "item.h"
+#include "item_timefunc.h"
 #include "sql_type_uuid_v1.h"
 #include "sql_type_uuid_v4.h"
 #include "sql_type_uuid_v7.h"
@@ -115,4 +116,27 @@ class Item_func_uuid_v7: public Item_func_uuid_vx<UUIDv7>
   Item *do_get_copy(THD *thd) const override
   { return get_item_copy<Item_func_uuid_v7>(thd, this); }
 };
+
+
+class Item_func_uuid_timestamp: public Item_timestampfunc
+{
+  bool check_arguments() const override
+  {
+    return args[0]->check_type_can_return_str(func_name_cstring());
+  }
+  bool get_timestamp(my_time_t *sec, ulong *usec);
+public:
+  Item_func_uuid_timestamp(THD *thd, Item *arg1)
+    : Item_timestampfunc(thd, arg1) {}
+
+  LEX_CSTRING func_name_cstring() const override
+  { return {STRING_WITH_LEN("uuid_timestamp")}; }
+
+  bool fix_length_and_dec(THD *thd) override;
+  bool val_native(THD *thd, Native *to) override;
+
+  Item *do_get_copy(THD *thd) const override
+  { return get_item_copy<Item_func_uuid_timestamp>(thd, this); }
+};
+
 #endif // ITEM_UUIDFUNC_INCLUDED

plugin/type_uuid/mysql-test/type_uuid/func_uuid_timestamp.result

@@ -0,0 +1,88 @@
+SET time_zone='+00:00';
+#
+# UUIDv1 with known timestamps
+#
+SELECT '4bd352dc-e593-11f0-8de9-0242ac120002' AS uuid,
+UUID_TIMESTAMP('4bd352dc-e593-11f0-8de9-0242ac120002') AS ts;
+uuid	ts
+4bd352dc-e593-11f0-8de9-0242ac120002	2025-12-30 15:22:04.357910
+SELECT 'bec1046a-e593-11f0-8de9-0242ac120002' AS uuid,
+UUID_TIMESTAMP('bec1046a-e593-11f0-8de9-0242ac120002') AS ts;
+uuid	ts
+bec1046a-e593-11f0-8de9-0242ac120002	2025-12-30 15:25:17.175921
+SELECT 'c28c09a0-e593-11f0-8de9-0242ac120002' AS uuid,
+UUID_TIMESTAMP('c28c09a0-e593-11f0-8de9-0242ac120002') AS ts;
+uuid	ts
+c28c09a0-e593-11f0-8de9-0242ac120002	2025-12-30 15:25:23.539600
+#
+# UUIDv7 with known timestamps (ms precision)
+#
+SELECT '019b6fdd-4937-7bb5-95c7-53363c6df927' AS uuid,
+UUID_TIMESTAMP('019b6fdd-4937-7bb5-95c7-53363c6df927') AS ts;
+uuid	ts
+019b6fdd-4937-7bb5-95c7-53363c6df927	2025-12-30 15:25:31.831000
+SELECT '019b6fdd-5f17-7cf2-b034-248b9c207db6' AS uuid,
+UUID_TIMESTAMP('019b6fdd-5f17-7cf2-b034-248b9c207db6') AS ts;
+uuid	ts
+019b6fdd-5f17-7cf2-b034-248b9c207db6	2025-12-30 15:25:37.431000
+SELECT '019b6fdd-7327-7a5b-935c-4de00dd0e7c6' AS uuid,
+UUID_TIMESTAMP('019b6fdd-7327-7a5b-935c-4de00dd0e7c6') AS ts;
+uuid	ts
+019b6fdd-7327-7a5b-935c-4de00dd0e7c6	2025-12-30 15:25:42.567000
+#
+# UUIDv4 returns NULL (no timestamp)
+#
+SELECT UUID_TIMESTAMP(UUID_V4()) IS NULL AS v4_returns_null;
+v4_returns_null
+1
+SELECT UUID_TIMESTAMP('a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11') IS NULL AS v4_string_returns_null;
+v4_string_returns_null
+1
+#
+# NULL and invalid input
+#
+SELECT UUID_TIMESTAMP(NULL) IS NULL AS null_input;
+null_input
+1
+SELECT UUID_TIMESTAMP('not-a-valid-uuid');
+UUID_TIMESTAMP('not-a-valid-uuid')
+NULL
+Warnings:
+Warning	1292	Incorrect uuid value: 'not-a-valid-uuid'
+#
+# Native UUID type
+#
+SELECT '019b6fdd-4937-7bb5-95c7-53363c6df927' AS uuid,
+UUID_TIMESTAMP(CAST('019b6fdd-4937-7bb5-95c7-53363c6df927' AS UUID)) AS ts;
+uuid	ts
+019b6fdd-4937-7bb5-95c7-53363c6df927	2025-12-30 15:25:31.831000
+#
+# Return type is TIMESTAMP(6)
+#
+CREATE TABLE t1 AS SELECT UUID_TIMESTAMP('019b6fdd-4937-7bb5-95c7-53363c6df927') AS ts;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `ts` timestamp(6) NULL DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
+DROP TABLE t1;
+#
+# Edge cases
+#
+SELECT '00000000-0000-1000-8000-000000000000' AS uuid,
+UUID_TIMESTAMP('00000000-0000-1000-8000-000000000000') IS NULL AS before_unix_epoch;
+uuid	before_unix_epoch
+00000000-0000-1000-8000-000000000000	1
+SELECT '00000000-0000-7000-8000-000000000000' AS uuid,
+UUID_TIMESTAMP('00000000-0000-7000-8000-000000000000') AS ts;
+uuid	ts
+00000000-0000-7000-8000-000000000000	0000-00-00 00:00:00.000000
+SELECT 'ffffffff-ffff-7fff-8000-000000000000' AS uuid,
+UUID_TIMESTAMP('ffffffff-ffff-7fff-8000-000000000000') AS ts;
+uuid	ts
+ffffffff-ffff-7fff-8000-000000000000	2042-12-13 16:54:30.655000
+SELECT 'ffffffff-ffff-1fff-8000-000000000000' AS uuid,
+UUID_TIMESTAMP('ffffffff-ffff-1fff-8000-000000000000') AS ts;
+uuid	ts
+ffffffff-ffff-1fff-8000-000000000000	2105-11-25 16:30:52.684697
+SET time_zone=DEFAULT;

plugin/type_uuid/mysql-test/type_uuid/func_uuid_timestamp.test

@@ -0,0 +1,66 @@
+# MDEV-33710: UUID_TIMESTAMP() extracts timestamp from UUIDv1 and UUIDv7
+
+SET time_zone='+00:00';
+
+--echo #
+--echo # UUIDv1 with known timestamps
+--echo #
+SELECT '4bd352dc-e593-11f0-8de9-0242ac120002' AS uuid,
+       UUID_TIMESTAMP('4bd352dc-e593-11f0-8de9-0242ac120002') AS ts;
+SELECT 'bec1046a-e593-11f0-8de9-0242ac120002' AS uuid,
+       UUID_TIMESTAMP('bec1046a-e593-11f0-8de9-0242ac120002') AS ts;
+SELECT 'c28c09a0-e593-11f0-8de9-0242ac120002' AS uuid,
+       UUID_TIMESTAMP('c28c09a0-e593-11f0-8de9-0242ac120002') AS ts;
+
+--echo #
+--echo # UUIDv7 with known timestamps (ms precision)
+--echo #
+SELECT '019b6fdd-4937-7bb5-95c7-53363c6df927' AS uuid,
+       UUID_TIMESTAMP('019b6fdd-4937-7bb5-95c7-53363c6df927') AS ts;
+SELECT '019b6fdd-5f17-7cf2-b034-248b9c207db6' AS uuid,
+       UUID_TIMESTAMP('019b6fdd-5f17-7cf2-b034-248b9c207db6') AS ts;
+SELECT '019b6fdd-7327-7a5b-935c-4de00dd0e7c6' AS uuid,
+       UUID_TIMESTAMP('019b6fdd-7327-7a5b-935c-4de00dd0e7c6') AS ts;
+
+--echo #
+--echo # UUIDv4 returns NULL (no timestamp)
+--echo #
+SELECT UUID_TIMESTAMP(UUID_V4()) IS NULL AS v4_returns_null;
+SELECT UUID_TIMESTAMP('a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11') IS NULL AS v4_string_returns_null;
+
+--echo #
+--echo # NULL and invalid input
+--echo #
+SELECT UUID_TIMESTAMP(NULL) IS NULL AS null_input;
+SELECT UUID_TIMESTAMP('not-a-valid-uuid');
+
+--echo #
+--echo # Native UUID type
+--echo #
+SELECT '019b6fdd-4937-7bb5-95c7-53363c6df927' AS uuid,
+       UUID_TIMESTAMP(CAST('019b6fdd-4937-7bb5-95c7-53363c6df927' AS UUID)) AS ts;
+
+--echo #
+--echo # Return type is TIMESTAMP(6)
+--echo #
+CREATE TABLE t1 AS SELECT UUID_TIMESTAMP('019b6fdd-4937-7bb5-95c7-53363c6df927') AS ts;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+
+--echo #
+--echo # Edge cases
+--echo #
+# UUIDv1 before Unix epoch
+SELECT '00000000-0000-1000-8000-000000000000' AS uuid,
+       UUID_TIMESTAMP('00000000-0000-1000-8000-000000000000') IS NULL AS before_unix_epoch;
+# UUIDv7 at Unix epoch (ts=0)
+SELECT '00000000-0000-7000-8000-000000000000' AS uuid,
+       UUID_TIMESTAMP('00000000-0000-7000-8000-000000000000') AS ts;
+# UUIDv7 max 48-bit timestamp
+SELECT 'ffffffff-ffff-7fff-8000-000000000000' AS uuid,
+       UUID_TIMESTAMP('ffffffff-ffff-7fff-8000-000000000000') AS ts;
+# UUIDv1 max timestamp
+SELECT 'ffffffff-ffff-1fff-8000-000000000000' AS uuid,
+       UUID_TIMESTAMP('ffffffff-ffff-1fff-8000-000000000000') AS ts;
+
+SET time_zone=DEFAULT;

plugin/type_uuid/plugin.cc

@@ -180,16 +180,33 @@ class Create_func_uuid_v7 : public Create_func_arg0
   virtual ~Create_func_uuid_v7() {}
 };
 
+class Create_func_uuid_timestamp : public Create_func_arg1
+{
+public:
+  Item *create_1_arg(THD *thd, Item *arg1) override
+  {
+    DBUG_ENTER("Create_func_uuid_timestamp::create_1_arg");
+    DBUG_RETURN(new (thd->mem_root) Item_func_uuid_timestamp(thd, arg1));
+  }
+  static Create_func_uuid_timestamp s_singleton;
+
+protected:
+  Create_func_uuid_timestamp() {}
+  virtual ~Create_func_uuid_timestamp() {}
+};
+
 Create_func_uuid Create_func_uuid::s_singleton;
 Create_func_sys_guid Create_func_sys_guid::s_singleton;
 Create_func_uuid_v4 Create_func_uuid_v4::s_singleton;
 Create_func_uuid_v7 Create_func_uuid_v7::s_singleton;
+Create_func_uuid_timestamp Create_func_uuid_timestamp::s_singleton;
 
 static Plugin_function
   plugin_descriptor_function_uuid(&Create_func_uuid::s_singleton),
   plugin_descriptor_function_sys_guid(&Create_func_sys_guid::s_singleton),
   plugin_descriptor_function_uuid_v4(&Create_func_uuid_v4::s_singleton),
-  plugin_descriptor_function_uuid_v7(&Create_func_uuid_v7::s_singleton);
+  plugin_descriptor_function_uuid_v7(&Create_func_uuid_v7::s_singleton),
+  plugin_descriptor_function_uuid_timestamp(&Create_func_uuid_timestamp::s_singleton);
 
 static constexpr Name type_name={STRING_WITH_LEN("uuid")};
 
@@ -301,5 +318,20 @@ maria_declare_plugin(type_uuid)
   NULL,                         // System variables
   "1.0.1",                      // String version representation
   MariaDB_PLUGIN_MATURITY_STABLE// Maturity(see include/mysql/plugin.h)*/
+},
+{
+  MariaDB_FUNCTION_PLUGIN,      // the plugin type (see include/mysql/plugin.h)
+  &plugin_descriptor_function_uuid_timestamp, // pointer to type-specific plugin descriptor
+  "uuid_timestamp",             // plugin name
+  "Varun Deep Saini",           // plugin author
+  "Function UUID_TIMESTAMP()",  // the plugin description
+  PLUGIN_LICENSE_GPL,           // the plugin license (see include/mysql/plugin.h)
+  0,                            // Pointer to plugin initialization function
+  0,                            // Pointer to plugin deinitialization function
+  0x0100,                       // Numeric version 0xAABB means AA.BB version
+  NULL,                         // Status variables
+  NULL,                         // System variables
+  "1.0",                        // String version representation
+  MariaDB_PLUGIN_MATURITY_STABLE// Maturity(see include/mysql/plugin.h)*/
 }
 maria_declare_plugin_end;