Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 226 insertions, 0 deletions

diff --git a/mysys/my_uuid.c b/mysys/my_uuid.c
new file mode 100644
index 00000000..7925f801
--- /dev/null
+++ b/mysys/my_uuid.c
@@ -0,0 +1,226 @@
+/* Copyright (C) 2007 MySQL AB, Sergei Golubchik & Michael Widenius
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/*
+  implements Universal Unique Identifiers (UUIDs), as in
+    DCE 1.1: Remote Procedure Call,
+    Open Group Technical Standard Document Number C706, October 1997,
+    (supersedes C309 DCE: Remote Procedure Call 8/1994,
+    which was basis for ISO/IEC 11578:1996 specification)
+
+  A UUID has the following structure:
+
+  Field                     NDR Data Type  Octet #          Note
+ time_low                   unsigned long    0-3     The low field of the
+                                                     timestamp.
+ time_mid                   unsigned short   4-5     The middle field of
+                                                     the timestamp.
+ time_hi_and_version        unsigned short   6-7     The high field of the
+                                                     timestamp multiplexed
+                                                     with the version number.
+ clock_seq_hi_and_reserved  unsigned small   8       The high field of the
+                                                     clock sequence multi-
+                                                     plexed with the variant.
+ clock_seq_low              unsigned small   9       The low field of the
+                                                     clock sequence.
+ node                       character        10-15   The spatially unique node
+                                                     identifier.
+*/
+
+#include "mysys_priv.h"
+#include <my_rnd.h>
+#include <m_string.h>
+#include <myisampack.h> /* mi_int2store, mi_int4store */
+
+static my_bool my_uuid_inited= 0;
+static struct my_rnd_struct uuid_rand;
+static uint nanoseq;
+static ulonglong uuid_time= 0;
+static longlong interval_timer_offset;
+static uchar uuid_suffix[2+6]; /* clock_seq and node */
+
+static mysql_mutex_t LOCK_uuid_generator;
+
+/*
+  Number of 100-nanosecond intervals between
+  1582-10-15 00:00:00.00 and 1970-01-01 00:00:00.00
+*/
+
+#define UUID_TIME_OFFSET ((ulonglong) 141427 * 24 * 60 * 60 * \
+                          1000 * 1000 * 10)
+#define UUID_VERSION      0x1000
+#define UUID_VARIANT      0x8000
+
+
+/* Helper function */
+
+static void set_clock_seq()
+{
+  uint16 clock_seq= ((uint)(my_rnd(&uuid_rand)*16383)) | UUID_VARIANT;
+  mi_int2store(uuid_suffix, clock_seq);
+  interval_timer_offset= (my_hrtime().val * 10 - my_interval_timer()/100 + 
+                          UUID_TIME_OFFSET);
+}
+
+
+/**
+  Init structures needed for my_uuid
+
+  @func my_uuid_init()
+  @param seed1		Seed for random generator
+  @param seed2		Seed for random generator
+
+  @note
+    Seed1 & seed2 should NOT depend on clock. This is to be able to
+    generate a random mac address according to UUID specs.
+*/
+
+void my_uuid_init(ulong seed1, ulong seed2)
+{
+  uchar *mac= uuid_suffix+2;
+  ulonglong now;
+
+  if (my_uuid_inited)
+    return;
+  my_uuid_inited= 1;
+  now= my_interval_timer()/100 + interval_timer_offset;
+  nanoseq= 0;
+
+  if (my_gethwaddr(mac))
+  {
+    uint i;
+    /*
+      Generating random "hardware addr"
+
+      Specs explicitly specify that node identifier should NOT
+      correlate with a clock_seq value, so we use a separate
+      randominit() here.
+    */
+    /* purecov: begin inspected */
+    my_rnd_init(&uuid_rand, (ulong) (seed2+ now/2), (ulong) (now+rand()));
+    for (i=0; i < array_elements(uuid_suffix) -2 ; i++)
+      mac[i]= (uchar)(my_rnd(&uuid_rand)*255);
+    /* purecov: end */
+  }
+  my_rnd_init(&uuid_rand, (ulong) (seed1 + now), (ulong) (now/2+ getpid()));
+  set_clock_seq();
+  mysql_mutex_init(key_LOCK_uuid_generator, &LOCK_uuid_generator, MY_MUTEX_INIT_FAST);
+}
+
+
+/**
+   Create a global unique identifier (uuid)
+
+   @func  my_uuid()
+   @param to   Store uuid here. Must be of size MY_UUID_SIZE (16)
+*/
+
+void my_uuid(uchar *to)
+{
+  ulonglong tv;
+  uint32 time_low;
+  uint16 time_mid, time_hi_and_version;
+
+  DBUG_ASSERT(my_uuid_inited);
+
+  mysql_mutex_lock(&LOCK_uuid_generator);
+  tv= my_interval_timer()/100 + interval_timer_offset + nanoseq;
+
+  if (likely(tv > uuid_time))
+  {
+    /*
+      Current time is ahead of last timestamp, as it should be.
+      If we "borrowed time", give it back, just as long as we
+      stay ahead of the previous timestamp.
+    */
+    if (nanoseq)
+    {
+      ulong delta;
+      DBUG_ASSERT((tv > uuid_time) && (nanoseq > 0));
+      /*
+        -1 so we won't make tv= uuid_time for nanoseq >= (tv - uuid_time)
+      */
+      delta= MY_MIN(nanoseq, (ulong)(tv - uuid_time -1));
+      tv-= delta;
+      nanoseq-= delta;
+    }
+  }
+  else
+  {
+    if (unlikely(tv == uuid_time))
+    {
+      /*
+        For low-res system clocks. If several requests for UUIDs
+        end up on the same tick, we add a nano-second to make them
+        different.
+        ( current_timestamp + nanoseq * calls_in_this_period )
+        may end up > next_timestamp; this is OK. Nonetheless, we'll
+        try to unwind nanoseq when we get a chance to.
+        If nanoseq overflows, we'll start over with a new numberspace
+        (so the if() below is needed so we can avoid the ++tv and thus
+        match the follow-up if() if nanoseq overflows!).
+      */
+      if (likely(++nanoseq))
+        ++tv;
+    }
+
+    if (unlikely(tv <= uuid_time))
+    {
+      /*
+        If the admin changes the system clock (or due to Daylight
+        Saving Time), the system clock may be turned *back* so we
+        go through a period once more for which we already gave out
+        UUIDs.  To avoid duplicate UUIDs despite potentially identical
+        times, we make a new random component.
+        We also come here if the nanoseq "borrowing" overflows.
+        In either case, we throw away any nanoseq borrowing since it's
+        irrelevant in the new numberspace.
+      */
+      set_clock_seq();
+      tv= my_interval_timer()/100 + interval_timer_offset;
+      nanoseq= 0;
+      DBUG_PRINT("uuid",("making new numberspace"));
+    }
+  }
+
+  uuid_time=tv;
+  mysql_mutex_unlock(&LOCK_uuid_generator);
+
+  time_low=            (uint32) (tv & 0xFFFFFFFF);
+  time_mid=            (uint16) ((tv >> 32) & 0xFFFF);
+  time_hi_and_version= (uint16) ((tv >> 48) | UUID_VERSION);
+
+  /*
+    Note, that the standard does NOT specify byte ordering in
+    multi-byte fields. it's implementation defined (but must be
+    the same for all fields).
+    We use big-endian, so we can use memcmp() to compare UUIDs
+    and for straightforward UUID to string conversion.
+  */
+  mi_int4store(to, time_low);
+  mi_int2store(to+4, time_mid);
+  mi_int2store(to+6, time_hi_and_version);
+  bmove(to+8, uuid_suffix, sizeof(uuid_suffix));
+}
+
+
+void my_uuid_end()
+{
+  if (my_uuid_inited)
+  {
+    my_uuid_inited= 0;
+    mysql_mutex_destroy(&LOCK_uuid_generator);
+  }
+}