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These are the common methods for BDB1::Btree, BDB1::Hash,
type[hash]
type[bdb1]
create a new temporary db file, populated with the given object
create([name, flags, mode, options])
new([name, flags, mode, options])
open([name, flags, mode, options])
open the database
The argument name is used as the name of a single physical file on disk that will be used to back the database.
The flags must be the string "r", "r+", "w", "w+", "a", "a+" or and integer value.
The flags value must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values
Create any underlying files, as necessary. If the files do not already exist and the DB_CREATE flag is not specified, the call will fail.
Return an error if the database already exists. Underlying filesystem primitives are used to implement this flag. For this reason it is only applicable to the physical database file and cannot be used to test if a subdatabase already exists.
Do not map this database into process memory.
Open the database for reading only. Any attempt to modify items in the database will fail regardless of the actual permissions of any underlying files.
Physically truncate the underlying database file, discarding all previous subdatabases or databases. Underlying filesystem primitives are used to implement this flag. For this reason it is only applicable to the physical database file and cannot be used to discard subdatabases.
The DB_TRUNCATE flag cannot be transaction protected, and it is an error to specify it in a transaction protected environment.
Open the database for writing. Without this flag, any attempt to modify items in the database will fail.
Hash, Possible options are
general database configuration
set the database cache size
set the underlying database page size
set the database byte order
specify a Proc called before a key is stored
specify a Proc called after a key is read
specify a Proc called before a value is stored
specify a Proc called after a value is read
specify a Btree comparison function
set the minimum number of keys per Btree page
specify a Btree prefix comparison function
set the Hash table density
specify a hashing function
set the Hash table size
Proc given to set_bt_compare, set_bt_prefix, set_h_hash, set_store_key, set_fetch_key, set_store_value and set_fetch_value can be also specified as a method (replace the prefix set_ with bdb1_)
For example
module BDB1 class Btreesort < Btree def bdb1_bt_compare(a, b) b.downcase <=> a.downcase end end end
self[key]
Returns the value corresponding the key
db_get(key [, flags])
get(key [, flags])
fetch(key [, flags])
Returns the value correspondind the key
self[key] = value
Stores the value associating with key
return value
db_put(key, value [, flags])
put(key, value [, flags])
store(key, value [, flags])
Stores the value associating with key
Return the value correspondind the key
flags can have the value DBD::NOOVERWRITE, in this case it will return nil if the specified key exist, otherwise true
append(key, value)
db_append(key, value)
Append the value associating with key
byteswapped?
get_byteswapped
Return if the underlying database is in host order
close([flags])
db_close([flags])
Closes the file.
delete(key)
db_del(key)
Removes the association from the key.
It return the object deleted or nil if the specified key don't exist.
delete_if([set]) { |key, value| ... }
reject!([set]) { |key, value| ... }
Deletes associations if the evaluation of the block returns true.
Only for BDB1::Btree
duplicates(key [, assoc = true])
Return an array of all duplicate associations for key
if assoc is false return only the values.
Only for BDB1::Btree
each { |key, value| ... }
each_pair { |key, value| ... }
Iterates over associations.
each_dup(key) { |key, value| ... }
Iterates over each duplicate associations for key
Only for BDB1::Btree
each_dup_value(key) { |value| ... }
Iterates over each duplicate values for key
Only for BDB1::Btree
each_key { |key| ... }
Iterates over keys.
each_value { |value| ... }
Iterates over values.
empty?()
Returns true if the database is empty.
has_key?(key)
key?(key)
include?(key)
member?(key)
Returns true if the association from the key exists.
has_both?(key, value)
both?(key, value)
Returns true if the association from key is value
has_value?(value)
value?(value)
Returns true if the association to the value exists.
index(value)
Returns the first key associated with value
indexes(value1, value2, )
Returns the keys associated with value1, value2, ...
keys
Returns the array of the keys in the database
length
size
Returns the number of association in the database.
reject { |key, value| ... }
Create an hash without the associations if the evaluation of the block returns true.
reverse_each { |key, value| ... }
reverse_each_pair { |key, value| ... }
Iterates over associations in reverse order
Only for BDB1::Btree
reverse_each_key { |key| ... }
Iterates over keys in reverse order
Only for BDB1::Btree
reverse_each_value { |value| ... }
Iterates over values in reverse order.
Only for BDB1::Btree
to_a
Return an array of all associations [key, value]
to_hash
Return an hash of all associations {key => value}
truncate
clear
Empty a database
values
Returns the array of the values in the database.