thanks guys
2013/9/17 Alexander Barkov <bar@xxxxxxxxxxx <mailto:bar@xxxxxxxxxxx>>
Hi Monty,
thanks for review.
I have addressed most of your suggestions. See the new version attached,
and the detailed comments inline:
On 09/12/2013 04:32 PM, Michael Widenius wrote:
Hi!
Here is the review for the code that we should put into 10.0
First the base64:
=== modified file 'mysql-test/t/func_str.test'
--- mysql-test/t/func_str.test 2013-05-07 11:05:09 +0000
+++ mysql-test/t/func_str.test 2013-08-28 13:14:24 +0000
@@ -1555,3 +1555,118 @@ drop table t1,t2;
--echo # End of 5.5 tests
--echo #
+
+--echo #
+--echo # Start of 5.6 tests
+--echo #
Shouldn't this be start of 10.0 tests ?
(I know that this code is from MySQL 5.6, but still for us this
is 10.0...)
This code is (almost) copy-and-paste from MySQL-5.6.
I think it's a good idea when looking inside a test file
to be able to see which tests are coming from MySQL-5.6,
and which tests are coming from MariaDB-10.0.
I'd suggest to keep "Start of 5.6 tests" in this particular case,
and also when merging the tests for the other merged MySQL-5.6 features.
=== modified file 'mysys/base64.c'
--- mysys/base64.c 2011-06-30 15:46:53 +0000
+++ mysys/base64.c 2013-03-09 06:22:59 +0000
@@ -1,5 +1,4 @@
-/* Copyright (c) 2003-2008 MySQL AB, 2009 Sun Microsystems,
Inc.
- Use is subject to license terms.
+/* Copyright (c) 2003, 2010, Oracle and/or its affiliates.
All rights reserved.
Removed 'all rights reserved'. You can't have that for GPL code.
If there is any new code from us, please add a copyright message
for the
MariaDB foundation too!
Removed 'all rights reserved' and added "MariaDB", as there are some
our own changes.
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
@@ -25,6 +24,28 @@ static char base64_table[] = "ABCDEFGHIJ
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
+/**
+ * Maximum length base64_needed_encoded_length()
+ * can handle without overflow.
+ */
+int
+base64_encode_max_arg_length(__)
+{
+#if (SIZEOF_INT == 8)
+ /*
+ 6827690988321067803 -> 9223372036854775805
+ 6827690988321067804 -> -9223372036854775807
+ */
Please describe from where the following number comes from
(so that anyone can recalculate and check the number if needed):
I added more comments where these numbers come from.
+ return 0x5EC0D4C77B03531BLL
+#else
+ /*
+ 1589695686 -> 2147483646 <tel:2147483646>
+ 1589695687 -> -2147483645 <tel:2147483645>
+ */
+ return 0x5EC0D4C6;
+#endif
+}
+
int
base64_needed_encoded_length(__int length_of_data)
@@ -39,6 +60,21 @@ base64_needed_encoded_length(__int length_
}
+/**
+ * Maximum length base64_needed_decoded_length()
+ * can handle without overflow.
+ */
+int
+base64_decode_max_arg_length(__)
+{
The following also need a comment.
Also added comments.
+#if (SIZEOF_INT == 8)
+ return 0x2AAAAAAAAAAAAAAALL;
+#else
+ return 0x2AAAAAAA;
+#endif
+}
+
+
<cut>
+/**
+ * Get the next character from a base64 encoded stream.
+ * Skip spaces, then scan the next base64 character or a
pad character
+ * and collect bits into decoder->c.
+ *
+ * @param decoder Pointer to MY_BASE64_DECODER
+ * @return
+ * FALSE on success (a valid base64 encoding character found)
+ * TRUE on error (unexpected character or unexpected
end-of-input found)
+ */
Add an empty line here.
Done.
It would also be good to have a good description of the base64
format
in this file so that one can understand what the functions are
supposed to do (or at least a link to the specification).
Some thing I figured out by asking bar on IRC:
- We never generate spaces
- When decoding, we allow spaces anywhere.
- The end of an 64 base decoded string is always padded with '='
so that the final length is dividable with 4.
I added a reference to http://en.wikipedia.org/wiki/__Base64
<http://en.wikipedia.org/wiki/Base64>,
as well all added these your comments in proper places of the code.
+static inline my_bool
+my_base64_decoder_getch(MY___BASE64_DECODER *decoder)
Remove inline from the above; It's likely to make the code
slower, not
faster as this is a big function with lot of if's.
Removed "inline".
{
- char b[3];
- size_t i= 0;
- char *dst_base= (char *)dst;
- char const *src= src_base;
- char *d= dst_base;
- size_t j;
+ if (my_base64_decoder_skip___spaces(decoder))
+ return TRUE; /* End-of-input */
- while (i < len)
+ if (!my_base64_add(decoder)) /* Valid base64 character
found */
{
- unsigned c= 0;
- size_t mark= 0;
+ if (decoder->mark)
+ {
+ /* If we have scanned '=' already, then only '=' is
valid */
+ DBUG_ASSERT(decoder->state == 3);
+ decoder->error= 1;
+ decoder->src--;
+ return TRUE; /* expected '=', but encoding character
found */
+ }
+ decoder->state++;
+ return FALSE;
+ }
If you want to have the funtion inline, then move the following to
another not inline function; We don't need to generate code for
this
for every function call:
+
+ /* Process error */
+ switch (decoder->state)
+ {
+ case 0:
+ case 1:
+ decoder->src--;
+ return TRUE; /* base64 character expected */
+ break;
+
+ case 2:
+ case 3:
+ if (decoder->src[-1] == '=')
+ {
+ decoder->error= 0; /* Not an error - it's a pad
character */
+ decoder->mark++;
+ }
+ else
+ {
+ decoder->src--;
+ return TRUE; /* base64 character or '=' expected */
+ }
+ break;
+ default:
+ DBUG_ASSERT(0);
+ return TRUE; /* Wrong state, should not happen */
+ }
<cut>
Add to the comment for base64_decode that the 'dst' buffer has to be
at least 2 character longer than what is needed to decode src_base.
I added this comment:
* Note: 'dst' must have sufficient space to store the decoded data.
* Use base64_needed_decoded_length() to calculate the correct space
size.
+int
+base64_decode(const char *src_base, size_t len,
+ void *dst, const char **end_ptr, int flags)
+{
+ if (my_base64_decoder_getch(&__decoder) ||
+ my_base64_decoder_getch(&__decoder) ||
+ my_base64_decoder_getch(&__decoder) ||
+ my_base64_decoder_getch(&__decoder))
+ break;
Generating the error handling with a switch for every of the
above is wasteful. See previous comment.
Right. my_base64_decoder_getch() is not inline anymore.
+ /* Return error if there are more non-space characters */
+ decoder.state= 0;
+ if (!my_base64_decoder_skip___spaces(&decoder))
+ decoder.error= 1;
+
if (end_ptr != NULL)
Note that base64_needed_decoded_length() used ceil() when it's
not needed.
Removed.
<cut>
=== modified file 'sql/item_strfunc.cc'
@@ -451,6 +452,101 @@ void Item_func_aes_decrypt::fix___length_a
set_persist_maybe_null(1);
}
+
+void Item_func_to_base64::fix___length_and_dec()
+{
+ maybe_null= args[0]->maybe_null;
+ collation.set(default_charset(__), DERIVATION_COERCIBLE,
MY_REPERTOIRE_ASCII);
Maybe better to cast both arguments to (ulonglong) as the rest
of the code
is depending on this.
Also, why is base64_encode_max_arg_length() int instead of uint or
even better size_t?
This is because base64_encode() and base64_decode() are used
in the replication code using "int" as return value.
When exposing TO_BASE64() and FROM_BASE64() to the SQL level,
I did not want to touch the replication code.
+ if (args[0]->max_length > (uint)
base64_encode_max_arg_length()__)
+ {
+ maybe_null= 1;
+ fix_char_length_ulonglong((__ulonglong)
base64_encode_max_arg_length()__);
+ }
+ else
+ {
+ int length= base64_needed_encoded_length((__int)
args[0]->max_length);
+ DBUG_ASSERT(length > 0);
Don't think assert is needed as the function gurantees it already.
+ fix_char_length_ulonglong((__ulonglong) length - 1);
+ }
+}
<cut>
+String *Item_func_from_base64::val___str(String *str)
+{
+ String *res= args[0]->val_str_ascii(str);
+ bool too_long= false;
+ int length;
+ const char *end_ptr;
+
+ if (!res ||
+ res->length() > (uint) base64_decode_max_arg_length() ||
+ (too_long=
+ ((uint) (length=
base64_needed_decoded_length((__int) res->length())) >
+ current_thd->variables.max___allowed_packet)) ||
+ tmp_value.alloc((uint) length) ||
+ (length= base64_decode(res->ptr(), (int) res->length(),
+ (char *) tmp_value.ptr(),
&end_ptr, 0)) < 0 ||
+ end_ptr < res->ptr() + res->length())
+ {
Shouldn't we get a readable error or warning if the string
contained wrong
characters?
Now it looks like we will just return null.
Something like 'Malformed base64 string. Error at position %d" would
be nice.
Good idea. I have added a warning. Now it looks clear what went wrong
if FROM_BASE64() returns NULL.
+ null_value= 1; // NULL input, too long input, OOM, or
badly formed input
+ if (too_long)
+ {
+ push_warning_printf(current___thd,
Sql_condition::WARN_LEVEL___WARN,
+ ER_WARN_ALLOWED_PACKET___OVERFLOWED,
+
ER(ER_WARN_ALLOWED_PACKET___OVERFLOWED), func_name(),
+
current_thd->variables.max___allowed_packet);
+ }
+ return 0;
+ }
+ tmp_value.length((uint) length);
+ null_value= 0;
+ return &tmp_value;
+}
<cut>
<cut>
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SPAEmpresarial
