API¶
The function `tcbdberrmsg' is used in order to get the message
string corresponding to an error code.
const char *tcbdberrmsg(int ecode);
`ecode' specifies the error code.
The return value is the message string of the error
code.
The function `tcbdbnew' is used in order to create a B+ tree
database object.
TCBDB *tcbdbnew(void);
The return value is the new B+ tree database
object.
The function `tcbdbdel' is used in order to delete a B+ tree
database object.
void tcbdbdel(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbecode' is used in order to get the last
happened error code of a B+ tree database object.
int tcbdbecode(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbsetmutex' is used in order to set mutual
exclusion control of a B+ tree database object for threading.
bool tcbdbsetmutex(TCBDB *bdb);
`bdb' specifies the B+ tree database object which
is not opened.
If successful, the return value is true, else, it is
false.
Note that the mutual exclusion control of the database
should be set before the database is opened.
The function `tcbdbsetcmpfunc' is used in order to set the custom
comparison function of a B+ tree database object.
bool tcbdbsetcmpfunc(TCBDB *bdb, TCCMP cmp, void
*cmpop);
`bdb' specifies the B+ tree database object which
is not opened.
`cmp' specifies the pointer to the custom
comparison function. It receives five parameters. The first parameter is the
pointer to the region of one key. The second parameter is the size of the
region of one key. The third parameter is the pointer to the region of the
other key. The fourth parameter is the size of the region of the other key.
The fifth parameter is the pointer to the optional opaque object. It returns
positive if the former is big, negative if the latter is big, 0 if both are
equivalent.
`cmpop' specifies an arbitrary pointer to be given
as a parameter of the comparison function. If it is not needed, `NULL' can be
specified.
If successful, the return value is true, else, it is
false.
The default comparison function compares keys of two
records by lexical order. The functions `tccmplexical' (default),
`tccmpdecimal', `tccmpint32', and `tccmpint64' are built-in. Note that the
comparison function should be set before the database is opened. Moreover,
user-defined comparison functions should be set every time the database is
being opened.
The function `tcbdbtune' is used in order to set the tuning
parameters of a B+ tree database object.
bool tcbdbtune(TCBDB *bdb, int32_t lmemb, int32_t
nmemb, int64_t bnum, int8_t apow,
int8_t fpow, uint8_t opts);
`bdb' specifies the B+ tree database object which
is not opened.
`lmemb' specifies the number of members in each
leaf page. If it is not more than 0, the default value is specified. The
default value is 128.
`nmemb' specifies the number of members in each
non-leaf page. If it is not more than 0, the default value is specified. The
default value is 256.
`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 16381. Suggested size of the bucket array is about from 1 to
4 times of the number of all pages 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 8 standing for 2^8=256.
`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:
`BDBTLARGE' specifies that the size of the database can be larger than 2GB by
using 64-bit bucket array, `BDBTDEFLATE' specifies that each page is
compressed with Deflate encoding, `BDBTBZIP' specifies that each page is
compressed with BZIP2 encoding, `BDBTTCBS' specifies that each page 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 `tcbdbsetcache' is used in order to set the caching
parameters of a B+ tree database object.
bool tcbdbsetcache(TCBDB *bdb, int32_t lcnum,
int32_t ncnum);
`bdb' specifies the B+ tree database object which
is not opened.
`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 1024.
`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.
The function `tcbdbsetxmsiz' is used in order to set the size of
the extra mapped memory of a B+ tree database object.
bool tcbdbsetxmsiz(TCBDB *bdb, int64_t
xmsiz);
`bdb' specifies the B+ tree 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. It is
disabled by default.
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 `tcbdbsetdfunit' is used in order to set the unit
step number of auto defragmentation of a B+ tree database object.
bool tcbdbsetdfunit(TCBDB *bdb, int32_t
dfunit);
`bdb' specifies the B+ tree 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 parameter should be set
before the database is opened.
The function `tcbdbopen' is used in order to open a database file
and connect a B+ tree database object.
bool tcbdbopen(TCBDB *bdb, const char *path, int
omode);
`bdb' specifies the B+ tree database object which
is not opened.
`path' specifies the path of the database
file.
`omode' specifies the connection mode:
`BDBOWRITER' as a writer, `BDBOREADER' as a reader. If the mode is
`BDBOWRITER', the following may be added by bitwise-or: `BDBOCREAT', which
means it creates a new database if not exist, `BDBOTRUNC', which means it
creates a new database regardless if one exists, `BDBOTSYNC', which means
every transaction synchronizes updated contents with the device. Both of
`BDBOREADER' and `BDBOWRITER' can be added to by bitwise-or: `BDBONOLCK',
which means it opens the database file without file locking, or `BDBOLCKNB',
which means locking is performed without blocking.
If successful, the return value is true, else, it is
false.
The function `tcbdbclose' is used in order to close a B+ tree
database object.
bool tcbdbclose(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbput' is used in order to store a record into a
B+ tree database object.
bool tcbdbput(TCBDB *bdb, const void *kbuf, int
ksiz, const void *vbuf, int
vsiz);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`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 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 `tcbdbput2' is used in order to store a string record
into a B+ tree database object.
bool tcbdbput2(TCBDB *bdb, const char *kstr,
const char *vstr);
`bdb' specifies the B+ tree database object
connected as a writer.
`kstr' specifies the string of the key.
`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.
The function `tcbdbputkeep' is used in order to store a new record
into a B+ tree database object.
bool tcbdbputkeep(TCBDB *bdb, const void *kbuf,
int ksiz, const void *vbuf, int
vsiz);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`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 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 `tcbdbputkeep2' is used in order to store a new
string record into a B+ tree database object.
bool tcbdbputkeep2(TCBDB *bdb, const char *kstr,
const char *vstr);
`bdb' specifies the B+ tree database object
connected as a writer.
`kstr' specifies the string of the key.
`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.
The function `tcbdbputcat' is used in order to concatenate a value
at the end of the existing record in a B+ tree database object.
bool tcbdbputcat(TCBDB *bdb, const void *kbuf,
int ksiz, const void *vbuf, int
vsiz);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`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 successful, the return value is true, else, it is
false.
If there is no corresponding record, a new record is
created.
The function `tcbdbputcat2' is used in order to concatenate a
string value at the end of the existing record in a B+ tree database
object.
bool tcbdbputcat2(TCBDB *bdb, const char *kstr,
const char *vstr);
`bdb' specifies the B+ tree database object
connected as a writer.
`kstr' specifies the string of the key.
`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.
The function `tcbdbputdup' is used in order to store a record into
a B+ tree database object with allowing duplication of keys.
bool tcbdbputdup(TCBDB *bdb, const void *kbuf,
int ksiz, const void *vbuf, int
vsiz);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`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 successful, the return value is true, else, it is
false.
If a record with the same key exists in the database, the
new record is placed after the existing one.
The function `tcbdbputdup2' is used in order to store a string
record into a B+ tree database object with allowing duplication of keys.
bool tcbdbputdup2(TCBDB *bdb, const char *kstr,
const char *vstr);
`bdb' specifies the B+ tree database object
connected as a writer.
`kstr' specifies the string of the key.
`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, the
new record is placed after the existing one.
The function `tcbdbputdup3' is used in order to store records into
a B+ tree database object with allowing duplication of keys.
bool tcbdbputdup3(TCBDB *bdb, const void *kbuf,
int ksiz, const TCLIST *vals);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
common key.
`ksiz' specifies the size of the region of the
common key.
`vals' specifies a list object containing
values.
If successful, the return value is true, else, it is
false.
If a record with the same key exists in the database, the
new records are placed after the existing one.
The function `tcbdbout' is used in order to remove a record of a
B+ tree database object.
bool tcbdbout(TCBDB *bdb, const void *kbuf, int
ksiz);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is true, else, it is
false.
If the key of duplicated records is specified, the first
one is selected.
The function `tcbdbout2' is used in order to remove a string
record of a B+ tree database object.
bool tcbdbout2(TCBDB *bdb, const char *kstr);
`bdb' specifies the B+ tree database object
connected as a writer.
`kstr' specifies the string of the key.
If successful, the return value is true, else, it is
false.
If the key of duplicated records is specified, the first
one is selected.
The function `tcbdbout3' is used in order to remove records of a
B+ tree database object.
bool tcbdbout3(TCBDB *bdb, const void *kbuf, int
ksiz);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is true, else, it is
false.
If the key of duplicated records is specified, all of
them are removed.
The function `tcbdbget' is used in order to retrieve a record in a
B+ tree database object.
void *tcbdbget(TCBDB *bdb, const void *kbuf, int
ksiz, int *sp);
`bdb' specifies the B+ tree database object.
`kbuf' specifies the pointer to the region of the
key.
`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.
If the key of duplicated records is specified, the first
one is selected. 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 `tcbdbget2' is used in order to retrieve a string
record in a B+ tree database object.
char *tcbdbget2(TCBDB *bdb, const char
*kstr);
`bdb' specifies the B+ tree database object.
`kstr' specifies the string of the key.
If successful, the return value is the string of the
value of the corresponding record. `NULL' is returned if no record
corresponds.
If the key of duplicated records is specified, the first
one is selected. 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 `tcbdbget3' is used in order to retrieve a record in
a B+ tree database object as a volatile buffer.
const void *tcbdbget3(TCBDB *bdb, const void
*kbuf, int ksiz, int *sp);
`bdb' specifies the B+ tree database object.
`kbuf' specifies the pointer to the region of the
key.
`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.
If the key of duplicated records is specified, the first
one is selected. 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 volatile and it may be
spoiled by another operation of the database, the data should be copied into
another involatile buffer immediately.
The function `tcbdbget4' is used in order to retrieve records in a
B+ tree database object.
TCLIST *tcbdbget4(TCBDB *bdb, const void *kbuf,
int ksiz);
`bdb' specifies the B+ tree database object.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is a list object of the
values of the corresponding records. `NULL' is returned 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 `tcbdbvnum' is used in order to get the number of
records corresponding a key in a B+ tree database object.
int tcbdbvnum(TCBDB *bdb, const void *kbuf, int
ksiz);
`bdb' specifies the B+ tree database object.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is the number of the
corresponding records, else, it is 0.
The function `tcbdbvnum2' is used in order to get the number of
records corresponding a string key in a B+ tree database object.
int tcbdbvnum2(TCBDB *bdb, const char *kstr);
`bdb' specifies the B+ tree database object.
`kstr' specifies the string of the key.
If successful, the return value is the number of the
corresponding records, else, it is 0.
The function `tcbdbvsiz' is used in order to get the size of the
value of a record in a B+ tree database object.
int tcbdbvsiz(TCBDB *bdb, const void *kbuf, int
ksiz);
`bdb' specifies the B+ tree database object.
`kbuf' specifies the pointer to the region of the
key.
`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.
If the key of duplicated records is specified, the first
one is selected.
The function `tcbdbvsiz2' is used in order to get the size of the
value of a string record in a B+ tree database object.
int tcbdbvsiz2(TCBDB *bdb, const char *kstr);
`bdb' specifies the B+ tree database object.
`kstr' specifies the string of the key.
If successful, the return value is the size of the value
of the corresponding record, else, it is -1.
If the key of duplicated records is specified, the first
one is selected.
The function `tcbdbrange' is used in order to get keys of ranged
records in a B+ tree database object.
TCLIST *tcbdbrange(TCBDB *bdb, const void *bkbuf,
int bksiz, bool binc, const void
*ekbuf, int eksiz, bool einc, int
max);
`bdb' specifies the B+ tree database object.
`bkbuf' specifies the pointer to the region of the
key of the beginning border. If it is `NULL', the first record is
specified.
`bksiz' specifies the size of the region of the
beginning key.
`binc' specifies whether the beginning border is
inclusive or not.
`ekbuf' specifies the pointer to the region of the
key of the ending border. If it is `NULL', the last record is specified.
`eksiz' specifies the size of the region of the
ending key.
`einc' specifies whether the ending border is
inclusive or not.
`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 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 `tcbdbrange2' is used in order to get string keys of
ranged records in a B+ tree database object.
TCLIST *tcbdbrange2(TCBDB *bdb, const char
*bkstr, bool binc, const char
*ekstr, bool einc, int max);
`bdb' specifies the B+ tree database object.
`bkstr' specifies the string of the key of the
beginning border. If it is `NULL', the first record is specified.
`binc' specifies whether the beginning border is
inclusive or not.
`ekstr' specifies the string of the key of the
ending border. If it is `NULL', the last record is specified.
`einc' specifies whether the ending border is
inclusive or not.
`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 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 `tcbdbfwmkeys' is used in order to get forward
matching keys in a B+ tree database object.
TCLIST *tcbdbfwmkeys(TCBDB *bdb, const void
*pbuf, int psiz, int max);
`bdb' specifies the B+ tree 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.
The function `tcbdbfwmkeys2' is used in order to get forward
matching string keys in a B+ tree database object.
TCLIST *tcbdbfwmkeys2(TCBDB *bdb, const char
*pstr, int max);
`bdb' specifies the B+ tree 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.
The function `tcbdbaddint' is used in order to add an integer to a
record in a B+ tree database object.
int tcbdbaddint(TCBDB *bdb, const void *kbuf, int
ksiz, int num);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
`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.
The function `tcbdbadddouble' is used in order to add a real
number to a record in a B+ tree database object.
double tcbdbadddouble(TCBDB *bdb, const void
*kbuf, int ksiz, double num);
`bdb' specifies the B+ tree database object
connected as a writer.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
`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.
The function `tcbdbsync' is used in order to synchronize updated
contents of a B+ tree database object with the file and the device.
bool tcbdbsync(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdboptimize' is used in order to optimize the file
of a B+ tree database object.
bool tcbdboptimize(TCBDB *bdb, int32_t lmemb,
int32_t nmemb, int64_t bnum, int8_t
apow, int8_t fpow, uint8_t
opts);
`bdb' specifies the B+ tree database object
connected as a writer.
`lmemb' specifies the number of members in each
leaf page. If it is not more than 0, the current setting is not changed.
`nmemb' specifies the number of members in each
non-leaf page. If it is not more than 0, the current setting is not
changed.
`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 pages.
`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:
`BDBTLARGE' specifies that the size of the database can be larger than 2GB by
using 64-bit bucket array, `BDBTDEFLATE' specifies that each record is
compressed with Deflate encoding, `BDBTBZIP' specifies that each page is
compressed with BZIP2 encoding, `BDBTTCBS' specifies that each page 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 `tcbdbvanish' is used in order to remove all records
of a B+ tree database object.
bool tcbdbvanish(TCBDB *bdb);
`bdb' specifies the B+ tree database object
connected as a writer.
If successful, the return value is true, else, it is
false.
The function `tcbdbcopy' is used in order to copy the database
file of a B+ tree database object.
bool tcbdbcopy(TCBDB *bdb, const char *path);
`bdb' specifies the B+ tree 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 `tcbdbtranbegin' is used in order to begin the
transaction of a B+ tree database object.
bool tcbdbtranbegin(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbtrancommit' is used in order to commit the
transaction of a B+ tree database object.
bool tcbdbtrancommit(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbtranabort' is used in order to abort the
transaction of a B+ tree database object.
bool tcbdbtranabort(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbpath' is used in order to get the file path of
a B+ tree database object.
const char *tcbdbpath(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbrnum' is used in order to get the number of
records of a B+ tree database object.
uint64_t tcbdbrnum(TCBDB *bdb);
`bdb' specifies the B+ tree database object.
The return value is the number of records or 0 if the
object does not connect to any database file.
The function `tcbdbfsiz' is used in order to get the size of the
database file of a B+ tree database object.
uint64_t tcbdbfsiz(TCBDB *bdb);
`bdb' specifies the B+ tree 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 `tcbdbcurnew' is used in order to create a cursor
object.
BDBCUR *tcbdbcurnew(TCBDB *bdb);
`bdb' specifies the B+ tree database object.
The return value is the new cursor object.
Note that the cursor is available only after
initialization with the `tcbdbcurfirst' or the `tcbdbcurjump' functions and so
on. Moreover, the position of the cursor will be indefinite when the database
is updated after the initialization of the cursor.
The function `tcbdbcurdel' is used in order to delete a cursor
object.
void tcbdbcurdel(BDBCUR *cur);
`cur' specifies the cursor object.
The function `tcbdbcurfirst' is used in order to move a cursor
object to the first record.
bool tcbdbcurfirst(BDBCUR *cur);
`cur' specifies the cursor object.
If successful, the return value is true, else, it is
false. False is returned if there is no record in the database.
The function `tcbdbcurlast' is used in order to move a cursor
object to the last record.
bool tcbdbcurlast(BDBCUR *cur);
`cur' specifies the cursor object.
If successful, the return value is true, else, it is
false. False is returned if there is no record in the database.
The function `tcbdbcurjump' is used in order to move a cursor
object to the front of records corresponding a key.
bool tcbdbcurjump(BDBCUR *cur, const void *kbuf,
int ksiz);
`cur' specifies the cursor object.
`kbuf' specifies the pointer to the region of the
key.
`ksiz' specifies the size of the region of the
key.
If successful, the return value is true, else, it is
false. False is returned if there is no record corresponding the
condition.
The cursor is set to the first record corresponding the
key or the next substitute if completely matching record does not exist.
The function `tcbdbcurjump2' is used in order to move a cursor
object to the front of records corresponding a key string.
bool tcbdbcurjump2(BDBCUR *cur, const char
*kstr);
`cur' specifies the cursor object.
`kstr' specifies the string of the key.
If successful, the return value is true, else, it is
false. False is returned if there is no record corresponding the
condition.
The cursor is set to the first record corresponding the
key or the next substitute if completely matching record does not exist.
The function `tcbdbcurprev' is used in order to move a cursor
object to the previous record.
bool tcbdbcurprev(BDBCUR *cur);
`cur' specifies the cursor object.
If successful, the return value is true, else, it is
false. False is returned if there is no previous record.
The function `tcbdbcurnext' is used in order to move a cursor
object to the next record.
bool tcbdbcurnext(BDBCUR *cur);
`cur' specifies the cursor object.
If successful, the return value is true, else, it is
false. False is returned if there is no next record.
The function `tcbdbcurput' is used in order to insert a record
around a cursor object.
bool tcbdbcurput(BDBCUR *cur, const void *vbuf,
int vsiz, int cpmode);
`cur' specifies the cursor object of writer
connection.
`vbuf' specifies the pointer to the region of the
value.
`vsiz' specifies the size of the region of the
value.
`cpmode' specifies detail adjustment:
`BDBCPCURRENT', which means that the value of the current record is
overwritten, `BDBCPBEFORE', which means that the new record is inserted before
the current record, `BDBCPAFTER', which means that the new record is inserted
after the current record.
If successful, the return value is true, else, it is
false. False is returned when the cursor is at invalid position.
After insertion, the cursor is moved to the inserted
record.
The function `tcbdbcurput2' is used in order to insert a string
record around a cursor object.
bool tcbdbcurput2(BDBCUR *cur, const char *vstr,
int cpmode);
`cur' specifies the cursor object of writer
connection.
`vstr' specifies the string of the value.
`cpmode' specifies detail adjustment:
`BDBCPCURRENT', which means that the value of the current record is
overwritten, `BDBCPBEFORE', which means that the new record is inserted before
the current record, `BDBCPAFTER', which means that the new record is inserted
after the current record.
If successful, the return value is true, else, it is
false. False is returned when the cursor is at invalid position.
After insertion, the cursor is moved to the inserted
record.
The function `tcbdbcurout' is used in order to remove the record
where a cursor object is.
bool tcbdbcurout(BDBCUR *cur);
`cur' specifies the cursor object of writer
connection.
If successful, the return value is true, else, it is
false. False is returned when the cursor is at invalid position.
After deletion, the cursor is moved to the next record if
possible.
The function `tcbdbcurkey' is used in order to get the key of the
record where the cursor object is.
char *tcbdbcurkey(BDBCUR *cur, int *sp);
`cur' specifies the cursor 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 key, else, it is `NULL'. `NULL' is returned when the cursor is
at invalid position.
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 `tcbdbcurkey2' is used in order to get the key string
of the record where the cursor object is.
char *tcbdbcurkey2(BDBCUR *cur);
`cur' specifies the cursor object.
If successful, the return value is the string of the key,
else, it is `NULL'. `NULL' is returned when the cursor is at invalid
position.
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 `tcbdbcurkey3' is used in order to get the key of the
record where the cursor object is, as a volatile buffer.
const char *tcbdbcurkey3(BDBCUR *cur, int
*sp);
`cur' specifies the cursor 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 key, else, it is `NULL'. `NULL' is returned when the cursor is
at invalid position.
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 volatile and it may be
spoiled by another operation of the database, the data should be copied into
another involatile buffer immediately.
The function `tcbdbcurval' is used in order to get the value of
the record where the cursor object is.
char *tcbdbcurval(BDBCUR *cur, int *sp);
`cur' specifies the cursor 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 value, else, it is `NULL'. `NULL' is returned when the cursor is
at invalid position.
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 `tcbdbcurval2' is used in order to get the value
string of the record where the cursor object is.
char *tcbdbcurval2(BDBCUR *cur);
`cur' specifies the cursor object.
If successful, the return value is the string of the
value, else, it is `NULL'. `NULL' is returned when the cursor is at invalid
position.
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 `tcbdbcurval3' is used in order to get the value of
the record where the cursor object is, as a volatile buffer.
const char *tcbdbcurval3(BDBCUR *cur, int
*sp);
`cur' specifies the cursor 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 value, else, it is `NULL'. `NULL' is returned when the cursor is
at invalid position.
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 volatile and it may be
spoiled by another operation of the database, the data should be copied into
another involatile buffer immediately.
The function `tcbdbcurrec' is used in order to get the key and the
value of the record where the cursor object is.
bool tcbdbcurrec(BDBCUR *cur, TCXSTR *kxstr,
TCXSTR *vxstr);
`cur' specifies the cursor object.
`kxstr' specifies the object into which the key is
wrote down.
`vxstr' specifies the object into which the value
is wrote down.
If successful, the return value is true, else, it is
false. False is returned when the cursor is at invalid position.
