tcbdb.h

高性能嵌入式数据库在高并发的环境下使用最好是64位系统比较好

   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. */
double tcbdbadddouble(TCBDB *bdb, const void *kbuf, int ksiz, double num);


/* Synchronize updated contents of a B+ tree database object with the file and the device.
   `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. */
bool tcbdbsync(TCBDB *bdb);


/* Optimize the file of a B+ tree database object.
   `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. */
bool tcbdboptimize(TCBDB *bdb, int32_t lmemb, int32_t nmemb,
                   int64_t bnum, int8_t apow, int8_t fpow, uint8_t opts);


/* Remove all records of a B+ tree database object.
   `bdb' specifies the B+ tree database object connected as a writer.
   If successful, the return value is true, else, it is false. */
bool tcbdbvanish(TCBDB *bdb);


/* Copy the database file of a B+ tree database object.
   `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. */
bool tcbdbcopy(TCBDB *bdb, const char *path);


/* Begin the transaction of a B+ tree database object.
   `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. */
bool tcbdbtranbegin(TCBDB *bdb);


/* Commit the transaction of a B+ tree database object.
   `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. */
bool tcbdbtrancommit(TCBDB *bdb);


/* Abort the transaction of a B+ tree database object.
   `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. */
bool tcbdbtranabort(TCBDB *bdb);


/* Get the file path of a B+ tree database object.
   `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. */
const char *tcbdbpath(TCBDB *bdb);


/* Get the number of records of a B+ tree database object.
   `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. */
uint64_t tcbdbrnum(TCBDB *bdb);


/* Get the size of the database file of a B+ tree database object.
   `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. */
uint64_t tcbdbfsiz(TCBDB *bdb);


/* Create a cursor object.
   `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. */
BDBCUR *tcbdbcurnew(TCBDB *bdb);


/* Delete a cursor object.
   `cur' specifies the cursor object. */
void tcbdbcurdel(BDBCUR *cur);


/* Move a cursor object to the first record.
   `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. */
bool tcbdbcurfirst(BDBCUR *cur);


/* Move a cursor object to the last record.
   `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. */
bool tcbdbcurlast(BDBCUR *cur);


/* Move a cursor object to the front of records corresponding a key.
   `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. */
bool tcbdbcurjump(BDBCUR *cur, const void *kbuf, int ksiz);


/* Move a cursor object to the front of records corresponding a key string.
   `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. */
bool tcbdbcurjump2(BDBCUR *cur, const char *kstr);


/* Move a cursor object to the previous record.
   `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. */
bool tcbdbcurprev(BDBCUR *cur);


/* Move a cursor object to the next record.
   `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. */
bool tcbdbcurnext(BDBCUR *cur);


/* Insert a record around a cursor object.
   `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. */
bool tcbdbcurput(BDBCUR *cur, const void *vbuf, int vsiz, int cpmode);


/* Insert a string record around a cursor object.
   `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. */
bool tcbdbcurput2(BDBCUR *cur, const char *vstr, int cpmode);


/* Remove the record where a cursor object is.
   `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. */
bool tcbdbcurout(BDBCUR *cur);


/* Get the key of the record where the cursor object is.
   `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. */
char *tcbdbcurkey(BDBCUR *cur, int *sp);


/* Get the key string of the record where the cursor object is.
   `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. */
char *tcbdbcurkey2(BDBCUR *cur);


/* Get the key of the record where the cursor object is, as a volatile buffer.
   `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. */
const char *tcbdbcurkey3(BDBCUR *cur, int *sp);


/* Get the value of the record where the cursor object is.
   `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. */
char *tcbdbcurval(BDBCUR *cur, int *sp);


/* Get the value string of the record where the cursor object is.
   `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. */
char *tcbdbcurval2(BDBCUR *cur);


/* Get the value of the record where the cursor object is, as a volatile buffer.
   `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. */
const char *tcbdbcurval3(BDBCUR *cur, int *sp);


/* Get the key and the value of the record where the cursor object is.
   `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.