#include <chert_cursor.h>
Inheritance diagram for MutableChertCursor:
Collaboration diagram for MutableChertCursor:
Public Member Functions | |
| MutableChertCursor (ChertTable *B_) | |
| Create a mutable cursor attached to a Btree. More... | |
| bool | del () |
| Delete the current key/tag pair, leaving the cursor on the next entry. More... | |
| Public Member Functions inherited from ChertCursor | |
| ChertCursor (const ChertTable *B) | |
| Create a cursor attached to a Btree. More... | |
| ~ChertCursor () | |
| Destroy the ChertCursor. More... | |
| bool | read_tag (bool keep_compressed=false) |
| Read the tag from the table and store it in current_tag. More... | |
| bool | next () |
| Advance to the next key. More... | |
| bool | prev () |
| Move to the previous key. More... | |
| bool | find_entry (const string &key) |
| Position the cursor on the highest entry with key <= key. More... | |
| void | find_entry_lt (const string &key) |
| Position the cursor on the highest entry with key < key. More... | |
| bool | find_entry_ge (const string &key) |
| Position the cursor on the lowest entry with key >= key. More... | |
| void | to_end () |
| Set the cursor to be off the end of the table. More... | |
| bool | after_end () const |
| Determine whether cursor is off the end of table. More... | |
| const ChertTable * | get_table () const |
| Return a pointer to the ChertTable we're a cursor for. More... | |
Additional Inherited Members | |
| Public Attributes inherited from ChertCursor | |
| string | current_key |
| Current key pointed to by cursor. More... | |
| string | current_tag |
| Current tag pointed to by cursor. More... | |
| Protected Attributes inherited from ChertCursor | |
| bool | is_positioned |
| Whether the cursor is positioned at a valid entry. More... | |
| bool | is_after_end |
| Whether the cursor is off the end of the table. More... | |
| const ChertTable * | B |
| The Btree table. More... | |
Detailed Description
Definition at line 244 of file chert_cursor.h.
Constructor & Destructor Documentation
◆ MutableChertCursor()
|
inlineexplicit |
Create a mutable cursor attached to a Btree.
A mutable cursor allows the items to be deleted.
Creates a cursor, which can be used to remember a position inside the B-tree. The position is simply the item (key and tag) to which the cursor points. A cursor is either positioned or unpositioned, and is initially unpositioned.
NB: You must not try to use a MutableChertCursor after the Btree it is attached to is destroyed. It's safe to destroy the MutableChertCursor after the Btree though, you just may not use the MutableChertCursor.
Definition at line 259 of file chert_cursor.h.
Member Function Documentation
◆ del()
| bool MutableChertCursor::del | ( | ) |
Delete the current key/tag pair, leaving the cursor on the next entry.
- Returns
- false if the cursor ends up unpositioned.
Definition at line 316 of file chert_cursor.cc.
References Assert, ChertCursor::B, ChertCursor::current_key, ChertCursor::find_entry_ge(), ChertCursor::is_after_end, ChertCursor::is_positioned, and ChertCursor::next().
Referenced by ChertPostListTable::merge_changes().
The documentation for this class was generated from the following files:
- backends/chert/chert_cursor.h
- backends/chert/chert_cursor.cc