table of contents
TCFDB(3) | Tokyo Cabinet | TCFDB(3) |
NAME¶
tcfdb - the fixed-length database APIDESCRIPTION¶
Fixed-length database is a file containing an array of fixed-length elements and is handled with the fixed-length database API. To use the fixed-length database API, include ` tcutil.h', `tcfdb.h', and related standard header files. Usually, write the following description near the front of a source file.API¶
The function `tcfdberrmsg' is used in order to get the message string corresponding to an error code.`ecode' specifies the error code.
The return value is the message string of the error
code.
The return value is the new fixed-length database
object.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length database object
which is not opened.
`width' specifies the width of the value of each
record. If it is not more than 0, the default value is specified. The default
value is 255.
`limsiz' specifies the limit size of the database
file. If it is not more than 0, the default value is specified. The default
value is 268435456.
If successful, the return value is true, else, it is
false.
Note that the tuning parameters should be set before the
database is opened.
`fdb' specifies the fixed-length database object
which is not opened.
`path' specifies the path of the database
file.
`omode' specifies the connection mode:
`FDBOWRITER' as a writer, `FDBOREADER' as a reader. If the mode is
`FDBOWRITER', the following may be added by bitwise-or: `FDBOCREAT', which
means it creates a new database if not exist, `FDBOTRUNC', which means it
creates a new database regardless if one exists, `FDBOTSYNC', which means
every transaction synchronizes updated contents with the device. Both of
`FDBOREADER' and `FDBOWRITER' can be added to by bitwise-or: `FDBONOLCK',
which means it opens the database file without file locking, or `FDBOLCKNB',
which means locking is performed without blocking.
If successful, the return value is true, else, it is
false.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length database object
connected as a writer.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDPREV', the number less by one than the minimum ID
number of existing records is specified. If it is `FDBIDMAX', the maximum ID
number of existing records is specified. If it is `FDBIDNEXT', the number
greater by one than the maximum ID number of existing records is
specified.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value. If the size of the value is greater than the width tuning parameter of
the database, the size is cut down to the width.
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.
`fdb' specifies the fixed-length database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
decimal key. It should be more than 0. If it is "min", the minimum
ID number of existing records is specified. If it is "prev", the
number less by one than the minimum ID number of existing records is
specified. If it is "max", the maximum ID number of existing records
is specified. If it is "next", the number greater by one than the
maximum ID number of existing records is specified.
`ksiz' specifies the size of the region of the
key.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value. If the size of the value is greater than the width tuning parameter of
the database, the size is cut down to the width.
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.
`fdb' specifies the fixed-length database object
connected as a writer.
`kstr' specifies the string of the decimal key. It
should be more than 0. If it is "min", the minimum ID number of
existing records is specified. If it is "prev", the number less by
one than the minimum ID number of existing records is specified. If it is
"max", the maximum ID number of existing records is specified. If it
is "next", the number greater by one than the maximum ID number of
existing records is specified.
`vstr' specifies the string of the value.
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.
`fdb' specifies the fixed-length database object
connected as a writer.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDPREV', the number less by one than the minimum ID
number of existing records is specified. If it is `FDBIDMAX', the maximum ID
number of existing records is specified. If it is `FDBIDNEXT', the number
greater by one than the maximum ID number of existing records is
specified.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value. If the size of the value is greater than the width tuning parameter of
the database, the size is cut down to the width.
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.
`fdb' specifies the fixed-length database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
decimal key. It should be more than 0. If it is "min", the minimum
ID number of existing records is specified. If it is "prev", the
number less by one than the minimum ID number of existing records is
specified. If it is "max", the maximum ID number of existing records
is specified. If it is "next", the number greater by one than the
maximum ID number of existing records is specified.
`ksiz' specifies the size of the region of the
key.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value. If the size of the value is greater than the width tuning parameter of
the database, the size is cut down to the width.
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.
`fdb' specifies the fixed-length database object
connected as a writer.
`kstr' specifies the string of the decimal key. It
should be more than 0. If it is "min", the minimum ID number of
existing records is specified. If it is "prev", the number less by
one than the minimum ID number of existing records is specified. If it is
"max", the maximum ID number of existing records is specified. If it
is "next", the number greater by one than the maximum ID number of
existing records is specified.
`vstr' specifies the string of the value.
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.
`fdb' specifies the fixed-length database object
connected as a writer.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDPREV', the number less by one than the minimum ID
number of existing records is specified. If it is `FDBIDMAX', the maximum ID
number of existing records is specified. If it is `FDBIDNEXT', the number
greater by one than the maximum ID number of existing records is
specified.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value. If the size of the value is greater than the width tuning parameter of
the database, the size is cut down to the width.
If successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
`fdb' specifies the fixed-length database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
decimal key. It should be more than 0. If it is "min", the minimum
ID number of existing records is specified. If it is "prev", the
number less by one than the minimum ID number of existing records is
specified. If it is "max", the maximum ID number of existing records
is specified. If it is "next", the number greater by one than the
maximum ID number of existing records is specified.
`ksiz' specifies the size of the region of the
key.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value. If the size of the value is greater than the width tuning parameter of
the database, the size is cut down to the width.
If successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
`fdb' specifies the fixed-length database object
connected as a writer.
`kstr' specifies the string of the decimal key. It
should be more than 0. If it is "min", the minimum ID number of
existing records is specified. If it is "prev", the number less by
one than the minimum ID number of existing records is specified. If it is
"max", the maximum ID number of existing records is specified. If it
is "next", the number greater by one than the maximum ID number of
existing records is specified.
`vstr' specifies the string of the value.
If successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
`fdb' specifies the fixed-length database object
connected as a writer.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDMAX', the maximum ID number of existing records is
specified.
If successful, the return value is true, else, it is
false.
`fdb' specifies the fixed-length database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
decimal key. It should be more than 0. If it is "min", the minimum
ID number of existing records is specified. If it is "max", the
maximum ID number of existing records is specified.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is true, else, it is
false.
`fdb' specifies the fixed-length database object
connected as a writer.
`kstr' specifies the string of the decimal key. It
should be more than 0. If it is "min", the minimum ID number of
existing records is specified. If it is "max", the maximum ID number
of existing records is specified.
If successful, the return value is true, else, it is
false.
`fdb' specifies the fixed-length database
object.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDMAX', the maximum ID number of existing records is
specified.
`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 value 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.
`fdb' specifies the fixed-length database
object.
`kbuf' specifies the pointer to the region of the
decimal key. It should be more than 0. If it is "min", the minimum
ID number of existing records is specified. If it is "max", the
maximum ID number of existing records is specified.
`ksiz' specifies the size of the region of the
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 value 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.
`fdb' specifies the fixed-length database
object.
`kstr' specifies the string of the decimal key. It
should be more than 0. If it is "min", the minimum ID number of
existing records is specified. If it is "max", the maximum ID number
of existing records is specified.
If successful, the return value is the string of the
value 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.
`fdb' specifies the fixed-length database
object.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDMAX', the maximum ID number of existing records is
specified.
`vbuf' specifies the pointer to the buffer into
which the value of the corresponding record is written.
`max' specifies the size of the buffer.
If successful, the return value is the size of the
written data, else, it is -1. -1 is returned if no record corresponds to the
specified key.
Note that an additional zero code is not appended at the
end of the region of the writing buffer.
`fdb' specifies the fixed-length database
object.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDMAX', the maximum ID number of existing records is
specified.
If successful, the return value is the size of the value
of the corresponding record, else, it is -1.
`fdb' specifies the fixed-length database
object.
`kbuf' specifies the pointer to the region of the
decimal key. It should be more than 0. If it is "min", the minimum
ID number of existing records is specified. If it is "max", the
maximum ID number of existing records is specified.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is the size of the value
of the corresponding record, else, it is -1.
`fdb' specifies the fixed-length database
object.
`kstr' specifies the string of the decimal key. It
should be more than 0. If it is "min", the minimum ID number of
existing records is specified. If it is "max", the maximum ID number
of existing records is specified.
If successful, the return value is the size of the value
of the corresponding record, else, it is -1.
`fdb' specifies the fixed-length database
object.
If successful, the return value is true, else, it is
false.
The iterator is used in order to access the key of every
record stored in a database.
`fdb' specifies the fixed-length database
object.
If successful, the return value is the next ID number of
the iterator, else, it is 0. 0 is returned when no record is to be get out of
the iterator.
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. The order of this traversal access method is
ascending of the ID number.
`fdb' specifies the fixed-length 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 decimal 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. The order of this traversal access method is ascending of the ID
number.
`fdb' specifies the fixed-length database
object.
If successful, the return value is the string of the next
decimal 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. It is allowed to update or remove records whose keys are
fetched while the iteration. The order of this traversal access method is
ascending of the ID number.
`fdb' specifies the fixed-length database
object.
`lower' specifies the lower limit of the range. If
it is `FDBIDMIN', the minimum ID is specified.
`upper' specifies the upper limit of the range. If
it is `FDBIDMAX', the maximum ID is specified.
`max' specifies the maximum number of keys to be
fetched. If it is negative, no limit is specified.
`np' specifies the pointer to the variable into
which the number of elements of the return value is assigned.
If successful, the return value is the pointer to an
array of ID numbers of the corresponding records. `NULL' is returned on
failure. This function does never fail. It returns an empty array even if no
key 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.
`fdb' specifies the fixed-length database
object.
`lbuf' specifies the pointer to the region of the
lower key. If it is "min", the minimum ID number of existing records
is specified.
`lsiz' specifies the size of the region of the
lower key.
`ubuf' specifies the pointer to the region of the
upper key. If it is "max", the maximum ID number of existing records
is specified.
`usiz' specifies the size of the region of the
upper key.
`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
decimal 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.
`fdb' specifies the fixed-length database
object.
`lstr' specifies the string of the lower key. If
it is "min", the minimum ID number of existing records is
specified.
`ustr' specifies the string of the upper key. If
it is "max", the maximum ID number of existing records is
specified.
`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
decimal 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.
`fdb' specifies the fixed-length database
object.
`ibuf' specifies the pointer to the region of the
interval notation.
`isiz' specifies the size of the region of the
interval notation.
`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
decimal 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.
`fdb' specifies the fixed-length database
object.
`istr' specifies the pointer to the region of the
interval notation string.
`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
decimal 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.
`fdb' specifies the fixed-length database object
connected as a writer.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDPREV', the number less by one than the minimum ID
number of existing records is specified. If it is `FDBIDMAX', the maximum ID
number of existing records is specified. If it is `FDBIDNEXT', the number
greater by one than the maximum ID number of existing records is
specified.
`num' specifies the additional value.
If successful, the return value is the summation value,
else, it is `INT_MIN'.
If the corresponding record exists, the value is treated
as an integer and is added to. If no record corresponds, a new record of the
additional value is stored.
`fdb' specifies the fixed-length database object
connected as a writer.
`id' specifies the ID number. It should be more
than 0. If it is `FDBIDMIN', the minimum ID number of existing records is
specified. If it is `FDBIDPREV', the number less by one than the minimum ID
number of existing records is specified. If it is `FDBIDMAX', the maximum ID
number of existing records is specified. If it is `FDBIDNEXT', the number
greater by one than the maximum ID number of existing records is
specified.
`num' specifies the additional value.
If successful, the return value is the summation value,
else, it is Not-a-Number.
If the corresponding record exists, the value is treated
as a real number and is added to. If no record corresponds, a new record of
the additional value is stored.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length database object
connected as a writer.
`width' specifies the width of the value of each
record. If it is not more than 0, the current setting is not changed.
`limsiz' specifies the limit size of the database
file. If it is not more than 0, the current setting is not changed.
If successful, the return value is true, else, it is
false.
`fdb' specifies the fixed-length database object
connected as a writer.
If successful, the return value is true, else, it is
false.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length 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. All updated regions
are kept track of by write ahead logging while the transaction. If the
database is closed during transaction, the transaction is aborted
implicitly.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length 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.
`fdb' specifies the fixed-length database
object.
The return value is the path of the database file or
`NULL' if the object does not connect to any database file.
`fdb' specifies the fixed-length database
object.
The return value is the number of records or 0 if the
object does not connect to any database file.
`fdb' specifies the fixed-length database
object.
The return value is the size of the database file or 0 if
the object does not connect to any database file.
SEE ALSO¶
tcftest(1), tcfmttest(1), tcfmgr(1), tokyocabinet(3)2012-08-18 | Man Page |