Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream

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

1 files changed, 209 insertions, 0 deletions

diff --git a/mysys/my_compress.c b/mysys/my_compress.c
new file mode 100644
index 00000000..11603e7b
--- /dev/null
+++ b/mysys/my_compress.c
@@ -0,0 +1,209 @@
+/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+
+   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 St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+/* Written by Sinisa Milivojevic <sinisa@mysql.com> */
+
+#include <mysys_priv.h>
+#ifdef HAVE_COMPRESS
+#include <my_sys.h>
+#ifndef SCO
+#include <m_string.h>
+#endif
+#include <zlib.h>
+
+/*
+   This replaces the packet with a compressed packet
+
+   SYNOPSIS
+     my_compress()
+     packet	Data to compress. This is is replaced with the compressed data.
+     len	Length of data to compress at 'packet'
+     complen	out: 0 if packet was not compressed
+
+   RETURN
+     1   error. 'len' is not changed'
+     0   ok.  In this case 'len' contains the size of the compressed packet
+*/
+
+my_bool my_compress(uchar *packet, size_t *len, size_t *complen)
+{
+  DBUG_ENTER("my_compress");
+  if (*len < MIN_COMPRESS_LENGTH)
+  {
+    *complen=0;
+    DBUG_PRINT("note",("Packet too short: Not compressed"));
+  }
+  else
+  {
+    uchar *compbuf=my_compress_alloc(packet,len,complen);
+    if (!compbuf)
+      DBUG_RETURN(*complen ? 0 : 1);
+    memcpy(packet,compbuf,*len);
+    my_free(compbuf);
+  }
+  DBUG_RETURN(0);
+}
+
+
+/*
+  Valgrind normally gives false alarms for zlib operations, in the form of
+  "conditional jump depends on uninitialised values" etc. The reason is
+  explained in the zlib FAQ (http://www.zlib.net/zlib_faq.html#faq36):
+
+    "That is intentional for performance reasons, and the output of deflate
+    is not affected."
+
+  Also discussed on a blog
+  (http://www.sirena.org.uk/log/2006/02/19/zlib-generating-valgrind-warnings/):
+
+    "...loop unrolling in the zlib library causes the mentioned
+    “Conditional jump or move depends on uninitialised value(s)”
+    warnings. These are safe since the results of the comparison are
+    subsequently ignored..."
+
+    "the results of the calculations are discarded by bounds checking done
+    after the loop exits"
+
+  Fix by initializing the memory allocated by zlib when running under Valgrind.
+
+  This fix is safe, since such memory is only used internally by zlib, so we
+  will not hide any bugs in mysql this way.
+*/
+void *my_az_allocator(void *dummy __attribute__((unused)), unsigned int items,
+                      unsigned int size)
+{
+  return my_malloc(key_memory_my_compress_alloc, (size_t)items*(size_t)size,
+                   IF_VALGRIND(MY_ZEROFILL, MYF(0)));
+}
+
+void my_az_free(void *dummy __attribute__((unused)), void *address)
+{
+  my_free(address);
+}
+
+/*
+  This works like zlib compress(), but using custom memory allocators to work
+  better with my_malloc leak detection and Valgrind.
+*/
+int my_compress_buffer(uchar *dest, size_t *destLen,
+                       const uchar *source, size_t sourceLen)
+{
+    z_stream stream;
+    int err;
+
+    stream.next_in = (Bytef*)source;
+    stream.avail_in = (uInt)sourceLen;
+    stream.next_out = (Bytef*)dest;
+    stream.avail_out = (uInt)*destLen;
+    if ((size_t)stream.avail_out != *destLen)
+      return Z_BUF_ERROR;
+
+    stream.zalloc = (alloc_func)my_az_allocator;
+    stream.zfree = (free_func)my_az_free;
+    stream.opaque = (voidpf)0;
+
+    err = deflateInit(&stream, Z_DEFAULT_COMPRESSION);
+    if (err != Z_OK) return err;
+
+    err = deflate(&stream, Z_FINISH);
+    if (err != Z_STREAM_END) {
+        deflateEnd(&stream);
+        return err == Z_OK ? Z_BUF_ERROR : err;
+    }
+    *destLen = stream.total_out;
+
+    err = deflateEnd(&stream);
+    return err;
+}
+
+uchar *my_compress_alloc(const uchar *packet, size_t *len, size_t *complen)
+{
+  uchar *compbuf;
+  int res;
+  *complen=  *len * 120 / 100 + 12;
+
+  if (!(compbuf= (uchar *) my_malloc(key_memory_my_compress_alloc,
+                                     *complen, MYF(MY_WME))))
+    return 0;
+
+  res= my_compress_buffer(compbuf, complen, packet, *len);
+
+  if (res != Z_OK)
+  {
+    my_free(compbuf);
+    return 0;
+  }
+
+  if (*complen >= *len)
+  {
+    *complen= 0;
+    my_free(compbuf);
+    DBUG_PRINT("note",("Packet got longer on compression; Not compressed"));
+    return 0;
+  }
+  /* Store length of compressed packet in *len */
+  swap_variables(size_t, *len, *complen);
+  return compbuf;
+}
+
+
+/*
+  Uncompress packet
+
+   SYNOPSIS
+     my_uncompress()
+     packet	Compressed data. This is is replaced with the original data.
+     len	Length of compressed data
+     complen	Length of the packet buffer (must be enough for the original
+	        data)
+
+   RETURN
+     1   error
+     0   ok.  In this case 'complen' contains the updated size of the
+              real data.
+*/
+
+my_bool my_uncompress(uchar *packet, size_t len, size_t *complen)
+{
+  uLongf tmp_complen;
+  DBUG_ENTER("my_uncompress");
+
+  if (*complen)					/* If compressed */
+  {
+    uchar *compbuf= (uchar *) my_malloc(key_memory_my_compress_alloc,
+                                        *complen,MYF(MY_WME));
+    int error;
+    if (!compbuf)
+      DBUG_RETURN(1);				/* Not enough memory */
+
+    tmp_complen= (uLongf) *complen;
+    error= uncompress((Bytef*) compbuf, &tmp_complen, (Bytef*) packet,
+                      (uLong) len);
+    *complen= tmp_complen;
+    if (error != Z_OK)
+    {						/* Probably wrong packet */
+      DBUG_PRINT("error",("Can't uncompress packet, error: %d",error));
+      my_free(compbuf);
+      DBUG_RETURN(1);
+    }
+    memcpy(packet, compbuf, *complen);
+    my_free(compbuf);
+  }
+  else
+    *complen= len;
+  DBUG_RETURN(0);
+}
+
+#endif /* HAVE_COMPRESS */