Class: SDBM
Overview
SDBM provides a simple file-based key-value store, which can only store String keys and values.
Note that Ruby comes with the source code for SDBM, while the DBM and GDBM standard libraries rely on external libraries and headers.
Examples
Insert values:
require 'sdbm'
SDBM.open 'my_database' do |db|
db['apple'] = 'fruit'
db['pear'] = 'fruit'
db['carrot'] = 'vegetable'
db['tomato'] = 'vegetable'
end
Bulk update:
require 'sdbm'
SDBM.open 'my_database' do |db|
db.update('peach' => 'fruit', 'tomato' => 'fruit')
end
Retrieve values:
require 'sdbm'
SDBM.open 'my_database' do |db|
db.each do |key, value|
puts "Key: #{key}, Value: #{value}"
end
end
Outputs:
Key: apple, Value: fruit
Key: pear, Value: fruit
Key: carrot, Value: vegetable
Key: peach, Value: fruit
Key: tomato, Value: fruit
Class Method Summary collapse
-
.open(*args) ⇒ Object
If called without a block, this is the same as SDBM.new.
Instance Method Summary collapse
-
#[](key) ⇒ nil
Returns the
value
in the database associated with the givenkey
string. -
#[]=(keystr, valstr) ⇒ Object
Stores a new
value
in the database with the givenkey
as an index. -
#clear ⇒ self
Deletes all data from the database.
-
#close ⇒ nil
Closes the database file.
-
#closed? ⇒ Boolean
Returns
true
if the database is closed. -
#delete(keystr) ⇒ Object
Deletes the key-value pair corresponding to the given
key
. -
#delete_if ⇒ Object
Iterates over the key-value pairs in the database, deleting those for which the block returns
true
. -
#each ⇒ Object
Iterates over each key-value pair in the database.
-
#each_key ⇒ Object
Iterates over each
key
in the database. -
#each_pair ⇒ Object
Iterates over each key-value pair in the database.
-
#each_value ⇒ Object
Iterates over each
value
in the database. -
#empty? ⇒ Boolean
Returns
true
if the database is empty. -
#fetch(*args) ⇒ Object
Returns the
value
in the database associated with the givenkey
string. -
#has_key?(keystr) ⇒ Boolean
Returns
true
if the database contains the givenkey
. -
#has_value?(valstr) ⇒ Boolean
Returns
true
if the database contains the givenvalue
. -
#include?(keystr) ⇒ Boolean
Returns
true
if the database contains the givenkey
. -
#index(value) ⇒ Object
:nodoc:.
-
#new(filename, mode = 0666) ⇒ Object
constructor
Creates a new database handle by opening the given
filename
. -
#invert ⇒ Hash
Returns a Hash in which the key-value pairs have been inverted.
-
#key(value) ⇒ Object
Returns the
key
associated with the givenvalue
. -
#key?(keystr) ⇒ Boolean
Returns
true
if the database contains the givenkey
. -
#keys ⇒ Array
Returns a new Array containing the keys in the database.
-
#length ⇒ Object
Returns the number of keys in the database.
-
#member?(keystr) ⇒ Boolean
Returns
true
if the database contains the givenkey
. -
#reject {|key, value| ... } ⇒ Hash
Creates a new Hash using the key-value pairs from the database, then calls Hash#reject with the given block, which returns a Hash with only the key-value pairs for which the block returns
false
. -
#reject! ⇒ Object
Iterates over the key-value pairs in the database, deleting those for which the block returns
true
. -
#replace(pairs) ⇒ self
Empties the database, then inserts the given key-value pairs.
-
#select {|key, value| ... } ⇒ Array
Returns a new Array of key-value pairs for which the block returns
true
. -
#shift ⇒ Array?
Removes a key-value pair from the database and returns them as an Array.
-
#size ⇒ Object
Returns the number of keys in the database.
-
#store(keystr, valstr) ⇒ Object
Stores a new
value
in the database with the givenkey
as an index. -
#to_a ⇒ Array
Returns a new Array containing each key-value pair in the database.
-
#to_hash ⇒ Hash
Returns a new Hash containing each key-value pair in the database.
-
#update(pairs) ⇒ self
Insert or update key-value pairs.
-
#value?(valstr) ⇒ Boolean
Returns
true
if the database contains the givenvalue
. -
#values ⇒ Array
Returns a new Array containing the values in the database.
-
#values_at(key, ...) ⇒ Array
Returns an Array of values corresponding to the given keys.
Constructor Details
#new(filename, mode = 0666) ⇒ Object
Creates a new database handle by opening the given filename
. SDBM actually uses two physical files, with extensions ‘.dir’ and ‘.pag’. These extensions will automatically be appended to the filename
.
If the file does not exist, a new file will be created using the given mode
, unless mode
is explicitly set to nil. In the latter case, no database will be created.
If the file exists, it will be opened in read/write mode. If this fails, it will be opened in read-only mode.
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# File 'init.c', line 179
static VALUE
fsdbm_initialize(int argc, VALUE *argv, VALUE obj)
{
volatile VALUE file;
VALUE vmode;
DBM *dbm;
struct dbmdata *dbmp;
int mode;
if (rb_scan_args(argc, argv, "11", &file, &vmode) == 1) {
mode = 0666; /* default value */
}
else if (NIL_P(vmode)) {
mode = -1; /* return nil if DB not exist */
}
else {
mode = NUM2INT(vmode);
}
FilePathValue(file);
dbm = 0;
if (mode >= 0)
dbm = sdbm_open(RSTRING_PTR(file), O_RDWR|O_CREAT, mode);
if (!dbm)
dbm = sdbm_open(RSTRING_PTR(file), O_RDWR, 0);
if (!dbm)
dbm = sdbm_open(RSTRING_PTR(file), O_RDONLY, 0);
if (!dbm) {
if (mode == -1) return Qnil;
rb_sys_fail_str(file);
}
dbmp = ALLOC(struct dbmdata);
DATA_PTR(obj) = dbmp;
dbmp->di_dbm = dbm;
dbmp->di_size = -1;
return obj;
}
|
Class Method Details
.open(filename, mode = 0666) ⇒ Object .open(filename, mode = 0666) {|sdbm| ... } ⇒ Object
If called without a block, this is the same as SDBM.new.
If a block is given, the new database will be passed to the block and will be safely closed after the block has executed.
Example:
require 'sdbm'
SDBM.open('my_database') do |db|
db['hello'] = 'world'
end
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# File 'init.c', line 238
static VALUE
fsdbm_s_open(int argc, VALUE *argv, VALUE klass)
{
VALUE obj = fsdbm_alloc(klass);
if (NIL_P(fsdbm_initialize(argc, argv, obj))) {
return Qnil;
}
if (rb_block_given_p()) {
return rb_ensure(rb_yield, obj, fsdbm_close, obj);
}
return obj;
}
|
Instance Method Details
#[](key) ⇒ nil
Returns the value
in the database associated with the given key
string.
If no value is found, returns nil
.
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# File 'init.c', line 283
static VALUE
fsdbm_aref(VALUE obj, VALUE keystr)
{
return fsdbm_fetch(obj, keystr, Qnil);
}
|
#[]=(key) ⇒ Object #store(key, value) ⇒ Object
Stores a new value
in the database with the given key
as an index.
If the key
already exists, this will update the value
associated with the key
.
Returns the given value
.
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# File 'init.c', line 619
static VALUE
fsdbm_store(VALUE obj, VALUE keystr, VALUE valstr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
if (valstr == Qnil) {
fsdbm_delete(obj, keystr);
return Qnil;
}
fdbm_modify(obj);
ExportStringValue(keystr);
ExportStringValue(valstr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
val.dptr = RSTRING_PTR(valstr);
val.dsize = RSTRING_LENINT(valstr);
GetDBM2(obj, dbmp, dbm);
dbmp->di_size = -1;
if (sdbm_store(dbm, key, val, DBM_REPLACE)) {
#ifdef HAVE_DBM_CLAERERR
sdbm_clearerr(dbm);
#endif
if (errno == EPERM) rb_sys_fail(0);
rb_raise(rb_eDBMError, "sdbm_store failed");
}
return valstr;
}
|
#clear ⇒ self
Deletes all data from the database.
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# File 'init.c', line 552
static VALUE
fsdbm_clear(VALUE obj)
{
datum key;
struct dbmdata *dbmp;
DBM *dbm;
fdbm_modify(obj);
GetDBM2(obj, dbmp, dbm);
dbmp->di_size = -1;
while (key = sdbm_firstkey(dbm), key.dptr) {
if (sdbm_delete(dbm, key)) {
rb_raise(rb_eDBMError, "sdbm_delete failed");
}
}
dbmp->di_size = 0;
return obj;
}
|
#close ⇒ nil
Closes the database file.
Raises SDBMError if the database is already closed.
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# File 'init.c', line 127
static VALUE
fsdbm_close(VALUE obj)
{
struct dbmdata *dbmp;
GetDBM(obj, dbmp);
sdbm_close(dbmp->di_dbm);
dbmp->di_dbm = 0;
return Qnil;
}
|
#closed? ⇒ Boolean
Returns true
if the database is closed.
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# File 'init.c', line 145
static VALUE
fsdbm_closed(VALUE obj)
{
struct dbmdata *dbmp;
TypedData_Get_Struct(obj, struct dbmdata, &sdbm_type, dbmp);
if (dbmp == 0)
return Qtrue;
if (dbmp->di_dbm == 0)
return Qtrue;
return Qfalse;
}
|
#delete(key) ⇒ nil #delete(key) {|key, value| ... } ⇒ Object
Deletes the key-value pair corresponding to the given key
. If the key
exists, the deleted value will be returned, otherwise nil
.
If a block is provided, the deleted key
and value
will be passed to the block as arguments. If the key
does not exist in the database, the value will be nil
.
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# File 'init.c', line 434
static VALUE
fsdbm_delete(VALUE obj, VALUE keystr)
{
datum key, value;
struct dbmdata *dbmp;
DBM *dbm;
VALUE valstr;
fdbm_modify(obj);
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
GetDBM2(obj, dbmp, dbm);
dbmp->di_size = -1;
value = sdbm_fetch(dbm, key);
if (value.dptr == 0) {
if (rb_block_given_p()) return rb_yield(keystr);
return Qnil;
}
/* need to save value before sdbm_delete() */
valstr = rb_external_str_new(value.dptr, value.dsize);
if (sdbm_delete(dbm, key)) {
dbmp->di_size = -1;
rb_raise(rb_eDBMError, "dbm_delete failed");
}
else if (dbmp->di_size >= 0) {
dbmp->di_size--;
}
return valstr;
}
|
#delete_if {|key, value| ... } ⇒ self #reject! {|key, value| ... } ⇒ self
Iterates over the key-value pairs in the database, deleting those for which the block returns true
.
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# File 'init.c', line 507
static VALUE
fsdbm_delete_if(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE keystr, valstr;
VALUE ret, ary = rb_ary_new();
int i, status = 0, n;
fdbm_modify(obj);
GetDBM2(obj, dbmp, dbm);
n = dbmp->di_size;
dbmp->di_size = -1;
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
keystr = rb_external_str_new(key.dptr, key.dsize);
valstr = rb_external_str_new(val.dptr, val.dsize);
ret = rb_protect(rb_yield, rb_assoc_new(rb_str_dup(keystr), valstr), &status);
if (status != 0) break;
if (RTEST(ret)) rb_ary_push(ary, keystr);
GetDBM2(obj, dbmp, dbm);
}
for (i = 0; i < RARRAY_LEN(ary); i++) {
keystr = RARRAY_PTR(ary)[i];
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
if (sdbm_delete(dbm, key)) {
rb_raise(rb_eDBMError, "sdbm_delete failed");
}
}
if (status) rb_jump_tag(status);
if (n > 0) dbmp->di_size = n - RARRAY_LENINT(ary);
return obj;
}
|
#each ⇒ Object #each {|key, value| ... } ⇒ Object #each_pair ⇒ Object #each_pair {|key, value| ... } ⇒ Object
Iterates over each key-value pair in the database.
If no block is given, returns an Enumerator.
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# File 'init.c', line 816
static VALUE
fsdbm_each_pair(VALUE obj)
{
datum key, val;
DBM *dbm;
struct dbmdata *dbmp;
VALUE keystr, valstr;
RETURN_ENUMERATOR(obj, 0, 0);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
keystr = rb_external_str_new(key.dptr, key.dsize);
valstr = rb_external_str_new(val.dptr, val.dsize);
rb_yield(rb_assoc_new(keystr, valstr));
GetDBM2(obj, dbmp, dbm);
}
return obj;
}
|
#each_key ⇒ Object #each_key {|key| ... } ⇒ Object
Iterates over each key
in the database.
If no block is given, returns an Enumerator.
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# File 'init.c', line 788
static VALUE
fsdbm_each_key(VALUE obj)
{
datum key;
struct dbmdata *dbmp;
DBM *dbm;
RETURN_ENUMERATOR(obj, 0, 0);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
rb_yield(rb_external_str_new(key.dptr, key.dsize));
GetDBM2(obj, dbmp, dbm);
}
return obj;
}
|
#each ⇒ Object #each {|key, value| ... } ⇒ Object #each_pair ⇒ Object #each_pair {|key, value| ... } ⇒ Object
Iterates over each key-value pair in the database.
If no block is given, returns an Enumerator.
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# File 'init.c', line 816
static VALUE
fsdbm_each_pair(VALUE obj)
{
datum key, val;
DBM *dbm;
struct dbmdata *dbmp;
VALUE keystr, valstr;
RETURN_ENUMERATOR(obj, 0, 0);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
keystr = rb_external_str_new(key.dptr, key.dsize);
valstr = rb_external_str_new(val.dptr, val.dsize);
rb_yield(rb_assoc_new(keystr, valstr));
GetDBM2(obj, dbmp, dbm);
}
return obj;
}
|
#each_value ⇒ Object #each_value {|value| ... } ⇒ Object
Iterates over each value
in the database.
If no block is given, returns an Enumerator.
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# File 'init.c', line 761
static VALUE
fsdbm_each_value(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
RETURN_ENUMERATOR(obj, 0, 0);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
rb_yield(rb_external_str_new(val.dptr, val.dsize));
GetDBM2(obj, dbmp, dbm);
}
return obj;
}
|
#empty? ⇒ Boolean
Returns true
if the database is empty.
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# File 'init.c', line 730
static VALUE
fsdbm_empty_p(VALUE obj)
{
datum key;
struct dbmdata *dbmp;
DBM *dbm;
GetDBM(obj, dbmp);
if (dbmp->di_size < 0) {
dbm = dbmp->di_dbm;
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
return Qfalse;
}
}
else {
if (dbmp->di_size)
return Qfalse;
}
return Qtrue;
}
|
#fetch(key) ⇒ nil #fetch(key) {|key| ... } ⇒ Object
Returns the value
in the database associated with the given key
string.
If a block is provided, the block will be called when there is no value
associated with the given key
. The key
will be passed in as an argument to the block.
If no block is provided and no value is associated with the given key
, then an IndexError will be raised.
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# File 'init.c', line 303
static VALUE
fsdbm_fetch_m(int argc, VALUE *argv, VALUE obj)
{
VALUE keystr, valstr, ifnone;
rb_scan_args(argc, argv, "11", &keystr, &ifnone);
valstr = fsdbm_fetch(obj, keystr, ifnone);
if (argc == 1 && !rb_block_given_p() && NIL_P(valstr))
rb_raise(rb_eIndexError, "key not found");
return valstr;
}
|
#include?(key) ⇒ Boolean #key?(key) ⇒ Boolean #member?(key) ⇒ Boolean #has_key?(key) ⇒ Boolean
Returns true
if the database contains the given key
.
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# File 'init.c', line 894
static VALUE
fsdbm_has_key(VALUE obj, VALUE keystr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
GetDBM2(obj, dbmp, dbm);
val = sdbm_fetch(dbm, key);
if (val.dptr) return Qtrue;
return Qfalse;
}
|
#value?(key) ⇒ Boolean #has_value?(key) ⇒ Boolean
Returns true
if the database contains the given value
.
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# File 'init.c', line 918
static VALUE
fsdbm_has_value(VALUE obj, VALUE valstr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(valstr);
val.dptr = RSTRING_PTR(valstr);
val.dsize = RSTRING_LENINT(valstr);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
if (val.dsize == RSTRING_LENINT(valstr) &&
memcmp(val.dptr, RSTRING_PTR(valstr), val.dsize) == 0)
return Qtrue;
}
return Qfalse;
}
|
#include?(key) ⇒ Boolean #key?(key) ⇒ Boolean #member?(key) ⇒ Boolean #has_key?(key) ⇒ Boolean
Returns true
if the database contains the given key
.
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# File 'init.c', line 894
static VALUE
fsdbm_has_key(VALUE obj, VALUE keystr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
GetDBM2(obj, dbmp, dbm);
val = sdbm_fetch(dbm, key);
if (val.dptr) return Qtrue;
return Qfalse;
}
|
#index(value) ⇒ Object
:nodoc:
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# File 'init.c', line 348
static VALUE
fsdbm_index(VALUE hash, VALUE value)
{
rb_warn("SDBM#index is deprecated; use SDBM#key");
return fsdbm_key(hash, value);
}
|
#invert ⇒ Hash
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# File 'init.c', line 588
static VALUE
fsdbm_invert(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE keystr, valstr;
VALUE hash = rb_hash_new();
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
keystr = rb_external_str_new(key.dptr, key.dsize);
valstr = rb_external_str_new(val.dptr, val.dsize);
rb_hash_aset(hash, valstr, keystr);
}
return hash;
}
|
#key(value) ⇒ Object
Returns the key
associated with the given value
. If more than one key
corresponds to the given value
, then the first key to be found will be returned. If no keys are found, nil
will be returned.
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# File 'init.c', line 324
static VALUE
fsdbm_key(VALUE obj, VALUE valstr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(valstr);
val.dptr = RSTRING_PTR(valstr);
val.dsize = RSTRING_LENINT(valstr);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
if (val.dsize == RSTRING_LEN(valstr) &&
memcmp(val.dptr, RSTRING_PTR(valstr), val.dsize) == 0)
return rb_external_str_new(key.dptr, key.dsize);
}
return Qnil;
}
|
#include?(key) ⇒ Boolean #key?(key) ⇒ Boolean #member?(key) ⇒ Boolean #has_key?(key) ⇒ Boolean
Returns true
if the database contains the given key
.
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# File 'init.c', line 894
static VALUE
fsdbm_has_key(VALUE obj, VALUE keystr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
GetDBM2(obj, dbmp, dbm);
val = sdbm_fetch(dbm, key);
if (val.dptr) return Qtrue;
return Qfalse;
}
|
#keys ⇒ Array
Returns a new Array containing the keys in the database.
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# File 'init.c', line 844
static VALUE
fsdbm_keys(VALUE obj)
{
datum key;
struct dbmdata *dbmp;
DBM *dbm;
VALUE ary;
GetDBM2(obj, dbmp, dbm);
ary = rb_ary_new();
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
rb_ary_push(ary, rb_external_str_new(key.dptr, key.dsize));
}
return ary;
}
|
#length ⇒ Integer #size ⇒ Integer
Returns the number of keys in the database.
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# File 'init.c', line 705
static VALUE
fsdbm_length(VALUE obj)
{
datum key;
struct dbmdata *dbmp;
DBM *dbm;
int i = 0;
GetDBM2(obj, dbmp, dbm);
if (dbmp->di_size > 0) return INT2FIX(dbmp->di_size);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
i++;
}
dbmp->di_size = i;
return INT2FIX(i);
}
|
#include?(key) ⇒ Boolean #key?(key) ⇒ Boolean #member?(key) ⇒ Boolean #has_key?(key) ⇒ Boolean
Returns true
if the database contains the given key
.
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# File 'init.c', line 894
static VALUE
fsdbm_has_key(VALUE obj, VALUE keystr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
GetDBM2(obj, dbmp, dbm);
val = sdbm_fetch(dbm, key);
if (val.dptr) return Qtrue;
return Qfalse;
}
|
#reject {|key, value| ... } ⇒ Hash
Creates a new Hash using the key-value pairs from the database, then calls Hash#reject with the given block, which returns a Hash with only the key-value pairs for which the block returns false
.
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# File 'init.c', line 1007
static VALUE
fsdbm_reject(VALUE obj)
{
return rb_hash_delete_if(fsdbm_to_hash(obj));
}
|
#delete_if {|key, value| ... } ⇒ self #reject! {|key, value| ... } ⇒ self
Iterates over the key-value pairs in the database, deleting those for which the block returns true
.
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# File 'init.c', line 507
static VALUE
fsdbm_delete_if(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE keystr, valstr;
VALUE ret, ary = rb_ary_new();
int i, status = 0, n;
fdbm_modify(obj);
GetDBM2(obj, dbmp, dbm);
n = dbmp->di_size;
dbmp->di_size = -1;
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
keystr = rb_external_str_new(key.dptr, key.dsize);
valstr = rb_external_str_new(val.dptr, val.dsize);
ret = rb_protect(rb_yield, rb_assoc_new(rb_str_dup(keystr), valstr), &status);
if (status != 0) break;
if (RTEST(ret)) rb_ary_push(ary, keystr);
GetDBM2(obj, dbmp, dbm);
}
for (i = 0; i < RARRAY_LEN(ary); i++) {
keystr = RARRAY_PTR(ary)[i];
ExportStringValue(keystr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
if (sdbm_delete(dbm, key)) {
rb_raise(rb_eDBMError, "sdbm_delete failed");
}
}
if (status) rb_jump_tag(status);
if (n > 0) dbmp->di_size = n - RARRAY_LENINT(ary);
return obj;
}
|
#replace(pairs) ⇒ self
Empties the database, then inserts the given key-value pairs.
This method will work with any object which implements an each_pair method, such as a Hash.
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# File 'init.c', line 690
static VALUE
fsdbm_replace(VALUE obj, VALUE other)
{
fsdbm_clear(obj);
rb_block_call(other, rb_intern("each_pair"), 0, 0, update_i, obj);
return obj;
}
|
#select {|key, value| ... } ⇒ Array
Returns a new Array of key-value pairs for which the block returns true
.
Example:
require 'sdbm'
SDBM.open 'my_database' do |db|
db['apple'] = 'fruit'
db['pear'] = 'fruit'
db['spinach'] = 'vegetable'
veggies = db.select do |key, value|
value == 'vegetable'
end #=> [["apple", "fruit"], ["pear", "fruit"]]
end
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# File 'init.c', line 374
static VALUE
fsdbm_select(VALUE obj)
{
VALUE new = rb_ary_new();
datum key, val;
DBM *dbm;
struct dbmdata *dbmp;
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
VALUE assoc, v;
val = sdbm_fetch(dbm, key);
assoc = rb_assoc_new(rb_external_str_new(key.dptr, key.dsize),
rb_external_str_new(val.dptr, val.dsize));
v = rb_yield(assoc);
if (RTEST(v)) {
rb_ary_push(new, assoc);
}
GetDBM2(obj, dbmp, dbm);
}
return new;
}
|
#shift ⇒ Array?
Removes a key-value pair from the database and returns them as an Array. If the database is empty, returns nil
.
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# File 'init.c', line 476
static VALUE
fsdbm_shift(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE keystr, valstr;
fdbm_modify(obj);
GetDBM2(obj, dbmp, dbm);
key = sdbm_firstkey(dbm);
if (!key.dptr) return Qnil;
val = sdbm_fetch(dbm, key);
keystr = rb_external_str_new(key.dptr, key.dsize);
valstr = rb_external_str_new(val.dptr, val.dsize);
sdbm_delete(dbm, key);
if (dbmp->di_size >= 0) {
dbmp->di_size--;
}
return rb_assoc_new(keystr, valstr);
}
|
#length ⇒ Integer #size ⇒ Integer
Returns the number of keys in the database.
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# File 'init.c', line 705
static VALUE
fsdbm_length(VALUE obj)
{
datum key;
struct dbmdata *dbmp;
DBM *dbm;
int i = 0;
GetDBM2(obj, dbmp, dbm);
if (dbmp->di_size > 0) return INT2FIX(dbmp->di_size);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
i++;
}
dbmp->di_size = i;
return INT2FIX(i);
}
|
#[]=(key) ⇒ Object #store(key, value) ⇒ Object
Stores a new value
in the database with the given key
as an index.
If the key
already exists, this will update the value
associated with the key
.
Returns the given value
.
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# File 'init.c', line 619
static VALUE
fsdbm_store(VALUE obj, VALUE keystr, VALUE valstr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
if (valstr == Qnil) {
fsdbm_delete(obj, keystr);
return Qnil;
}
fdbm_modify(obj);
ExportStringValue(keystr);
ExportStringValue(valstr);
key.dptr = RSTRING_PTR(keystr);
key.dsize = RSTRING_LENINT(keystr);
val.dptr = RSTRING_PTR(valstr);
val.dsize = RSTRING_LENINT(valstr);
GetDBM2(obj, dbmp, dbm);
dbmp->di_size = -1;
if (sdbm_store(dbm, key, val, DBM_REPLACE)) {
#ifdef HAVE_DBM_CLAERERR
sdbm_clearerr(dbm);
#endif
if (errno == EPERM) rb_sys_fail(0);
rb_raise(rb_eDBMError, "sdbm_store failed");
}
return valstr;
}
|
#to_a ⇒ Array
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# File 'init.c', line 955
static VALUE
fsdbm_to_a(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE ary;
GetDBM2(obj, dbmp, dbm);
ary = rb_ary_new();
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
rb_ary_push(ary, rb_assoc_new(rb_external_str_new(key.dptr, key.dsize),
rb_external_str_new(val.dptr, val.dsize)));
}
return ary;
}
|
#to_hash ⇒ Hash
Returns a new Hash containing each key-value pair in the database.
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# File 'init.c', line 980
static VALUE
fsdbm_to_hash(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE hash;
GetDBM2(obj, dbmp, dbm);
hash = rb_hash_new();
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
rb_hash_aset(hash, rb_external_str_new(key.dptr, key.dsize),
rb_external_str_new(val.dptr, val.dsize));
}
return hash;
}
|
#update(pairs) ⇒ self
Insert or update key-value pairs.
This method will work with any object which implements an each_pair method, such as a Hash.
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# File 'init.c', line 674
static VALUE
fsdbm_update(VALUE obj, VALUE other)
{
rb_block_call(other, rb_intern("each_pair"), 0, 0, update_i, obj);
return obj;
}
|
#value?(key) ⇒ Boolean #has_value?(key) ⇒ Boolean
Returns true
if the database contains the given value
.
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# File 'init.c', line 918
static VALUE
fsdbm_has_value(VALUE obj, VALUE valstr)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
ExportStringValue(valstr);
val.dptr = RSTRING_PTR(valstr);
val.dsize = RSTRING_LENINT(valstr);
GetDBM2(obj, dbmp, dbm);
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
if (val.dsize == RSTRING_LENINT(valstr) &&
memcmp(val.dptr, RSTRING_PTR(valstr), val.dsize) == 0)
return Qtrue;
}
return Qfalse;
}
|
#values ⇒ Array
Returns a new Array containing the values in the database.
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# File 'init.c', line 867
static VALUE
fsdbm_values(VALUE obj)
{
datum key, val;
struct dbmdata *dbmp;
DBM *dbm;
VALUE ary;
GetDBM2(obj, dbmp, dbm);
ary = rb_ary_new();
for (key = sdbm_firstkey(dbm); key.dptr; key = sdbm_nextkey(dbm)) {
val = sdbm_fetch(dbm, key);
rb_ary_push(ary, rb_external_str_new(val.dptr, val.dsize));
}
return ary;
}
|
#values_at(key, ...) ⇒ Array
Returns an Array of values corresponding to the given keys.
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# File 'init.c', line 403
static VALUE
fsdbm_values_at(int argc, VALUE *argv, VALUE obj)
{
VALUE new = rb_ary_new2(argc);
int i;
for (i=0; i<argc; i++) {
rb_ary_push(new, fsdbm_fetch(obj, argv[i], Qnil));
}
return new;
}
|