leo_backend_db_server¶
The gen_server process for the process of database as part of a supervision tree.
Behaviours: `gen_server <gen_server.html>`__.
References
Description¶
The gen_server process for the process of database as part of a supervision tree
Function Index¶
close/1 | Close the database. |
code_change/3 | Convert process state when code is changed. |
delete/2 | Delete an object from backend-db. |
fetch/4 | Fetch records from backend-db. |
finish_compaction/2 | Direct to end a compaction. |
first/1 | Retrieve a first record from backend-db. |
get/2 | Retrieve an object from backend-db. |
get_db_raw_filepath/1 | get database file path for calculating disk size. |
handle_call/3 | gen_server callback - Module:handle_call(Request, From, State) -> Result. |
handle_cast/2 | gen_server callback - Module:handle_cast(Request, State) -> Result. |
handle_info/2 | gen_server callback - Module:handle_info(Info, State) -> Result. |
init/1 | gen_server callback - Module:init(Args) -> Result. |
put/3 | Insert an object into backend-db. |
put_value_to_new_db/3 | Direct to put a record to a temporary new data file. |
run_compaction/1 | Direct to start a compaction. |
start_link/3 | Creates the gen_server process as part of a supervision tree. |
status/1 | Retrieve the current status from the database. |
stop/1 | Close the process. |
terminate/2 | This function is called by a gen_server when it is about to terminate. |
Function Details¶
code_change/3¶
code_change(OldVsn, State, Extra) -> any()
Convert process state when code is changed
gen_server callback - Module:code_change(OldVsn, State, Extra) -> {ok, NewState} | {error, Reason}.
delete/2¶
Delete an object from backend-db.
fetch/4¶
fetch(Id, KeyBin, Fun, MaxKeys) -> {ok, list()} | not_found | {error, any()}
- Id = atom()
- KeyBin = binary()
- Fun = function()
- MaxKeys = integer()
Fetch records from backend-db.
finish_compaction/2¶
finish_compaction(Id, Commit) -> ok | {error, any()}
- Id = atom()
- Commit = boolean()
Direct to end a compaction.
first/1¶
first(Id) -> {ok, any(), any()} | {error, any()}
- Id = atom()
Retrieve a first record from backend-db.
get/2¶
get(Id, KeyBin) -> {ok, binary()} | not_found | {error, any()}
- Id = atom()
- KeyBin = binary()
Retrieve an object from backend-db.
get_db_raw_filepath/1¶
get_db_raw_filepath(Id) -> {ok, string()} | {error, any()}
- Id = atom()
get database file path for calculating disk size.
handle_call/3¶
handle_call(X1, From, State) -> any()
gen_server callback - Module:handle_call(Request, From, State) -> Result
handle_cast/2¶
handle_cast(Msg, State) -> any()
gen_server callback - Module:handle_cast(Request, State) -> Result
handle_info/2¶
handle_info(Info, State) -> any()
gen_server callback - Module:handle_info(Info, State) -> Result
put/3¶
put(Id, KeyBin, ValueBin) -> ok | {error, any()}
- Id = atom()
- KeyBin = binary()
- ValueBin = binary()
Insert an object into backend-db.
put_value_to_new_db/3¶
put_value_to_new_db(Id, KeyBin, ValueBin) -> ok | {error, any()}
- Id = atom()
- KeyBin = binary()
- ValueBin = binary()
Direct to put a record to a temporary new data file.
run_compaction/1¶
run_compaction(Id) -> ok | {error, any()}
- Id = atom()
Direct to start a compaction.
start_link/3¶
start_link(Id, DBModule, Path) -> {ok, pid()} | ignore | {error, any()}
- Id = atom()
- DBModule = atom()
- Path = string()
Creates the gen_server process as part of a supervision tree
status/1¶
status(Id) -> [{atom(), term()}]
- Id = atom()
Retrieve the current status from the database
terminate/2¶
terminate(Reason, State) -> any()
This function is called by a gen_server when it is about to terminate. It should be the opposite of Module:init/1 and do any necessary cleaning up. When it returns, the gen_server terminates with Reason. The return value is ignored.
gen_server callback - Module:terminate(Reason, State)