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Public Member Functions | Friends
kyototycoon::RemoteDB::Cursor Class Reference

Cursor to indicate a record. More...

`#include <ktremotedb.h>`

List of all members.

## Public Member Functions

| Cursor (RemoteDB *db)
| Constructor.
virtual | ~Cursor ()
| Destructor.
bool | jump ()
| Jump the cursor to the first record for forward scan.
bool | jump (const char *kbuf, size_t ksiz)
| Jump the cursor to a record for forward scan.
bool | jump (const std::string &key)
| Jump the cursor to a record for forward scan.
bool | jump_back ()
| Jump the cursor to the last record for backward scan.
bool | jump_back (const char *kbuf, size_t ksiz)
| Jump the cursor to a record for backward scan.
bool | jump_back (const std::string &key)
| Jump the cursor to a record for backward scan.
bool | step ()
| Step the cursor to the next record.
bool | step_back ()
| Step the cursor to the previous record.
bool | set_value (const char *vbuf, size_t vsiz, int64_t xt=kc::INT64MAX, bool step=false)
| Set the value of the current record.
bool | set_value_str (const std::string &value, int64_t xt=kc::INT64MAX, bool step=false)
| Set the value of the current record.
bool | remove ()
| Remove the current record.
char * | get_key (size_t *sp, bool step=false)
| Get the key of the current record.
bool | get_key (std::string *key, bool step=false)
| Get the key of the current record.
char * | get_value (size_t *sp, bool step=false)
| Get the value of the current record.
bool | get_value (std::string *value, bool step=false)
| Get the value of the current record.
char * | get (size_t *ksp, const char **vbp, size_t *vsp, int64_t *xtp=NULL, bool step=false)
| Get a pair of the key and the value of the current record.
bool | get (std::string *key, std::string *value, int64_t *xtp=NULL, bool step=false)
| Get a pair of the key and the value of the current record.
char * | seize (size_t *ksp, const char **vbp, size_t *vsp, int64_t *xtp=NULL)
| Get a pair of the key and the value of the current record and remove it atomically.
bool | seize (std::string *key, std::string *value, int64_t *xtp=NULL)
| Get a pair of the key and the value of the current record and remove it atomically.
RemoteDB * | db ()
| Get the database object.
Error | error ()
| Get the last happened error.

## Friends

class | RemoteDB

## Detailed Description

Cursor to indicate a record.

## Constructor & Destructor Documentation

kyototycoon::RemoteDB::Cursor::Cursor | ( | RemoteDB * | db | ) | `[explicit]`

Constructor.

Parameters:

  db | the container database object.

virtual kyototycoon::RemoteDB::Cursor::~Cursor | ( |  | ) | `[virtual]`

Destructor.

## Member Function Documentation

bool kyototycoon::RemoteDB::Cursor::jump | ( |  | ) |

Jump the cursor to the first record for forward scan.

Returns:
  true on success, or false on failure.

bool kyototycoon::RemoteDB::Cursor::jump | ( | const char * | kbuf,
|  | size_t | ksiz
| ) |  |

Jump the cursor to a record for forward scan.

Parameters:

  kbuf | the pointer to the key region.
  ksiz | the size of the key region.

Returns:
  true on success, or false on failure.

bool kyototycoon::RemoteDB::Cursor::jump | ( | const std::string & | key | ) |

Jump the cursor to a record for forward scan.

Note:
  Equal to the original Cursor::jump method except that the parameter is std::string.

bool kyototycoon::RemoteDB::Cursor::jump_back | ( |  | ) |

Jump the cursor to the last record for backward scan.

Returns:
  true on success, or false on failure.

Note:
  This method is dedicated to tree databases. Some database types, especially hash databases, may provide a dummy implementation.

bool kyototycoon::RemoteDB::Cursor::jump_back | ( | const char * | kbuf,
|  | size_t | ksiz
| ) |  |

Jump the cursor to a record for backward scan.

Parameters:

  kbuf | the pointer to the key region.
  ksiz | the size of the key region.

Returns:
  true on success, or false on failure.

Note:
  This method is dedicated to tree databases. Some database types, especially hash databases, will provide a dummy implementation.

bool kyototycoon::RemoteDB::Cursor::jump_back | ( | const std::string & | key | ) |

Jump the cursor to a record for backward scan.

Note:
  Equal to the original Cursor::jump_back method except that the parameter is std::string.

bool kyototycoon::RemoteDB::Cursor::step | ( |  | ) |

Step the cursor to the next record.

Returns:
  true on success, or false on failure.

bool kyototycoon::RemoteDB::Cursor::step_back | ( |  | ) |

Step the cursor to the previous record.

Returns:
  true on success, or false on failure.

Note:
  This method is dedicated to tree databases. Some database types, especially hash databases, may provide a dummy implementation.

bool kyototycoon::RemoteDB::Cursor::set_value | ( | const char * | vbuf,
|  | size_t | vsiz,
|  | int64_t | xt = `kc::INT64MAX`,
|  | bool | step = `false`
| ) |  |

Set the value of the current record.

Parameters:

  vbuf | the pointer to the value region.
  vsiz | the size of the value region.
  xt | the expiration time from now in seconds. If it is negative, the absolute value is treated as the epoch time.
  step | true to move the cursor to the next record, or false for no move.

Returns:
  true on success, or false on failure.

bool kyototycoon::RemoteDB::Cursor::set_value_str | ( | const std::string & | value,
|  | int64_t | xt = `kc::INT64MAX`,
|  | bool | step = `false`
| ) |  |

Set the value of the current record.

Note:
  Equal to the original Cursor::set_value method except that the parameter is std::string.

bool kyototycoon::RemoteDB::Cursor::remove | ( |  | ) |

Remove the current record.

Returns:
  true on success, or false on failure.

Note:
  If no record corresponds to the key, false is returned. The cursor is moved to the next record implicitly.

char* kyototycoon::RemoteDB::Cursor::get_key | ( | size_t * | sp,
|  | bool | step = `false`
| ) |  |

Get the key of the current record.

Parameters:

  sp | the pointer to the variable into which the size of the region of the return value is assigned.
  step | true to move the cursor to the next record, or false for no move.

Returns:
  the pointer to the key region of the current record, or NULL on failure.

Note:
  If the cursor is invalidated, NULL is returned. 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 C-style string. Because the region of the return value is allocated with the the new[] operator, it should be released with the delete[] operator when it is no longer in use.

bool kyototycoon::RemoteDB::Cursor::get_key | ( | std::string * | key,
|  | bool | step = `false`
| ) |  |

Get the key of the current record.

Note:
  Equal to the original Cursor::get_key method except that a parameter is a string to contain the result and the return value is bool for success.

char* kyototycoon::RemoteDB::Cursor::get_value | ( | size_t * | sp,
|  | bool | step = `false`
| ) |  |

Get the value of the current record.

Parameters:

  sp | the pointer to the variable into which the size of the region of the return value is assigned.
  step | true to move the cursor to the next record, or false for no move.

Returns:
  the pointer to the value region of the current record, or NULL on failure.

Note:
  If the cursor is invalidated, NULL is returned. 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 C-style string. Because the region of the return value is allocated with the the new[] operator, it should be released with the delete[] operator when it is no longer in use.

bool kyototycoon::RemoteDB::Cursor::get_value | ( | std::string * | value,
|  | bool | step = `false`
| ) |  |

Get the value of the current record.

Note:
  Equal to the original Cursor::get_value method except that a parameter is a string to contain the result and the return value is bool for success.

char* kyototycoon::RemoteDB::Cursor::get | ( | size_t * | ksp,
|  | const char ** | vbp,
|  | size_t * | vsp,
|  | int64_t * | xtp = `NULL`,
|  | bool | step = `false`
| ) |  |

Get a pair of the key and the value of the current record.

Parameters:

  ksp | the pointer to the variable into which the size of the region of the return value is assigned.
  vbp | the pointer to the variable into which the pointer to the value region is assigned.
  vsp | the pointer to the variable into which the size of the value region is assigned.
  xtp | the pointer to the variable into which the absolute expiration time is assigned. If it is NULL, it is ignored.
  step | true to move the cursor to the next record, or false for no move.

Returns:
  the pointer to the pair of the key region, or NULL on failure.

Note:
  If the cursor is invalidated, NULL is returned. Because an additional zero code is appended at the end of each region of the key and the value, each region can be treated as a C-style string. The return value should be deleted explicitly by the caller with the detele[] operator.

bool kyototycoon::RemoteDB::Cursor::get | ( | std::string * | key,
|  | std::string * | value,
|  | int64_t * | xtp = `NULL`,
|  | bool | step = `false`
| ) |  |

Get a pair of the key and the value of the current record.

Note:
  Equal to the original Cursor::get method except that parameters are strings to contain the result and the return value is bool for success.

char* kyototycoon::RemoteDB::Cursor::seize | ( | size_t * | ksp,
|  | const char ** | vbp,
|  | size_t * | vsp,
|  | int64_t * | xtp = `NULL`
| ) |  |

Get a pair of the key and the value of the current record and remove it atomically.

Parameters:

  ksp | the pointer to the variable into which the size of the region of the return value is assigned.
  vbp | the pointer to the variable into which the pointer to the value region is assigned.
  vsp | the pointer to the variable into which the size of the value region is assigned.
  xtp | the pointer to the variable into which the absolute expiration time is assigned. If it is NULL, it is ignored.

Returns:
  the pointer to the pair of the key region, or NULL on failure.

Note:
  If the cursor is invalidated, NULL is returned. Because an additional zero code is appended at the end of each region of the key and the value, each region can be treated as a C-style string. The return value should be deleted explicitly by the caller with the detele[] operator. The cursor is moved to the next record implicitly.

bool kyototycoon::RemoteDB::Cursor::seize | ( | std::string * | key,
|  | std::string * | value,
|  | int64_t * | xtp = `NULL`
| ) |  |

Get a pair of the key and the value of the current record and remove it atomically.

Note:
  Equal to the original Cursor::seize method except that parameters are strings to contain the result and the return value is bool for success.

RemoteDB* kyototycoon::RemoteDB::Cursor::db | ( |  | ) |

Get the database object.

Returns:
  the database object.

Error kyototycoon::RemoteDB::Cursor::error | ( |  | ) |

Get the last happened error.

Returns:
  the last happened error.