Class Reference
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abstract class %SYSTEM.Util extends Help

The %SYSTEM.Util class provides an interface for managing Caché utility functions.

You can use it via the special $SYSTEM object:

You can call help to get a list of all entrypoints:

Do $SYSTEM.Util.Help()

Inventory

Parameters Properties Methods Queries Indices ForeignKeys Triggers
42


Summary

Methods
BinaryDirectory CheckSwitch Collation Compress
CreateDecimalGUID CreateGUID DatabaseLatency DecimalToHex
Decompress GetEnviron GetFrameStackSize GetOSVersionInfo
GetPrio GetSessionId GetSwitch GlobalBuffers
Help HexToDecimal InstallDirectory IsDST
JavaExe JavaHomeDirectory JobPrio LocalWithZTIMEZONEtoUTC
ManagerDirectory NumberOfCPUs PurgeSYSLOG RevCollation
RoutineBufferSize RoutineBuffers SetBatch SetFrameStackSize
SetPrio SetSwitch UTCtoLocalWithZTIMEZONE ValidateRoutineBuffers


Methods

• classmethod BinaryDirectory() as %String
Returns the location of the binaries directory, where executables, DLL's, shared libraries, scripts, etc are kept.
• classmethod CheckSwitch(SwitchNumber As %Integer) as %Integer
Check if this job could be blocked by the specific switch represented by 'SwitchNumber'.
Returns 1 if the job could pass this check (not blocked), returns 0 if this job will be blocked.
For switch 10 and 11, if the job could not pass this test it also returns the PID of the job who set this switch in the '0,PID' format.
• classmethod Collation(String As %String, flag As %Integer, len As %Integer) as %String
Performs collation conversion.

Parameters

String : An expression specifying a string or number to be converted to a specified collation type.

flag : An integer code used to specify the desired collation type. Valid values are 0 through 9.

len : Optional -- The truncation length in characters, specified as an integer. Truncation is performed on the collation-converted string. This option can only be used with flag values of 7, 8, or 9. A decimal len value is truncated to its integer part. A negative or nonnumeric len value is treated as 0.

Description

Collation applies the collation type specified in flag to string. The following flag values are supported:

0 - EXACT : Returns string unchanged. Does not convert NULLs. Corresponds to the Cache SQL %EXACT function.

1 - SPACE : Appends a blank to beginning of string.

2 - MVR : Returns its argument converted to the MultiValue collation sequence. It is used when a string contains both numeric and non-numeric characters. It divides the expression string into substrings, each substring containing either all numeric or all non-numeric characters. The numeric substrings are sorted in signed numeric order. The non-numeric substrings are sorted in case-sensitive ASCII collation sequence.

3 - PLUS : Converts numerics and numeric strings to canonical numbers. A nonnumeric string is returned as 0.

4 - MINUS : Converts numerics and numeric strings to canonical numbers and prepends a minus sign. A nonnumeric string is returned as 0.

5 - UPPER : Converts letters to uppercase. Corresponds to the Cache SQL %UPPER function.

6 - ALPHAUP : Removes leading, trailing, and embedded blanks. Removes all punctuation characters, except commas (,) and question marks (?). Converts letters to uppercase. Corresponds to the Cache SQL %ALPHAUP function.

7 - SQLUPPER : Removes trailing blanks. Converts letters to uppercase. Appends a blank to beginning of string. Corresponds to the Cache SQL %SQLUPPER function.

8 - SQLSTRING : Removes trailing blanks. Appends a blank to beginning of string. Corresponds to the Cache SQL %SQLSTRING function.

9 - STRING : Removes leading, trailing, and embedded blanks. Removes all punctuation characters, except commas (,). Converts letters to uppercase. Appends a blank to beginning of string. Corresponds to the Cache SQL %STRING function.

Several of these collation conversions append a blank to the string. This forces numerics and the empty string to be collated as strings.

Numerics are converted to canonical form: leading and trailing zeros are removed, as is a trailing decimal point. Multiple plus and minus signs are resolved; if the resulting sign is a plus sign, it is removed.

The MINUS collation type appends a minus sign to the supplied sign before canonical resolution. Thus the MINUS collation of a negative number is a positive number. PLUS and MINUS resolve mixed numeric strings (such as "7dwarves") by truncating the string at the first nonnumeric character. PLUS and MINUS resolve nonnumeric strings by assigning them a value of 0.

• classmethod Compress(OriginalString As %String) as %String
Returns the compressed form of a given string.
A Cache compressed string is a ZLIB compressed data block (as defined in RFC 1950) with a Cache-proprietary wrapper. Use Decompress to decompress it.
• classmethod CreateDecimalGUID() as %String
Creates and returns the decimal representation of a globally unique identifier.
A GUID is a 16 byte (128 bit) globally unique identifier.
• classmethod CreateGUID() as %String
Creates and returns a globally unique identifier.
A GUID is a 16 byte (128 bit) globally unique identifier.
• classmethod DatabaseLatency(Directory As %String = "") as %Integer
The class method call $SYSTEM.Util.DatabaseLatency(Directory) returns an integer value that describes the health of the mounted database residing in the specified directory. If the Directory argument is missing or is the empty string then the returned value describes health of the database that holds the data for the current default namespace.

If the specified directory does not exist or does not contain a mounted database then the <DIRECTORY> error is signaled.

If the directory does exist and the directory contains a mounted database then $SYSTEM.Util.DatabaseLatency(Directory) method will return an integer value representing the number milliseconds required to access block 1 of the database CACHE.DAT file.

NOTE: On many lightly loaded platforms a call on this method will often return 0, or maybe 1. On most systems there is high speed RAM memory built into the disc drive hardware in order to speed up disc operations. This is followed by some disk cache blocks in the system memory managed by the operating system. This is further followed by a database cache in the shared memory managed by the Caché kernel. The existence of these levels of cache memory means that reading block 1 of a CACHE.DAT file will often be done by copying data from one of these levels of cache memory rather than reading data from the spinning platters of the disk drive.

NOTE: Certain database files may not support this method. For example, calling $SYSTEM.Util.DatabaseLatency(Directory) specifying a database directory which is cluster mounted on a VMS system may signal the <DIRECTORY> error.

• classmethod DecimalToHex(decimal As %String) as %String
Converts a decimal string to a hexadecimal string.
• classmethod Decompress(CompressedString As %String) as %String
Returns the original form of a Cache compressed string (see Compress).
• classmethod GetEnviron(VariableName As %String) as %String
Returns the value of an environment variable.
• classmethod GetFrameStackSize() as %Integer
Returns the configured frame stack size, in bytes.
This is the size that will be used for any new processes that are created.
• classmethod GetOSVersionInfo() as %String
Returns MajorVersion.MinorVersion.BuildNumber on Windows.
Returns an unimplemented error on Unix or VMS.
• classmethod GetPrio(pid As %Integer = "") as %Integer
Returns the priority of the current process or another process.
• classmethod GetSessionId(arg As %Integer) as %Numeric
Returns the session Id on Windows.
If arg = 0 or no argument, returns the physical console Session Id or 0xffffffff if there is no session attached to the physical console. The physical console is the monitor, keyboard, and mouse.
If arg = 1, returns the session Id of the current process. On error, returns -GetLastError().
Returns an unimplemented error on Unix or VMS.
• classmethod GetSwitch(SwitchNumber As %Integer) as %Integer
Returns the value of one system switch, or the values of all switches.

When the SwitchNumber is not specified, GetSwitch returns one value containing the state of all system switches.
Each system switch is represented by a bit in this value, with switch 0 as the least significant bit and switch 31 as the most significant.
For example:
Switch 0 -> 1
Switch 1 -> 2
Switch 2 -> 4
...
Switch 31 -> 0x80000000

When the SwitchNumber is specified (0 to 31), GetSwitch returns the state of the specific switch represented by SwitchNumber.
The return value is 1 if this switch is set, or 0 if it is cleared.
For switch 10 and 11, it also returns the PID of the job that set this switch in the '1,PID' format.

Switch Definitions -

Switches 0 to 7 are not used by the system and are reserved for the user.
Switch 8 (0x100) : Inhibits responding to network request for DCP, DDP and DTM. It does not block ECP traffic.
Switch 9 (0x200) : Inhibits new network signons, this only apply for DCP.
Switch 10(0x400) : Inhibits all global and lock access except by the job setting this switch.
Switch 11(0x800) : Inhibits all global and lock access except by the job setting this switch. This overrides switch 10 and is reserved for use by the system (should only be set by the system).
Switch 12(0x1000) : Inhibits new users to signon the system.
Switch 13(0x2000) : Inhibits sets, kills, and zsaves.
Switch 14(0x4000) : Inhibits access to globals and routines.
Switch 15(0x8000) : Allow network references from peers, even if switch 10,13, or 14 would normally prevent the access.
Switch 16(0x10000) : Used in ^SHUTDOWN only.
Switch 17(0x20000) : Used internally by system to skip waiting in journal synch.
Switch 18(0x40000) : Used internally by system to disable pausing processes in gblkrd() if the queue for a block gets too long.
Switch 19(0x80000) : Inhibits TSTART.
• classmethod GlobalBuffers() as %List
Returns a list of the number of global buffers for each buffer size.
• classmethod HexToDecimal(hex As %String) as %String
Converts a hexadecimal string to a decimal string.
• classmethod InstallDirectory() as %String
Returns the location of the installation directory, i.e. that which is displayed by ccontrol on Unix and VMS, where the .cpf configuration file is kept.
• classmethod IsDST(TimeStamp As %String) as %Integer
Determines whether $HOROLOG includes a daylight saving time adjustment.

TimeStamp is a UTC time stamp value (same format as $ZTIMESTAMP). If TimeStamp is not specified, the current time is used with $HOROLOG adjusted by the $ZTIMEZONE special variable.

The return value reports whether the corresponding $HOROLOG time is adjusted by an additional DST hour.

Changes to $ZTIMEZONE will change the value of $HOROLOG but the time zone rules do not change. The time zone rules are always those used by the operating system on which the Cache process is running. The time zone rules of the Cache process will be applied to the local time.

The UTC time stamp is converted to a time_t value (taking into account adjustments to $ztimezone) which is then used as input to call the C Programming Language standard library routine localtime(). The tm_isdst element of the returned tm struct is examined to determine if the daylight savings time is in effect.
Return Values:
0 - DST is not in effect.
1 - DST is in effect.
-1 - It cannot be determined if DST is in effect.

• classmethod JavaExe() as %String
Returns the path name of the Java executable, which can be used to build a command line.
This method returns the pathname of the Java executable, which can be used to build a command line on your system. The return value has been normalized, and is suitable for passing to $zf(-1) or $zf(-2).
The method uses the return value from the JavaHomeDirectory() method, appends the subdirectory "bin" to it, and then adds the Java executable name to the end. If the JavaHomeDirectory() method returns "", then it is assumed that the Java executable location is in the process path, and the return value of the method is simply the Java executable name.

Notes:
This method does not test for the existence of the Java executable. It assumes it is located in the "bin" directory if JavaHomeDirectory() returns a non-null value, otherwise it must be in the path of the process executing the method.
Example:
s JavaExe=$SYSTEM.Util.JavaExe()
s Status=$zf(-1,JavaExe_" -version")
• classmethod JavaHomeDirectory() as %String
Returns the location of the Java Home directory.
This method returns the location of the Java Home directory on your system. The return value has been normalized, and is suitable for passing to $zf(-1) or $zf(-2).
The location of the Java Home directory which is returned is determined in the following order:
1) The directory location returned by the configuration parameter JavaHome in the Cache.CPF file.
2) The directory location returned by the environment variable "JAVA_HOME".
3) If none of the above, a null string.
Example:
s JavaHome=$SYSTEM.Util.JavaHomeDirectory()
• classmethod JobPrio(jprio As %Integer) as %Integer
Sets the system-wide job priority delta to the specified number.
The priority of any jobbed process on the system = priority of parent + system job priority.
The new jobprio value is returned

Note: changing priority is almost never needed and can compromise system stability

• classmethod LocalWithZTIMEZONEtoUTC(h As %String) as %String
Converts Local time to UTC time.

Parameter

h : A string representing Local time in the same format as that returned by $HOROLOG.

Return Value

A string representing the corresponding UTC time in the same format as that returned by $ZTIMESTAMP.

Note: This method only supports dates between December 31, 1969 and January 18, 2038. Dates outside this range will give an <ILLEGAL VALUE> error.

Note: $ZTIMEZONE Warning

This method is unusual in that it adjusts the Local time by any changes made to the $ZTIMEZONE special variable. Use of the $ZTIMEZONE variable is limited to a few special situations. $ZTIMEZONE affects the value returned by $HOROLOG but most other date/time features and functions (including $ZDATETIME and $ZDATETIMEH) ignore $ZTIMEZONE changes. Even though changing $ZTIMEZONE will change the value returned by $HOROLOG, the time zone rules do not change. The time zone rules are always those used by the operating system on which the process is running. The $ZTIMEZONE special variable will probably become a legacy feature in future versions of the system. If possible, applications should avoid changing $ZTIMEZONE and should use $ZDATETIME(h,-3) to convert Local time to UTC time.

• classmethod ManagerDirectory() as %String
Returns the location of the manager directory, where the CACHESYS database and runtime files are kept.
• classmethod NumberOfCPUs() as %Integer
Returns the number of virtual CPUs (also known as logical CPUs or threads) on the system.
For more details see %SYSTEM.CPU.
• classmethod PurgeSYSLOG() as %Numeric
Purges existing error report records from SYSLOG.
• classmethod RevCollation(String As %String, flag As %Integer) as %String
Performs reverse collation conversion.

Parameters

String : An expression specifying a collated string to be converted back to POSSIBLE original value.

flag : An integer code used to specify the desired collation type. Valid value is 2.

Description

RevCollation applies the collation type specified in flag to string. The following flag values are supported:

2 - MVR : Returns its argument converted from the MultiValue collation sequence. It is used when a string contains both numeric and non-numeric characters. It divides the expression string into substrings, each substring containing either all numeric or all non-numeric characters. The numeric substrings are sorted in signed numeric order. The non-numeric substrings are sorted in case-sensitive ASCII collation sequence. The result can differ from the original due to sign and leading zero suppression applied during the conversion to MVR collation.

• classmethod RoutineBufferSize() as %Integer
Returns the largest routine buffer size that been configured.
• classmethod RoutineBuffers(Arg As %Integer) as %String
Returns information about the routine buffers that have been allocated.
The return value is a comma-delimited string with a value for each possible buffer size. The pieces correspond to buffer sizes 2K,4K,8K,16K,32K,64K.

If Arg is 0 or is omitted, the values are the amount of memory, in MegaBytes, allocated for each buffer size.
If Arg is 1, the values are the number of buffers allocated for each buffer size.
• classmethod SetBatch(flag As %Integer, pid As %Integer = "") as %Integer
Sets or clears batch mode for the calling process, or the one identified by pid

Processes that will access large portions of a database may be set into batch mode to limit their impact on other (non-batch mode) processes running on the system. In particular, batch mode processes are prevented from overwhelming the database cache with the database blocks that they read or modify.

Parameters

flag : 1 sets batch mode; 0 clears batch mode

pid : (optional) target pid; if null or omitted target is the calling process

Return Value

Returns the old value of the batch flag, or -1 if error

• classmethod SetFrameStackSize(size As %Integer) as %Integer
Sets the configured frame stack size, in bytes, for new processes.
If size is 0, the system default size is set.
Returns the previous configured value.
• classmethod SetPrio(delta As %Integer, pid As %Integer = "") as %String
Adjusts the priority of the current process or another process up or down by delta amount.
The new priority is returned.

Note: changing process priority is almost never needed and can compromise system stability

• classmethod SetSwitch(SwitchNumber As %Integer, SwitchValue As %Integer) as %Integer
Sets the value of a system switch.

When one parameter is specified, SetSwitch(SwitchValue) sets the value of all system switches to SwitchValue.
It returns the original value of all switches.
This is not recommended to be used by users.

When two parameters are specified, SetSwitch(SwitchNumber,SwitchValue) sets the value of the specific switch SwitchNumber to SwitchValue.
It returns the original switch value.
To set switch 10 or (11 in cluster), if the switch was set then the SetSwitch won't do anything and the original value with the owner PID is returned in '1,PID' format..
To clear switch 10 or (11 in cluster), if the switch was cleared or was set by different process then the SetSwitch won't do anything and the original value is returned.

See GetSwitch for a definition of the switches.
• classmethod UTCtoLocalWithZTIMEZONE(TimeStamp As %String) as %String
Converts UTC time to Local time.

Parameter

TimeStamp : A string representing a UTC time in the same format as that returned by $ZTIMESTAMP.

Return Value

A string representing the corresponding Local time in the same format as that returned by $HOROLOG.

Note: This method only supports dates between January 1, 1970 and January 18, 2038. Dates outside this range will give an <ILLEGAL VALUE> error.

Note: $ZTIMEZONE Warning

This function is unusual in that it adjusts the Local time by any changes made to the $ZTIMEZONE special variable. Use of the $ZTIMEZONE variable is limited to a few special situations. $ZTIMEZONE affects the value returned by $HOROLOG but most other date/time features and functions (including $ZDATETIME and $ZDATETIMEH) ignore $ZTIMEZONE changes. Even though changing $ZTIMEZONE will change the value of returned by $HOROLOG, the time zone rules do not change. The time zone rules are always those used by the operating system on which the process is running. The $ZTIMEZONE special variable will probably become a legacy feature in future versions of the system. If possible, applications should avoid changing $ZTIMEZONE and should use $ZDATETIMEH(timestamp,-3) to convert UTC time to Local time.

• classmethod ValidateRoutineBuffers(flag As %Integer, numbuf As %Integer)
Performs validation of the routine buffers in memory

Parameters

flag : 1 = stop if an error is found. Default is 0.

numbuf : For a big-endian system, specifies the number of buffers to allocate as a work area. Routines larger than this will not be checked. Default is 8. Little-endian systems do not allocate a work area.

Return value

The return value is a $LIST with at least one element.
The first element is the number of buffers (routines) that were checked.
If errors are found, there will be one list element for each error.
If numbuf is specified, there will be one element with the size of the largest routine found. If this value is larger than numbuf on a big-endian system then at least one routine was skipped.

Each error is itself a $LIST with these elements:

The buffer number.
The routine name.
The error code.
Additional information specific to the error code.

Error code 1 is a crc error. The additional information is the expected crc value and the actual value.



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