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/* $Id$ */
Leto DB Server is a multiplatform database server or a database
management system, chiefly intended for client programs, written on Harbour,
be able to work with dbf/cdx files, located on a remote server.
Contents
--------
1. Directory structure
2. Building binaries
2.1 Borland Win32 C compiler
2.2 Linux GNU C compiler
2.3 xHarbour Builder
2.4 Mingw C compiler
2.5 Building letodb with hbmk
2.6 Addition functions support
3. Running and stopping server
4. Server configuration
4.1 letodb.ini
4.2 Authentication
5. Features of work with the letodb server
5.1 Connecting to the server from client programs
5.2 Filters
6. Variables management
7. Functions list
7.1 Connection management functions
7.2 Transaction functions
7.3 Additional functions for current workarea
7.4 Additional rdd functions
7.5 Setting client paramenter
7.6 File functions
7.7 Management functions
7.8 User account management functions
7.9 Server variable management functions
7.10 Calling udf-functions on the server
7.11 Functions for bitmap filters
8. Management utility
9. Server-side functions
1. Directory structure
bin/ - server executable file
doc/ - documentation
include/ - source header files
lib/ - rdd library
source/
client/ - rdd sources
common/ - some common source files
client/ - server sources
tests/ - test programs, samples
utils/
manage/ - server management utilities
2. Building binaries
The letodb server can be compiled only by the Harbour compiler, and client
library - both Harbour, and xHarbour. For OS Windows the letodb server can be
compiled as Windows service (the macro by __WIN_SERVICE__ should be initialized),
or as the daemon (process) for what it's necessary to set a macro __WIN_DAEMON__.
For Linux it is necessary to set a macro __LINUX_DAEMON__.
The server and the client library can be built with the support of the driver
BMDBFCDX/BMDBFNTX. In this case, the basic rdd letodb server will be used instead
DBFCDX/DBFNTX driver BMDBFCDX/BMDBFNTX, and supported the same functionality that
BMDBF*. To build on this mode, in build scripts (letodb.hbp, rddleto.hbp for hbmk2
and makefile.* for other compilers) it's need to set a macro __BM.
You can pass option -env for hbmk2 utility:
hbmk2 -env:__BM=yes letodb.hbp
hbmk2 -env:__BM=yes rddleto.hbp
The server can be built with the support of functions leto_Zip and leto_UnZip.
To build on this mode, in build script (letodb.hbp) it's need to set a macro __ZIP:
hbmk2 -env:__ZIP=yes letodb.hbp
2.1 Borland Win32 C compiler
An environment variable HB_PATH, which defines a path to the Harbour
directory, must be set before compiling. This can be done, for example,
by adding a line in a make_b32.bat:
SET HB_PATH=c:\harbour
If you use xHarbour, uncomment a line 'XHARBOUR = yes' in makefile.bc.
Then run the make_b32.bat and you will get server executable file letodb.exe in a bin/
directory and rdd library rddleto.lib in a lib/ directory.
2.2 Linux GNU C compiler
An environment variable HB_ROOT, which defines a path to the Harbour
directory, must be set before compiling. Or just change the value of HRB_DIR
in the Makefile.linux.
Then run the make_linux.sh and you will get server executable file letodb in a bin/
directory and rdd library librddleto.a in a lib/ directory.
2.3 xHarbour Builder
Run the make_xhb.bat to build binaries with this compiler. Probably,
you will need to change the path to your xHarbour Builder copy in the
make_xhb.bat. Default value is:
set XHB_PATH=c:\xhb
2.4 Mingw C compiler
An environment variable HB_PATH, which defines a path to the Harbour
directory, must be set before compiling. This can be done, for example,
by adding a line in a make_mingw.bat:
SET HB_PATH=c:\harbour
If you use xHarbour, uncomment a line 'XHARBOUR = yes' in makefile.gcc.
Then run the make_mingw.bat and you will get server executable file letodb.exe in a bin/
directory and rdd library librddleto.a in a lib/ directory.
2.5 Building letodb with hbmk
Now there is a possibility to build letodb with a Harbour make utility, provided by
Viktor Szakats. The command line syntax is:
hbmk2 [-hb10|-xhb] rddleto.hbp letodb.hbp [-target=tests/test_ta.prg]
Optional parameters: -hb10 - Harbour version is 1.0 or 1.0.1,
-xhb - xHarbour,
-target="blank"\test_ta.prg - build the test, too.
2.6 Addition functions support
LetoDB use Harbour expression engine for evaluating index expressions and filters,
and allows a call of the following functions:
ABS, ALLTRIM, AT, CHR, CTOD, DATE, DAY, DELETED, DESCEND, DTOC, DTOS,
EMPTY, I2BIN, L2BIN, LEFT, LEN, LOWER, LTRIM, MAX, MIN, MONTH, PAD, PADC,
PADL, PADR, RAT, RECNO, RIGHT, ROUND, RTRIM, SPACE, STOD, STR, STRZERO,
SUBSTR, REPLICATE, TIME, TRANSFORM, TRIM, UPPER, VAL, YEAR,
hb_ATokens, hb_WildMatch
If it's necessary to add this set of functions, in the source/server.prg module
it's necessary to add a line:
REQUEST <cFName1>[, ...]
And then rebuild server.
3. Running and stopping server
Just run it:
letodb.exe ( under Windows )
./letodb ( under Linux )
To shutdown the server, run the same executable with a 'stop' parameter:
letodb.exe stop ( under Windows )
./letodb stop ( under Linux )
To reload letoudf.hrb module, run the same executable with a 'reload' parameter:
letodb.exe reload ( under Windows )
./letodb reload ( under Linux )
For windows service (server should be compiled with __WIN_SERVICE__ flag):
To install and uninstall service, you must have administrative privileges.
To install service, run letodb with 'install' parameter:
letodb.exe install
To uninstall service, run letodb with 'uninstall' parameter:
letodb.exe uninstall
To start and stop server, run service manager.
4. Server configuration
4.1 letodb.ini
You may provide configuration file letodb.ini if you isn't satisfied with
default parameters values. Currently following parameters exists ( default
values are designated ), they should be written in section [MAIN]:
[MAIN]
Port = 2812 - server port number;
Ip = - ip address, where Letodb listens for connections;
If it doesn't set, all net interfaces ( all ip addresses ),
available on the computer, are used.
TimeOut = -1 - connection timeout;
DataPath = - path to a data directory on a server;
LogPath = letodb.log - path and name of a log file;
Default_Driver = CDX - default RDD to open files on server ( CDX/NTX );
Memo_Type = - memo type ( FPT/DBT ). Default: FPT for DBFCDX, DBT for DBFNTX;
Lower_Path = 0 - if 1, convert all paths to lower case;
EnableFileFunc = 0 - if 1, using of file functions ( leto_file(),
leto_ferase(), leto_frename() is enabled;
EnableAnyExt = 0 - if 1, creating of data tables and indexes with
any extention, other than standard ( dbf,cdx,ntx )
is enabled;
EnableUDF = 1 - if 1 (by default), using of udf functions with prefix "UDF_*" is enabled,
if 2, using of udf functions with any names is enabled,
if 0, udf calls is disabled;
Pass_for_Login = 0 - if 1, user authentication is necessary to
login to the server;
Pass_for_Manage = 0 - if 1, user authentication is necessary to
use management functions ( Leto_mggetinfo(), etc. );
Pass_for_Data = 0 - if 1, user authentication is necessary to
have write access to the data;
Pass_File = "leto_users" - the path and name of users info file;
Crypt_Traffic = 0 - if 1, the data passes to the network encrypted;
Share_Tables = 0 - if 0 (default, this mode server was the only from the
start of a letodb project), the letodb opens all
tables in an exclusive mode, what allows to increase
the speed. If 1 (new mode, added since June 11, 2009),
tables are opened in the same mode as client
applications opens them, exclusive or shared, what
allows the letodb to work in coexistence with other
types of applications.
No_Save_WA = 0 - When this mode is set, each dbUseArea() will cause
a real file open operation and creating a new
workarea on the server ( in default mode each file
is opened only one time and have only one real
workarea for all users ).
Theoretically this new mode may increase the speed
in case of a big number of active users. It isn't
properly tested yet, so for production use default
mode is recommended.
Cache_Records - The number of records to read into the cache
Max_Vars_Number = 10000 - Maximum number of shared variables
Max_Var_Size = 10000 - Maximim size of a text variable
Trigger = <cFuncName> - Global function letodb RDDI_TRIGGER
PendingTrigger = <cFuncName>- Global function letodb RDDI_PENDINGTRIGGER
EnableSetTrigger = 0 - if 1, allows to change trigger settings,
using dbInfo( DBI_TRIGGER, ... )
Tables_Max = 5000 - Number of tables
Users_Max = 500 - Number of users
Debug = 0 - Debug level
Optimize = 0 - if 1, SET HARDCOMMIT OFF
AutOrder = 0 - SET AUTORDER setting
ForceOpt = 0 - _SET_FORCEOPT setting
It is possible to define [DATABASE] structure if you need to have a
directory, where files are opened via other RDD:
[DATABASE]
DataPath = - (mandatory option)
Driver = CDX - ( CDX/NTX )
You can define as many [DATABASE] sections, as needed.
In Windows environment the letodb.ini must be placed in a directory, from
where server is started.
In Linux the program looks for it in the directory from where the server
is started and, if unsuccessfully, in the /etc directory.
4.2 Authentication
To turn authentication subsystem on you need to set one of the following
letodb.ini parameters to 1: Pass_for_Login, Pass_for_Manage, Pass_for_Data. But before
you need to create, at least, one user with admin rights, because when authentication
subsystem works, only authenticated users with admin rights are able to add/change users
and passwords.
To add a user, you need to include a call of LETO_USERADD() in your client side
program, for example:
LETO_USERADD( "admin", "secret:)", "YYY" )
where "YYY" is a string, which gives rights to admin, manage and write access. You may
also use the utils/manager/console.prg program to set or change authentication data.
To connect to a server with an authentication data ( username and password ) you need to
use LETO_CONNECT() function.
5. Features of work with the letodb server
5.1 Connecting to the server from client programs
To be able to connect to the server you need to link the rddleto library
to your aplication and add at start of a main source file two lines:
REQUEST LETO
RDDSETDEFAULT( "LETO" )
To open a dbf file on a server, you need to write in a SET PATH TO
statement or in the USE command directly a path to the server in a standard
form //ip_address:port/data_path/file_name.
If a 'DataPath' parameter of a server configuration file is set to a non
empty value, you need to designate not the full path to a file on the server,
but only a relative ( relatively the 'DataPath' ).
For example, if the you need to open a file test.dbf, which is located on
a server 192.168.5.22 in a directory /data/mydir and the 'DataPath' parameter
value ( of a letodb.ini server configuration file ) is '/data', the syntax
will be the following:
USE "//192.168.5.22:2812/mydir/test"
If the server doesn't run or you write a wrong path, you'll get open error.
It is possible to check accessibility of a server before opening files by using
the leto_Connect( cAddress ) function, which returns -1 in case of unsuccessful
attempt:
IF leto_Connect( "//192.168.5.22:2812/mydir/" ) == -1
Alert( "Can't connect to server ..." )
ENDIF
At connection with the server the client send to it information about codepage,
which the server then uses for operations of indexation, a filtration and for some
other operations. The client codepage should be established before connection with
the letodb server.
5.2 Filters
The filter is established usually: by the SET FILTER TO command or by a call
dbSetFilter() function. The filter which can be executed on the server, is called optimized.
If the filter can't be executed on the server, it is not optimized. Such filter
is slow as from the server all records, which are all the same requested then
are filtered on the client. To set the optimized filter, it is necessary, that in logical
expression for the filter there were no variables or the functions defined on the client.
To check, whether the filter is optimized, it is necessary to caall the LETO_ISFLTOPTIM()
function.
6. Variables management
Letodb allows to manage variables, which are shared between applications, connected
to the server. Variables are separated into groups and may be of logical, integer or
character type. You can set a variable, get it, delete or increment/decrement
( numerical, of course ). All operations on variables are performed consecutively by
one thread, so the variables may work as semaphores. See the functions list for a syntax
of appropriate functions and tests/test_var.prg for a sample.
Letodb.ini may contain lines to determine the maximum number of variables and a
maximum size of a text variable.
7. Functions list
7.1 Connection management functions
Below is a full ( at least, for the moment I write it ) list of functions,
available for using in client applications with RDD LETO linked.
LETO_CONNECT( cAddress, [ cUserName ], [ cPassword ], [ nTimeOut ], [ nBufRefreshTime ] )
--> nConnection, -1 if failed
nBufRefreshTime defines the time interval in 0.01 sec. After this
time is up, the records buffer must be refreshed, 100 by default (1 sec)
LETO_CONNECT_ERR() --> nError
LETO_DISCONNECT( [ cConnString | nConnection ] ) --> nil
LETO_SETCURRENTCONNECTION( [ cConnString | nConnection ] ) --> nConnection
LETO_GETCURRENTCONNECTION() --> nConnection
LETO_GETSERVERVERSION() --> cVersion
LETO_GETLOCALIP() --> IP address of client station
LETO_ADDCDPTRANSLATE(cClientCdp, cServerCdp ) --> nil
LETO_PATH( [<cPath>], [cConnString | nConnection] ) --> cOldPath
LETO_PING( [ cConnString | nConnection ] ) --> lResult
7.2 Transaction functions
LETO_BEGINTRANSACTION( [ nBlockLen ], [ lParseTrans ] )
Parameter <nBlockLen> can be used for set memory allocation block size.
For big transaction it can improve transaction speed at the client side.
if parameter <lParseTransRec> is .F., transaction buffer isn't
processing during record parsing from server.
LETO_ROLLBACK()
LETO_COMMITTRANSACTION( [ lUnlockAll ] ) --> lSuccess
LETO_INTRANSACTION() --> lTransactionActive
7.3 Additional functions for current workarea
LETO_COMMIT()
This function can be used for current workarea instead of calls:
dbCommit()
dbUnlock()
The client sends to the server 3 packages: for record updating
on the server, for commit record and area unlock. Leto_Commit sends
only one package for all these operations
LETO_SUM( <cFieldNames>|<cExpr>, [ cFilter ], [xScope], [xScopeBottom] )
--> nSumma if one field or expression passed, or
{nSumma1, nSumma2, ...} for several fields
The first parameter of leto_sum if comma separated fields or expressions:
leto_sum("Sum1,Sum2", cFilter, cScopeTop, cScopeBottom) return
an array with values of sum fields Sum1 and Sum2.
If "#" symbol passed as field name, leto_sum returns a count of
evaluated records, f.e:
leto_sum("Sum1,Sum2,Sum1+Sum2,#", cFilter, cScopeTop, cScopeBottom) -->
{nSum1, nSum2, nSum3, nCount}
If only one field name or expression is passed, leto_sum() returns a numeric value
LETO_GROUPBY(cGroup, <cFields>|<cExpr>, [cFilter], [xScopeTop], [xScopeBottom]) --> aValues
{{xGroup1, nSumma1, nSumma2, ...}, ...}
This function return two-dimensional array. The first element of each row is
a value of <cGroup> field, elements from 2 - sum of comma separated fields or
expressions, represented in <cFields>. If "#" symbol passed as field name in cFields,
leto_groupby return a count of evaluated records in each group
LETO_ISFLTOPTIM() --> lFilterOptimized
dbInfo( DBI_BUFREFRESHTIME[, nNewVal]) --> nOldVal
Setting new value for area skip and seek buffers refresh time in 0.01 sec.
If -1: using connection setting. If 0 - buffers are used anyway.
dbInfo( DBI_CLEARBUFFER )
This command cleared skip buffer.
7.4 Additional rdd functions
leto_CloseAll( [ cConnString | nConnection ] ) --> nil
Close all workareas for specified or default connection
7.5 Setting client paramenter
LETO_SETSKIPBUFFER( nSkip ) --> nCount (buffer statistic using)
This buffer is intended for optimization of multiple calls of skip.
This function set size in records of skip buffer for current workarea.
By default, the size of skip buffer is 10 records. Skip buffer is bidirectional.
Skip buffer is refreshed after BUFF_REFRESH_TIME (1 sec)
If parameter <nSkip> is absent, function returns bufferr statictic (number of buffer shooting)
LETO_SETSEEKBUFFER( nRecsInBuf ) --> nCount (buffer statistic using)
This buffer is intended for optimization of multiple calls of seek.
This function set size in records of seek buffer for current index order.
If record is found in seek buffer on dbSeek(), it's not loaded from server.
Like skip buffer, seek buffer is refreshed after BUFF_REFRESH_TIME (1 sec)
If parameter <nRecsInBuf> is absent, function returns bufferr statictic
(number of buffer shooting)
By default, seek buffer is turned off.
LETO_SETFASTAPPEND( lFastAppend ) --> lFastAppend (previous value)
If the fast append mode isn't set, record is added on the server at once
after a dbAppend() function call. If this mode is set, record is added
by dbCommit() call, or after a call of functions of navigation. By default
a mode fast append isn't set. The switch working on all workareas.
RddInfo( RDDI_REFRESHCOUNT, <lSet>,, [nConnection] )
By default, the RDDI_REFRESHCOUNT flag is set to true. If this flag is set,
RecCount() function retrieve records count from server, if doesn't set -
use last value from server. If other applications are appending records
to the table, new value of records count won't be immediately received.
If RDDI_REFRESHCOUNT flag is cleared, dbGoto(0) cleared record buffer and
set eof and other flags instead of server request.
RddInfo( RDDI_BUFKEYCOUNT, <lSet>,, [nConnection] )
By default, the RDDI_BUFKEYCOUNT flag is set to false. If this flag isn't set,
ordKeyCount() function retrieve key count from server, if set -
use last value from server.
RddInfo( RDDI_BUFKEYNO, <lSet>,, [nConnection] )
By default, the RDDI_BUFKEYNO flag is set to false. If this flag isn't set,
ordKeyNo() function retrieve value from server, if set - use last value from server.
RddInfo( RDDI_CLIENTID,,, [nConnection] )
Returns self client ID (nUserStru) number.
7.6 File functions
The <cFileName> parameter of all file functions can contain a connection string
to the letodb server in a format:
//ip_address:port/data_path/file_name.
If the connection string is omitted, the current active connection is used:
/data_path/file_name.
All files is searching at the DataPath catalog on the server. The ".."
symbols are disabled.
LETO_FILE( cFileName ) --> lFileExists
Determine if file exist at the server, analog of File() function
LETO_FERASE( cFileName ) --> -1 if failed
Delete a file at the server.
LETO_FRENAME( cFileName, cFileNewName ) --> -1 if failed
Rename a file: <cFileName> --> <cFileNewName>. <cFileNewName> should be without
connection string.
LETO_MEMOREAD( cFileName ) --> cStr
Returns the contents of file at the server as character string, analog of
MemoRead() function.
Leto_MemoWrite( cFileName, cBuf ) --> lSuccess
Writes a character string into a file at the server, analog of
MemoWrit() function.
LETO_MAKEDIR( cDirName ) --> -1 if failed
Creates a directory at the server
LETO_DIREXIST( cDirName ) --> lDirExists
Determine if directory exist at the server
LETO_DIRREMOVE( cDirName ) --> -1 if failed
Delete a directory at the server.
LETO_FERROR() --> nError
Returns an error code of last file function.
Leto_FileRead( cFileName, nStart, nLen, @cBuf ) --> -1 if failed
Read a content of file at the server from <nStart> offset and <nLen> length
Leto_FileWrite( cFileName, nStart, cBuf ) --> lSuccess
Write <cBuf> character string to a file at the server from <nStart> offset
Leto_FileSize( cFileName ) --> -1 if failed
Returns a length of a file at the server
Leto_FileAttr( cFileName [, cNewAttr] ) --> cAttr
Get or set file attributes
Leto_Directory( cDir[, cAttr] ) --> aDirectory
Returns a content of directory at the server in the same format as Directory() function
7.7 Management functions
LETO_MGGETINFO() --> aInfo
This function returns parameters of current connection as 17-element array
of char type values:
1 - count of active users
2 - max count of users
3 - opened tables
4 - max opened tables
5 - time elapsed
6 - count of operations
7 - bytes sent
8 - bytes read
9 - opened indexes
10 - max opened indexes
11 - data path
12 - max day wait
13 - ulWait
14 - count of transactions
15 - count successfully of transactions
16 - current memory used
17 - max memory used
LETO_MGGETUSERS( [<cTableId>|<nTable>] ) --> aInfo
Function returns two-dimensional array, each row is info about user:
aInfo[i,1] - user number
aInfo[i,2] - ip address
aInfo[i,3] - net name of client
aInfo[i,4] - program name
aInfo[i,5] - timeout
LETO_MGGETTABLES( [<cUserId>|<nUser>] ) --> aInfo
Function returns two-dimensional array, each row is info about opened tables:
aInfo[i,1] - table number
aInfo[i,2] - table name
LETO_MGGETLOCKS( [<cUserId>|<nUser>] ) --> aInfo
Function returns two-dimensional array, each row is info about locks:
aInfo[i,1] - table name
aInfo[i,2] - character string with list of locked records
LETO_MGGETTIME() --> aDateTime
Function returns array {<dDate>, <nSeconds>}:
dDate - server date;
nSeconds - seconds after midnight.
Convert this values to datetime variable (Harbour):
hb_DTOT( aDateTime[1], aDateTime[2] )
LETO_MGKILL( <nUser>|<cUserId> )
Kill user number <nUser>
LETO_LOCKCONN( lOnOff ) --> lSuccess
After leto_lockconn( .t. ) request new connections are blocked by server, until
leto_lockconn( .f. ) called
LETO_LOCKLOCK( lOnOff, nSecs ) --> lSuccess
This function wait until any updates are closed, commit all changes and
trying to lock server from any updates from clients.
It returns True, if lock is succesfull.
7.8 User account management functions
LETO_USERADD( cUserName, cPass [, cRights ] ) --> lSuccess
LETO_USERPASSWD( cUserName, cPass ) --> lSuccess
LETO_USERRIGHTS( cUserName, cRights ) --> lSuccess
LETO_USERFLUSH() --> lSuccess
LETO_USERGETRIGHTS() --> cRights
7.9 Server variable management functions
LETO_VARSET( cGroupName, cVarName, xValue[, nFlags[, @xRetValue]] ) --> lSuccess
This function assign value <xValue> to variable <cVarName> from group <cGroupName>
Optional parameter <nFlags> defines function mode:
LETO_VCREAT - if variable doesn't exist, it's created;
LETO_VOWN - own user variable (free after user disconnect);
LETO_VDENYWR - write deny for other users;
LETO_VDENYRD - read deny for other users;
LETO_VPREVIOUS - retusn previos value to <xRetValue> parameter.
LETO_VARGET( cGroupName, cVarName ) --> xValue
Function return value of variable <cVarName> from group <cGroupName>
LETO_VARINCR( cGroupName, cVarName ) --> nValue
Function increment value of variable <cVarName> from group <cGroupName>
LETO_VARDECR( cGroupName, cVarName ) --> nValue
Function decrement value of variable <cVarName> from group <cGroupName>
LETO_VARDEL( cGroupName, cVarName ) --> lSuccess
Function delete variable <cVarName> from group <cGroupName>
LETO_VARGETLIST( [cGroupName [, nMaxLen]] ) --> aList
Function return two-dimensional array with variables: { {<cVarName>, <value>}, ...}
7.10 Calling udf-functions on the server
LETO_UDF( cSeverFunc, xParam1, ... ) --> xResult
This function is called from client application. A string
<cServerFunc> contains a server connection string and name
of udf function:
//ip_address:port/funcname
A <funcname> function should be defined on the letodb server.
The first parameter of udf function is nUserStru.
Udf function can return result (any type) to client.
Examples of udf-functions are in the tests/letoudf.prg
LETO_UDFEXIST( cSeverFunc ) --> lExist
leto_udfExist check the existance of udf-function at the letodb server.
<cSeverFunc> parameter is the same as for leto_udf().
LETO_PARSEREC( cRecBuf ) --> nil
This function is necessary for calling, if udf-function returns as
result the buffer of record which should be current after of it
works.
LETO_PARSERECODRS( cRecBuf ) --> nil
This function is necessary for calling to fill the skip-buffer as a result
of udf-function UDF_dbEval. After calling this function, the data from the
skip-buffer can be received by dbSkip() calls. See sample in comments for
UDF_dbEval() in tests/letoudf.prg
7.11 Functions for bitmap filters
If letodb compiled with rdd BMDBFCDX/BMDBFNTX, then there is support
the following functions:
LBM_DbGetFilterArray() --> aFilterRec
LBM_DbSetFilterArray( aFilterRec ) --> nil
LBM_DbSetFilterArrayAdd( aFilterRec ) --> nil
LBM_DbSetFilterArrayDel( aFilterRec ) --> nil
Purpose and the parameters of these functions is the same as for the
corresponding functions BM_*.
LBM_DbSetFilter( [<xScope>], [<xScopeBottom>], [<cFilter>] ) -> nil
This function set bitmap filter by current index order and for condition,
defined in <xScope>, <xScopeBottom>, <cFilter> parameters.
The current record after LBM_DbSetFilter() is the first record satisfying
filter condition.
8. Management utility
There are two management utilities, GUI and console, the sources are in
utils/manage directory.
GUI utility, manage.prg, is made with the HwGUI library. If you have HwGUI,
just write in the line 'set HWGUI_INSTALL=' in utils/manage/bld.bat a path
to your HwGUI directory and run the bld.bat, it will build manage.exe for you.
For those, who doesn't use HwGUI, there is a console mode utility,
console.prg. Build a console.exe with a make/bat files, which you use to build
Harbour single-file programs, you just need to add rddleto.lib to the libraries
list. Run the console.exe with a server name or ip and port as a parameter:
console.exe server_name:nPort
console.exe ip_address:nPort
The server_name and ip_address in a command line must be without leading
slashes ( '//' ), because Clipper/Harbour interprets them in a special way.
9. Server-side functions
These functions can be run from the client by function leto_udf,
and also from the functions defined in a file letoudf.hrb.
The first parameter such function always nUserStru
leto_Alias( nUserStru, cClientAlias ) --> cRealAlias
This function return server alias for client alias <cClientAlias>.
The server alias then can be user in usial rdd-operations
leto_RecLock( nUserStru [, nRecord] ) --> lSuccess
leto_Reclock function locked record with <nRecord> number, or a current record.
leto_RecUnLock( nUserStru [, nRecord] ) --> Nil
leto_RecUnlock function unlocked record with <nRecord> number, or a current
record.
leto_RecLockList( nUserStru, aRecNo ) --> lSuccess
leto_ReclockList function locked records with number in the <aRecNo> array.
If any record isn't locked, all records are unlocked, and function returns
.F. result.
This function can be used at the server from letoodf.prg module, or from
client by a call leto_UDF( "leto_RecLockList", aRecNo ).
leto_TableLock( <nUserStru>, [<nFlag>], [<Secs>]) --> lSuccess
leto_TableUnLock( <nUserStru>, [<nFlag>])
nFlag - parameter from 1 to 32, nSecs - seconds for wait locking (1 by default)
These functions are intended for concurrent access to the table for
actions except updating of the data.
leto_SelectArea( nUserStru, nAreaId ) --> lSuccess
leto_areaID( nUserStru ) --> nAreaId
Function return internal id of current workarea
leto_ClientID() --> nUserStru
Function return client ID (nUserStru), -1 if failed
letoUseArea( nUserStru, cFileName, cAlias, lShared, lReadOnly, cdp ) --> nAreaId
letoOrdListAdd( nUserStru, cBagName ) --> Nil
letoOrdCreate( nUserStru, cBagName, cKey, cTagName,
lUnique, cFor, cWhile, lAll, nRecNo,
nNext, lRest, lDesc, lCustom,
lAdditive ) --> Nil
letoCloseArea( nUserStru ) --> Nil
The functions letoUseArea, letoOrdListAdd, letoOrdCreate, letoCloseArea,
leto_RecLock, leto_RecLock is intended for using in udf-functions instead
of rdd functions: dbUseArea, OrdListAdd, OrdCreate, dbCloseArea, RLock, dbUnlock
Server variable management functions:
LETO_VARSET( nUserStru, cGroupName, cVarName, xValue[, nFlags )
--> lSuccess
LETO_VARGET( nUserStru, cGroupName, cVarName ) --> xValue
LETO_VARINCR( nUserStru, cGroupName, cVarName ) --> nValue
LETO_VARDECR( nUserStru, cGroupName, cVarName ) --> nValue
LETO_VARDEL( nUserStru, cGroupName, cVarName ) --> lSuccess
LETO_VARGETLIST( nUserStru, [cGroupName, [lValue]] ) --> aList
Zip/Unzip functions:
leto_Zip( nUserStru, [cDirName], [acFiles], [nLevel], [lOverwrite], [cPassword], [acExclude], [lWithPath] )
--> cZip
leto_UnZip( nUserStru, [cDirName], cZip, [cPassword], [lWithPath] ) --> lSuccess
parameters:
cDirName - directory relatively DataPath;
cZip - archive body to unzip;
other parameters is the same as parameters of hb_ZipFile/hb_UnZipFile functions.
Calling functions from a client:
leto_UDF("leto_Zip", [cDirName], ...)
leto_UDF("leto_UnZip", [cDirName], cZip, ...)