Hi

2016-01-04 12:46 GMT+01:00 Shulgin, Oleksandr <oleksandr.shul...@zalando.de>
:

> On Wed, Dec 30, 2015 at 8:28 PM, Pavel Stehule <pavel.steh...@gmail.com>
> wrote:
>
>>
>>
>> 2015-12-30 17:33 GMT+01:00 Robert Haas <robertmh...@gmail.com>:
>>
>>> On Mon, Dec 28, 2015 at 8:45 AM, Shulgin, Oleksandr
>>> <oleksandr.shul...@zalando.de> wrote:
>>> > I didn't check out earlier versions of this patch, but the latest one
>>> still
>>> > changes pg_size_pretty() to emit PB suffix.
>>> >
>>> > I don't think it is worth it to throw a number of changes together like
>>> > that.  We should focus on adding pg_size_bytes() first and make it
>>> > compatible with both pg_size_pretty() and existing GUC units: that is
>>> > support suffixes up to TB and make sure they have the meaning of
>>> powers of
>>> > 2^10, not 10^3.  Re-using the table present in guc.c would be a plus.
>>> >
>>> > Next, we could think about adding handling of PB suffix on input and
>>> output,
>>> > but I don't see a big problem if that is emitted as 1024TB or the user
>>> has
>>> > to specify it as 1024TB in a GUC or argument to pg_size_bytes(): an
>>> minor
>>> > inconvenience only.
>>>
>>> +1 to everything in this email.
>>>
>>
>> so I removed support for PB and SI units. Now the
>> memory_unit_conversion_table is shared.
>>
>
> Looks better, thanks.
>
> I'm not sure why the need to touch the regression test for
> pg_size_pretty():
>
> !                10.5 | 10.5 bytes     | -10.5 bytes
> !              1000.5 | 1000.5 bytes   | -1000.5 bytes
> !           1000000.5 | 977 kB         | -977 kB
> !        1000000000.5 | 954 MB         | -954 MB
> !     1000000000000.5 | 931 GB         | -931 GB
> !  1000000000000000.5 | 909 TB         | -909 TB
>
>
fixed


> A nitpick, this loop:
>
> + while (*cp)
> + {
> + if ((isdigit(*cp) || *cp == '.') && ndigits < MAX_DIGITS)
> + digits[ndigits++] = *cp++;
> + else
> + break;
> + }
>
> would be a bit easier to parse if spelled as:
>
> + while (*cp && (isdigit(*cp) || *cp == '.') && ndigits < MAX_DIGITS)
> + digits[ndigits++] = *cp++;
>

fixed


>
> On the other hand, this seems to truncate the digits silently:
>
> + digits[ndigits] = '\0';
>
> I don't think we want that, e.g:
>
> postgres=# select pg_size_bytes('9223372036854775807.9');
> ERROR:  invalid unit "9"
> HINT:  Valid units for this parameter are "kB", "MB", "GB", and "TB".
>
> I think making a mutable copy of the input string and truncating it before
> passing to numeric_in() would make more sense--no need to hard-code
> MAX_DIGITS.  The same goes for hard-coding MAX_UNIT_LEN, e.g. compare the
> following two outputs:
>
> postgres=# select pg_size_bytes('1 KiB');
> ERROR:  invalid unit "KiB"
> HINT:  Valid units for this parameter are "kB", "MB", "GB", and "TB".
>
> postgres=# select pg_size_bytes('1024 bytes');
> ERROR:  invalid format
>
>
fixed


> I believe we should see a similar error message and a hint in the latter
> case.  (No, I don't think we should add support for 'bytes' as a unit, not
> even for "compatibility" with pg_size_pretty()--for one, I don't think it
> would be wise to expect pg_size_bytes() to be able to deparse *every*
> possible output produced by pg_size_pretty() as it's purpose is
> human-readable display; also, pg_size_pretty() can easily produce output
> that doesn't fit into bigint type, or is just negative)
>
> Code comments and doc change need proof-reading by a native English
> speaker, which I am not.
>


Regards

Pavel


>
> --
> Alex
>
>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
new file mode 100644
index 8ef9fce..6b921ae
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
*************** postgres=# SELECT * FROM pg_xlogfile_nam
*** 17607,17612 ****
--- 17607,17615 ----
      <primary>pg_relation_size</primary>
     </indexterm>
     <indexterm>
+     <primary>pg_size_bytes</primary>
+    </indexterm>
+    <indexterm>
      <primary>pg_size_pretty</primary>
     </indexterm>
     <indexterm>
*************** postgres=# SELECT * FROM pg_xlogfile_nam
*** 17677,17682 ****
--- 17680,17696 ----
         </entry>
        </row>
        <row>
+        <entry>
+         <literal><function>pg_size_bytes(<type>text</type>)</function></literal>
+         </entry>
+        <entry><type>bigint</type></entry>
+        <entry>
+          Converts a size in human-readable format with size units
+          into bytes.  The parameter is case insensitive string. Following
+          units are supported: kB, MB, GB, TB.
+        </entry>
+       </row>
+       <row>
         <entry>
          <literal><function>pg_size_pretty(<type>bigint</type>)</function></literal>
          </entry>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
new file mode 100644
index 2084692..ce97467
*** a/src/backend/utils/adt/dbsize.c
--- b/src/backend/utils/adt/dbsize.c
***************
*** 25,30 ****
--- 25,31 ----
  #include "storage/fd.h"
  #include "utils/acl.h"
  #include "utils/builtins.h"
+ #include "utils/guc.h"
  #include "utils/numeric.h"
  #include "utils/rel.h"
  #include "utils/relfilenodemap.h"
*************** pg_size_pretty_numeric(PG_FUNCTION_ARGS)
*** 700,705 ****
--- 701,811 ----
  }
  
  /*
+  * Convert human readable size to long int.
+  *
+  * Due suppor decimal value and case insensitivity of units
+  * a function parse_intcannot be used.
+  */
+ Datum
+ pg_size_bytes(PG_FUNCTION_ARGS)
+ {
+ 	text		   *arg = PG_GETARG_TEXT_PP(0);
+ 	const char	   *str = text_to_cstring(arg);
+ 	const char	*strptr = str;
+ 	char		  *buffer;
+ 	char	*bufptr;
+ 	Numeric			num;
+ 	int64 result;
+ 
+ 	/* working buffer cannot be longer than original string */
+ 	buffer = (char *) palloc(VARSIZE_ANY_EXHDR(arg) + 1);
+ 	bufptr = buffer;
+ 
+ 	/* Skip leading spaces */
+ 	while (isspace((unsigned char) *strptr))
+ 		strptr++;
+ 
+ 	switch (*strptr)
+ 	{
+ 		/* ignore plus symbol */
+ 		case '+':
+ 			strptr++;
+ 			break;
+ 		case '-':
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("size cannot be negative")));
+ 	}
+ 
+ 	/* copy digits to working buffer */
+ 	while (*strptr && (isdigit(*strptr) || *strptr == '.'))
+ 		*bufptr++ = *strptr++;
+ 	*bufptr = '\0';
+ 
+ 	/* don't allow empty string */
+ 	if (*buffer == '\0')
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("\"%s\" is not number", str)));
+ 
+ 	num = DatumGetNumeric(DirectFunctionCall3(numeric_in,
+ 							CStringGetDatum(buffer), 0, -1));
+ 
+ 	/* allow whitespace between integer and unit */
+ 	while (isspace(*strptr))
+ 		strptr++;
+ 
+ 	/* Handle possible unit */
+ 	if (*strptr != '\0')
+ 	{
+ 		int		multiplier;
+ 		Numeric			mul_num;
+ 		const char	*hintmsg;
+ 		const char *unitstr = strptr;
+ 
+ 		bufptr = buffer;
+ 
+ 		/* copy chars to buffer and stop on space */
+ 		while (*strptr && !isspace(*strptr))
+ 			*bufptr++ = *strptr++;
+ 		*bufptr = '\0';
+ 
+ 		/*
+ 		 * Use buffer as unit if there are not any nonspace char,
+ 		 * else use a original unit string.
+ 		 */
+ 		while (isspace(*strptr))
+ 			strptr++;
+ 		if (*strptr == '\0')
+ 			unitstr = buffer;
+ 
+ 		if (!parse_memory_unit(unitstr, &multiplier, &hintmsg))
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("invalid unit: \"%s\"", unitstr),
+ 					 errhint("%s", _(hintmsg))));
+ 
+ 		/*
+ 		 * Now, the multiplier is in KB unit. It should be multiplied by 1024
+ 		 * before usage
+ 		 */
+ 		mul_num = DatumGetNumeric(DirectFunctionCall1(int8_numeric,
+ 						    Int64GetDatum(multiplier * 1024L)));
+ 
+ 		num = DatumGetNumeric(DirectFunctionCall2(numeric_mul,
+ 							    NumericGetDatum(mul_num),
+ 							    NumericGetDatum(num)));
+ 	}
+ 
+ 	result = DatumGetInt64(DirectFunctionCall1(numeric_int8, NumericGetDatum(num)));
+ 
+ 	pfree(buffer);
+ 	pfree(str);
+ 
+ 	PG_RETURN_INT64(result);
+ }
+ 
+ /*
   * Get the filenode of a relation
   *
   * This is expected to be used in queries like
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
new file mode 100644
index 38ba82f..00021fd
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
*************** convert_from_base_unit(int64 base_value,
*** 5238,5243 ****
--- 5238,5272 ----
  
  
  /*
+  * Parse value as some known memory unit to their size in bytes.
+  * Used in pg_size_bytes function. Against convert_to_base_unit, a string
+  * comparation is case insensitive.
+  */
+ bool
+ parse_memory_unit(const char *unit, int *multiplier,
+ 					    const char **hintmsg)
+ {
+ 	int			i;
+ 
+ 	for (i = 0; *memory_unit_conversion_table[i].unit; i++)
+ 	{
+ 		const unit_conversion *conv = &memory_unit_conversion_table[i];
+ 
+ 		if ( conv->base_unit == GUC_UNIT_KB &&
+ 			strcasecmp(unit, conv->unit) == 0)
+ 		{
+ 			*multiplier = conv->multiplier;
+ 			return true;
+ 		}
+ 	}
+ 
+ 	*hintmsg = memory_units_hint;
+ 
+ 	return false;
+ }
+ 
+ 
+ /*
   * Try to parse value as an integer.  The accepted formats are the
   * usual decimal, octal, or hexadecimal formats, optionally followed by
   * a unit name if "flags" indicates a unit is allowed.
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
new file mode 100644
index e5d6c77..4b73e72
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
*************** DATA(insert OID = 2286 ( pg_total_relati
*** 3662,3667 ****
--- 3662,3669 ----
  DESCR("total disk space usage for the specified table and associated indexes");
  DATA(insert OID = 2288 ( pg_size_pretty			PGNSP PGUID 12 1 0 0 0 f f f f t f v s 1 0 25 "20" _null_ _null_ _null_ _null_ _null_ pg_size_pretty _null_ _null_ _null_ ));
  DESCR("convert a long int to a human readable text using size units");
+ DATA(insert OID = 3317 ( pg_size_bytes			PGNSP PGUID 12 1 0 0 0 f f f f t f v s 1 0 20 "25" _null_ _null_ _null_ _null_ _null_ pg_size_bytes _null_ _null_ _null_ ));
+ DESCR("convert a human readable text with size units to long int bytes");
  DATA(insert OID = 3166 ( pg_size_pretty			PGNSP PGUID 12 1 0 0 0 f f f f t f v s 1 0 25 "1700" _null_ _null_ _null_ _null_ _null_ pg_size_pretty_numeric _null_ _null_ _null_ ));
  DESCR("convert a numeric to a human readable text using size units");
  DATA(insert OID = 2997 ( pg_table_size			PGNSP PGUID 12 1 0 0 0 f f f f t f v s 1 0 20 "2205" _null_ _null_ _null_ _null_ _null_ pg_table_size _null_ _null_ _null_ ));
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
new file mode 100644
index bbaa2ce..5b08a6a
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
*************** extern Datum pg_relation_size(PG_FUNCTIO
*** 462,467 ****
--- 462,468 ----
  extern Datum pg_total_relation_size(PG_FUNCTION_ARGS);
  extern Datum pg_size_pretty(PG_FUNCTION_ARGS);
  extern Datum pg_size_pretty_numeric(PG_FUNCTION_ARGS);
+ extern Datum pg_size_bytes(PG_FUNCTION_ARGS);
  extern Datum pg_table_size(PG_FUNCTION_ARGS);
  extern Datum pg_indexes_size(PG_FUNCTION_ARGS);
  extern Datum pg_relation_filenode(PG_FUNCTION_ARGS);
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
new file mode 100644
index e1de1a5..3bfe0f4
*** a/src/include/utils/guc.h
--- b/src/include/utils/guc.h
*************** extern int	NewGUCNestLevel(void);
*** 357,362 ****
--- 357,364 ----
  extern void AtEOXact_GUC(bool isCommit, int nestLevel);
  extern void BeginReportingGUCOptions(void);
  extern void ParseLongOption(const char *string, char **name, char **value);
+ extern bool parse_memory_unit(const char *unit, int *multiplier,
+ 					    const char **hintmsg);
  extern bool parse_int(const char *value, int *result, int flags,
  		  const char **hintmsg);
  extern bool parse_real(const char *value, double *result);
diff --git a/src/test/regress/expected/dbsize.out b/src/test/regress/expected/dbsize.out
new file mode 100644
index aa513e7..89a2308
*** a/src/test/regress/expected/dbsize.out
--- b/src/test/regress/expected/dbsize.out
*************** SELECT size, pg_size_pretty(size), pg_si
*** 35,37 ****
--- 35,77 ----
   1000000000000000.5 | 909 TB         | -909 TB
  (12 rows)
  
+ SELECT pg_size_bytes(size) FROM
+    (VALUES('1'), ('1kB'), ('1MB'), (' 1 GB'), ('1.5 GB '),
+           ('1TB'), ('3000 TB')) x(size);
+   pg_size_bytes   
+ ------------------
+                 1
+              1024
+           1048576
+        1073741824
+        1610612736
+     1099511627776
+  3298534883328000
+ (7 rows)
+ 
+ -- case insensitive units are supported
+ SELECT pg_size_bytes(size) FROM
+    (VALUES('1'), ('1kb'), ('1mb'), (' 1 Gb'), ('1.5 gB '),
+           ('1tb')) x(size);
+  pg_size_bytes 
+ ---------------
+              1
+           1024
+        1048576
+     1073741824
+     1610612736
+  1099511627776
+ (6 rows)
+ 
+ --should fail
+ SELECT pg_size_bytes('1 AB');
+ ERROR:  invalid unit: "AB"
+ HINT:  Valid units for this parameter are "kB", "MB", "GB", and "TB".
+ SELECT pg_size_bytes('1 AB A');
+ ERROR:  invalid unit: "AB A"
+ HINT:  Valid units for this parameter are "kB", "MB", "GB", and "TB".
+ select pg_size_bytes('9223372036854775807.9');
+ ERROR:  bigint out of range
+ select pg_size_bytes('1024 bytes');
+ ERROR:  invalid unit: "bytes"
+ HINT:  Valid units for this parameter are "kB", "MB", "GB", and "TB".
diff --git a/src/test/regress/sql/dbsize.sql b/src/test/regress/sql/dbsize.sql
new file mode 100644
index c118090..5caab78
*** a/src/test/regress/sql/dbsize.sql
--- b/src/test/regress/sql/dbsize.sql
*************** SELECT size, pg_size_pretty(size), pg_si
*** 10,12 ****
--- 10,27 ----
              (10.5::numeric), (1000.5::numeric), (1000000.5::numeric),
              (1000000000.5::numeric), (1000000000000.5::numeric),
              (1000000000000000.5::numeric)) x(size);
+ 
+ SELECT pg_size_bytes(size) FROM
+    (VALUES('1'), ('1kB'), ('1MB'), (' 1 GB'), ('1.5 GB '),
+           ('1TB'), ('3000 TB')) x(size);
+ 
+ -- case insensitive units are supported
+ SELECT pg_size_bytes(size) FROM
+    (VALUES('1'), ('1kb'), ('1mb'), (' 1 Gb'), ('1.5 gB '),
+           ('1tb')) x(size);
+ 
+ --should fail
+ SELECT pg_size_bytes('1 AB');
+ SELECT pg_size_bytes('1 AB A');
+ select pg_size_bytes('9223372036854775807.9');
+ select pg_size_bytes('1024 bytes');
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