Module leo_backend_db_api

Description
Function Index
Function Details

leo_backend_db's API.

References

https://github.com/leo-project/leo_backend_db/blob/master/src/leo_backend_db_api.erl

Description

leo_backend_db's API

Function Index

count/1	Count the number of records from backend-db.
delete/2	Delete an object from backend-db.
fetch/3	Fetch objects from backend-db by key with function.
fetch/4
finish_compaction/2	End the data-compaction.
first/1	Retrieve a first record from backend-db.
first_n/2	Fetch first N records from backend-db.
first_n/3
get/2	Retrieve an object from backend-db.
get_db_raw_filepath/1	get the database filepath for calculating disk size.
has_instance/1	has the instance into the db.
new/4	create storage-processes.
new/5
put/3	Insert an object into backend-db.
put_value_to_new_db/3	Put a record to a new db.
run_compaction/1	Start the data-compaction.
status/1	Retrieve status from backend-db.
status_compaction/1	Retrieve compaction status from backend-db.
stop/1	Stop the instance.

Function Details

count/1

count(InstanceName) -> Count

Count = non_neg_integer()
InstanceName = atom()

Count the number of records from backend-db.

delete/2

delete(InstanceName, KeyBin) -> ok | {error, any()}

InstanceName = atom()
KeyBin = binary()

Delete an object from backend-db.

fetch/3

fetch(InstanceName, KeyBin, Fun) -> {ok, list()} | not_found | {error, any()}

InstanceName = atom()
KeyBin = binary()
Fun = function()

Fetch objects from backend-db by key with function.

fetch/4

fetch(InstanceName, KeyBin, Fun, MaxKeys) -> {ok, list()} | not_found | {error, any()}

InstanceName = atom()
KeyBin = binary()
Fun = function()
MaxKeys = pos_integer()

finish_compaction/2

finish_compaction(InstanceName, Commit) -> ok | {error, any()}

InstanceName = atom()
Commit = boolean()

End the data-compaction

first/1

first(InstanceName) -> {ok, list()} | {error, any()}

InstanceName = atom()

Retrieve a first record from backend-db.

first_n/2

first_n(InstanceName, N) -> {ok, list()} | not_found | {error, any()}

InstanceName = atom()
N = pos_integer()

Fetch first N records from backend-db.

first_n/3

first_n(InstanceName, N, Condition) -> {ok, list()} | not_found | {error, any()}

InstanceName = atom()
N = pos_integer()
Condition = function()

get/2

get(InstanceName, KeyBin) -> {ok, binary()} | not_found | {error, any()}

InstanceName = atom()
KeyBin = binary()

Retrieve an object from backend-db.

get_db_raw_filepath/1

get_db_raw_filepath(InstanceName) -> {ok, string()} | {error, any()}

InstanceName = atom()

get the database filepath for calculating disk size

has_instance/1

has_instance(InstanceName) -> boolean()

InstanceName = atom()

has the instance into the db

new/4

new(InstanceName, NumOfDBProcs, BackendDB, DBRootPath) -> ok | {error, any()}

InstanceName = atom()
NumOfDBProcs = pos_integer()
BackendDB = backend_db()
DBRootPath = string()

create storage-processes.

new/5

new(InstanceName, NumOfDBProcs, BackendDB, DBRootPath, IsStrictCheck) -> ok | {error, any()}

InstanceName = atom()
NumOfDBProcs = pos_integer()
BackendDB = backend_db()
DBRootPath = string()
IsStrictCheck = boolean()

put/3

put(InstanceName, KeyBin, ValueBin) -> ok | {error, any()}

InstanceName = atom()
KeyBin = binary()
ValueBin = binary()

Insert an object into backend-db.

put_value_to_new_db/3

put_value_to_new_db(InstanceName, KeyBin, ValueBin) -> ok | {error, any()}

InstanceName = atom()
KeyBin = binary()
ValueBin = binary()

Put a record to a new db

run_compaction/1

run_compaction(InstanceName) -> ok | {error, any()}

InstanceName = atom()

Start the data-compaction

status/1

status(InstanceName) -> [{atom(), term()}]

InstanceName = atom()

Retrieve status from backend-db.

status_compaction/1

status_compaction(InstanceName) -> [{atom(), term()}]

InstanceName = atom()

Retrieve compaction status from backend-db.

stop/1

stop(InstanceName) -> ok | {error, any()}

InstanceName = atom()

Stop the instance

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