NAME
tctdb - the table database API
DESCRIPTION
Table database is a file containing records composed of the primary
keys and arbitrary columns and is handled with the table database API.
To use the table database API, include ‘tcutil.h’, ‘tctdb.h’, and
related standard header files. Usually, write the following
description near the front of a source file.
#include <tcutil.h>
#include <tctdb.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
Objects whose type is pointer to ‘TCTDB’ are used to handle table
databases. A table database object is created with the function
‘tctdbnew’ and is deleted with the function ‘tctdbdel’. To avoid
memory leak, it is important to delete every object when it is no
longer in use.
Before operations to store or retrieve records, it is necessary to open
a database file and connect the table database object to it. The
function ‘tctdbopen’ is used to open a database file and the function
‘tctdbclose’ is used to close the database file. To avoid data missing
or corruption, it is important to close every database file when it is
no longer in use. It is forbidden for multible database objects in a
process to open the same database at the same time.
API
The function ‘tctdberrmsg’ is used in order to get the message string
corresponding to an error code.
const char *tctdberrmsg(int ecode);
‘ecode’ specifies the error code.
The return value is the message string of the error code.
The function ‘tctdbnew’ is used in order to create a table database
object.
TCTDB *tctdbnew(void);
The return value is the new table database object.
The function ‘tctdbdel’ is used in order to delete a table database
object.
void tctdbdel(TCTDB *tdb);
‘tdb’ specifies the table database object.
If the database is not closed, it is closed implicitly.
Note that the deleted object and its derivatives can not
be used anymore.
The function ‘tctdbecode’ is used in order to get the last happened
error code of a table database object.
int tctdbecode(TCTDB *tdb);
‘tdb’ specifies the table database object.
The return value is the last happened error code.
The following error codes are defined: ‘TCESUCCESS’ for
success, ‘TCETHREAD’ for threading error, ‘TCEINVALID’
for invalid operation, ‘TCENOFILE’ for file not found,
‘TCENOPERM’ for no permission, ‘TCEMETA’ for invalid meta
data, ‘TCERHEAD’ for invalid record header, ‘TCEOPEN’ for
open error, ‘TCECLOSE’ for close error, ‘TCETRUNC’ for
trunc error, ‘TCESYNC’ for sync error, ‘TCESTAT’ for stat
error, ‘TCESEEK’ for seek error, ‘TCEREAD’ for read
error, ‘TCEWRITE’ for write error, ‘TCEMMAP’ for mmap
error, ‘TCELOCK’ for lock error, ‘TCEUNLINK’ for unlink
error, ‘TCERENAME’ for rename error, ‘TCEMKDIR’ for mkdir
error, ‘TCERMDIR’ for rmdir error, ‘TCEKEEP’ for existing
record, ‘TCENOREC’ for no record found, and ‘TCEMISC’ for
miscellaneous error.
The function ‘tctdbsetmutex’ is used in order to set mutual exclusion
control of a table database object for threading.
bool tctdbsetmutex(TCTDB *tdb);
‘tdb’ specifies the table database object which is not
opened.
If successful, the return value is true, else, it is
false.
Note that the mutual exclusion control is needed if the
object is shared by plural threads and this function
should be called before the database is opened.
The function ‘tctdbtune’ is used in order to set the tuning parameters
of a table database object.
bool tctdbtune(TCTDB *tdb, int64_t bnum, int8_t apow, int8_t
fpow, uint8_t opts);
‘tdb’ specifies the table database object which is not
opened.
‘bnum’ specifies the number of elements of the bucket
array. If it is not more than 0, the default value is
specified. The default value is 131071. Suggested size
of the bucket array is about from 0.5 to 4 times of the
number of all records to be stored.
‘apow’ specifies the size of record alignment by power of
2. If it is negative, the default value is specified.
The default value is 4 standing for 2^4=16.
‘fpow’ specifies the maximum number of elements of the
free block pool by power of 2. If it is negative, the
default value is specified. The default value is 10
standing for 2^10=1024.
‘opts’ specifies options by bitwise-or: ‘TDBTLARGE’
specifies that the size of the database can be larger
than 2GB by using 64-bit bucket array, ‘TDBTDEFLATE’
specifies that each record is compressed with Deflate
encoding, ‘TDBTBZIP’ specifies that each record is
compressed with BZIP2 encoding, ‘TDBTTCBS’ specifies that
each record is compressed with TCBS encoding.
If successful, the return value is true, else, it is
false.
Note that the tuning parameters should be set before the
database is opened.
The function ‘tctdbsetcache’ is set the caching parameters of a table
database object.
bool tctdbsetcache(TCTDB *tdb, int32_t rcnum, int32_t lcnum,
int32_t ncnum);
‘tdb’ specifies the table database object which is not
opened.
‘rcnum’ specifies the maximum number of records to be
cached. If it is not more than 0, the record cache is
disabled. It is disabled by default.
‘lcnum’ specifies the maximum number of leaf nodes to be
cached. If it is not more than 0, the default value is
specified. The default value is 4096.
‘ncnum’ specifies the maximum number of non-leaf nodes to
be cached. If it is not more than 0, the default value
is specified. The default value is 512.
If successful, the return value is true, else, it is
false.
Note that the caching parameters should be set before the
database is opened. Leaf nodes and non-leaf nodes are
used in column indices.
The function ‘tctdbsetxmsiz’ is used in order to set the size of the
extra mapped memory of a table database object.
bool tctdbsetxmsiz(TCTDB *tdb, int64_t xmsiz);
‘tdb’ specifies the table database object which is not
opened.
‘xmsiz’ specifies the size of the extra mapped memory.
If it is not more than 0, the extra mapped memory is
disabled. The default size is 67108864.
If successful, the return value is true, else, it is
false.
Note that the mapping parameters should be set before the
database is opened.
The function ‘tctdbsetdfunit’ is used in order to set the unit step
number of auto defragmentation of a table database object.
bool tctdbsetdfunit(TCTDB *tdb, int32_t dfunit);
‘tdb’ specifies the table database object which is not
opened.
‘dfunit’ specifie the unit step number. If it is not
more than 0, the auto defragmentation is disabled. It is
disabled by default.
If successful, the return value is true, else, it is
false.
Note that the defragmentation parameters should be set
before the database is opened.
The function ‘tctdbopen’ is used in order to open a database file and
connect a table database object.
bool tctdbopen(TCTDB *tdb, const char *path, int omode);
‘tdb’ specifies the table database object which is not
opened.
‘path’ specifies the path of the database file.
‘omode’ specifies the connection mode: ‘TDBOWRITER’ as a
writer, ‘TDBOREADER’ as a reader. If the mode is
‘TDBOWRITER’, the following may be added by bitwise-or:
‘TDBOCREAT’, which means it creates a new database if not
exist, ‘TDBOTRUNC’, which means it creates a new database
regardless if one exists, ‘TDBOTSYNC’, which means every
transaction synchronizes updated contents with the
device. Both of ‘TDBOREADER’ and ‘TDBOWRITER’ can be
added to by bitwise-or: ‘TDBONOLCK’, which means it opens
the database file without file locking, or ‘TDBOLCKNB’,
which means locking is performed without blocking.
If successful, the return value is true, else, it is
false.
The function ‘tctdbclose’ is used in order to close a table database
object.
bool tctdbclose(TCTDB *tdb);
‘tdb’ specifies the table database object.
If successful, the return value is true, else, it is
false.
Update of a database is assured to be written when the
database is closed. If a writer opens a database but
does not close it appropriately, the database will be
broken.
The function ‘tctdbput’ is used in order to store a record into a table
database object.
bool tctdbput(TCTDB *tdb, const void *pkbuf, int pksiz, TCMAP
*cols);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘cols’ specifies a map object containing columns.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database, it
is overwritten.
The function ‘tctdbput2’ is used in order to store a string record into
a table database object with a zero separated column string.
bool tctdbput2(TCTDB *tdb, const void *pkbuf, int pksiz, const
void *cbuf, int csiz);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘cbuf’ specifies the pointer to the region of the zero
separated column string where the name and the value of
each column are situated one after the other.
‘csiz’ specifies the size of the region of the column
string.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database, it
is overwritten.
The function ‘tctdbput3’ is used in order to store a string record into
a table database object with a tab separated column string.
bool tctdbput3(TCTDB *tdb, const char *pkstr, const char *cstr);
‘tdb’ specifies the table database object connected as a
writer.
‘pkstr’ specifies the string of the primary key.
‘cstr’ specifies the string of the the tab separated
column string where the name and the value of each column
are situated one after the other.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database, it
is overwritten.
The function ‘tctdbputkeep’ is used in order to store a new record into
a table database object.
bool tctdbputkeep(TCTDB *tdb, const void *pkbuf, int pksiz,
TCMAP *cols);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘cols’ specifies a map object containing columns.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database,
this function has no effect.
The function ‘tctdbputkeep2’ is used in order to store a new string
record into a table database object with a zero separated column
string.
bool tctdbputkeep2(TCTDB *tdb, const void *pkbuf, int pksiz,
const void *cbuf, int csiz);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘cbuf’ specifies the pointer to the region of the zero
separated column string where the name and the value of
each column are situated one after the other.
‘csiz’ specifies the size of the region of the column
string.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database,
this function has no effect.
The function ‘tctdbputkeep3’ is used in order to store a new string
record into a table database object with a tab separated column string.
bool tctdbputkeep3(TCTDB *tdb, const char *pkstr, const char
*cstr);
‘tdb’ specifies the table database object connected as a
writer.
‘pkstr’ specifies the string of the primary key.
‘cstr’ specifies the string of the the tab separated
column string where the name and the value of each column
are situated one after the other.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database,
this function has no effect.
The function ‘tctdbputcat’ is used in order to concatenate columns of
the existing record in a table database object.
bool tctdbputcat(TCTDB *tdb, const void *pkbuf, int pksiz, TCMAP
*cols);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘cols’ specifies a map object containing columns.
If successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
The function ‘tctdbputcat2’ is used in order to concatenate columns in
a table database object with a zero separated column string.
bool tctdbputcat2(TCTDB *tdb, const void *pkbuf, int pksiz,
const void *cbuf, int csiz);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘cbuf’ specifies the pointer to the region of the zero
separated column string where the name and the value of
each column are situated one after the other.
‘csiz’ specifies the size of the region of the column
string.
If successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
The function ‘tctdbputcat3’ is used in order to concatenate columns in
a table database object with with a tab separated column string.
bool tctdbputcat3(TCTDB *tdb, const char *pkstr, const char
*cstr);
‘tdb’ specifies the table database object connected as a
writer.
‘pkstr’ specifies the string of the primary key.
‘cstr’ specifies the string of the the tab separated
column string where the name and the value of each column
are situated one after the other.
If successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
The function ‘tctdbout’ is used in order to remove a record of a table
database object.
bool tctdbout(TCTDB *tdb, const void *pkbuf, int pksiz);
‘tdb’ specifies the table database object connected as a
writer.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
If successful, the return value is true, else, it is
false.
The function ‘tctdbout2’ is used in order to remove a string record of
a table database object.
bool tctdbout2(TCTDB *tdb, const char *pkstr);
‘tdb’ specifies the table database object connected as a
writer.
‘pkstr’ specifies the string of the primary key.
If successful, the return value is true, else, it is
false.
The function ‘tctdbget’ is used in order to retrieve a record in a
table database object.
TCMAP *tctdbget(TCTDB *tdb, const void *pkbuf, int pksiz);
‘tdb’ specifies the table database object.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
If successful, the return value is a map object of the
columns of the corresponding record. ‘NULL’ is returned
if no record corresponds.
Because the object of the return value is created with
the function ‘tcmapnew’, it should be deleted with the
function ‘tcmapdel’ when it is no longer in use.
The function ‘tctdbget2’ is used in order to retrieve a record in a
table database object as a zero separated column string.
char *tctdbget2(TCTDB *tdb, const void *pkbuf, int pksiz, int
*sp);
‘tdb’ specifies the table database object.
‘pkbuf’ specifies the pointer to the region of the
primary key.
‘pksiz’ specifies the size of the region of the primary
key.
‘sp’ specifies the pointer to the variable into which the
size of the region of the return value is assigned.
If successful, the return value is the pointer to the
region of the column string of the corresponding record.
‘NULL’ is returned if no record corresponds.
Because an additional zero code is appended at the end of
the region of the return value, the return value can be
treated as a character string. Because the region of the
return value is allocated with the ‘malloc’ call, it
should be released with the ‘free’ call when it is no
longer in use.
The function ‘tctdbget3’ is used in order to retrieve a string record
in a table database object as a tab separated column string.
char *tctdbget3(TCTDB *tdb, const char *pkstr);
‘tdb’ specifies the table database object.
‘pkstr’ specifies the string of the primary key.
If successful, the return value is the tab separated
column string of the corresponding record. ‘NULL’ is
returned if no record corresponds.
Because the region of the return value is allocated with
the ‘malloc’ call, it should be released with the ‘free’
call when it is no longer in use.
The function ‘tctdbvsiz’ is used in order to get the size of the value
of a record in a table database object.
int tctdbvsiz(TCTDB *tdb, const void *pkbuf, int pksiz);
‘tdb’ specifies the table database object.
‘kbuf’ specifies the pointer to the region of the primary
key.
‘ksiz’ specifies the size of the region of the primary
key.
If successful, the return value is the size of the value
of the corresponding record, else, it is -1.
The function ‘tctdbvsiz2’ is used in order to get the size of the value
of a string record in a table database object.
int tctdbvsiz2(TCTDB *tdb, const char *pkstr);
‘tdb’ specifies the table database object.
‘kstr’ specifies the string of the primary key.
If successful, the return value is the size of the value
of the corresponding record, else, it is -1.
The function ‘tctdbiterinit’ is used in order to initialize the
iterator of a table database object.
bool tctdbiterinit(TCTDB *tdb);
‘tdb’ specifies the table database object.
If successful, the return value is true, else, it is
false.
The iterator is used in order to access the primary key
of every record stored in a database.
The function ‘tctdbiternext’ is used in order to get the next primary
key of the iterator of a table database object.
void *tctdbiternext(TCTDB *tdb, int *sp);
‘tdb’ specifies the table database object.
‘sp’ specifies the pointer to the variable into which the
size of the region of the return value is assigned.
If successful, the return value is the pointer to the
region of the next primary key, else, it is ‘NULL’.
‘NULL’ is returned when no record is to be get out of the
iterator.
Because an additional zero code is appended at the end of
the region of the return value, the return value can be
treated as a character string. Because the region of the
return value is allocated with the ‘malloc’ call, it
should be released with the ‘free’ call when it is no
longer in use. It is possible to access every record by
iteration of calling this function. It is allowed to
update or remove records whose keys are fetched while the
iteration. However, it is not assured if updating the
database is occurred while the iteration. Besides, the
order of this traversal access method is arbitrary, so it
is not assured that the order of storing matches the one
of the traversal access.
The function ‘tctdbiternext2’ is used in order to get the next primary
key string of the iterator of a table database object.
char *tctdbiternext2(TCTDB *tdb);
‘tdb’ specifies the table database object.
If successful, the return value is the string of the next
primary key, else, it is ‘NULL’. ‘NULL’ is returned when
no record is to be get out of the iterator.
Because the region of the return value is allocated with
the ‘malloc’ call, it should be released with the ‘free’
call when it is no longer in use. It is possible to
access every record by iteration of calling this
function. However, it is not assured if updating the
database is occurred while the iteration. Besides, the
order of this traversal access method is arbitrary, so it
is not assured that the order of storing matches the one
of the traversal access.
The function ‘tctdbiternext3’ is used in order to get the columns of
the next record of the iterator of a table database object.
TCMAP *tctdbiternext3(TCTDB *tdb);
‘tdb’ specifies the table database object.
If successful, the return value is a map object of the
columns of the next record, else, it is ‘NULL’. ‘NULL’
is returned when no record is to be get out of the
iterator. The primary key is added into the map as a
column of an empty string key.
Because the object of the return value is created with
the function ‘tcmapnew’, it should be deleted with the
function ‘tcmapdel’ when it is no longer in use. It is
possible to access every record by iteration of calling
this function. However, it is not assured if updating
the database is occurred while the iteration. Besides,
the order of this traversal access method is arbitrary,
so it is not assured that the order of storing matches
the one of the traversal access.
The function ‘tctdbfwmkeys’ is used in order to get forward matching
primary keys in a table database object.
TCLIST *tctdbfwmkeys(TCTDB *tdb, const void *pbuf, int psiz, int
max);
‘tdb’ specifies the table database object.
‘pbuf’ specifies the pointer to the region of the prefix.
‘psiz’ specifies the size of the region of the prefix.
‘max’ specifies the maximum number of keys to be fetched.
If it is negative, no limit is specified.
The return value is a list object of the corresponding
keys. This function does never fail. It returns an
empty list even if no key corresponds.
Because the object of the return value is created with
the function ‘tclistnew’, it should be deleted with the
function ‘tclistdel’ when it is no longer in use. Note
that this function may be very slow because every key in
the database is scanned.
The function ‘tctdbfwmkeys2’ is used in order to get forward matching
string primary keys in a table database object.
TCLIST *tctdbfwmkeys2(TCTDB *tdb, const char *pstr, int max);
‘tdb’ specifies the table database object.
‘pstr’ specifies the string of the prefix.
‘max’ specifies the maximum number of keys to be fetched.
If it is negative, no limit is specified.
The return value is a list object of the corresponding
keys. This function does never fail. It returns an
empty list even if no key corresponds.
Because the object of the return value is created with
the function ‘tclistnew’, it should be deleted with the
function ‘tclistdel’ when it is no longer in use. Note
that this function may be very slow because every key in
the database is scanned.
The function ‘tctdbaddint’ is used in order to add an integer to a
column of a record in a table database object.
int tctdbaddint(TCTDB *tdb, const void *pkbuf, int pksiz, int
num);
‘tdb’ specifies the table database object connected as a
writer.
‘kbuf’ specifies the pointer to the region of the primary
key.
‘ksiz’ specifies the size of the region of the primary
key.
‘num’ specifies the additional value.
If successful, the return value is the summation value,
else, it is ‘INT_MIN’.
The additional value is stored as a decimal string value
of a column whose name is "_num". If no record
corresponds, a new record with the additional value is
stored.
The function ‘tctdbadddouble’ is used in order to add a real number to
a column of a record in a table database object.
double tctdbadddouble(TCTDB *tdb, const void *pkbuf, int pksiz,
double num);
‘tdb’ specifies the table database object connected as a
writer.
‘kbuf’ specifies the pointer to the region of the primary
key.
‘ksiz’ specifies the size of the region of the primary
key.
‘num’ specifies the additional value.
If successful, the return value is the summation value,
else, it is Not-a-Number.
The additional value is stored as a decimal string value
of a column whose name is "_num". If no record
corresponds, a new record with the additional value is
stored.
The function ‘tctdbsync’ is used in order to synchronize updated
contents of a table database object with the file and the device.
bool tctdbsync(TCTDB *tdb);
‘tdb’ specifies the table database object connected as a
writer.
If successful, the return value is true, else, it is
false.
This function is useful when another process connects to
the same database file.
The function ‘tctdboptimize’ is used in order to optimize the file of a
table database object.
bool tctdboptimize(TCTDB *tdb, int64_t bnum, int8_t apow, int8_t
fpow, uint8_t opts);
‘tdb’ specifies the table database object connected as a
writer.
‘bnum’ specifies the number of elements of the bucket
array. If it is not more than 0, the default value is
specified. The default value is two times of the number
of records.
‘apow’ specifies the size of record alignment by power of
2. If it is negative, the current setting is not
changed.
‘fpow’ specifies the maximum number of elements of the
free block pool by power of 2. If it is negative, the
current setting is not changed.
‘opts’ specifies options by bitwise-or: ‘TDBTLARGE’
specifies that the size of the database can be larger
than 2GB by using 64-bit bucket array, ‘TDBTDEFLATE’
specifies that each record is compressed with Deflate
encoding, ‘TDBTBZIP’ specifies that each record is
compressed with BZIP2 encoding, ‘TDBTTCBS’ specifies that
each record is compressed with TCBS encoding. If it is
‘UINT8_MAX’, the current setting is not changed.
If successful, the return value is true, else, it is
false.
This function is useful to reduce the size of the
database file with data fragmentation by successive
updating.
The function ‘tctdbvanish’ is used in order to remove all records of a
table database object.
bool tctdbvanish(TCTDB *tdb);
‘tdb’ specifies the table database object connected as a
writer.
If successful, the return value is true, else, it is
false.
The function ‘tctdbcopy’ is used in order to copy the database file of
a table database object.
bool tctdbcopy(TCTDB *tdb, const char *path);
‘tdb’ specifies the table database object.
‘path’ specifies the path of the destination file. If it
begins with ‘@’, the trailing substring is executed as a
command line.
If successful, the return value is true, else, it is
false. False is returned if the executed command returns
non-zero code.
The database file is assured to be kept synchronized and
not modified while the copying or executing operation is
in progress. So, this function is useful to create a
backup file of the database file.
The function ‘tctdbtranbegin’ is used in order to begin the transaction
of a table database object.
bool tctdbtranbegin(TCTDB *tdb);
‘tdb’ specifies the table database object connected as a
writer.
If successful, the return value is true, else, it is
false.
The database is locked by the thread while the
transaction so that only one transaction can be activated
with a database object at the same time. Thus, the
serializable isolation level is assumed if every database
operation is performed in the transaction. Because all
pages are cached on memory while the transaction, the
amount of referred records is limited by the memory
capacity. If the database is closed during transaction,
the transaction is aborted implicitly.
The function ‘tctdbtrancommit’ is used in order to commit the
transaction of a table database object.
bool tctdbtrancommit(TCTDB *tdb);
‘tdb’ specifies the table database object connected as a
writer.
If successful, the return value is true, else, it is
false.
Update in the transaction is fixed when it is committed
successfully.
The function ‘tctdbtranabort’ is used in order to abort the transaction
of a table database object.
bool tctdbtranabort(TCTDB *tdb);
‘tdb’ specifies the table database object connected as a
writer.
If successful, the return value is true, else, it is
false.
Update in the transaction is discarded when it is
aborted. The state of the database is rollbacked to
before transaction.
The function ‘tctdbpath’ is used in order to get the file path of a
table database object.
const char *tctdbpath(TCTDB *tdb);
‘tdb’ specifies the table database object.
The return value is the path of the database file or
‘NULL’ if the object does not connect to any database
file.
The function ‘tctdbrnum’ is used in order to get the number of records
ccccof a table database object.
uint64_t tctdbrnum(TCTDB *tdb);
‘tdb’ specifies the table database object.
The return value is the number of records or 0 if the
object does not connect to any database file.
The function ‘tctdbfsiz’ is used in order to get the size of the
database file of a table database object.
uint64_t tctdbfsiz(TCTDB *tdb);
‘tdb’ specifies the table database object.
The return value is the size of the database file or 0 if
the object does not connect to any database file.
The function ‘tctdbsetindex’ is used in order to set a column index to
a table database object.
bool tctdbsetindex(TCTDB *tdb, const char *name, int type);
‘tdb’ specifies the table database object connected as a
writer.
‘name’ specifies the name of a column. If the name of an
existing index is specified, the index is rebuilt. An
empty string means the primary key.
‘type’ specifies the index type: ‘TDBITLEXICAL’ for
lexical string, ‘TDBITDECIMAL’ for decimal string,
‘TDBITTOKEN’ for token inverted index, ‘TDBITQGRAM’ for
q-gram inverted index. If it is ‘TDBITOPT’, the index is
optimized. If it is ‘TDBITVOID’, the index is removed.
If ‘TDBITKEEP’ is added by bitwise-or and the index
exists, this function merely returns failure.
If successful, the return value is true, else, it is
false.
Note that the setting indices should be set after the
database is opened.
The function ‘tctdbgenuid’ is used in order to generate a unique ID
number of a table database object.
int64_t tctdbgenuid(TCTDB *tdb);
‘tdb’ specifies the table database object connected as a
writer.
The return value is the new unique ID number or -1 on
failure.
The function ‘tctdbqrynew’ is used in order to create a query object.
TDBQRY *tctdbqrynew(TCTDB *tdb);
‘tdb’ specifies the table database object.
The return value is the new query object.
The function ‘tctdbqrydel’ is used in order to delete a query object.
void tctdbqrydel(TDBQRY *qry);
‘qry’ specifies the query object.
The function ‘tctdbqryaddcond’ is used in order to add a narrowing
condition to a query object.
void tctdbqryaddcond(TDBQRY *qry, const char *name, int op,
const char *expr);
‘qry’ specifies the query object.
‘name’ specifies the name of a column. An empty string
means the primary key.
‘op’ specifies an operation type: ‘TDBQCSTREQ’ for string
which is equal to the expression, ‘TDBQCSTRINC’ for
string which is included in the expression, ‘TDBQCSTRBW’
for string which begins with the expression, ‘TDBQCSTREW’
for string which ends with the expression, ‘TDBQCSTRAND’
for string which includes all tokens in the expression,
‘TDBQCSTROR’ for string which includes at least one token
in the expression, ‘TDBQCSTROREQ’ for string which is
equal to at least one token in the expression,
‘TDBQCSTRRX’ for string which matches regular expressions
of the expression, ‘TDBQCNUMEQ’ for number which is equal
to the expression, ‘TDBQCNUMGT’ for number which is
greater than the expression, ‘TDBQCNUMGE’ for number
which is greater than or equal to the expression,
‘TDBQCNUMLT’ for number which is less than the
expression, ‘TDBQCNUMLE’ for number which is less than or
equal to the expression, ‘TDBQCNUMBT’ for number which is
between two tokens of the expression, ‘TDBQCNUMOREQ’ for
number which is equal to at least one token in the
expression, ‘TDBQCFTSPH’ for full-text search with the
phrase of the expression, ‘TDBQCFTSAND’ for full-text
search with all tokens in the expression, ‘TDBQCFTSOR’
for full-text search with at least one token in the
expression, ‘TDBQCFTSEX’ for full-text search with the
compound expression. All operations can be flagged by
bitwise-or: ‘TDBQCNEGATE’ for negation, ‘TDBQCNOIDX’ for
using no index.
‘expr’ specifies an operand exression.
The function ‘tctdbqrysetorder’ is used in order to set the order of a
query object.
void tctdbqrysetorder(TDBQRY *qry, const char *name, int type);
‘qry’ specifies the query object.
‘name’ specifies the name of a column. An empty string
means the primary key.
‘type’ specifies the order type: ‘TDBQOSTRASC’ for string
ascending, ‘TDBQOSTRDESC’ for string descending,
‘TDBQONUMASC’ for number ascending, ‘TDBQONUMDESC’ for
number descending.
The function ‘tctdbqrysetlimit’ is used in order to set the limit
number of records of the result of a query object.
void tctdbqrysetlimit(TDBQRY *qry, int max, int skip);
‘qry’ specifies the query object.
‘max’ specifies the maximum number of records of the
result. If it is negative, no limit is specified.
‘skip’ specifies the number of skipped records of the
result. If it is not more than 0, no record is skipped.
The function ‘tctdbqrysearch’ is used in order to execute the search of
a query object.
TCLIST *tctdbqrysearch(TDBQRY *qry);
‘qry’ specifies the query object.
The return value is a list object of the primary keys of
the corresponding records. This function does never
fail. It returns an empty list even if no record
corresponds.
Because the object of the return value is created with
the function ‘tclistnew’, it should be deleted with the
function ‘tclistdel’ when it is no longer in use.
The function ‘tctdbqrysearchout’ is used in order to remove each record
corresponding to a query object.
bool tctdbqrysearchout(TDBQRY *qry);
‘qry’ specifies the query object of the database
connected as a writer.
If successful, the return value is true, else, it is
false.
The function ‘tctdbqryproc’ is used in order to process each record
corresponding to a query object.
bool tctdbqryproc(TDBQRY *qry, TDBQRYPROC proc, void *op);
‘qry’ specifies the query object of the database
connected as a writer.
‘proc’ specifies the pointer to the iterator function
called for each record. It receives four parameters.
The first parameter is the pointer to the region of the
primary key. The second parameter is the size of the
region of the primary key. The third parameter is a map
object containing columns. The fourth parameter is the
pointer to the optional opaque object. It returns flags
of the post treatment by bitwise-or: ‘TDBQPPUT’ to modify
the record, ‘TDBQPOUT’ to remove the record, ‘TDBQPSTOP’
to stop the iteration.
‘op’ specifies an arbitrary pointer to be given as a
parameter of the iterator function. If it is not needed,
‘NULL’ can be specified.
If successful, the return value is true, else, it is
false.
The function ‘tctdbqryhint’ is used in order to get the hint string of
a query object.
const char *tctdbqryhint(TDBQRY *qry);
‘qry’ specifies the query object.
The return value is the hint string.
The function ‘tctdbmetasearch’ is used in order to retrieve records
with multiple query objects and get the set of the result.
TCLIST *tctdbmetasearch(TDBQRY **qrys, int num, int type);
‘qrys’ specifies an array of the query objects.
‘num’ specifies the number of elements of the array.
‘type’ specifies a set operation type: ‘TDBMSUNION’ for
the union set, ‘TDBMSISECT’ for the intersection set,
‘TDBMSDIFF’ for the difference set.
The return value is a list object of the primary keys of
the corresponding records. This function does never
fail. It returns an empty list even if no record
corresponds.
If the first query object has the order setting, the
result array is sorted by the order. Because the object
of the return value is created with the function
‘tclistnew’, it should be deleted with the function
‘tclistdel’ when it is no longer in use.
SEE ALSO
tcttest(1), tctmttest(1), tctmgr(1), tokyocabinet(3)